FE-2 Nicole Stott works on the CBEF Space Seed Experiment

NASA Image and Video Library

2009-10-13

ISS021-E-006261 (13 Oct. 2009) --- NASA astronaut Nicole Stott, Expedition 21 flight engineer, works with the Cell Biology Experiment Facility (CBEF) SPACE SEED experiment in the Kibo laboratory of the International Space Station.

FE-2 Nicole Stott works on the CBEF Space Seed Experiment

NASA Image and Video Library

2009-10-13

ISS021-E-006267 (13 Oct. 2009) --- NASA astronaut Nicole Stott, Expedition 21 flight engineer, works with the Cell Biology Experiment Facility (CBEF) SPACE SEED experiment in the Kibo laboratory of the International Space Station.

A multi-sensor study of the impact of ground-based glaciogenic seeding on clouds and precipitation over mountains in Wyoming. Part II: Seeding impact analysis

NASA Astrophysics Data System (ADS)

Pokharel, Binod; Geerts, Bart; Jing, Xiaoqin; Friedrich, Katja; Ikeda, Kyoko; Rasmussen, Roy

2017-01-01

The AgI Seeding Cloud Impact Investigation (ASCII) campaign, conducted in early 2012 and 2013 over two mountain ranges in southern Wyoming, was designed to examine the impact of ground-based glaciogenic seeding on snow growth in winter orographic clouds. Part I of this study (Pokharel and Geerts, 2016) describes the project design, instrumentation, as well as the ambient atmospheric conditions and macrophysical and microphysical properties of the clouds sampled in ASCII. This paper (Part II) explores how the silver iodide (AgI) seeding affects snow growth in these orographic clouds in up to 27 intensive operation periods (IOPs), depending on the instrument used. In most cases, 2 h without seeding (NOSEED) were followed by 2 h of seeding (SEED). In situ data at flight level (2D-probes) indicate higher concentrations of small snow particles during SEED in convective clouds. The double difference of radar reflectivity Z (SEED - NOSEED in the target region, compared to the same trend in the control region) indicates an increase in Z for the composite of ASCII cases, over either mountain range, and for any of the three radar systems (WCR, MRR, and DOW), each with their own control and target regions, and for an array of snow gauges. But this double difference varies significantly from case to case, which is attributed to uncertainties related to sampling representativeness and to differences in natural trends between control and target regions. We conclude that a sample much larger than ASCII's sample is needed for clear observational evidence regarding the sensitivity of seeding efficacy to atmospheric and cloud conditions.

Ground and space experiments to determine the ability of plant seeds to survive in space

NASA Astrophysics Data System (ADS)

Tepfer, David; Zalar, Andreja; Leach, Sydney

2008-09-01

The EXPOSE consortium seeks to understand the capacity of organisms (including extremophiles) to survive under space conditions, i.e. to withstand a long voyage through space. We have proposed that plant seeds are suited for space travel. In our current SEEDS experiment on the Columbus module of the ISS, Arabidopsis seeds were chosen for their small size (approx. 300 μm) and the availability of mutants lacking UV screens. These mutants should allow us to establish the role of flavonoids and sinapic acid esters in resistance to UV and other stresses encountered during space travel. The importance of these substances is indicated by simulations (manuscripts in preparation) and spectroscopy (Zalar 2004; Zalar et al. 2007; Zalar et al. 2007), the results of which will be discussed. Zalar A, (2004) Résistance des graines d'arabidopsis aux UV et à d'autres conditions néfastes dans l'espace. Journal DESS Zalar A, Tepfer D, Hoffmann SV, Kenney JM, Leach S (2007) Directed exospermia: I. Biological modes of resistance to UV light are implied through absorption spectroscopy of DNA and potential UV screens. International Journal of Astrobiology 6: 229-240 Zalar A, Tepfer D, Hoffmann SV, Kollmann A, Leach S (2007) Directed exospermia: II. VUV-UV spectroscopy of specialized UV screens, including plant flavonoids, suggests using metabolic engineering to improve survival in space. International Journal of Astrobiology 6: 291-301

Radiobiological experiments with plant seeds aboard the biosatellite Kosmos 1887

NASA Technical Reports Server (NTRS)

Anikeeva, I. D.; Vaulina, E. N.; Kostina, L. N.; Marenny, A. M.; Portman, A. I.; Rusin, S. V.; Benton, E. V.

1990-01-01

The effects of spaceflight factors on the seeds of Arabidopsis thaliana and Crepis capillaris were studied provided with various protective measures: the seeds were located inside the satellite and in open space, protected with aluminium foil and also exposed without the foil cover. When the seeds were in open space without any protection, their viability was found to be suppressed; the survival rate and fertility of plants grown from these seeds were also diminished. An increase in the frequency of chromosome aberrations (CA) and in the number of multiple injuries was registered in this case. Experiments with the aluminium foil shielding showed a decrease in the suppression of the seeds' viability, but mutational changes were found to be even more increased, while the survival and fertility of the plants decreased. An increase in the thickness of shielding resulted in a decrease in the effects up to the level of the control, except for the effects connected with CA and fertility of the plants. Analysis of the results shows that these impairments can be ascribed to the action of single heavy charged particles (HCP). The seeds can be thus regarded as an integral biological 'dosimeter' which allows estimation of the total effects of radiation, ecological and biological factors.

Radiobiological experiments with plant seeds aboard the biosatellite Cosmos 1887

NASA Technical Reports Server (NTRS)

Benton, E. V.; Anikeeva, I. D.; Akatov, Yu. A.; Vaulina, E. N.; Kostina, L. N.; Marenny, A.; Portman, A. I.; Rusin, S. V.

1995-01-01

The effects of spaceflight factors on the seeds of Arabidopsis thaliana and Crepis capillaris were studied. The seeds were located inside the satellite in an open space, protected with aluminum foil and also exposed without the foil cover. When the seeds were in open space without any protection, their viability was found to be suppressed; the survival rate and fertility of plants grown from these seeds were also diminished. An increase in the frequency of chromosome aberrations (CA) and in the number of multiple injuries was registered in this case. Experiments with the aluminum foil shielding showed a decrease in the suppression of the seeds' viability, but mutational changes were found to be even more increased, while the survival rate and fertility of the plants decreased. An increase in the thickness of shielding resulted in a decrease in the effects up to the level of the control, except for the effects connected with CA and fertility of the plants. Analysis of the results shows that these impairments can be ascribed to the action of single heavy charged particles (HCP). The seeds can thus be regarded as an integral biological 'dosimeter' which allows estimation of the total effects of radiation, ecological and biological factors.

Radiobiological experiments with plant seeds aboard the biosatellite Kosmos 1887.

PubMed

Anikeeva, I D; Akatov YuA; Vaulina, E N; Kostina, L N; Marenny, A M; Portman, A I; Rusin, S V; Benton, E V

1990-01-01

The effects of spaceflight factors on the seeds of Arabidopsis thaliana and Crepis capillaris were studied provided with various protective measures: the seeds were located inside the satellite and in open space, protected with aluminium foil and also exposed without the foil cover. When the seeds were in open space without any protection, their viability was found to be suppressed; the survival rate and fertility of plants grown from these seeds were also diminished. An increase in the frequency of chromosome aberrations (CA) and in the number of multiple injuries was registered in this case. Experiments with the aluminium foil shielding showed a decrease in the suppression of the seeds' viability, but mutational changes were found to be even more increased, while the survival and fertility of the plants decreased. An increase in the thickness of shielding resulted in a decrease in the effects up to the level of the control, except for the effects connected with CA and fertility of the plants. Analysis of the results shows that these impairments can be ascribed to the action of single heavy charged particles (HCP). The seeds can be thus regarded as an integral biological 'dosimeter' which allows estimation of the total effects of radiation, ecological and biological factors.

Anti-cyanobacterial activity of Moringa oleifera seeds

PubMed Central

Beekman, Wendy

2009-01-01

Filtrates from crushed Moringa oleifera seeds were tested for their effects on growth and Photosystem II efficiency of the common bloom-forming cyanobacterium Microcystis aeruginosa. M. aeruginosa populations exhibited good growth in controls and treatments with 4- and 8-mg crushed Moringa seeds per liter, having similar growth rates of 0.50 (±0.01) per day. In exposures of 20- to 160-mg crushed Moringa seeds L−1, growth rates were negative and on average −0.23 (±0.05) .day−1. Presumably, in the higher doses of 20- to 160-mg crushed seeds per liter, the cyanobacteria died, which was supported by a rapid drop in the Photosystem II efficiency (ΦPSII), while the ΦPSII was high and unaffected in 0, 4, and 8 mg L−1. High-density populations of M. aeruginosa (chlorophyll-a concentrations of ∼270 µg L−1) were reduced to very low levels within 2 weeks of exposure to ≥80-mg crushed seeds per liter. At the highest dosage of 160 mg L−1, the ΦPSII dropped to zero rapidly and remained nil during the course of the experiment (14 days). Hence, under laboratory conditions, a complete wipeout of the bloom could be achieved. This is the first study that yielded evidence for cyanobactericidal activity of filtrate from crushed Moringa seeds, suggesting that Moringa seed extracts might have a potential as an effect-oriented measure lessening cyanobacterial nuisance. PMID:20676212

FE-2 Nicole Stott works on the CBEF Space Seed Experiment

NASA Image and Video Library

2009-10-14

ISS021-E-006292 (14 Oct. 2009) --- NASA astronaut Nicole Stott, Expedition 21 flight engineer, using a watering syringe, supplies water to the Cell Biology Experiment Facility (CBEF) SPACE SEED experiment in the Kibo laboratory on the International Space Station.

Reconsidering the effects of tannin on seed dispersal by rodents: evidence from enclosure and field experiments with artificial seeds.

PubMed

Zhang, Mingming; Steele, Michael A; Yi, Xianfeng

2013-11-01

The question of how tannin affects feeding and hoarding preferences of rodents still remains poorly understood, in part, because it is difficult to control for other seed traits when considering the sole effect of tannin. Here, we constructed a series of artificial 'seeds' with different tannin levels, made from wheat flour, peanut powder and hydrolysable tannins, to determine the direct effects of tannin on both feeding and hoarding preferences. We first presented 'seeds' to individual rodents of two species (Tamias sibiricus and Apodemus peninsulae) confined in semi-natural enclosures and then monitored patterns of seed dispersal and consumption by free-ranging animals in a temperate forest in the Xiaoxing'an Mountains, Heilongjiang Province of China. Our results showed that small rodents displayed a significant preference for low-tannin 'seeds' for both consumption and caching in both captive and field experiments. Moreover, our two-year study consistently showed that tannin concentration was significantly and negatively correlated with the number of cached 'seeds' at both the individual and population levels. Seed size, compared with tannin concentrations, appeared to have little effect on dispersal distances and the number of 'seeds' cached. Low-tannin 'seeds' tended to be dispersed greater distances by rodents in the field than those with higher levels of tannin. These results failed to support those of previous reports indicating that acorns containing higher tannins are more likely to be cached by food hoarding animals. Copyright © 2013 Elsevier B.V. All rights reserved.

How seed orchard culture affects seed quality: experience with the southern pines

Treesearch

James P. Barnett

1996-01-01

Tree improvement programs have influenced significantly the quality of southern pine seeds produced when compared to collections from native stands. Seed orchard management practices such as fertilization can increase seed size and reduce seed dormancy. These result in the need for less complex pregermination treatments. Repeated cone collections from the same clones...

The seed dormancy defect of Arabidopsis mutants lacking the transcript elongation factor TFIIS is caused by reduced expression of the DOG1 gene.

PubMed

Mortensen, Simon A; Grasser, Klaus D

2014-01-03

TFIIS is a transcript elongation factor that facilitates transcription by RNA polymerase II, as it assists the enzyme to bypass blocks to mRNA synthesis. Previously, we have reported that Arabidopsis plants lacking TFIIS exhibit reduced seed dormancy. Among the genes differentially expressed in tfIIs seeds, the DOG1 gene was identified that is a known QTL for seed dormancy. Here we have analysed plants that overexpress TFIIS in wild type background, or that harbour an additional copy of DOG1 in tfIIs mutant background. These experiments demonstrate that the down-regulation of DOG1 expression causes the seed dormancy phenotype of tfIIs mutants. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Final results of the Space Exposed Experiment Developed for Students (SEEDS) P-0004-2

NASA Technical Reports Server (NTRS)

Grigsby, Doris K.

1992-01-01

Space Exposed Experiment Developed for Students (SEEDS), resulted in the distribution of over 132,000 SEED kits in 1990. The kits contained Rutger's tomato seeds that had flown on the Long Duration Exposure Facility (LDEF) as well as seeds that had been stored in a climate controlled warehouse for the same period of time. Students compared germination and growth rate characteristics of the two seeds groups and returned data to NASA for analysis. The scientific information gained was valuable as students shared the excitement of taking part in a national project. Of greater importance was the subsequent interest generated in science education.

The seed bank longevity index revisited: limited reliability evident from a burial experiment and database analyses.

PubMed

Saatkamp, Arne; Affre, Laurence; Dutoit, Thierry; Poschlod, Peter

2009-09-01

Seed survival in the soil contributes to population persistence and community diversity, creating a need for reliable measures of soil seed bank persistence. Several methods estimate soil seed bank persistence, most of which count seedlings emerging from soil samples. Seasonality, depth distribution and presence (or absence) in vegetation are then used to classify a species' soil seed bank into persistent or transient, often synthesized into a longevity index. This study aims to determine if counts of seedlings from soil samples yield reliable seed bank persistence estimates and if this is correlated to seed production. Seeds of 38 annual weeds taken from arable fields were buried in the field and their viability tested by germination and tetrazolium tests at 6 month intervals for 2.5 years. This direct measure of soil seed survival was compared with indirect estimates from the literature, which use seedling emergence from soil samples to determine seed bank persistence. Published databases were used to explore the generality of the influence of reproductive capacity on seed bank persistence estimates from seedling emergence data. There was no relationship between a species' soil seed survival in the burial experiment and its seed bank persistence estimate from published data using seedling emergence from soil samples. The analysis of complementary data from published databases revealed that while seed bank persistence estimates based on seedling emergence from soil samples are generally correlated with seed production, estimates of seed banks from burial experiments are not. The results can be explained in terms of the seed size-seed number trade-off, which suggests that the higher number of smaller seeds is compensated after germination. Soil seed bank persistence estimates correlated to seed production are therefore not useful for studies on population persistence or community diversity. Confusion of soil seed survival and seed production can be avoided by

Seeds in space experiment. [long duration exposure facility

NASA Technical Reports Server (NTRS)

Alston, Jim A.

1992-01-01

Two million seeds of 120 different varieties representing 106 species, 97 genera, and 55 plant families were flown aboard the Long Duration Exposure Facility (LDEF). The seeds were housed in one sealed canister and in two small vented canisters. After being returned to earth, the seeds were germinated and the germination rates and development of the resulting plants were compared to the performance of the control seeds that stayed in the Park Seed's seed storage facility. There was a better survival rate in the sealed canister in space than at the storage facility at Park Seed. At least some of the seeds in each of the vented canisters survived the exposure to vacuum for almost six years. The number of observed apparent mutations was very low.

Seed harvesting is influenced by associational effects in mixed seed neighbourhoods, not just by seed density

USGS Publications Warehouse

Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan; Klinger, Robert C.

2013-01-01

Rodents frequently forage in a density-dependent manner, increasing harvesting in patches with greater seed densities. Although seldom considered, seed harvesting may also depend on the species identities of other individuals in the seed neighbourhood. When the seed harvest of a focal species increases in association with another seed species, the focal species suffers from Associational Susceptibility. In contrast, if seeds of the focal species are harvested less when in association with a second species, the focal species benefits from Associational Resistance.To evaluate density dependence and associational effects among seeds in mixtures, we conducted seed removal experiments using a completely additive design patterned after a two-species competition experiment using seeds of either Achnatherum hymenoides(Indian ricegrass), Leymus cinereus (basin wildrye) or Pseudoroegneria spicata (bluebunch wheatgrass), all native perennial grasses, combined with seeds of Bromus tectorum(cheatgrass), a non-native annual grass. The experiment involved placing five fixed quantities of the native seeds mixed with five fixed quantities of B. tectorum seeds in a factorial design, resulting in 35 seed mixture combinations. The seed-eating rodent community at our study sites, in order of abundance, is composed of Peromyscus maniculatus (North American deer mouse), Dipodomys ordii (Ord's kangaroo rat) and Perognathus parvus (Great Basin pocket mouse).Native seed harvesting was density dependent, with a greater proportion of seeds being harvested as density increased. In the mixed density model, the presence of B. tectorumdid not affect harvest of any of the native species' seeds when analysed individually. However, when all three native species were analysed together, increasing quantities of B. tectorum resulted in reduced harvest of native seeds, demonstrating weak but significant Associational Resistance. In contrast, harvest of B. tectorum seeds increased

The Study of Blocking Agent on Lengkeng (Euphoria Logan Lour) Fruit Shell and Seed for Adsorption of Pb (II) from Aqueous Solution

NASA Astrophysics Data System (ADS)

Kurniawati, D.; Zein, R.; Chaidir, Z.; Aziz, H.

2018-04-01

The study focuses on the roles played by mayor functional groups(carboxyl) in the lengkeng shell for sorption of Pb (II). The biosorbent was characterized by FTIR and elemental analyses. The parameters such as pH, initial concentration, particle sizes, adsorbent dose and flow rate were also studied. The results showed that the optimum condition was at pH = 3, concentration 400 mg/l, 250 μm particle sizes, adsorbent dose 0,5 g and 2 ml/min flow rate with adsorption capacity 4,8933 mg/g(shell) and 5,2720 mg/g(seed). It is show that ion exchange play as a more important role in the sorption of Pb (II) on lengkeng shell and seed. Blocking of COOH groups by chemical esterification resulted in Pb important reduction in metal binding.The result showed that adsorption capacity of lengkeng shell uncreases until 63.67 % and lengkeng seed uncreases 98.70%.

The Woody Plant Seed Manual

Treesearch

Franklin T. Bonner; Robert P. Karrfalt

2008-01-01

The first comprehensive handbook on the seeds of trees and shrubs produced by the USDA Forest Service was USDA Misc. Pub. 654, Woody-Plant Seed Manual. The manuscript was ready for publication in 1941, but World War II delayed publication until 1948. The boom in tree planting in the 1950s and 1960s created a large demand for seeds and exposed the gaps in our knowledge...

Effect of dietary supplementation of hemp seed (Cannabis sativa L.) on meat quality and egg fatty acid composition of Japanese quail (Coturnix coturnix japonica).

PubMed

Yalcin, H; Konca, Y; Durmuscelebi, F

2018-02-01

This study was conducted in two separate experiments. Experiment I was conducted to investigate the effects of hemp seed (HS) on meat quality traits, and experiment II was designed to determine egg fatty acid (FA) composition in Japanese quail (Coturnix coturnix japonica). In experiment I and experiment II treatments, groups were as follows: (i) control (not included HS0), (ii) 5% HS inclusion to diets, (iii) 10% HS inclusion to diets and (iv) 20% HS inclusion to diets. In experiment I, a total of 192 7-day-old-quail were fed with HS diets for 5 weeks, and end of the experiment I, a total of 64 quail (16 each) slaughtered and meat samples were analysed for meat colour, pH, cooking and thawing loss and FA composition. In experiment II, a total of 120 8-week-old laying quail were fed with experimental diets for 6 weeks and egg FA composition were determined. Breast meat cooking loss was significantly lower in 20% supplemented group (p < 0.01). Hemp seed inclusion to diets caused a linear and cubic increase in redness (a*) of hip meat (p < 0.01). Palmitoleic and oleic FAs were decreased with HS addition in breast meat (p < 0.05); however, linoleic and linolenic acid contents of meat were linearly increased (p < 0.01). In experiment II, the linoleic and linolenic FA contents of egg samples were linearly increased with increasing the dietary HS ratio (p < 0.01). Hemp seed addition was provided lower palmitoleic and oleic FAs in quail eggs (p < 0.05). In conclusion, HS supplementation to quail diets may increase quail meat redness and meat and egg yolk omega-3 FA content and decrease cooking loss of quail meats. © 2017 Blackwell Verlag GmbH.

Seed-to-seed-to-seed growth and development of Arabidopsis in microgravity.

PubMed

Link, Bruce M; Busse, James S; Stankovic, Bratislav

2014-10-01

Arabidopsis thaliana was grown from seed to seed wholly in microgravity on the International Space Station. Arabidopsis plants were germinated, grown, and maintained inside a growth chamber prior to returning to Earth. Some of these seeds were used in a subsequent experiment to successfully produce a second (back-to-back) generation of microgravity-grown Arabidopsis. In general, plant growth and development in microgravity proceeded similarly to those of the ground controls, which were grown in an identical chamber. Morphologically, the most striking feature of space-grown Arabidopsis was that the secondary inflorescence branches and siliques formed nearly perpendicular angles to the inflorescence stems. The branches grew out perpendicularly to the main inflorescence stem, indicating that gravity was the key determinant of branch and silique angle and that light had either no role or a secondary role in Arabidopsis branch and silique orientation. Seed protein bodies were 55% smaller in space seed than in controls, but protein assays showed only a 9% reduction in seed protein content. Germination rates for space-produced seed were 92%, indicating that the seeds developed in microgravity were healthy and viable. Gravity is not necessary for seed-to-seed growth of plants, though it plays a direct role in plant form and may influence seed reserves.

New design of experiment combined with UV-Vis spectroscopy for extraction and estimation of polyphenols from Basil seeds, Red seeds, Sesame seeds and Ajwan seeds

NASA Astrophysics Data System (ADS)

Mabood, Fazal; Gilani, Syed Abdullah; Hussain, Javid; Alshidani, Sulaiman; Alghawi, Said; Albroumi, Mohammed; Alameri, Saif; Jabeen, Farah; Hussain, Zahid; Al-Harrasi, Ahmed; Al Abri, Zahra K. M.; Farooq, Saima; Naureen, Zakira; Hamaed, Ahmad; Rasul Jan, M.; Shah, Jasmin

2017-05-01

New experimental designs for the extraction of polyphenols from different seeds including Basil seed, Red seed, Sesame seeds and Ajwan seeds were investigated. Four variables the concentration and volume of methanol and NaOH solutions as well as the temperature and time of extraction were varied to see their effect on total phenol extraction. The temperature was varied in the range from 25 °C to 200 °C while the time in the range from 30 to 200 minutes. Response surface methodology was used to optimize the extraction parameters. The estimation of polyphenols was measured through phenols reduction UV-Vis spectroscopic method of phosphotungstic-phosphomolybdic acids (Folin-Ciocalteu's reagent). Calibration curve was made by using tannic acid as a polyphenols standard in the concentration range from 0.1 to 10 ppm. The regression line obtained shows the value of correlation coefficient i.e. R = 0.930 and Root mean square error of cross validation (RMSEC) value of 0.0654. The Basil seeds were found containing the highest amount of total phenols i.e. 785.76 mg/100 g. While the Sesame seeds having the least amount i.e. 33.08 mg/100 g. The Ajwan seeds and the Red seeds are containing the medium amounts i.e. 379 mg/100 g and 220.54 mg/100 g respectively.

New design of experiment combined with UV-Vis spectroscopy for extraction and estimation of polyphenols from Basil seeds, Red seeds, Sesame seeds and Ajwan seeds.

PubMed

Mabood, Fazal; Gilani, Syed Abdullah; Hussain, Javid; Alshidani, Sulaiman; Alghawi, Said; Albroumi, Mohammed; Alameri, Saif; Jabeen, Farah; Hussain, Zahid; Al-Harrasi, Ahmed; Al Abri, Zahra K M; Farooq, Saima; Naureen, Zakira; Hamaed, Ahmad; Rasul Jan, M; Shah, Jasmin

2017-05-05

New experimental designs for the extraction of polyphenols from different seeds including Basil seed, Red seed, Sesame seeds and Ajwan seeds were investigated. Four variables the concentration and volume of methanol and NaOH solutions as well as the temperature and time of extraction were varied to see their effect on total phenol extraction. The temperature was varied in the range from 25°C to 200°C while the time in the range from 30 to 200minutes. Response surface methodology was used to optimize the extraction parameters. The estimation of polyphenols was measured through phenols reduction UV-Vis spectroscopic method of phosphotungstic-phosphomolybdic acids (Folin-Ciocalteu's reagent). Calibration curve was made by using tannic acid as a polyphenols standard in the concentration range from 0.1 to 10ppm. The regression line obtained shows the value of correlation coefficient i.e. R=0.930 and Root mean square error of cross validation (RMSEC) value of 0.0654. The Basil seeds were found containing the highest amount of total phenols i.e. 785.76mg/100g. While the Sesame seeds having the least amount i.e. 33.08mg/100g. The Ajwan seeds and the Red seeds are containing the medium amounts i.e. 379mg/100g and 220.54mg/100g respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

A nuclear gene for the iron-sulfur subunit of mitochondrial complex II is specifically expressed during Arabidopsis seed development and germination.

PubMed

Elorza, Alvaro; Roschzttardtz, Hannetz; Gómez, Isabel; Mouras, Armand; Holuigue, Loreto; Araya, Alejandro; Jordana, Xavier

2006-01-01

Three nuclear genes, SDH2-1, SDH2-2 and SDH2-3, encode the essential iron-sulfur subunit of mitochondrial complex II in Arabidopsis thaliana. SDH2-1 and SDH2-2 probably arose via a recent duplication event and we reported that both are expressed in all organs from adult plants. In contrast, transcripts from SDH2-3 were not detected. Here we present data demonstrating that SDH2-3 is specifically expressed during seed development. SDH2-3 transcripts appear during seed maturation, persist through desiccation, are abundant in dry seeds and markedly decline during germination. Analysis of transgenic Arabidopsis plants carrying the SDH2-3 promoter fused to the beta-glucuronidase reporter gene shows that the SDH2-3 promoter is activated in the embryo during maturation, from the bent-cotyledon stage. beta-Glucuronidase expression correlates with the appearance of endogenous SDH2-3 transcripts, suggesting that control of this nuclear gene is achieved through transcriptional regulation. Furthermore, progressive deletions of this promoter identified a 159 bp region (-223 to -65) important for SDH2-3 transcriptional activation in seeds. Interestingly, the SDH2-3 promoter remains active in embryonic tissues during germination and post-germinative growth, and is turned off in vegetative tissues (true leaves). In contrast to SDH2-3 transcripts, SDH2-1 and SDH2-2 transcripts are barely detected in dry seeds and increase during germination and post-germinative growth. The opposite expression patterns of SDH2 nuclear genes strongly suggest that during germination the embryo-specific SDH2-3 is replaced by SDH2-1 or SDH2-2 in mitochondrial complex II.

Seed-to-Seed-to-Seed Growth and Development of Arabidopsis in Microgravity

PubMed Central

Link, Bruce M.; Busse, James S.

2014-01-01

Abstract Arabidopsis thaliana was grown from seed to seed wholly in microgravity on the International Space Station. Arabidopsis plants were germinated, grown, and maintained inside a growth chamber prior to returning to Earth. Some of these seeds were used in a subsequent experiment to successfully produce a second (back-to-back) generation of microgravity-grown Arabidopsis. In general, plant growth and development in microgravity proceeded similarly to those of the ground controls, which were grown in an identical chamber. Morphologically, the most striking feature of space-grown Arabidopsis was that the secondary inflorescence branches and siliques formed nearly perpendicular angles to the inflorescence stems. The branches grew out perpendicularly to the main inflorescence stem, indicating that gravity was the key determinant of branch and silique angle and that light had either no role or a secondary role in Arabidopsis branch and silique orientation. Seed protein bodies were 55% smaller in space seed than in controls, but protein assays showed only a 9% reduction in seed protein content. Germination rates for space-produced seed were 92%, indicating that the seeds developed in microgravity were healthy and viable. Gravity is not necessary for seed-to-seed growth of plants, though it plays a direct role in plant form and may influence seed reserves. Key Words: Arabidopsis—Branch—Inflorescence—Microgravity—Morphology—Seed—Space. Astrobiology 14, 866–875. PMID:25317938

Survival of plant seeds, their UV screens, and nptII DNA for 18 months outside the International Space Station.

PubMed

Tepfer, David; Zalar, Andreja; Leach, Sydney

2012-05-01

The plausibility that life was imported to Earth from elsewhere can be tested by subjecting life-forms to space travel. Ultraviolet light is the major liability in short-term exposures (Horneck et al., 2001 ), and plant seeds, tardigrades, and lichens-but not microorganisms and their spores-are candidates for long-term survival (Anikeeva et al., 1990 ; Sancho et al., 2007 ; Jönsson et al., 2008 ; de la Torre et al., 2010 ). In the present study, plant seeds germinated after 1.5 years of exposure to solar UV, solar and galactic cosmic radiation, temperature fluctuations, and space vacuum outside the International Space Station. Of the 2100 exposed wild-type Arabidopsis thaliana and Nicotiana tabacum (tobacco) seeds, 23% produced viable plants after return to Earth. Survival was lower in the Arabidopsis Wassilewskija ecotype and in mutants (tt4-8 and fah1-2) lacking UV screens. The highest survival occurred in tobacco (44%). Germination was delayed in seeds shielded from solar light, yet full survival was attained, which indicates that longer space travel would be possible for seeds embedded in an opaque matrix. We conclude that a naked, seed-like entity could have survived exposure to solar UV radiation during a hypothetical transfer from Mars to Earth. Chemical samples of seed flavonoid UV screens were degraded by UV, but their overall capacity to absorb UV was retained. Naked DNA encoding the nptII gene (kanamycin resistance) was also degraded by UV. A fragment, however, was detected by the polymerase chain reaction, and the gene survived in space when protected from UV. Even if seeds do not survive, components (e.g., their DNA) might survive transfer over cosmic distances.

Space Exposed Experiment Developed for Students (SEEDS) (P0004-2)

NASA Technical Reports Server (NTRS)

Grigsby, Doris K.; Ehrlich, Nelson J.

1992-01-01

SEEDS, a cooperative endeavor of NASA Headquarters, the NASA Langley Research Center, and the George W. Park Seed Company, resulted in the distribution of approximately 132,000 SEEDS kits to 3.3 million students. Kits contained Rutger's tomato seeds that had flown on the Long Duration Exposure Facility (LDEF), as well as seeds that had been stored in a climate controlled warehouse for the same time period. Preliminary data indicates the germination rate for space exposed seeds was 73.8 percent while Earth based seeds germinated at a rate of 70.3 percent. Tests conducted within the first six months after retrieval indicated space exposed seeds germinated in an average of 8.0 days, while Earth based seeds' average germination time was 8.3 days. Some mutations (assumed to be radiation induced) include plants that added a leaf instead of the usual flower at the end of the flower frond. Also, fruit produced from a flower with a variegated calyx bore seeds producing albino plants, while fruit from a flower with a green calyx from the same plant bore seeds producing green plants.

Seeds: A Celebration of Science.

ERIC Educational Resources Information Center

Melton, Bob

The Space Exposed Experiment Developed for Students (SEEDS) Project offered science classes at the 5-12 and college levels the opportunity to conduct experiments involving tomato seeds that had been space-exposed over long periods of time. SEEDS kits were complete packages obtained from the National Aeronautics and Space Administration (NASA) for…

Implications of nonrandom seed abscission and global stilling for migration of wind-dispersed plant species.

PubMed

Thompson, Sally E; Katul, Gabriel G

2013-06-01

Migration of plant populations is a potential survival response to climate change that depends critically on seed dispersal. Biological and physical factors determine dispersal and migration of wind-dispersed species. Recent field and wind tunnel studies demonstrate biological adaptations that bias seed release toward conditions of higher wind velocity, promoting longer dispersal distances and faster migration. However, another suite of international studies also recently highlighted a global decrease in near-surface wind speeds, or 'global stilling'. This study assessed the implications of both factors on potential plant population migration rates, using a mechanistic modeling framework. Nonrandom abscission was investigated using models of three seed release mechanisms: (i) a simple drag model; (ii) a seed deflection model; and (iii) a 'wear and tear' model. The models generated a single functional relationship between the frequency of seed release and statistics of the near-surface wind environment, independent of the abscission mechanism. An Inertial-Particle, Coupled Eulerian-Lagrangian Closure model (IP-CELC) was used to investigate abscission effects on seed dispersal kernels and plant population migration rates under contemporary and potential future wind conditions (based on reported global stilling trends). The results confirm that nonrandom seed abscission increased dispersal distances, particularly for light seeds. The increases were mitigated by two physical feedbacks: (i) although nonrandom abscission increased the initial acceleration of seeds from rest, the sensitivity of the seed dispersal to this initial condition declined as the wind speed increased; and (ii) while nonrandom abscission increased the mean dispersal length, it reduced the kurtosis of seasonal dispersal kernels, and thus the chance of long-distance dispersal. Wind stilling greatly reduced the modeled migration rates under biased seed release conditions. Thus, species that require

Increased temperatures negatively affect Juniperus communis seeds: evidence from transplant experiments along a latitudinal gradient.

PubMed

Gruwez, R; De Frenne, P; Vander Mijnsbrugge, K; Vangansbeke, P; Verheyen, K

2016-05-01

With a distribution range that covers most of the Northern hemisphere, common juniper (Juniperus communis) has one of the largest ranges of all vascular plant species. In several regions in Europe, however, populations are decreasing in size and number due to failing recruitment. One of the main causes for this failure is low seed viability. Observational evidence suggests that this is partly induced by climate warming, but our mechanistic understanding of this effect remains incomplete. Here, we experimentally assess the influence of temperature on two key developmental phases during sexual reproduction, i.e. gametogenesis and fertilisation (seed phase two, SP2) and embryo development (seed phase three, SP3). Along a latitudinal gradient from southern France to central Sweden, we installed a transplant experiment with shrubs originating from Belgium, a region with unusually low juniper seed viability. Seeds of both seed phases were sampled during three consecutive years, and seed viability assessed. Warming temperatures negatively affected the seed viability of both SP2 and SP3 seeds along the latitudinal gradient. Interestingly, the effect on embryo development (SP3) only occurred in the third year, i.e. when the gametogenesis and fertilisation also took place in warmer conditions. We found strong indications that this negative influence mostly acts via disrupting growth of the pollen tube, the development of the female gametophyte and fertilisation (SP2). This, in turn, can lead to failing embryo development, for example, due to nutritional problems. Our results confirm that climate warming can negatively affect seed viability of juniper. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

Cone and seed yields in white spruce seed production areas

Treesearch

John A. Pitcher

1966-01-01

The source of seed is an important consideration in the reforestation program on the National Forests in the North Central Region. Thirty-five seed production areas have been set up in the Region, along the lines proposed by the North Central Forest Experiment Station, to provide control of seed source. Red pine, white pine, shortleaf and loblolly pine, and white...

Gerst during BASS-II experiment

NASA Image and Video Library

2014-07-30

ISS040-E-083576 (30 July 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, performs two tests with a combustion experiment known as the Burning and Suppression of Solids (BASS-II) in the Microgravity Science Glovebox (MSG) in the Destiny laboratory of the International Space Station. The experiment seeks to provide insight on how flames burn in space compared to Earth which may provide fire safety benefits aboard future spacecraft.

Gerst during BASS-II experiment

NASA Image and Video Library

2014-07-30

ISS040-E-083578 (30 July 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, performs two tests with a combustion experiment known as the Burning and Suppression of Solids (BASS-II) in the Microgravity Science Glovebox (MSG) in the Destiny laboratory of the International Space Station. The experiment seeks to provide insight on how flames burn in space compared to Earth which may provide fire safety benefits aboard future spacecraft.

[Supercritical CO2 extraction and component analysis of Aesculus wilsonii seed oil].

PubMed

Chen, Guang-Yu; Shi, Zhao-Hua; Li, Hai-Chi; Ge, Fa-Huan; Zhan, Hua-Shu

2013-03-01

To research the optimal extraction process of supercritical CO2 extraction and analyze the component of the oil extracted from Aesculus wilsonii seed. Using the yield of Aesculus wilsonii seed oil as the index, optimized supercritical CO2 extraction parameter by orthogonal experiment methodology and analysed the compounds of Aesculus wilsonii seed oil by GC-MS. The optimal parameters of the supercritical CO2 extraction of the oil extracted from Aesculus wilsoniit seed were determined: the extraction pressure was 28 MPa and the temperature was 38 degrees C, the separation I pressure was 12 MPa and the temperature was 40 degrees C, the separation II pressure was 5 MPa and the temperature was 40 degrees C, the extraction time was 110 min. The average extraction rate of Aesculus wilsonii seed oil was 1.264%. 26 kinds of compounds were identified by GC-MS in Aesculus wilsonii seed oil extracted by supercritical CO2. The main components were fatty acids. Comparing with the petroleum ether extraction, the supercritical CO2 extraction has higher extraction rate, shorter extraction time, more clarity oil. The kinds of fatty acids with high amounts in Aesculus wilsonii seed oil is identical in general, the kinds of fatty acids with low amounts in Aesculus wilsonii seed oil have differences.

An active Mitochondrial Complex II Present in Mature Seeds Contains an Embryo-Specific Iron-Sulfur Subunit Regulated by ABA and bZIP53 and Is Involved in Germination and Seedling Establishment.

PubMed

Restovic, Franko; Espinoza-Corral, Roberto; Gómez, Isabel; Vicente-Carbajosa, Jesús; Jordana, Xavier

2017-01-01

Complex II (succinate dehydrogenase) is an essential mitochondrial enzyme involved in both the tricarboxylic acid cycle and the respiratory chain. In Arabidopsis thaliana , its iron-sulfur subunit (SDH2) is encoded by three genes, one of them ( SDH2.3 ) being specifically expressed during seed maturation in the embryo. Here we show that seed SDH2.3 expression is regulated by abscisic acid (ABA) and we define the promoter region (-114 to +49) possessing all the cis -elements necessary and sufficient for high expression in seeds. This region includes between -114 and -32 three ABRE (ABA-responsive) elements and one RY-enhancer like element, and we demonstrate that these elements, although necessary, are not sufficient for seed expression, our results supporting a role for the region encoding the 5' untranslated region (+1 to +49). The SDH2.3 promoter is activated in leaf protoplasts by heterodimers between the basic leucine zipper transcription factors bZIP53 (group S1) and bZIP10 (group C) acting through the ABRE elements, and by the B3 domain transcription factor ABA insensitive 3 (ABI3). The in vivo role of bZIP53 is further supported by decreased SDH2.3 expression in a knockdown bzip53 mutant. By using the protein synthesis inhibitor cycloheximide and sdh2 mutants we have been able to conclusively show that complex II is already present in mature embryos before imbibition, and contains mainly SDH2.3 as iron-sulfur subunit. This complex plays a role during seed germination sensu-stricto since we have previously shown that seeds lacking SDH2.3 show retarded germination and now we demonstrate that low concentrations of thenoyltrifluoroacetone, a complex II inhibitor, also delay germination. Furthermore, complex II inhibitors completely block hypocotyl elongation in the dark and seedling establishment in the light, highlighting an essential role of complex II in the acquisition of photosynthetic competence and the transition from heterotrophy to autotrophy.

Greenhouse (III): Gas-Exchange and Seed-to-Seed Experiments on the Russian Space Station MIR and Earth-grown, Ethylene-Treated Wheat Plants

NASA Technical Reports Server (NTRS)

Campbell, William F.; Bingham, Gail; Carman, John; Bubenheim, David; Levinskikh, Margarita; Sytchev, Vladimir N.; Podolsky, Igor B.; Chernova, Lola; Nefodova, Yelena

2001-01-01

The Mir Space Station provided an outstanding opportunity to study long-term plant responses when exposed to a microgravity environment. Furthermore, if plants can be grown to maturity in a microgravity environment, they might be used in future bioregenerative life-support systems (BLSS). The primary objective of the Greenhouse experiment onboard Mir was to grow Super Dwarf and Apogee wheat through complete life cycles in microgravity; i.e., from seed-to-seed-to-seed. Additional objectives were to study chemical, biochemical, and structural changes in plant tissues as well as photosynthesis, respiration, and transpiration (evaporation of water from plants). Another major objective was to evaluate the suitability clothe facilities on Mir for advanced research with plants. The Greenhouse experiment was conducted in the Russian/Bulgarian plant growth chamber, the Svet, to which the United States added instrumentation systems to monitor changes in CO2 and water vapor caused by the plants (with four infrared gas analyzers monitoring air entering and leaving two small plastic chambers). In addition, the US instrumentation also monitored O2; air, leaf (IR), cabin pressure; photon flux; and substrate temperature and substrate moisture (16 probes in the root module). Facility modifications were first performed during the summer of 1995 during Mir 19, which began after STS-72 left Mir. Plant development was monitored by daily observations and some photographs.

7 CFR 52.1852 - Grades of raisins with seeds-except layer or cluster.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) “U.S. Grade A” is the quality of Raisins with Seeds that have similar varietal characteristics; that... requirements as outlined in Table II of this subpart. (b) “U.S. Grade B” is the quality of Raisins with Seeds... in Table II of this subpart. (c) “U.S. Grade C” is the quality of Raisins with Seeds that have...

Survival and DNA Damage in Plant Seeds Exposed for 558 and 682 Days outside the International Space Station

NASA Astrophysics Data System (ADS)

Tepfer, David; Leach, Sydney

2017-03-01

For life to survive outside the biosphere, it must be protected from UV light and other radiation by exterior shielding or through sufficient inherent resistance to survive without protection. We tested the plausibility of inherent resistance in plant seeds, reporting in a previous paper that Arabidopsis thaliana and tobacco (Nicotiana tabacum) seeds exposed for 558 days outside the International Space Station (ISS) germinated and developed into fertile plants after return to Earth. We have now measured structural genetic damage in tobacco seeds from this EXPOSE-E experiment by quantitatively amplifying a segment of an antibiotic resistance gene, nptII, inserted into the chloroplast genome. We also assessed the survival of the antibiotic resistance encoded by nptII, using marker rescue in a soil bacterium. Chloroplast DNA damage occurred, but morphological mutants were not detected among the survivors. In a second, longer mission (EXPOSE-R), a nearly lethal exposure was received by Arabidopsis seeds. Comparison between a ground simulation, lacking UV<200nm, and fully exposed seeds in space indicated severe damage from these short wavelengths and again suggested that DNA degradation was not limiting seed survival. To test UV resistance in long-lived, larger seeds, we exposed Arabidopsis, tobacco, and morning glory seeds in the laboratory to doses of UV254nm, ranging as high as 2420 MJ m-2. Morning glory seeds resisted this maximum dose, which killed tobacco and Arabidopsis. We thus confirm that a naked plant seed could survive UV exposures during direct transfer from Mars to Earth and suggest that seeds with a more protective seed coat (e.g., morning glory) should survive much longer space travel.

Recent experience in seeding transonic/supersonic flows at AEDC

NASA Astrophysics Data System (ADS)

Heltsley, F. L.

1985-10-01

The laser velocimeter has been utilized for several years at the Arnold Engineering and Development Center (AEDC) as a flow diagnostics tool. Most applications, following the initial proof-of-concept experiments, have involved relatively complex unknown flow fields in which the more conventional, intrusive techniques had either not been attempted or had yielded unsatisfactory results. A blunt-base nozzle-afterbody base flow study is discussed as a respresentative example of such applications. A wide variety of problems have been encountered during these tests, many of which have proven to be closely related to the size and/or size distribution of the seeding material within the fluid. Resulting measurement uncertainties could often not be conclusively resolved because of the unknown nature of the flow field. The other experiments listed were conducted to provide known aerodynamic conditions for comparison with the velocimeter results.

Recent experience in seeding transonic/supersonic flows at AEDC

NASA Technical Reports Server (NTRS)

Heltsley, F. L.

1985-01-01

The laser velocimeter has been utilized for several years at the Arnold Engineering and Development Center (AEDC) as a flow diagnostics tool. Most applications, following the initial proof-of-concept experiments, have involved relatively complex unknown flow fields in which the more conventional, intrusive techniques had either not been attempted or had yielded unsatisfactory results. A blunt-base nozzle-afterbody base flow study is discussed as a respresentative example of such applications. A wide variety of problems have been encountered during these tests, many of which have proven to be closely related to the size and/or size distribution of the seeding material within the fluid. Resulting measurement uncertainties could often not be conclusively resolved because of the unknown nature of the flow field. The other experiments listed were conducted to provide known aerodynamic conditions for comparison with the velocimeter results.

Quantitative proteome analysis of barley seeds using ruthenium(II)-tris-(bathophenanthroline-disulphonate) staining.

PubMed

Witzel, Katja; Surabhi, Giridara-Kumar; Jyothsnakumari, Gottimukkala; Sudhakar, Chinta; Matros, Andrea; Mock, Hans-Peter

2007-04-01

This paper describes the application of the recently introduced fluorescence stain Ruthenium(II)-tris-(bathophenanthroline-disulphonate) (RuBP) on a comparative proteome analysis of two phenotypically different barley lines. We carried out an analysis of protein patterns from 2-D gels of the parental lines of the Oregon Wolfe Barley mapping population DOM and REC and stained with either the conventional colloidal Coomassie Brilliant Blue (cCBB) or with the novel RuBP solution. We wished to experimentally verify the usefulness of such a stain in evaluating the complex pattern of a seed proteome, in comparison to the previously used cCBB staining technique. To validate the efficiency of visualization by both stains, we first compared the overall number of detected protein spots. On average, 790 spots were visible by cCBB staining and 1200 spots by RuBP staining. Then, the intensity of a set of spots was assessed, and changes in relative abundance were determined using image analysis software. As expected, staining with RuBP performed better in quantitation in terms of sensitivity and dynamic range. Furthermore, spots from a cultivar-specific region in the protein map were chosen for identification to asses the gain of biological information due to the staining procedure. From this particular region, eight spots were visualized exclusively by RuBP and identification was successful for all spots, proving the ability to identify even very low abundant proteins. Performance in MS analysis was comparable for both protein stains. Proteins were identified by MALDI-TOF MS peptide mass fingerprinting. This approach was not successful for all spots, due to the restricted entry number for barley in the database. Therefore, we subsequently used LC-ESI-Q-TOF MS/MS and de novo sequencing for identification. Because only an insufficient number of proteins from barley is annotated, an EST-based identification strategy was chosen for our experiment. We wished to test whether under

Responses of seed germination, seedling growth, and seed yield traits to seed pretreatment in maize (Zea mays L.).

PubMed

Tian, Yu; Guan, Bo; Zhou, Daowei; Yu, Junbao; Li, Guangdi; Lou, Yujie

2014-01-01

A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method.

Survival and DNA Damage in Plant Seeds Exposed for 558 and 682 Days outside the International Space Station.

PubMed

Tepfer, David; Leach, Sydney

2017-03-01

For life to survive outside the biosphere, it must be protected from UV light and other radiation by exterior shielding or through sufficient inherent resistance to survive without protection. We tested the plausibility of inherent resistance in plant seeds, reporting in a previous paper that Arabidopsis thaliana and tobacco (Nicotiana tabacum) seeds exposed for 558 days outside the International Space Station (ISS) germinated and developed into fertile plants after return to Earth. We have now measured structural genetic damage in tobacco seeds from this EXPOSE-E experiment by quantitatively amplifying a segment of an antibiotic resistance gene, nptII, inserted into the chloroplast genome. We also assessed the survival of the antibiotic resistance encoded by nptII, using marker rescue in a soil bacterium. Chloroplast DNA damage occurred, but morphological mutants were not detected among the survivors. In a second, longer mission (EXPOSE-R), a nearly lethal exposure was received by Arabidopsis seeds. Comparison between a ground simulation, lacking UV <200nm , and fully exposed seeds in space indicated severe damage from these short wavelengths and again suggested that DNA degradation was not limiting seed survival. To test UV resistance in long-lived, larger seeds, we exposed Arabidopsis, tobacco, and morning glory seeds in the laboratory to doses of UV 254nm , ranging as high as 2420 MJ m -2 . Morning glory seeds resisted this maximum dose, which killed tobacco and Arabidopsis. We thus confirm that a naked plant seed could survive UV exposures during direct transfer from Mars to Earth and suggest that seeds with a more protective seed coat (e.g., morning glory) should survive much longer space travel. Key Words: UV light-Flavonoids-Sinapate-DNA degradation-Arabidopsis-Tobacco-Seeds-Space-International Space Station-EXPOSE-E-EXPOSE-R. Astrobiology 17, 205-215.

Ecotypic variability in the metabolic response of seeds to diurnal hydration-dehydration cycles and its relationship to seed vigor.

PubMed

Bai, Bing; Sikron, Noga; Gendler, Tanya; Kazachkova, Yana; Barak, Simon; Grafi, Gideon; Khozin-Goldberg, Inna; Fait, Aaron

2012-01-01

Seeds in the seed bank experience diurnal cycles of imbibition followed by complete dehydration. These conditions pose a challenge to the regulation of germination. The effect of recurring hydration-dehydration (Hy-Dh) cycles were tested on seeds from four Arabidopsis thaliana accessions [Col-0, Cvi, C24 and Ler]. Diurnal Hy-Dh cycles had a detrimental effect on the germination rate and on the final percentage of germination in Col-0, Cvi and C24 ecotypes, but not in the Ler ecotype, which showed improved vigor following the treatments. Membrane permeability measured by ion conductivity was generally increased following each Hy-Dh cycle and was correlated with changes in the redox status represented by the GSSG/GSH (oxidized/reduced glutathione) ratio. Among the ecotypes, Col-0 seeds displayed the highest membrane permeability, whilst Ler was characterized by the greatest increase in electrical conductivity following Hy-Dh cycles. Following Dh 2 and Dh 3, the respiratory activity of Ler seeds significantly increased, in contrast to the other ecotypes, indicative of a dramatic shift in metabolism. These differences were associated with accession-specific content and patterns of change of (i) cell wall-related laminaribiose and mannose; (ii) fatty acid composition, specifically of the unsaturated oleic acid and α-linoleic acid; and (iii) asparagine, ornithine and the related polyamine putrescine. Furthermore, in the Ler ecotype the content of the tricarboxylic acid (TCA) cycle intermediates fumarate, succinate and malate increased in response to dehydration, in contrast to a decrease in the other three ecotypes. These findings provide a link between seed respiration, energy metabolism, fatty acid β-oxidation, nitrogen mobilization and membrane permeability and the improved germination of Ler seeds following Hy-Dh cycles.

Survival and DNA Damage in Plant Seeds Exposed for 558 and 682 Days outside the International Space Station

PubMed Central

Leach, Sydney

2017-01-01

Abstract For life to survive outside the biosphere, it must be protected from UV light and other radiation by exterior shielding or through sufficient inherent resistance to survive without protection. We tested the plausibility of inherent resistance in plant seeds, reporting in a previous paper that Arabidopsis thaliana and tobacco (Nicotiana tabacum) seeds exposed for 558 days outside the International Space Station (ISS) germinated and developed into fertile plants after return to Earth. We have now measured structural genetic damage in tobacco seeds from this EXPOSE-E experiment by quantitatively amplifying a segment of an antibiotic resistance gene, nptII, inserted into the chloroplast genome. We also assessed the survival of the antibiotic resistance encoded by nptII, using marker rescue in a soil bacterium. Chloroplast DNA damage occurred, but morphological mutants were not detected among the survivors. In a second, longer mission (EXPOSE-R), a nearly lethal exposure was received by Arabidopsis seeds. Comparison between a ground simulation, lacking UV<200nm, and fully exposed seeds in space indicated severe damage from these short wavelengths and again suggested that DNA degradation was not limiting seed survival. To test UV resistance in long-lived, larger seeds, we exposed Arabidopsis, tobacco, and morning glory seeds in the laboratory to doses of UV254nm, ranging as high as 2420 MJ m−2. Morning glory seeds resisted this maximum dose, which killed tobacco and Arabidopsis. We thus confirm that a naked plant seed could survive UV exposures during direct transfer from Mars to Earth and suggest that seeds with a more protective seed coat (e.g., morning glory) should survive much longer space travel. Key Words: UV light—Flavonoids—Sinapate—DNA degradation—Arabidopsis—Tobacco—Seeds—Space—International Space Station—EXPOSE-E—EXPOSE-R. Astrobiology 17, 205–215. PMID:28263676

Seed predators exert selection on the subindividual variation of seed size.

PubMed

Sobral, M; Guitián, J; Guitián, P; Larrinaga, A R

2014-07-01

Subindividual variation among repeated organs in plants constitutes an overlooked level of variation in phenotypic selection studies, despite being a major component of phenotypic variation. Animals that interact with plants could be selective agents on subindividual variation. This study examines selective pressures exerted during post-dispersal seed predation and germination on the subindividual variation of seed size in hawthorn (Crataegus monogyna). With a seed offering experiment and a germination test, we estimated phenotypic selection differentials for average and subindividual variation of seed size due to seed predation and germination. Seed size affects germination, growth rate and the probability of an individual seed of escaping predation. Longer seeds showed higher germination rates, but this did not result in significant selection on phenotypes of the maternal trees. On the other hand, seed predators avoided wider seeds, and by doing so exerted phenotypic selection on adult average and subindividual variation of seed size. The detected selection on subindividual variation suggests that the levels of phenotypic variation within individual plants may be, at least partly, the adaptive consequence of animal-mediated selection. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

USGS Publications Warehouse

Du, X.; Guo, Q.; Gao, X.; Ma, K.

2007-01-01

Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms. We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan, southwestern China. The results showed that: (1) there were marked differences in (mature) seed production between mast (733,700 seeds in 2001) and regular (51,200 and 195,600 seeds in 2002 and 2003, respectively) years for C. fargesii. (2) Most seeds were dispersed in leaf litter, humus and 0-2 cm depth soil in seed bank. (3) Frequency distributions of both DBH and height indicated that C. fargesii had a relatively stable population. (4) Seed rain, seed ground density, seed loss, and leaf fall were highly dynamic and certain quantity of seeds were preserved on the ground for a prolonged time due to predator satiation in both the mast and regular years so that the continuous presence of seed bank and seedling recruitments in situ became possible. Both longer time observations and manipulative experiments should be carried out to better understand the roles of seed dispersal and regeneration process in the ecosystem performance. ?? 2006 Elsevier B.V. All rights reserved.

Postfire drill-seeding of Great Basin plants: Effects of contrasting drills on seeded and nonseeded species

Treesearch

Jeffrey E. Ott; Robert D. Cox; Nancy L. Shaw; Beth A. Newingham; Amy C. Ganguli; Mike Pellant; Bruce A. Roundy; Dennis L. Eggett

2016-01-01

Objectives of postfire seeding in the Great Basin include reestablishment of perennial cover, suppression of exotic annual weeds, and restoration of diverse plant communities. Nonconventional seeding techniques may be required when seeding mixes of grasses, forbs, and shrubs containing seeds of different sizes. We conducted an operational-scale experiment to...

Cross-seeding and cross-competition in mouse apolipoprotein A-II amyloid fibrils and protein A amyloid fibrils.

PubMed

Yan, Jingmin; Fu, Xiaoying; Ge, Fengxia; Zhang, Beiru; Yao, Junjie; Zhang, Huanyu; Qian, Jinze; Tomozawa, Hiroshi; Naiki, Hironobu; Sawashita, Jinko; Mori, Masayuki; Higuchi, Keiichi

2007-07-01

Murine senile [apolipoprotein A-II amyloid (AApoAII)] and reactive [protein A amyloid (AA)] amyloidosis are reported to be transmissible diseases via a seeding mechanism similar to that observed in the prion-associated disorders, although de novo amyloidogenesis and the progression of AApoAII or AA amyloidosis remain unclear. We examined the effect of co-injection of AApoAII and AA fibrils and multiple inflammatory stimuli in R1.P1-Apoa2(c) mice with the amyloidogenic Apoa2(c) allele. Both AApoAII and AA amyloidosis could be induced in this system, but the two types of amyloid fibrils preferentially promote the formation of the same type of fibrils while inhibiting the formation of the other. Furthermore, we demonstrate that AA or AApoAII amyloidosis could be cross-seeded by predeposited AApoAII or AA fibrils and that the predeposited amyloid fibrils were degraded when the fibril formation was reduced or stopped. In addition, a large proportion of the two amyloid fibrils colocalized during the formation of new fibrils in the spleen and liver. Thus, we propose that AApoAII and AA can both cross-seed and cross-compete with regard to amyloid formation, depending on the stage of amyloidogenesis. These results will aid in the clarification of the mechanisms of pathogenesis and progression of amyloid disorders.

Upgrade for Phase II of the Gerda experiment

NASA Astrophysics Data System (ADS)

Agostini, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D'Andrea, V.; Demidova, E. V.; Di Marco, N.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hakenmüller, J.; Hegai, A.; Heisel, M.; Hemmer, S.; Hiller, R.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Ioannucci, L.; Janicskó Csáthy, J.; Jochum, J.; Junker, M.; Kazalov, V.; Kermaïdic, Y.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Kish, A.; Klimenko, A.; Kneißl, R.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Medinaceli, E.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Nisi, S.; Panas, K.; Pandola, L.; Pelczar, K.; Pullia, A.; Ransom, C.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Salathe, M.; Schmitt, C.; Schneider, B.; Schönert, S.; Schreiner, J.; Schütz, A.-K.; Schulz, O.; Schwingenheuer, B.; Selivanenko, O.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Vanhoefer, L.; Vasenko, A. A.; Veresnikova, A.; von Sturm, K.; Wagner, V.; Wegmann, A.; Wester, T.; Wiesinger, C.; Wojcik, M.; Yanovich, E.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zsigmond, A. J.; Zuber, K.; Zuzel, G.

2018-05-01

The Gerda collaboration is performing a sensitive search for neutrinoless double beta decay of ^{76}Ge at the INFN Laboratori Nazionali del Gran Sasso, Italy. The upgrade of the Gerda experiment from Phase I to Phase II has been concluded in December 2015. The first Phase II data release shows that the goal to suppress the background by one order of magnitude compared to Phase I has been achieved. Gerda is thus the first experiment that will remain "background-free" up to its design exposure (100 kg year). It will reach thereby a half-life sensitivity of more than 10^{26} year within 3 years of data collection. This paper describes in detail the modifications and improvements of the experimental setup for Phase II and discusses the performance of individual detector components.

The Cloud Ice Mountain Experiment (CIME) 1998: experiment overview and modelling of the microphysical processes during the seeding by isentropic gas expansion

NASA Astrophysics Data System (ADS)

Wobrock, Wolfram; Flossmann, Andrea I.; Monier, Marie; Pichon, Jean-Marc; Cortez, Laurent; Fournol, Jean-François; Schwarzenböck, Alfons; Mertes, Stephan; Heintzenberg, Jost; Laj, Paolo; Orsi, Giordano; Ricci, Loretta; Fuzzi, Sandro; Brink, Harry Ten; Jongejan, Piet; Otjes, René

The second field campaign of the Cloud Ice Mountain Experiment (CIME) project took place in February 1998 on the mountain Puy de Dôme in the centre of France. The content of residual aerosol particles, of H 2O 2 and NH 3 in cloud droplets was evaluated by evaporating the drops larger than 5 μm in a Counterflow Virtual Impactor (CVI) and by measuring the residual particle concentration and the released gas content. The same trace species were studied behind a round jet impactor for the complementary interstitial aerosol particles smaller than 5 μm diameter. In a second step of experiments, the ambient supercooled cloud was converted to a mixed phase cloud by seeding the cloud with ice particles by the gas release from pressurised gas bottles. A comparison between the physical and chemical characteristics of liquid drops and ice particles allows a study of the fate of the trace constituents during the presence of ice crystals in the cloud. In the present paper, an overview is given of the CIME 98 experiment and the instrumentation deployed. The meteorological situation during the experiment was analysed with the help of a cloud scale model. The microphysics processes and the behaviour of the scavenged aerosol particles before and during seeding are analysed with the detailed microphysical model ExMix. The simulation results agreed well with the observations and confirmed the assumption that the Bergeron-Findeisen process was dominating during seeding and was influencing the partitioning of aerosol particles between drops and ice crystals. The results of the CIME 98 experiment give an insight on microphysical changes, redistribution of aerosol particles and cloud chemistry during the Bergeron-Findeisen process when acting also in natural clouds.

Relating seed treatments to nursery performance: Experience with southern pines

Treesearch

James P. Barnett

2008-01-01

Producing good quality seeds that perform well in the nursery continues to be challenging. High quality conifer seeds are obtained by optimizing collecting, processing, storing, and treating methodologies, and such quality is needed to consistently produce uniform nursery crops. Although new technologies are becoming available to evaluate seed quality, they have not...

Genetic control of soybean seed oil: II. QTL and genes that increase oil concentration without decreasing protein or with increased seed yield.

PubMed

Eskandari, Mehrzad; Cober, Elroy R; Rajcan, Istvan

2013-06-01

Soybean [Glycine max (L.) Merrill] seed oil is the primary global source of edible oil and a major renewable and sustainable feedstock for biodiesel production. Therefore, increasing the relative oil concentration in soybean is desirable; however, that goal is complex due to the quantitative nature of the oil concentration trait and possible effects on major agronomic traits such as seed yield or protein concentration. The objectives of the present study were to study the relationship between seed oil concentration and important agronomic and seed quality traits, including seed yield, 100-seed weight, protein concentration, plant height, and days to maturity, and to identify oil quantitative trait loci (QTL) that are co-localized with the traits evaluated. A population of 203 F4:6 recombinant inbred lines, derived from a cross between moderately high oil soybean genotypes OAC Wallace and OAC Glencoe, was developed and grown across multiple environments in Ontario, Canada, in 2009 and 2010. Among the 11 QTL associated with seed oil concentration in the population, which were detected using either single-factor ANOVA or multiple QTL mapping methods, the number of QTL that were co-localized with other important traits QTL were six for protein concentration, four for seed yield, two for 100-seed weight, one for days to maturity, and one for plant height. The oil-beneficial allele of the QTL tagged by marker Sat_020 was positively associated with seed protein concentration. The oil favorable alleles of markers Satt001 and GmDGAT2B were positively correlated with seed yield. In addition, significant two-way epistatic interactions, where one of the interacting markers was solely associated with seed oil concentration, were identified for the selected traits in this study. The number of significant epistatic interactions was seven for yield, four for days to maturity, two for 100-seed weight, one for protein concentration, and one for plant height. The identified molecular

[Effects of illumination and seed-soaking reagent on seed germination of Solanum nigrum].

PubMed

Yang, Chuan-Jie; Wei, Shu-He; Zhou, Qi-Xing; Hu, Ya-Hu; Niu, Rong-Cheng

2009-05-01

To explore a rapid seed germination method for hyperaccumulator Solanum nigrum, a germination experiment with different illumination and seed-soaking treatments was conducted in constant temperature box and greenhouse, with filter as burgeon base. Under illumination, the germination rate was about 5 times high of that without illumination (P < 0.05), indicating that illumination was one of the prerequisites for the seed germination of S. nigrum. All test seed-soaking reagents could significantly improve the germination rate of S. nigrum (P < 0.05), with the best effect of H2O2. The seeds treated with H2O2 had the shortest germination time. The germination rate of seeds soaked but without cleaning was 2-3 times as high as that of seeds soaked and cleaned with water.

[Growth of wheat from seed-to-seed in space flight

NASA Technical Reports Server (NTRS)

Levinskikh, M. A.; Sychev, V. N.; Derendiaeva, T. A.; Signalova, O. B.; Podol'skii, I. G.; Padalka, G. I.; Avdeev, S. V.; Bingham, G. E.; Campbell, W. F. (Principal Investigator)

2000-01-01

In our earlier space experiment with super dwarf wheat we found the spikes developed in space to be barren. The cause of the full crop sterility was sensitivity of this wheat species to the ethylene concentration of 0.3-0.8 mg/m3 during the experiment. The follow-up ground experiments were made to identify species of dwarf wheat that could be raised in space greenhouse Svet and are distinguished by partial tolerance of their reproductive organs to elevated ethylene in air. The choice fell on the USU-Apogee cultivar specially developed for planting in growth chambers as an integral part of various bioregenerative life support systems, including the space ones. An experiment with wheat Apogee was performed in greenhouse Svet on board MIR. The period of the full crop vegetation cycle was not significantly altered under the spaceflight conditions. The experiment yielded 508 seeds from 12 plants, i.e. by 38% less than in laboratory experiments and by 69% more as compared with results of growing crops in ethylene-contaminated atmosphere (1 mg/m3). Mass of the space seeds was low if compared with the laboratory crops. This was the first time when the feasibility of gathering seeds from wheat that had passed the whole vegetation cycle in space flight was demonstrated. The experiment will give mightly impetus to the advancement of research on space biological LSS and gravitational biology.

The design of the MEG II experiment

NASA Astrophysics Data System (ADS)

Baldini, A. M.; Baracchini, E.; Bemporad, C.; Berg, F.; Biasotti, M.; Boca, G.; Cattaneo, P. W.; Cavoto, G.; Cei, F.; Chiappini, M.; Chiarello, G.; Chiri, C.; Cocciolo, G.; Corvaglia, A.; de Bari, A.; De Gerone, M.; D'Onofrio, A.; Francesconi, M.; Fujii, Y.; Galli, L.; Gatti, F.; Grancagnolo, F.; Grassi, M.; Grigoriev, D. N.; Hildebrandt, M.; Hodge, Z.; Ieki, K.; Ignatov, F.; Iwai, R.; Iwamoto, T.; Kaneko, D.; Kasami, K.; Kettle, P.-R.; Khazin, B. I.; Khomutov, N.; Korenchenko, A.; Kravchuk, N.; Libeiro, T.; Maki, M.; Matsuzawa, N.; Mihara, S.; Milgie, M.; Molzon, W.; Mori, Toshinori; Morsani, F.; Mtchedilishvili, A.; Nakao, M.; Nakaura, S.; Nicolò, D.; Nishiguchi, H.; Nishimura, M.; Ogawa, S.; Ootani, W.; Panareo, M.; Papa, A.; Pepino, A.; Piredda, G.; Popov, A.; Raffaelli, F.; Renga, F.; Ripiccini, E.; Ritt, S.; Rossella, M.; Rutar, G.; Sawada, R.; Signorelli, G.; Simonetta, M.; Tassielli, G. F.; Uchiyama, Y.; Usami, M.; Venturini, M.; Voena, C.; Yoshida, K.; Yudin, Yu. V.; Zhang, Y.

2018-05-01

The MEG experiment, designed to search for the {μ ^+ → e^+ γ } decay, completed data-taking in 2013 reaching a sensitivity level of {5.3× 10^{-13}} for the branching ratio. In order to increase the sensitivity reach of the experiment by an order of magnitude to the level of 6× 10^{-14}, a total upgrade, involving substantial changes to the experiment, has been undertaken, known as MEG II. We present both the motivation for the upgrade and a detailed overview of the design of the experiment and of the expected detector performance.

Dispersal of seeds from splash-cup plants

NASA Astrophysics Data System (ADS)

Pepper, Rachel

2017-11-01

Splash cup plants disperse their seeds with the help of raindrops. The seeds sit in a small (mm-scale) conical cup and are ejected upon drop impact. The seeds are ejected at velocities up to five times the impact speed of the raindrop, and are dispersed up to 1 m away from the parent plant, which is only a few cm high. Previous work investigating the mechanism of this remarkable dispersal predicted an optimum cup opening angle of around 40°, which matched reasonably well with experiments performed with 3D-printed splash cup models. Those experiments were done with off-center drop impacts on initially empty cups with no seeds. We discuss similar experiments for cups that are not initially empty, but rather contain seed mimics, water, or both seeds and water. For some of these realistic initial states results are strikingly different from empty cups. Connections to theory will also be discussed.

Early harvest increases post-harvest physiological quality of Araucaria angustifolia (Araucariaceae) seeds.

PubMed

Shibata, Marília; Medeiros Coelho, Cileide Maria

2016-06-01

Araucaria angustifolia is a conifer native to Brazil and is an endangered species. Since this species seeds have a short period of viability, its vulnerability is higher. Thus the aim of this study was to evaluate the physiological quality of A. angustifolia seeds during the development and post-storage periods. For this, cones of A. angustifolia were collected from a natural population in Curitibanos, Santa Catarina, Brazil, in March, April, May and June 2012. The collected seeds were classified into developmental stages of cotyledonary, I, II and III according to the month of collection; a total of 10 cones were collected for each stage. Seeds were stored in a refrigerator for 60 and 120 days, and were submitted to a chamber germination test (25 °C-photoperiod 12 h). Additionally, seeds were tested for moisture content (105 °C for 24 hours), tetrazolium (0.1 % for 1 hour) and vigor (electric conductivity [75 mL distilled water at 25 °C], germination speed index, and shoot and root length). Our results showed that during seed development, moisture content decreased from the cotyledonary stage (66.54 %) to stage III (49.69 %), and vigor increased in the last stage. During storage, moisture content at cotyledonary stage and stage I was stable. On the other hand, stored seeds exhibited a decrease in moisture content after 120 days at stages II and III. Physiological quality at the cotyledonary stage resulted in an increased germination rate of 86 % and 93 % after 60 and 120 days of storage, respectively; unlike stages II and III exhibited a decrease in seed viability and vigor after storage. Electrical conductivity was higher for fresh seeds at the cotyledonary stage, than for those stored for 60 and 120 days. However, in other stages, released leachate content after 120 days of storage, increased with the advance of the collection period. Germination speed index and shoot and root lengths after storage were highest for seeds at the cotyledonary stage and stage I

Yellow-poplar seed quality varies by seed trees, stands, and years

Treesearch

G.A. Limstrom

1959-01-01

The number of year-old yellow-poplar (Liriodendron tulipifera L.) seedlings grown from equal quantities of seed varies as much among individual seed trees within a stand as among stands of different geographic location. Moreover, production will vary from one year to another. This information was obtained from an experiment begun in the Central...

Preparation and Evaluation of Adsorbents from Coal and Irvingia gabonensis Seed Shell

NASA Astrophysics Data System (ADS)

Ezeokonkwo, Mercy A.; Ofor, Okechukwu F.; Ani, Julius U.

2017-12-01

The adsorption of Cd(II) and Pb(II) ions on adsorbents prepared from sub-bituminous coal, lignite and a blend of coal and Irvingia gabonensis seed shells was investigated. Fourier transform infrared, scanning electron microscope and X-ray fluorescence analyses implicated hydroxyl, carbonyl, Al2O3 and SiO2 as being responsible for binding the metal ions on the porous adsorbents. The optimum adsorption of carbonized lignite for the removal of Cd(II) and Pb(II) ions from aqueous media were 80.93% and 87.85%, respectively. Batch adsorption was done by effect of adsorbent dosage, pH, contact time, temperature, particle size, and initial concentration. Equilibrium for the removal of Pb(II) and Cd(II) was established within 100 and 120 min respectively. Blending the lignite-derived adsorbent with Irvingia gabonensis seed shell improved the performance significantly. More improvement was observed on modification of the blend using NaOH and H3PO4. Pb(II) was preferentially adsorbed than Cd(II) in all cases. Adsorption of Cd(II) and Pb(II) ions followed Langmuir isotherm. The kinetics of adsorption was best described by pseudo-second order model. The potential for using a blend of coal and agricultural byproduct (Irvingia gabonensis seed shell) was found to be a viable alternative for removal of toxic heavy metals from aqueous solutions.

Gravity independence of seed-to-seed cycling in Brassica rapa

NASA Technical Reports Server (NTRS)

Musgrave, M. E.; Kuang, A.; Xiao, Y.; Stout, S. C.; Bingham, G. E.; Briarty, L. G.; Levenskikh, M. A.; Sychev, V. N.; Podolski, I. G.

2000-01-01

Growth of higher plants in the microgravity environment of orbital platforms has been problematic. Plants typically developed more slowly in space and often failed at the reproductive phase. Short-duration experiments on the Space Shuttle showed that early stages in the reproductive process could occur normally in microgravity, so we sought a long-duration opportunity to test gravity's role throughout the complete life cycle. During a 122-d opportunity on the Mir space station, full life cycles were completed in microgravity with Brassica rapa L. in a series of three experiments in the Svet greenhouse. Plant material was preserved in space by chemical fixation, freezing, and drying, and then compared to material preserved in the same way during a high-fidelity ground control. At sampling times 13 d after planting, plants on Mir were the same size and had the same number of flower buds as ground control plants. Following hand-pollination of the flowers by the astronaut, siliques formed. In microgravity, siliques ripened basipetally and contained smaller seeds with less than 20% of the cotyledon cells found in the seeds harvested from the ground control. Cytochemical localization of storage reserves in the mature embryos showed that starch was retained in the spaceflight material, whereas protein and lipid were the primary storage reserves in the ground control seeds. While these successful seed-to-seed cycles show that gravity is not absolutely required for any step in the plant life cycle, seed quality in Brassica is compromised by development in microgravity.

Magnetic stimulation of marigold seed

NASA Astrophysics Data System (ADS)

Afzal, I.; Mukhtar, K.; Qasim, M.; Basra, S. M. A.; Shahid, M.; Haq, Z.

2012-10-01

The effects of magnetic field treatments of French marigold seeds on germination, early seedling growth and biochemical changes of seedlings were studied under controlled conditions. For this purpose, seeds were exposed to five different magnetic seed treatments for 3 min each. Most of seed treatments resulted in improved germination speed and spread, root and shoot length, seed soluble sugars and a-amylase activity. Magnetic seed treatment with 100 mT maximally improved germination, seedling vigour and starch metabolism as compared to control and other seed treatments. In emergence experiment, higher emergence percentage (4-fold), emergence index (5-fold) and vigorous seedling growth were obtained in seeds treated with 100 mT. Overall, the enhancement of marigold seeds by magnetic seed treatment with 100 mT could be related to enhanced starch metabolism. The results suggest that magnetic field treatments of French marigold seeds have the potential to enhance germination, early growth and biochemical parameters of seedlings.

Binding of cadmium to Strychnos potatorum seed proteins in aqueous solution: adsorption kinetics and relevance to water purification.

PubMed

Saif, Mohammad Mansour Saleh; Kumar, N Siva; Prasad, M N V

2012-06-01

Strychnos potatorum seeds (cleaning nuts or nirmali) are extensively used by remote village tribals in the state of Andhra Pradesh, India for clarification of turbid and metal contaminated water. In the present study the ability of seed proteins to bind aqueous cadmium has been investigated. Biochemical characterization of the seed powder revealed the presence of coagulant proteins. These proteins were isolated from the soluble extracts of the seeds by ammonium sulfate fractionation. The (30-70%) fraction containing the bulk of proteins were separated by gel filtration into two peaks A and B. The (30-70%) ammonium sulfate precipitated proteins, as well as those from Peak A and B were separately immobilized to affigel-10. The Cd(II) biosorption efficiency by these proteins have been investigated. Different experiments have been conducted (i) over a range of pH (2.0-7.0), (ii) contact time (5-600 min), (iii) temperatures (4-40°C) and (iv) metal ion concentrations (80-110 mg L(-1)). The results showed that the optimum conditions for Cd(II) adsorption are almost same for the three proteins used in the study. Cd(II) removal is pH dependent and the maximum removal was at pH 5.0 in a time span of 360 min. The equilibrium data fit into Langmuir isotherm than Freundlich model. The correlation coefficient for the pseudo second order is high (~0.996-1.00) where as the correlation coefficient of the pseudo first order model is too low so the adsorption is better described by pseudo second order model. Copyright © 2012 Elsevier B.V. All rights reserved.

Natural Experiment Demonstrates That Bird Loss Leads to Cessation of Dispersal of Native Seeds from Intact to Degraded Forests

PubMed Central

HilleRisLambers, Janneke; Tewksbury, Joshua J.; Rogers, Haldre S.

2013-01-01

In healthy forests, vertebrate frugivores move seeds from intact to degraded forests, aiding in the passive regeneration of degraded forests. Yet vertebrate frugivores are declining around the world, and little is known about the impact of this loss on regeneration of degraded areas. Here, we use a unique natural experiment to assess how complete vertebrate frugivore loss affects native seed rain in degraded forest. All native vertebrate frugivores (which were primarily avian frugivores) have been functionally extirpated from the island of Guam by the invasive brown tree snake (Boiga irregularis), whereas the nearby island of Saipan has a relatively intact vertebrate frugivore community. We captured seed rain along transects extending from intact into degraded forest and compared the species richness, density and condition of the seed rain from native bird-dispersed tree species between the two islands. Considering seeds from native bird-dispersed species, approximately 1.66 seeds landed per 26 days in each square meter of degraded forest on Saipan, whereas zero seeds landed per 26 days per square meter in degraded forest on Guam. Additionally, on Saipan, 69% of native bird-dispersed seeds in intact forest and 77% of seeds in degraded forest lacked fleshy fruit pulp, suggesting ingestion by birds, compared to 0% of all seeds on Guam. Our results show an absence of seed rain in degraded forests on Guam, correlated with the absence of birds, whereas on Saipan, frugivorous birds regularly disperse seeds into degraded forests, providing a mechanism for re-colonization by native plants. These results suggest that loss of frugivores will slow regeneration of degraded forests on Guam. PMID:23741503

Natural experiment demonstrates that bird loss leads to cessation of dispersal of native seeds from intact to degraded forests.

PubMed

Caves, Eleanor M; Jennings, Summer B; Hillerislambers, Janneke; Tewksbury, Joshua J; Rogers, Haldre S

2013-01-01

In healthy forests, vertebrate frugivores move seeds from intact to degraded forests, aiding in the passive regeneration of degraded forests. Yet vertebrate frugivores are declining around the world, and little is known about the impact of this loss on regeneration of degraded areas. Here, we use a unique natural experiment to assess how complete vertebrate frugivore loss affects native seed rain in degraded forest. All native vertebrate frugivores (which were primarily avian frugivores) have been functionally extirpated from the island of Guam by the invasive brown tree snake (Boiga irregularis), whereas the nearby island of Saipan has a relatively intact vertebrate frugivore community. We captured seed rain along transects extending from intact into degraded forest and compared the species richness, density and condition of the seed rain from native bird-dispersed tree species between the two islands. Considering seeds from native bird-dispersed species, approximately 1.66 seeds landed per 26 days in each square meter of degraded forest on Saipan, whereas zero seeds landed per 26 days per square meter in degraded forest on Guam. Additionally, on Saipan, 69% of native bird-dispersed seeds in intact forest and 77% of seeds in degraded forest lacked fleshy fruit pulp, suggesting ingestion by birds, compared to 0% of all seeds on Guam. Our results show an absence of seed rain in degraded forests on Guam, correlated with the absence of birds, whereas on Saipan, frugivorous birds regularly disperse seeds into degraded forests, providing a mechanism for re-colonization by native plants. These results suggest that loss of frugivores will slow regeneration of degraded forests on Guam.

Seed germination, seedling traits, and seed bank of the tree Moringa peregrina (Moringaceae) in a hyper-arid environment.

PubMed

Gomaa, Nasr H; Picó, F Xavier

2011-06-01

Water-limited hot environments are good examples of hyper-aridity. Trees are scarce in these environments but some manage to survive, such as the tree Moringa peregrina. Understanding how trees maintain viable populations in extremely arid environments may provide insight into the adaptive mechanisms by which trees cope with extremely arid weather conditions. This understanding is relevant to the current increasing aridity in several regions of the world. Seed germination experiments were conducted to assess variation in seed mass, seed germination, and seedling traits of Moringa peregrina plants and the correlations among these traits. A seed burial experiment was also designed to study the fate of M. peregrina seeds buried at two depths in the soil for two time periods. On average, seeds germinated in three days and seedling shoots grew 0.7 cm per day over three weeks. Larger seeds decreased germination time and increased seedling growth rates relative to smaller seeds. Seeds remained quiescent in the soil and germination was very high at both depths and burial times. The after-ripening time of Moringa peregrina seeds is short and seeds germinate quickly after imbibition. Plants of M. peregrina may increase in hyper-arid environments from seeds with larger mass, shorter germination times, and faster seedling growth rates. The results also illustrate the adjustment in allocation to seed biomass and correlations among seed and seedling traits that allows M. peregrina to be successful in coping with aridity in its environment.

The oxygen requirement of germinating flax seeds

NASA Astrophysics Data System (ADS)

Kuznetsov, O.; Hasenstein, K.

Experiments for earth orbit are typically prepared on the ground and often germinated in orbit in order to study gravity effects on developing seedlings. Germination requires the breakdown of storage compounds and respiration. In orbit the formation of a water layer around the seed may further limit oxygen availability. Therefore, the oxygen content of the available gas volume is one of the limiting factors for seed germination. In preparation for an upcoming shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware. We tested per seed chamber (gas volume = 14 mL, O2 = 2.9 mL) between 4 to 32 seeds glued to germination paper by 1% (w/v) gum guar. A lexan cover and a gasket hermetically sealed each of the eight chambers. For imbibition of the seeds a previously optimized amount of distilled water was dispensed through sealed inlets. The seedlings were allowed to grow for either 32 to 48 h on a clinostat or without microgravity simulation. Then their root length was measured. With 32 seeds per chamber, four times the intended number of seeds for the flight, the germination rate decreased from 94 to 69%, and the root length was reduced by 20%. Experiments on the germination and root length in controlled atmospheres (5, 10, 15 and 21% O2 ) suggest that germination and growth for two days requires about 200 :l of O (1 mL air) per seed. Our2 experiments correlate oxygen dependency from seed mass and germination temperature, and analyze accumulation of gaseous metabolites (supported by NASA grant NAG10-0190).

Seeding Experiment of Liquid Carbon Dioxide for Enhancing Winter-time Precipitation in Saga Prefecture,Northern Kyushu,Japan

NASA Astrophysics Data System (ADS)

Wakimizu, K.; Nishiyama, K.; Tomine, K.; Maki, T.; Suzuki, Y.; Morita, O.

2012-12-01

ice perticles formed by LC seeding grew to the precipitable size and resultant snowfall was detected by radar in approximately 120 min. after seeding operation. In this study, based on these observed facts, optimum design for enhancing winter-time water resources by LC seeding method was suggested. Successive low-level horizontal penetrations of operational aircraft with seeding LC into many moving super-cooled cumuli towards the Japan Islands will lead to the spreading of cloud volume and subsequent coversion of large amount of iv active cloud volume into newly exploited artificial precipitation. As a result, these experiments succeeded, and the total amount of estimated radar precipitation of the be able to secure a large amount of water resource from these experiment results.

Seed size variation in the palm Euterpe edulis and the effects of seed predators on germination and seedling survival

NASA Astrophysics Data System (ADS)

Pizo, Marco A.; Von Allmen, Christiane; Morellato, L. Patricia C.

2006-05-01

Intraspecific variation in seed size is common in wild plant populations and has important consequences for the reproductive success of individual plants. Multiple, often conflicting evolutionary forces mediated by biotic as well as abiotic agents may maintain such a variation. In this paper we assessed seed size variation in a population of the threatened, commercially important palm Euterpe edulis in southeast Brazil. We investigated (i) how this variation affects the probability of attack by vertebrate and invertebrate post-dispersal seed predators, and (ii) if seed size influences the outcome of seeds damaged by beetles in terms of seed germination and early survival of seedlings. Euterpe edulis seeds varied in diameter from 8.3 to 14.1 mm. Neither insects nor rodents selected the seeds they preyed upon based on seed size. Seed germination and total, shoot and root biomasses of one-year seedlings were significantly and positively affected by seed size. Root biomass and seedling survival were negatively affected by seed damage caused by a scolytid beetle ( Coccotrypes palmarum) whose adults bore into seeds to consume part of the endosperm, but do not oviposit on them. Seed size had a marginally significant effect on seedling survival. Therefore, if any advantage is accrued by E. edulis individuals producing large seeds, this is because of greater seed germination success and seedling vigor. If this is so, even a relatively narrow range of variation in seed size as observed in the E. edulis population studied may translate into differential success of individual plants.

Concerning the preliminary results of space experiment with the seeds of rare plants (on the boad of BION-M No.1)

NASA Astrophysics Data System (ADS)

Gorelov, Yury; Kurganskaya, Lubov; Ilyin, Vyacheslav; Ruzaeva, Irina; Rozno, Svetlana; Kavelenova, Ludmila

The problem of native flora plants conservation appears today as one of the most actual for humanity. The wide spreading natural ecosystems degradation results in the status changes for formerly common species to rare, endangered or extincted ones. That is why the complex of biological diversity conservation measures must be used including ex situ and in situ forms. Last years the seed banks (special seed collections in controlled conditions, including temperature below zero) and field banks (special alive plants collections) were created in many countries taking in mind the future of humanity. The seed banks as long-term depositories can be placed on the space stations where the threat of earth catastrophes is removed. But we must make it clear how the complex of space flight factors effects upon the seed quality and germination and plants development from “cosmic” seeds. For instance, the action of residual ionizing radiation into space apparatus on plant seeds can alter its vitality maybe by the growth of free radicals pool in molecular and subcellular level. The unknown level of such action permits us to propose wide diapason of effects from the absence of any changes to the stimulation of vital activity, decrease of it, mutagenesis and maybe the death of seeds. Only the experiments that begin in space and continue on the Earth can show us the effect of space flight factors complex on plant seeds. Here we describe the first results of experiment held on the board of space apparatus “Bion-M” No1. Totally 79 experiments were included to the program of “Bion-M”, among them the experiment “Biocont-BS”. The equipment for it was prepared by Central Scientific Research Institute of Machine-building; the seed material was selected and prepared by the Botanical Garden of Samara State University. The equipment with seeds was into space apparatus, which working orbit was average 575 km and the flight lasted for 30 days. The seed samples of 9 rare plants

Math Carnival Nights (Planting the Seeds for Engineers in Elementary School),

DTIC Science & Technology

1991-06-01

A D -A 240 772 Project 10704-0188), Washington DC 205033RERTYPANDTSCORD 4 TITLE AND SUBLE 5FUDIG iLLcR MATH CARNIVAL NIGHTS (PLANTING THLE SEEDS FOR...Planting Seeds For Engineers In Elementary School T herese D o ugherty...M -6 6 0 MATH CARNIVAL NIGHTSI (Planting the Seeds for Engineers in Elementary School) Therese Dougherty i Abstract Ii A good grounding

Scatter Hoarding of Seeds Confers Survival Advantages and Disadvantages to Large-Seeded Tropical Plants at Different Life Stages

PubMed Central

Kuprewicz, Erin K.

2015-01-01

Scatter hoarding of seeds by animals contributes significantly to forest-level processes, including plant recruitment and forest community composition. However, the potential positive and negative effects of caching on seed survival, germination success, and seedling survival have rarely been assessed through experimental studies. Here, I tested the hypothesis that seed burial mimicking caches made by scatter hoarding Central American agoutis (Dasyprocta punctate) enhances seed survival, germination, and growth by protecting seeds from seed predators and providing favorable microhabitats for germination. In a series of experiments, I used simulated agouti seed caches to assess how hoarding affects seed predation by ground-dwelling invertebrates and vertebrates for four plant species. I tracked germination and seedling growth of intact and beetle-infested seeds and, using exclosures, monitored the effects of mammals on seedling survival through time. All experiments were conducted over three years in a lowland wet forest in Costa Rica. The majority of hoarded palm seeds escaped predation by both invertebrates and vertebrates while exposed seeds suffered high levels of infestation and removal. Hoarding had no effect on infestation rates of D. panamensis, but burial negatively affected germination success by preventing endocarp dehiscence. Non-infested palm seeds had higher germination success and produced larger seedlings than infested seeds. Seedlings of A. alatum and I. deltoidea suffered high mortality by seed-eating mammals. Hoarding protected most seeds from predators and enhanced germination success (except for D. panamensis) and seedling growth, although mammals killed many seedlings of two plant species; all seedling deaths were due to seed removal from the plant base. Using experimental caches, this study shows that scatter hoarding is beneficial to most seeds and may positively affect plant propagation in tropical forests, although tradeoffs in seed

Neighborhoods have little effect on fungal attack or insect predation of developing seeds in a grassland biodiversity experiment.

PubMed

Beckman, Noelle G; Dybzinski, Ray; Tilman, G David

2014-02-01

Numerous observational studies have documented conspecific negative density-dependence that is consistent with the Janzen-Connell Hypothesis (JCH) of diversity maintenance. However, there have been few experimental tests of a central prediction of the JCH: that removing host-specific enemies should lead to greater increases in per capita recruitment in areas of higher host density or lower relative phylogenetic diversity. Using spatially randomized plots of high and low host biomass in a temperate grassland biodiversity experiment, we treated developing seedheads of six prairie perennials to factorial applications of fungicide and insecticide. We measured predispersal seed production, seed viability, and seedling biomass. Results were highly species-specific and idiosyncratic. Effects of insect seed predators and fungal pathogens on predispersal responses varied with neither conspecific biomass nor phylogenetic diversity, suggesting that-at least at the predispersal stage and for the insect and fungal seed predators we were able to exclude-the JCH is not sufficient to contribute to negative conspecific density-dependence for these dominant prairie species.

The conservation physiology of seed dispersal

PubMed Central

Ruxton, Graeme D.; Schaefer, H. Martin

2012-01-01

At a time when plant species are experiencing increasing challenges from climate change, land-use change, harvesting and invasive species, dispersal has become a very important aspect of plant conservation. Seed dispersal by animals is particularly important because some animals disperse seeds to suitable sites in a directed fashion. Our review has two aims: (i) to highlight the various ways plant dispersal by animals can be affected by current anthropogenic change and (ii) to show the important role of plant and (particularly) animal physiology in shaping seed–dispersal interactions. We argue that large-bodied seed dispersers may be particularly important for plant conservation because seed dispersal of large-seeded plants is often more specialized and because large-bodied animals are targeted by human exploitation and have smaller population sizes. We further argue that more specialized seed-dispersal systems on island ecosystems might be particularly at risk from climate change both owing to small population sizes involved but also owing to the likely thermal specialization, particularly on tropical islands. More generally, the inherent vulnerability of seed-dispersal mutualisms to disruption driven by environmental change (as well as their ubiquity) demands that we continue to improve our understanding of their conservation physiology. PMID:22566677

Seed consumption and dispersal of ant-dispersed plants by slugs.

PubMed

Türke, Manfred; Heinze, Eric; Andreas, Kerstin; Svendsen, Sarah M; Gossner, Martin M; Weisser, Wolfgang W

2010-07-01

In beech-dominated forests in Central Europe, many spring geophytes show adaptations to seed dispersal by ants (myrmecochory). Ants, however, can be rare in such moist forests. Motivated by observations of slug feeding on seeds we investigated the seed consumption of two plant species, Anemone nemorosa and Asarum europaeum, by slugs, in a series of experiments. In a seed predation experiment in a beech forest, we found that seed removal was strongly reduced when gastropods were excluded from the seed depots. The contribution of insects, including ants, and rodents to seed removal was relatively less but differed between May and July. In the laboratory, slug species, in particular Arion sp., consumed seeds of both plant species. Slugs either consumed the elaiosomes of seeds or swallowed seeds intact. Swallowed seeds were defecated undamaged and germinated as well as control seeds when buried overwinter, indicating the potential for seed dispersal by slugs. We also recovered seeds of myrmecochores in the faeces of several slugs caught in forests. In a slug release experiment in the forest, slugs moved up to 14.6 m (mean 4.4 m) in 15 h, which is the median gut passage time of seeds based on measurements made in the laboratory. We also found that when slug-defecated seeds were offered to rodents, these were less attractive than control seeds, suggesting that passage through the slug gut reduces seed predation risk. Our results demonstrate that slugs are significant consumers of elaiosomes or entire seeds of ant-dispersed plants and that they can function as seed dispersers of these plants.

Differential predation of forage seed

USDA-ARS?s Scientific Manuscript database

In recent field experiments we observed that the main invertebrate seed predators of overseeded tall fescue (Festuca arundinacea Schreb.) or Italian ryegrass (Lolium multiflorum Lam.) seed in unimproved pastures were harvester ants (Pogonomyrmex sp.) and common field crickets (Gryllus sp.) To determ...

Surface rejuvenation for multilayer metal deposition on polymer microspheres via self-seeded electroless plating

NASA Astrophysics Data System (ADS)

Karagoz, Bunyamin; Sirkecioglu, Okan; Bicak, Niyazi

2013-11-01

A surface rejuvenation process was developed for generation variable thickness of metal deposits on polymer microspheres via electroless plating. Thus, Ni(II), Cu(II) and Ag(I) complexes formed on triethylenetetramine (TETA) functional crosslinked poly(glycidyl methacrylate) (PGMA) microspheres were reduced to zero-valent metals. The resulting metals (1.1-1.5 mmol g-1) were employed as seed points for electroless metal plating (self-seeding) without using Pd or tin pre-activating species. Treatment of the metalized surfaces with hydrazine or hydrazinium formate was demonstrated to reactivate (rejuvenate) the surface and allows further metal deposition from electroless plating solutions. Followed repeating of the surface rejuvenation-metalization steps resulted in step wise increasing of the metal deposits (90-290 mg per g in each cycle), as inferred from metal analyses, ESEM and XPS analysis. Experiments showed that, after 6 times of cycling the metal deposits exceed 1 g per g of the microspheres on average. The process seemed to be promising for tuning up of the metal thickness by stepwise electroless plating.

Dry Priming of Maize Seeds Reduces Aluminum Stress

PubMed Central

Alcântara, Berenice Kussumoto; Machemer-Noonan, Katja; Silva Júnior, Francides Gomes; Azevedo, Ricardo Antunes

2015-01-01

Aluminum (Al) toxicity is directly related to acidic soils and substantially limits maize yield. Earlier studies using hormones and other substances to treat the seeds of various crops have been carried out with the aim of inducing tolerance to abiotic stress, especially chilling, drought and salinity. However, more studies regarding the effects of seed treatments on the induction of Al tolerance are necessary. In this study, two independent experiments were performed to determine the effect of ascorbic acid (AsA) seed treatment on the tolerance response of maize to acidic soil and Al stress. In the first experiment (greenhouse), the AsA seed treatment was tested in B73 (Al-sensitive genotype). This study demonstrates the potential of AsA for use as a pre-sowing seed treatment (seed priming) because this metabolite increased root and shoot growth under acidic and Al stress conditions. In the second test, the evidence from field experiments using an Al-sensitive genotype (Mo17) and an Al-tolerant genotype (DA) suggested that prior AsA seed treatment increased the growth of both genotypes. Enhanced productivity was observed for DA under Al stress after priming the seeds. Furthermore, the AsA treatment decreased the activity of oxidative stress-related enzymes in the DA genotype. In this study, remarkable effects using AsA seed treatment in maize were observed, demonstrating the potential future use of AsA in seed priming. PMID:26714286

DISE: A Seed-Dependent RNAi Off-Target Effect That Kills Cancer Cells.

PubMed

Putzbach, William; Gao, Quan Q; Patel, Monal; Haluck-Kangas, Ashley; Murmann, Andrea E; Peter, Marcus E

2018-01-01

Off-target effects (OTEs) represent a significant caveat for RNAi caused by substantial complementarity between siRNAs and unintended mRNAs. We now discuss the existence of three types of seed-dependent OTEs (sOTEs). Type I involves unintended targeting through the guide strand seed of an siRNA. Type II is caused by the activity of the seed on the designated siRNA passenger strand when loaded into the RNA-induced silencing complex (RISC). Both type I and II sOTEs will elicit unpredictable cellular responses. By contrast, in sOTE type III the guide strand seed preferentially targets essential survival genes resulting in death induced by survival gene elimination (DISE). In this Opinion article, we discuss DISE as a consequence of RNAi that may preferentially affect cancer cells. Copyright © 2017 Elsevier Inc. All rights reserved.

The perspective effects of various seed coating substances on rice seed variety Khao Dawk Mali 105 storability II: the case study of chemical and biochemical properties.

PubMed

Thobunluepop, P; Pan-in, W; Pawelzik, E; Vearasilp, S

2009-04-01

The aim of this study was to investigate the effects of seed coating substances; chemical fungicide (CA) and biological fungicide polymers [chitosan-lignosulphonate polymer (CL) and eugenol incorporated into chitosan-lignosulphonate polymer (E+CL)] on chemical and biochemical changes of rice seeds cv. KDML 105, which have been studied during storage for 12 months. CA significantly affected the rice seed chemical properties and the associated seed deterioration. After 12 months storage, protein content decreased accompanied by declined of lipid content, increased free fatty acids and activated lipoxygenase enzyme. In the case of biological fungicide coated seeds, the antioxidative scavenging enzymes were ascorbate peroxidase and superoxide dismutase and a high antioxidant activity protected them. Moreover, the sugar content was positive correlated with seed germination and vigor. The biological coated seeds were found to maintain high sugar contents inside the seeds, which resulted high seed storability significantly. In contrast, under fungicide stress (CA), those compounds were lost that directly affected seed vigor during storage.

Seed-to-seed growth of Arabidopsis thaliana on the International Space Station

NASA Technical Reports Server (NTRS)

Link, B. M.; Durst, S. J.; Zhou, W.; Stankovic, B.

2003-01-01

The assembly of the International Space Station (ISS) as a permanent experimental outpost has provided the opportunity for quality plant research in space. To take advantage of this orbital laboratory, engineers and scientists at the Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison, developed a plant growth facility capable of supporting plant growth in the microgravity environment. Utilizing this Advanced Astroculture (ADVASC) plant growth facility, an experiment was conducted with the objective to grow Arabidopsis thaliana plants from seed-to-seed on the ISS. Dry Arabidopsis seeds were anchored in the root tray of the ADVASC growth chamber. These seeds were successfully germinated from May 10 until the end of June 2001. Arabidopsis plants grew and completed a full life cycle in microgravity. This experiment demonstrated that ADVASC is capable of providing environment conditions suitable for plant growth and development in microgravity. The normal progression through the life cycle, as well as the postflight morphometric analyses, demonstrate that Arabidopsis thaliana does not require the presence of gravity for growth and development. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

Transcriptome analysis of Phelipanche aegyptiaca seed germination mechanisms stimulated by fluridone, TIS108, and GR24

PubMed Central

Bao, Ya Zhou; Yao, Zhao Qun; Cao, Xiao Lei; Peng, Jin Feng; Xu, Ying; Chen, Mei Xiu

2017-01-01

P. aegyptiaca is one of the most destructive root parasitic plants worldwide, causing serious damage to many crop species. Under natural conditions P. aegyptiaca seeds must be conditioned and then stimulated by host root exudates before germinating. However, preliminary experiments indicated that TIS108 (a triazole-type inhibitor of strigolactone) and fluridone (FL, an inhibitor of carotenoid-biosynthesis) both stimulated the germination of P. aegyptiaca seeds without a water preconditioning step (i.e. unconditioned seeds). The objective of this study was to use deep RNA sequencing to learn more about the mechanisms by which TIS108 and FL stimulate the germination of unconditioned P. aegyptiaca seeds. Deep RNA sequencing was performed to compare the mechanisms of germination in the following treatments: (i) unconditioned P. aegyptiaca seeds with no other treatment, (ii) unconditioned seeds treated with 100 mg/L TIS108, (iii) unconditioned seeds treated with 100 mg/L FL + 100 mg/L GA3, (iv) conditioned seeds treated with sterile water, and (v) conditioned seeds treated with 0.03 mg/L GR24. The de novo assembled transcriptome was used to analyze transcriptional dynamics during seed germination. The key gene categories involved in germination were also identified. The results showed that only 119 differentially expressed genes were identified in the conditioned treatment vs TIS108 treatment. This indicated that the vast majority of conditions for germination were met during the conditioning stage. Abscisic acid (ABA) and gibberellic acid (GA) played important roles during P. aegyptiaca germination. The common pathway of TIS108, FL+GA3, and GR24 in stimulating P. aegyptiaca germination was the simultaneous reduction in ABA concentrations and increase GA concentrations. These results could potentially aid the identification of more compounds that are capable of stimulating P. aegyptiaca germination. Some potential target sites of TIS108 were also identified in our

Transcriptome analysis of Phelipanche aegyptiaca seed germination mechanisms stimulated by fluridone, TIS108, and GR24.

PubMed

Bao, Ya Zhou; Yao, Zhao Qun; Cao, Xiao Lei; Peng, Jin Feng; Xu, Ying; Chen, Mei Xiu; Zhao, Si Feng

2017-01-01

P. aegyptiaca is one of the most destructive root parasitic plants worldwide, causing serious damage to many crop species. Under natural conditions P. aegyptiaca seeds must be conditioned and then stimulated by host root exudates before germinating. However, preliminary experiments indicated that TIS108 (a triazole-type inhibitor of strigolactone) and fluridone (FL, an inhibitor of carotenoid-biosynthesis) both stimulated the germination of P. aegyptiaca seeds without a water preconditioning step (i.e. unconditioned seeds). The objective of this study was to use deep RNA sequencing to learn more about the mechanisms by which TIS108 and FL stimulate the germination of unconditioned P. aegyptiaca seeds. Deep RNA sequencing was performed to compare the mechanisms of germination in the following treatments: (i) unconditioned P. aegyptiaca seeds with no other treatment, (ii) unconditioned seeds treated with 100 mg/L TIS108, (iii) unconditioned seeds treated with 100 mg/L FL + 100 mg/L GA3, (iv) conditioned seeds treated with sterile water, and (v) conditioned seeds treated with 0.03 mg/L GR24. The de novo assembled transcriptome was used to analyze transcriptional dynamics during seed germination. The key gene categories involved in germination were also identified. The results showed that only 119 differentially expressed genes were identified in the conditioned treatment vs TIS108 treatment. This indicated that the vast majority of conditions for germination were met during the conditioning stage. Abscisic acid (ABA) and gibberellic acid (GA) played important roles during P. aegyptiaca germination. The common pathway of TIS108, FL+GA3, and GR24 in stimulating P. aegyptiaca germination was the simultaneous reduction in ABA concentrations and increase GA concentrations. These results could potentially aid the identification of more compounds that are capable of stimulating P. aegyptiaca germination. Some potential target sites of TIS108 were also identified in our

Contagious Deposition of Seeds in Spider Monkeys' Sleeping Trees Limits Effective Seed Dispersal in Fragmented Landscapes

PubMed Central

González-Zamora, Arturo; Arroyo-Rodríguez, Víctor; Escobar, Federico; Rös, Matthias; Oyama, Ken; Ibarra-Manríquez, Guillermo; Stoner, Kathryn E.; Chapman, Colin A.

2014-01-01

The repeated use of sleeping sites by frugivorous vertebrates promotes the deposition and aggregation of copious amounts of seeds in these sites. This spatially contagious pattern of seed deposition has key implications for seed dispersal, particularly because such patterns can persist through recruitment. Assessing the seed rain patterns in sleeping sites thus represents a fundamental step in understanding the spatial structure and regeneration of plant assemblages. We evaluated the seed rain produced by spider monkeys (Ateles geoffroyi) in latrines located beneath 60 sleeping trees in two continuous forest sites (CFS) and three forest fragments (FF) in the Lacandona rainforest, Mexico. We tested for differences among latrines, among sites, and between forest conditions in the abundance, diversity (α-, β- and, γ-components) and evenness of seed assemblages. We recorded 45,919 seeds ≥5 mm (in length) from 68 species. The abundance of seeds was 1.7 times higher in FF than in CFS, particularly because of the dominance of a few plant species. As a consequence, community evenness tended to be lower within FF. β-diversity of common and dominant species was two times greater among FF than between CFS. Although mean α-diversity per latrine did not differ among sites, the greater β-diversity among latrines in CFS increased γ-diversity in these sites, particularly when considering common and dominant species. Our results support the hypothesis that fruit scarcity in FF can ‘force’ spider monkeys to deplete the available fruit patches more intensively than in CFS. This feeding strategy can limit the effectiveness of spider monkeys as seed dispersers in FF, because (i) it can limit the number of seed dispersers visiting such fruit patches; (ii) it increases seed dispersal limitation; and (iii) it can contribute to the floristic homogenization (i.e., reduced β-diversity among latrines) in fragmented landscapes. PMID:24586705

Milkweed Seed Dispersal: A Means for Integrating Biology and Physics.

ERIC Educational Resources Information Center

Bisbee, Gregory D.; Kaiser, Cheryl A.

1997-01-01

Describes an activity that integrates biology and physics concepts by experimenting with the seed dispersal of common milkweed or similar wind-dispersed seeds. Student teams collect seeds and measure several parameters, review principles of trajectory motion, perform experiments, and graph data. Students examine the ideas of…

Oxygen requirement of germinating flax seeds

NASA Astrophysics Data System (ADS)

Kuznetsov, Oleg A.; Hasenstein, K. H.

2003-05-01

Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax ( Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume = 14 mL) and after 36 h measured the root length. At 90 μl O 2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O 2 we determined the lower limit of reliable germination to be 10 vol. % O 2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination.

Operational Experience from LCLS-II Cryomodule Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Renzhuo; Hansen, Benjamin; White, Michael

This paper describes the initial operational experience gained from testing Linac Coherent Light Source II (LCLS-II) cryomodules at Fermilab’s Cryomodule Test Facility (CMTF). Strategies for a controlled slow cooldown to 100 K and a fast cooldown past the niobium superconducting transition temperature of 9.2 K will be described. The test stand for the cryomodules at CMTF is sloped to match gradient in the LCLS-II tunnel at Stanford Linear Accelerator (SLAC) laboratory, which adds an additional challenge to stable liquid level control. Control valve regulation, Superconducting Radio-Frequency (SRF) power compensation, and other methods of stabilizing liquid level and pressure in themore » cryomodule 2.0 K SRF cavity circuit will be discussed. Several different pumping configurations using cold compressors and warm vacuum pumps have been used on the cryomodule 2.0 K return line and the associated results will be described.« less

Operational experience from LCLS-II cryomodule testing

NASA Astrophysics Data System (ADS)

Wang, R.; Hansen, B.; White, M.; Hurd, J.; Atassi, O. Al; Bossert, R.; Pei, L.; Klebaner, A.; Makara, J.; Theilacker, J.; Kaluzny, J.; Wu, G.; Harms, E.

2017-12-01

This paper describes the initial operational experience gained from testing Linac Coherent Light Source II (LCLS-II) cryomodules at Fermilab’s Cryomodule Test Facility (CMTF). Strategies for a controlled slow cooldown to 100 K and a fast cooldown past the niobium superconducting transition temperature of 9.2 K will be described. The test stand for the cryomodules at CMTF is sloped to match gradient in the LCLS-II tunnel at Stanford Linear Accelerator (SLAC) laboratory, which adds an additional challenge to stable liquid level control. Control valve regulation, Superconducting Radio-Frequency (SRF) power compensation, and other methods of stabilizing liquid level and pressure in the cryomodule 2.0 K SRF cavity circuit will be discussed. Several different pumping configurations using cold compressors and warm vacuum pumps have been used on the cryomodule 2.0 K return line and the associated results will be described.

Effects of environmental variation during seed production on seed dormancy and germination.

PubMed

Penfield, Steven; MacGregor, Dana R

2017-02-01

The environment during seed production has major impacts on the behaviour of progeny seeds. It can be shown that for annual plants temperature perception over the whole life history of the mother can affect the germination rate of progeny, and instances have been documented where these affects cross whole generations. Here we discuss the current state of knowledge of signal transduction pathways controlling environmental responses during seed production, focusing both on events that take place in the mother plant and those that occur directly as a result of environmental responses in the developing zygote. We show that seed production environment effects are complex, involving overlapping gene networks active independently in fruit, seed coat, and zygotic tissues that can be deconstructed using careful physiology alongside molecular and genetic experiments. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Experiments on the enhancement of compressible mixing via streamwise vorticity. II - Vortex strength assessment and seed particle dynamics

NASA Technical Reports Server (NTRS)

Naughton, J. W.; Cattafesta, L. N.; Settles, G. S.

1993-01-01

The effect of streamwise vorticity on compressible axisymmetric mixing layers is examined using vortex strength assessment and seed particle dynamics analysis. Experimental results indicate that the particles faithfully represent the dynamics of the turbulent swirling flow. A comparison of the previously determined mixing layer growth rates with the present vortex strength data reveals that the increase of turbulent mixing up to 60 percent scales with the degree of swirl. The mixing enhancement appears to be independent of the compressibility level of the mixing layer.

Mechanical response of common millet (Panicum miliaceum) seeds under quasi-static compression: Experiments and modeling.

PubMed

Hasseldine, Benjamin P J; Gao, Chao; Collins, Joseph M; Jung, Hyun-Do; Jang, Tae-Sik; Song, Juha; Li, Yaning

2017-09-01

The common millet (Panicum miliaceum) seedcoat has a fascinating complex microstructure, with jigsaw puzzle-like epidermis cells articulated via wavy intercellular sutures to form a compact layer to protect the kernel inside. However, little research has been conducted on linking the microstructure details with the overall mechanical response of this interesting biological composite. To this end, an integrated experimental-numerical-analytical investigation was conducted to both characterize the microstructure and ascertain the microscale mechanical properties and to test the overall response of kernels and full seeds under macroscale quasi-static compression. Scanning electron microscopy (SEM) was utilized to examine the microstructure of the outer seedcoat and nanoindentation was performed to obtain the material properties of the seedcoat hard phase material. A multiscale computational strategy was applied to link the microstructure to the macroscale response of the seed. First, the effective anisotropic mechanical properties of the seedcoat were obtained from finite element (FE) simulations of a microscale representative volume element (RVE), which were further verified from sophisticated analytical models. Then, macroscale FE models of the individual kernel and full seed were developed. Good agreement between the compression experiments and FE simulations were obtained for both the kernel and the full seed. The results revealed the anisotropic property and the protective function of the seedcoat, and showed that the sutures of the seedcoat play an important role in transmitting and distributing loads in responding to external compression. Copyright © 2017 Elsevier Ltd. All rights reserved.

Kinetics of Cd(ii) adsorption and desorption on ferrihydrite: experiments and modeling.

PubMed

Liang, Yuzhen; Tian, Lei; Lu, Yang; Peng, Lanfang; Wang, Pei; Lin, Jingyi; Cheng, Tao; Dang, Zhi; Shi, Zhenqing

2018-05-15

The kinetics of Cd(ii) adsorption/desorption on ferrihydrite is an important process affecting the fate, transport, and bioavailability of Cd(ii) in the environment, which was rarely systematically studied and understood at quantitative levels. In this work, a combination of stirred-flow kinetic experiments, batch adsorption equilibrium experiments, high-resolution transmission electron microscopy (HR-TEM), and mechanistic kinetic modeling were used to study the kinetic behaviors of Cd(ii) adsorption/desorption on ferrihydrite. HR-TEM images showed the open, loose, and sponge-like structure of ferrihydrite. The batch adsorption equilibrium experiments revealed that higher pH and initial metal concentration increased Cd(ii) adsorption on ferrihydrite. The stirred-flow kinetic results demonstrated the increased adsorption rate and capacity as a result of the increased pH, influent concentration, and ferrihydrite concentration. The mechanistic kinetic model successfully described the kinetic behaviors of Cd(ii) during the adsorption and desorption stages under various chemistry conditions. The model calculations showed that the adsorption rate coefficients varied as a function of solution chemistry, and the relative contributions of the weak and strong ferrihydrite sites for Cd(ii) binding varied with time at different pH and initial metal concentrations. Our model is able to quantitatively assess the contributions of each individual ferrihydrite binding site to the overall Cd(ii) adsorption/desorption kinetics. This study provided insights into the dynamic behavior of Cd(ii) and a predictive modeling tool for Cd(ii) adsorption/desorption kinetics when ferrihydrite is present, which may be helpful for the risk assessment and management of Cd contaminated sites.

Small-seeded Hakea species tolerate cotyledon loss better than large-seeded congeners

PubMed Central

El-Amhir, Sh-hoob; Lamont, Byron B.; He, Tianhua; Yan, George

2017-01-01

Six Hakea species varying greatly in seed size were selected for cotyledon damage experiments. The growth of seedlings with cotyledons partially or completely removed was monitored over 90 days. All seedlings perished by the fifth week when both cotyledons were removed irrespective of seed size. Partial removal of cotyledons caused a significant delay in the emergence of the first leaf, and reduction in root and shoot growth of the large-seeded species. The growth of seedlings of small-seeded species was less impacted by cotyledon damage. The rate of survival, root and shoot lengths and dry biomass of the seedlings were determined after 90 days. When seedlings were treated with balanced nutrient solutions following removal of the cotyledons, survival was 95–98%, but 0% when supplied with nutrient solutions lacking N or P or with water only. The addition of a balanced nutrient solution failed to restore complete growth of any species, but the rate of root elongation for the small-seeded species was maintained. Cotyledons provide nutrients to support early growth of Hakea seedlings, but other physiological roles for the cotyledons are also implicated. In conclusion, small-seeded Hakea species can tolerate cotyledons loss better than large-seeded species. PMID:28139668

Plasma wakefield acceleration experiments at FACET II

NASA Astrophysics Data System (ADS)

Joshi, C.; Adli, E.; An, W.; Clayton, C. E.; Corde, S.; Gessner, S.; Hogan, M. J.; Litos, M.; Lu, W.; Marsh, K. A.; Mori, W. B.; Vafaei-Najafabadi, N.; O'shea, B.; Xu, Xinlu; White, G.; Yakimenko, V.

2018-03-01

During the past two decades of research, the ultra-relativistic beam-driven plasma wakefield accelerator (PWFA) concept has achieved many significant milestones. These include the demonstration of ultra-high gradient acceleration of electrons over meter-scale plasma accelerator structures, efficient acceleration of a narrow energy spread electron bunch at high-gradients, positron acceleration using wakes in uniform plasmas and in hollow plasma channels, and demonstrating that highly nonlinear wakes in the ‘blow-out regime’ have the electric field structure necessary for preserving the emittance of the accelerating bunch. A new 10 GeV electron beam facility, Facilities for Accelerator Science and Experimental Test (FACET) II, is currently under construction at SLAC National Accelerator Laboratory for the next generation of PWFA research and development. The FACET II beams will enable the simultaneous demonstration of substantial energy gain of a small emittance electron bunch while demonstrating an efficient transfer of energy from the drive to the trailing bunch. In this paper we first describe the capabilities of the FACET II facility. We then describe a series of PWFA experiments supported by numerical and particle-in-cell simulations designed to demonstrate plasma wake generation where the drive beam is nearly depleted of its energy, high efficiency acceleration of the trailing bunch while doubling its energy and ultimately, quantifying the emittance growth in a single stage of a PWFA that has optimally designed matching sections. We then briefly discuss other FACET II plasma-based experiments including in situ positron generation and acceleration, and several schemes that are promising for generating sub-micron emittance bunches that will ultimately be needed for both an early application of a PWFA and for a plasma-based future linear collider.

Plasma wakefield acceleration experiments at FACET II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joshi, C.; Adli, E.; An, W.

During the past two decades of research, the ultra-relativistic beam-driven plasma wakefield accelerator (PWFA) concept has achieved many significant milestones. These include the demonstration of ultra-high gradient acceleration of electrons over meter-scale plasma accelerator structures, efficient acceleration of a narrow energy spread electron bunch at high-gradients, positron acceleration using wakes in uniform plasmas and in hollow plasma channels, and demonstrating that highly nonlinear wakes in the 'blow-out regime' have the electric field structure necessary for preserving the emittance of the accelerating bunch. A new 10 GeV electron beam facility, Facilities for Accelerator Science and Experimental Test (FACET) II, is currentlymore » under construction at SLAC National Accelerator Laboratory for the next generation of PWFA research and development. The FACET II beams will enable the simultaneous demonstration of substantial energy gain of a small emittance electron bunch while demonstrating an efficient transfer of energy from the drive to the trailing bunch. In this paper we first describe the capabilities of the FACET II facility. We then describe a series of PWFA experiments supported by numerical and particle-in-cell simulations designed to demonstrate plasma wake generation where the drive beam is nearly depleted of its energy, high efficiency acceleration of the trailing bunch while doubling its energy and ultimately, quantifying the emittance growth in a single stage of a PWFA that has optimally designed matching sections. Here, we briefly discuss other FACET II plasma-based experiments including in situ positron generation and acceleration, and several schemes that are promising for generating sub-micron emittance bunches that will ultimately be needed for both an early application of a PWFA and for a plasma-based future linear collider.« less

Plasma wakefield acceleration experiments at FACET II

DOE PAGES

Joshi, C.; Adli, E.; An, W.; ...

2018-01-12

During the past two decades of research, the ultra-relativistic beam-driven plasma wakefield accelerator (PWFA) concept has achieved many significant milestones. These include the demonstration of ultra-high gradient acceleration of electrons over meter-scale plasma accelerator structures, efficient acceleration of a narrow energy spread electron bunch at high-gradients, positron acceleration using wakes in uniform plasmas and in hollow plasma channels, and demonstrating that highly nonlinear wakes in the 'blow-out regime' have the electric field structure necessary for preserving the emittance of the accelerating bunch. A new 10 GeV electron beam facility, Facilities for Accelerator Science and Experimental Test (FACET) II, is currentlymore » under construction at SLAC National Accelerator Laboratory for the next generation of PWFA research and development. The FACET II beams will enable the simultaneous demonstration of substantial energy gain of a small emittance electron bunch while demonstrating an efficient transfer of energy from the drive to the trailing bunch. In this paper we first describe the capabilities of the FACET II facility. We then describe a series of PWFA experiments supported by numerical and particle-in-cell simulations designed to demonstrate plasma wake generation where the drive beam is nearly depleted of its energy, high efficiency acceleration of the trailing bunch while doubling its energy and ultimately, quantifying the emittance growth in a single stage of a PWFA that has optimally designed matching sections. Here, we briefly discuss other FACET II plasma-based experiments including in situ positron generation and acceleration, and several schemes that are promising for generating sub-micron emittance bunches that will ultimately be needed for both an early application of a PWFA and for a plasma-based future linear collider.« less

Pre-sowing Seed Treatments in Direct-seeded Early Rice: Consequences for Emergence, Seedling Growth and Associated Metabolic Events under Chilling Stress

NASA Astrophysics Data System (ADS)

Wang, Weiqin; Chen, Qian; Hussain, Saddam; Mei, Junhao; Dong, Huanglin; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Nie, Lixiao

2016-01-01

Double direct-seeding for double rice cropping is a simplified, labor saving, and efficient cropping system to improve multiple-crop index and total rice production in central China. However, poor crop establishment of direct-seeded early rice due to chilling stress is the main obstacle to wide spread of this system. A series of experiments were conducted to unravel the effects of pre-sowing seed treatments on emergence, seedling growth and associated metabolic events of direct-seeded early rice under chilling stress. Two seed priming treatments and two seed coating treatments were used in all the experiments. A non-treated control treatment was also maintained for comparison. In both the field and growth chamber studies, seed priming with selenium or salicylic acid significantly enhanced the emergence and seedling growth of rice compared with non-treated control. Nevertheless, such positive effects were not apparent for seed coating treatments. Better emergence and vigorous seedling growth of rice after seed priming was associated with enhanced α-amylase activity, higher soluble sugars contents, and greater respiration rate in primed rice seedlings under chilling stress. Taking together, these findings may provide new avenues for understanding and advancing priming-induced chilling tolerance in direct-seeded early rice in double rice cropping system.

Seeding and planting upland oaks

Treesearch

T. E. Russell

1971-01-01

Upland oaks can be established by seeding or planting, but additional experience is needed before these methods become economical alternatives to natural regeneration. Recently forested sites are generally more favorable than abandoned fields. Lack of repellents to protect acorns from animals severely limits direct seeding, but oaks can be planted readily by...

SPQR II: A beam-plasma interaction experiment

NASA Astrophysics Data System (ADS)

Bimbot, R.; Della-Negra, S.; Gardès, D.; Rivet, M. F.; Fleurier, C.; Dumax, B.; Hoffman, D. H. H.; Weyrich, K.; Deutsch, C.; Maynard, G.

1986-01-01

SPQR II is an interaction experiment designed to probe energy -and charge-exchange of Cn+ ions at 2 MeV/a.m.u., flowing through a fully ionized plasma column of hydrogen with nℓ=1019 e-cm-2 at T=5 eV. One expects a factor of two enhanced stopping over the cold gas case.

[Study on morphology, quality and germination characteristics of Acanthopanax trifoliatus seeds under different habitats].

PubMed

Xiao, Juan

2014-05-01

To preliminary explore the difference of the morphological, quality and germinal characteristics of Acanthopanax trifoliatus seeds under different habitats. Collect the wild seeds from different habitats in West Mountain, and then observe their external appearances and internal structure, and test the thousand seeds weight,water content and seed vigor. What's more, the influence to germination rates of the seeds from different temperatures and light intensities in artificial bioclimatic chamber was studied. Orthogonal test in experimental plots was carried out to screen the different sowing dates, matrix types and soil depths which may influence germination rate. The external appearances and quality characteristics of wild seeds from three habitats were different. Seeds could germinate in the both light and dark, the germination rate of the habitat II was as high as 70.5% at the optimum temperature 20 degrees C in artificial bioclimatic chamber. The optimal combination A1, B1, C1 was screened out through orthogonal test, namely, the germination rate would be the highest when the seeds sowed in autumn covering with 2 cm depth of matrix type which component of the ratio of soil, sand and organic fertilizer was 6: 3: 1. There was significant difference in the morphology and germination rate of the three habitats seeds. The habitat II seeds were the optimal choice when culture seedling. The influences of different temperatures on germination rate were different, and the dried seeds should sow in current autumn, better than the next spring.

Oxygen requirement of germinating flax seeds.

PubMed

Kuznetsov, Oleg A; Hasenstein, K H

2003-01-01

Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume=14 mL) and after 36 h measured the root length. At 90 microliters O2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O2 we determined the lower limit of reliable germination to be 10 vol. % O2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination. c2003 Published by Elsevier Ltd on behalf of COSPAR.

Oxygen requirement of germinating flax seeds

NASA Technical Reports Server (NTRS)

Kuznetsov, Oleg A.; Hasenstein, K. H.; Hasentein, K. H. (Principal Investigator)

2003-01-01

Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume=14 mL) and after 36 h measured the root length. At 90 microliters O2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O2 we determined the lower limit of reliable germination to be 10 vol. % O2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination. c2003 Published by Elsevier Ltd on behalf of COSPAR.

The sequence and structure of snake gourd (Trichosanthes anguina) seed lectin, a three-chain nontoxic homologue of type II RIPs.

PubMed

Sharma, Alok; Pohlentz, Gottfried; Bobbili, Kishore Babu; Jeyaprakash, A Arockia; Chandran, Thyageshwar; Mormann, Michael; Swamy, Musti J; Vijayan, M

2013-08-01

The sequence and structure of snake gourd seed lectin (SGSL), a nontoxic homologue of type II ribosome-inactivating proteins (RIPs), have been determined by mass spectrometry and X-ray crystallography, respectively. As in type II RIPs, the molecule consists of a lectin chain made up of two β-trefoil domains. The catalytic chain, which is connected through a disulfide bridge to the lectin chain in type II RIPs, is cleaved into two in SGSL. However, the integrity of the three-dimensional structure of the catalytic component of the molecule is preserved. This is the first time that a three-chain RIP or RIP homologue has been observed. A thorough examination of the sequence and structure of the protein and of its interactions with the bound methyl-α-galactose indicate that the nontoxicity of SGSL results from a combination of changes in the catalytic and the carbohydrate-binding sites. Detailed analyses of the sequences of type II RIPs of known structure and their homologues with unknown structure provide valuable insights into the evolution of this class of proteins. They also indicate some variability in carbohydrate-binding sites, which appears to contribute to the different levels of toxicity exhibited by lectins from various sources.

Rodent-Mediated Interactions Among Seed Species of Differing Quality in a Shrubsteppe Ecosystem

USGS Publications Warehouse

Beard, Karen H.; Faulhaber, Craig A.; Howe, Frank P.; Edwards, Thomas C.

2013-01-01

Interactions among seeds, mediated by granivorous rodents, are likely to play a strong role in shrubsteppe ecosystem restoration. Past studies typically consider only pairwise interactions between preferred and less preferred seed species, whereas rangeland seedings are likely to contain more than 2 seed species, potentially leading to complex interactions. We examined how the relative proportion of seeds in a 3-species polyculture changes rodent seed selectivity (i.e., removal) and indirect interactions among seeds. We presented 2 rodent species, Peromyscus maniculatus (deer mice) and Perognathus parvus (pocket mice), in arenas with 3-species seed mixtures that varied in the proportion of a highly preferred, moderately preferred, and least preferred seed species, based on preferences determined in this study. We then conducted a field experiment in a pocket mouse—dominated ecosystem with the same 3-species seed mixtures in both “treated” (reduced shrub and increased forb cover) and “untreated” shrubsteppe. In the arena experiment, we found that rodents removed more of the highly preferred seed when the proportions of all 3 seeds were equal. Moderately preferred seeds experienced increased removal when the least preferred seed was in highest proportion. Removal of the least preferred seed increased when the highly preferred seed was in highest proportion. In the field experiment, results were similar to those from the arena experiment and did not differ between treated and untreated shrubsteppe areas. Though our results suggest that 3-species mixtures induce complex interactions among seeds, managers applying these results to restoration efforts should carefully consider the rodent community present and the potential fate of removed seeds.

Hares promote seed dispersal and seedling establishment after volcanic eruptions

NASA Astrophysics Data System (ADS)

Nomura, Nanae; Tsuyuzaki, Shiro

2015-02-01

Although seed dispersal through animal guts (endozoochory) is a process that determines plant establishment, the behaviour of carriers mean that the seeds are not always dispersed to suitable habitats for germination. The germinable seeds of Gaultheria miqueliana were stored in the pellets of a hare (Lepus timidus ainu) on Mount Koma in northern Japan. To clarify the roles of hares in seed dispersal and germination, field censuses and laboratory experiments were conducted. The field observations were conducted on pellets and seeds in four habitats (bare ground, G. miqueliana shrub patch, Salix reinii patch, and Larix kaempferi understory), and the laboratory experiments were conducted on seed germination with different light, water potential and cold stratification treatments. The laboratory experiments confirmed that seed germination began a few weeks after the sowing of seeds, independent of cold stratification, when light was sufficient and the water potential was low. The seeds did not germinate at high water potential. The pellets were gradually degraded in situ. More seeds germinated from crushed than from intact pellets. Therefore, over the long term, seeds germinated when exposed to light due to the degradation of pellets. The pellets were proportionally dispersed among the four studied habitats. More seeds sown in the field germinated more in shaded habitats, such as in the Gaultheria patch and the Larix understory, and seeds did not germinate on bare ground, where drought often occurred. Thus, the hares had two roles in the dispersal and germination of seeds: (1) the expansion of G. miqueliana populations through seed dispersal to various habitats and (2) the facilitation of delayed seed germination to avoid risks of hazards such as drought. The relationships between small mammals represented by the hare and the shrubs that produce berries are likely to be more mutually evolved than was previously thought.

Automated seed manipulation and planting

NASA Technical Reports Server (NTRS)

Garcia, Ray; Herrera, Javier; Holcomb, Scott; Kelly, Paul; Myers, Scott; Rosendo, Manny; Sivitz, Herbert; Wolsefer, Dave

1988-01-01

Activities for the Fall Semester, 1987 focused on investigating the mechanical/electrical properties of wheat seeds and forming various Seed Planting System (SPS) concepts based on those properties. The Electrical Division of the design group was formed to devise an SPS using electrostatic charge fields for seeding operations. Experiments concerning seed separation using electrical induction (rearranging of the charges within the seed) were conducted with promising results. The seeds, when exposed to the high voltage and low current field produced by a Van de Graff generator, were observed to move back and forth between two electrodes. An SPS concept has been developed based on this phenomena, and will be developed throughout the Spring Semester, 1988. The Mechanical Division centered on SPS concepts involving valves, pumps, and fluids to separate and deliver seeds. An SPS idea utilizing the pressure difference caused by air as it rushes out of holes drilled in the wall of a closed container has been formulated and will be considered for future development. Also, a system of seed separation and delivery employing a combination of centrifugal force, friction, and air flow was considered.

Apollo Passive Seismic Experiments: lunar data in SEED format

NASA Astrophysics Data System (ADS)

Nunn, C.; Nakamura, Y.; Igel, H.

2017-12-01

As a part of the Apollo lunar missions, five seismometers were deployed on the near side of the Moon between 1969 and 1972, and four of them operated continuously until 1977. Seismic data were collected on the Moon and telemetered to Earth. The data were recorded on digital magnetic tapes, with timestamps representing the time of signal reception on Earth. The taped data have been widely used for many applications. Data from the tapes had also been transferred to SEED (Standard for the Exchange of Earthquake Data) format and these SEED files were previously available at IRIS (Incorporated Research Institutions for Seismology). However, there were some timing-related problems with the original SEED files. We have re-imported the long period data to SEED format, and will make these data available via IRIS. There are many gaps within the data caused by loss of signal or instrument problems. The signal is reconstructed to be read in as a continuous record, with gaps within the seismic trace where necessary. We also record the ground station which received the signal from the Moon, and we preserve the timestamps within the file. The timestamps indicate that the sampling rate varies by up to 0.01 %. We investigate how much this is a change in the apparent sampling rate (due to the orbital parameters of the Moon and the rotation of the Earth) and how much is due to the instrument not maintaining a constant sampling rate. We also provide response files. The new files will be a valuable resource for analyzing the structure of the Moon.

A Survey of MIKC Type MADS-Box Genes in Non-seed Plants: Algae, Bryophytes, Lycophytes and Ferns

PubMed Central

Thangavel, Gokilavani; Nayar, Saraswati

2018-01-01

MADS box transcription factors have been studied extensively in flowering plants but remain less studied in non-seed plants. MADS box is one such example of a gene which is prevalent across many classes of plants ranging from chlorophyta to embryophyta as well as fungi and animals. MADS box transcription factors are of two types, Type I and Type II. Type II transcription factors (TF) that consist of a MADS domain, I region, K domain, and C terminal domain are discussed in this review. The Type II/ MIKC class is widespread across charophytes and all major lineages of land plants but unknown in green and red algae. These transcription factors have been implicated in floral development in seed plants and thus the question arises, “What is their role in non-seed plants?” From the studies reviewed here it can be gathered that unlike seed plants, MIKCC genes in non-seed plants have roles in both gametophytic and sporophytic generations and contribute to the development of both vegetative and reproductive structures. On the other hand as previously observed in seed plants, MIKC* genes of non-seed plants have a conserved role during gametophyte development. With respect to evolution of MIKC genes in non-seed plants, the number of common ancestors is probably very few at each branch. The expansion of this gene family in seed plants and increased plant complexity seem to be correlated. As gradually the genomes of non-seed plants are becoming available it is worthwhile to gather the existing information about MADS box genes in non-seed plants. This review highlights various MIKC MADS box genes discovered so far in non-seed plants, their possible roles and an insight into their evolution. PMID:29720991

A Survey of MIKC Type MADS-Box Genes in Non-seed Plants: Algae, Bryophytes, Lycophytes and Ferns.

PubMed

Thangavel, Gokilavani; Nayar, Saraswati

2018-01-01

MADS box transcription factors have been studied extensively in flowering plants but remain less studied in non-seed plants. MADS box is one such example of a gene which is prevalent across many classes of plants ranging from chlorophyta to embryophyta as well as fungi and animals. MADS box transcription factors are of two types, Type I and Type II. Type II transcription factors (TF) that consist of a MADS domain, I region, K domain, and C terminal domain are discussed in this review. The Type II/ MIKC class is widespread across charophytes and all major lineages of land plants but unknown in green and red algae. These transcription factors have been implicated in floral development in seed plants and thus the question arises, "What is their role in non-seed plants?" From the studies reviewed here it can be gathered that unlike seed plants, MIKC C genes in non-seed plants have roles in both gametophytic and sporophytic generations and contribute to the development of both vegetative and reproductive structures. On the other hand as previously observed in seed plants, MIKC * genes of non-seed plants have a conserved role during gametophyte development. With respect to evolution of MIKC genes in non-seed plants, the number of common ancestors is probably very few at each branch. The expansion of this gene family in seed plants and increased plant complexity seem to be correlated. As gradually the genomes of non-seed plants are becoming available it is worthwhile to gather the existing information about MADS box genes in non-seed plants. This review highlights various MIKC MADS box genes discovered so far in non-seed plants, their possible roles and an insight into their evolution.

[Study on seed quality test and quality standard of Lonicera macranthoides].

PubMed

Zhang, Ying; Xu, Jin; Li, Long-Yun; Cui, Guang-Lin; She, Yue-Hui

2016-04-01

Referring to the rules for agricultural seed testing (GB/T 3543-1995) issued by China, the test of sampling, purity, thousand seed weight, moisture, viability, relative conductivity and germination rate had been studied for seed quality test methods of Lonicera macranthoides. The seed quality from 38 different collection areas was measured to establish quality classification standard by K-means clustering. The results showed that at least 7.5 g seeds should be sampled, and passed 20-mesh sieve for purity analysis.The 500-seed method used to measure thousand seed weight. The moisture was determined by crushed seeds dried in high temperature (130±2) ℃ for 3 h.The viability determined by 25 ℃ 0.1% TTC stained 5h in dark. 1.0 g seeds soaked in 50 ml ultra pure water in 25 ℃ for 12 hours to determine the relative conductivity. The seed by 4 ℃stratification for 80 days were cultured on paper at 15 ℃. Quality of the seeds from different areas was divided into three grades. The primary seed quality classification standard was established.The I grade and II grade were recommend use in production. Copyright© by the Chinese Pharmaceutical Association.

Arabidopsis seed production limited by CO2 in simulated space experiments

NASA Technical Reports Server (NTRS)

Hoshizaki, T.

1984-01-01

Several generations of Arabidopsis thaliana were grown axenically from seed to seed on nutrient agar medium. The Arabidopsis plants produce seeds within 30 days after seeding, when grown either in containers open to the ambient atmosphere or in large sealed jars, but not in sealed test tubes. Moreover, the plant height was directly proportional to the size of the sealed container. Periodic analyses of the CO2 levels in the sealed containers has shown a decrease during the first week, but a tenfold increase in the following weeks. It is speculated that, by the end of the second week, the cotyledons entering the senescence stage would release ethylene into the culture atmosphere with a concomitant release of CO2, which in turn would induce further release of ethylene, hastening the senescence process in other tissues. Thus, in a controlled ecological life-support system of a space station, various components of the plant atmosphere may have to be maintained within the prescribed limits.

Removal of lead from aqueous solutions using Cassia grandis seed gum-graft-poly(methylmethacrylate).

PubMed

Singh, Vandana; Tiwari, Stuti; Sharma, Ajit Kumar; Sanghi, Rashmi

2007-12-15

Using persulfate/ascorbic acid redox system, a series of Cassia grandis seed gum-graft-poly(methylmethacrylate) samples were synthesized. The copolymer samples were evaluated for lead(II) removal from the aqueous solutions where the sorption capacities were found proportional to the grafting extent. The conditions for the sorption were optimized using copolymer sample of highest percent grafting. The sorption was found pH and concentration dependent, pH 2.0 being the optimum value. Adsorption of lead by the grafted seed gum followed a pseudo-second-order kinetics with a rate constant of 4.64 x 10(-5) g/mg/min. The equilibrium data followed the Langmuir isotherm model with maximum sorption capacity of 126.58 mg/g. The influence of electrolytes NaCl, Na(2)SO(4) on lead uptake was also studied. Desorption with 2 N HCl could elute 76% of the lead ions from the lead-loaded copolymer. The regeneration experiments revealed that the copolymer could be successfully reused for at least four cycles though there was a successive loss in lead sorption capacity with every cycle. The adsorbent was also evaluated for Pb(II) removal from battery waste-water containing 2166 mg/L Pb(II). From 1000 times diluted waste water, 86.1% Pb(II) could be removed using 0.05 g/20 ml adsorbent dose, while 0.5 g/20 ml adsorbent dose was capable of removing 60.29% Pb from 10 times diluted waste water. Optimum Pb(II) binding under highly acidic conditions indicated that there was a significant contribution of nonelectrostatic interactions in the adsorption process. A possible mechanism for the adsorption has been discussed.

WIND DIRECTIONS ALOFT AND EFFECTS OF SEEDING ON PRECIPITATION IN THE WHITETOP EXPERIMENT*

PubMed Central

Lovasich, Jeanne L.; Neyman, Jerzy; Scott, Elizabeth L.; Smith, Jerome A.

1969-01-01

The subdivision of all the experimental days of the Whitetop project into two approximately equal groups, group W with predominantly westerly winds aloft and group E with frequent easterly winds, shows a remarkable difference in the apparent effect of seeding. On W days there was no detectable effect of seeding on rainfall. On E days with seeding, the average 24 hour precipitation in an area of about 100,000 square miles was significantly less than that without seeding by 46 per cent of the latter. The decrease resulted from a “decapitation” of the usual afternoon rise in rainfall. It may be significant that the afternoon maximum of natural precipitation on E days occurs some two hours later than on W days. If the actual cause of the differences in rainfall was seeding, then the loss of water resulting from operational, rather than experimental, seeding would have averaged eight million acre-feet per summer. PMID:16591800

Nutrient intake, digestibility and performance of Gaddi kids supplemented with tea seed or tea seed saponin extract.

PubMed

Kumar, M; Kannan, A; Bhar, R; Gulati, A; Gaurav, A; Sharma, V K

2017-04-01

An experiment was conducted to determine the nutrient intake, digestibility, microbial protein synthesis, haemato-biochemical attributes, immune response and growth performance of Gaddi kids fed with oat fodder based basal diet supplemented with either tea seed or tea seed saponin (TSS) extract. Eighteen male kids, 7.03±0.16 months of age and 19.72±0.64 kg body weight, were distributed into three groups, T 0 (control), T 1 , and T 2 , consisting of 6 animals each in a completely randomized design. The kids were fed a basal diet consisting of concentrate mixture and oat fodder (50:50). Animals in group III (T 2 ) were supplemented with TSS at 0.4% of dry matter intake (DMI), and group II (T 1 ) were supplemented with tea seed at 2.6% of DMI to provide equivalent dose of TSS as in T 2 . Two metabolism trials were conducted, 1st after 21 days and 2nd after 90 days of feeding to evaluate the short term and long term effects of supplementation. The tea seed (T 1 ) or TSS (T 2 ) supplementation did not affect DMI as well as the digestibility of dry matter, organic matter, crude protein, neutral detergent fibre, and acid detergent fibre. Nutritive value of diet and plane of nutrition were also comparable for both the periods. However, the average daily gain and feed conversion ratio (FCR) were improved (p<0.05) for T 1 and T 2 as compared to T 0 . The microbial protein supply was also higher (p<0.05) for T 1 and T 2 for both the periods. There was no effect of supplementation on most blood parameters. However, the triglyceride and low density lipoprotein cholesterol levels decreased (p<0.05) and high density lipoprotein-cholesterol level increased (p<0.05) in T 2 as compared with T 0 and T 1 . Supplementation also did not affect the cell mediated and humoral immune response in goats. Tea seed at 2.6% of DMI and TSS at 0.4% DMI can be fed to Gaddi goats to improve growth rate, FCR and microbial protein synthesis.

Nutrient intake, digestibility and performance of Gaddi kids supplemented with tea seed or tea seed saponin extract

PubMed Central

Kumar, M.; Kannan, A.; Bhar, R.; Gulati, A.; Gaurav, A.; Sharma, V. K.

2017-01-01

Objective An experiment was conducted to determine the nutrient intake, digestibility, microbial protein synthesis, haemato-biochemical attributes, immune response and growth performance of Gaddi kids fed with oat fodder based basal diet supplemented with either tea seed or tea seed saponin (TSS) extract. Methods Eighteen male kids, 7.03±0.16 months of age and 19.72±0.64 kg body weight, were distributed into three groups, T0 (control), T1, and T2, consisting of 6 animals each in a completely randomized design. The kids were fed a basal diet consisting of concentrate mixture and oat fodder (50:50). Animals in group III (T2) were supplemented with TSS at 0.4% of dry matter intake (DMI), and group II (T1) were supplemented with tea seed at 2.6% of DMI to provide equivalent dose of TSS as in T2. Two metabolism trials were conducted, 1st after 21 days and 2nd after 90 days of feeding to evaluate the short term and long term effects of supplementation. Results The tea seed (T1) or TSS (T2) supplementation did not affect DMI as well as the digestibility of dry matter, organic matter, crude protein, neutral detergent fibre, and acid detergent fibre. Nutritive value of diet and plane of nutrition were also comparable for both the periods. However, the average daily gain and feed conversion ratio (FCR) were improved (p<0.05) for T1 and T2 as compared to T0. The microbial protein supply was also higher (p<0.05) for T1 and T2 for both the periods. There was no effect of supplementation on most blood parameters. However, the triglyceride and low density lipoprotein cholesterol levels decreased (p<0.05) and high density lipoprotein-cholesterol level increased (p<0.05) in T2 as compared with T0 and T1. Supplementation also did not affect the cell mediated and humoral immune response in goats. Conclusion Tea seed at 2.6% of DMI and TSS at 0.4% DMI can be fed to Gaddi goats to improve growth rate, FCR and microbial protein synthesis. PMID:27608635

Abscisic Acid Levels and Seed Dormancy

PubMed Central

Sondheimer, E.; Tzou, D. S.; Galson, Eva C.

1968-01-01

Dormant seeds from Fraxinus species require cold-temperature after-ripening prior to germination. Earlier, we found that abscisic acid (ABA) will inhibit germination of excised nondormant embryos and that this can be reversed with a combination of gibberellic acid and kinetin. Using Milborrow's quantitative “racemate dilution” method the ABA concentration in 3 types of Fraxinus seed and pericarp were determined. While ABA was present in all tissues, the highest concentration was found in the seed and pericarp of dormant F. americana. During the chilling treatment of F. americana the ABA levels decreased 37% in the pericarp and 68% in the seed. The ABA concentration of the seed of the nondormant species, F. ornus, is as low as that found in F. americana seeds after cold treatment. Experiments with exogenously added ABA solutions indicate that it is unlikely that the ABA in the pericarp functions in the regulation of seed dormancy. However, the ABA in the seed does seem to have a regulatory role in germination. Images PMID:16656935

Direct seeding in northern forest types

Treesearch

Ralph H. Griffin

1977-01-01

Two direct-seeding experiments were established to determine the effect of time of seeding (spring 1962 versus fall 1962), type of seedbed (prepared versus unprepared), and species (red pine (Pinus resinosa Ait.) versus white spruce (Picea glauca (Moench) Voss)) upon the success attained in the reforestation of a pine-barren site...

Shear History Extensional Rheology Experiment II (SHERE II) Microgravity Rheology with Non-Newtonian Polymeric Fluids

NASA Technical Reports Server (NTRS)

Jaishankar, Aditya; Haward, Simon; Hall, Nancy Rabel; Magee, Kevin; McKinley, Gareth

2012-01-01

The primary objective of SHERE II is to study the effect of torsional preshear on the subsequent extensional behavior of filled viscoelastic suspensions. Microgravity environment eliminates gravitational sagging that makes Earth-based experiments of extensional rheology challenging. Experiments may serve as an idealized model system to study the properties of lunar regolith-polymeric binder based construction materials. Filled polymeric suspensions are ubiquitous in foods, cosmetics, detergents, biomedical materials, etc.

SHEFEX II - Aerodynamic Re-Entry Controlled Sharp Edge Flight Experiment

NASA Astrophysics Data System (ADS)

Longo, J. M. A.; Turner, J.; Weihs, H.

2009-01-01

In this paper the basic goals and architecture of the SHEFEX II mission is presented. Also launched by a two staged sounding rocket system SHEFEX II is a consequent next step in technology test and demonstration. Considering all experience and collected flight data obtained during the SHEFEX I Mission, the test vehicle has been re-designed and extended by an active control system, which allows active aerodynamic control during the re-entry phase. Thus, ceramic based aerodynamic control elements like rudders, ailerons and flaps, mechanical actuators and an automatic electronic control unit has been implemented. Special focus is taken on improved GNC Elements. In addition, some other experiments including an actively cooled thermal protection element, advanced sensor equipment, high temperature antenna inserts etc. are part of the SHEFEX II experimental payload. A final 2 stage configuration has been selected considering Brazilian solid rocket boosters derived from the S 40 family. During the experiment phase a maximum entry velocity of Mach around 10 is expected for 50 seconds. Considering these flight conditions, the heat loads are not representative for a RLV re-entry, however, it allows to investigate the principal behaviour of such a facetted ceramic TPS, a sharp leading edge at the canards and fins and all associated gas flow effects and their structural response.

Overview of TJ-II experiments

NASA Astrophysics Data System (ADS)

Sánchez, J.; Acedo, M.; Alonso, A.; Alonso, J.; Alvarez, P.; de Aragón, F.; Ascasíbar, E.; Baciero, A.; Balbín, R.; Barrera, L.; Blanco, E.; Botija, J.; Brañas, B.; de la Cal, E.; Calderón, E.; Calvo, I.; Cappa, A.; Carmona, J. A.; Carreras, B. A.; Carrasco, R.; Castejón, F.; Catalán, G.; Chmyga, A. A.; Dreval, N. B.; Chamorro, M.; Eguilior, S.; Encabo, J.; Eliseev, L.; Estrada, T.; Fernández, A.; Fernández, R.; Ferreira, J. A.; Fontdecaba, J. M.; Fuentes, C.; de la Gama, J.; García, A.; García, L.; García-Cortés, I.; García-Regaña, J. M.; Gonçalves, B.; Guasp, J.; Herranz, J.; Hidalgo, A.; Hidalgo, C.; Jiménez-Gómez, R.; Jiménez, J. A.; Jiménez, D.; Kirpitchev, I.; Komarov, A. D.; Kozachok, A. S.; Krupnik, L.; Lapayese, F.; Liniers, M.; López-Bruna, D.; López-Fraguas, A.; López-Rázola, J.; López-Sánchez, A.; de la Luna, E.; Marcon, G.; Martín, F.; Martínez-Fresno, L.; McCarthy, K. J.; Medina, F.; Medrano, M.; Melnikov, A. V.; Méndez, P.; Mirones, E.; van Milligen, B.; Nedzelskiy, I. S.; Ochando, M.; Olivares, J.; Orozco, R.; Ortiz, P.; de Pablos, J. L.; Pacios, L.; Pastor, I.; Pedrosa, M. A.; de la Peña, A.; Pereira, A.; Pérez-Risco, D.; Petrov, A.; Petrov, S.; Portas, A.; Rapisarda, D.; Ríos, L.; Rodríguez, C.; Rodríguez-Rodrigo, L.; Rodríguez-Solano, E.; Romero, J.; Ros, A.; Salas, A.; Sánchez, E.; Sánchez, M.; Sánchez-Sarabia, E.; Sarasola, X.; Sarksian, K.; Silva, C.; Schchepetov, S.; Skvortsova, N.; Soleto, A.; Tabarés, F.; Tafalla, D.; Tera, J.; Tolkachev, A.; Tribaldos, V.; Vargas, V. I.; Vega, J.; Velasco, G.; Weber, M.; Wolfers, G.; Zweben, S. J.; Zurro, B.

2007-10-01

This paper presents an overview of experimental results and progress made in investigating the link between magnetic topology, electric fields and transport in the TJ-II stellarator. The smooth change from positive to negative electric field observed in the core region as the density is raised is correlated with global and local transport data. A statistical description of transport is emerging as a new way to describe the coupling between profiles, plasma flows and turbulence. TJ-II experiments show that the location of rational surfaces inside the plasma can, in some circumstances, provide a trigger for the development of core transitions, providing a critical test for the various models that have been proposed to explain the appearance of transport barriers in relation to magnetic topology. In the plasma core, perpendicular rotation is strongly coupled to plasma density, showing a reversal consistent with neoclassical expectations. In contrast, spontaneous sheared flows in the plasma edge appear to be coupled strongly to plasma turbulence, consistent with the expectation for turbulent driven flows. The local injection of hydrocarbons through a mobile limiter and the erosion produced by plasmas with well-known edge parameters opens the possibility of performing carbon transport studies, relevant for understanding co-deposit formation in fusion devices.

Leaching and sorption of neonicotinoid insecticides and fungicides from seed coatings

USGS Publications Warehouse

Smalling, Kelly; Hladik, Michelle; Sanders, Corey; Kuivila, Kathryn

2018-01-01

Seed coatings are a treatment used on a variety of crops to improve production and offer protection against pests and fungal outbreaks. The leaching of the active ingredients associated with the seed coatings and the sorption to soil was evaluated under laboratory conditions using commercially available corn and soybean seeds to study the fate and transport of these pesticides under controlled conditions. The active ingredients (AI) included one neonicotinoid insecticide (thiamethoxam) and five fungicides (azoxystrobin, fludioxonil, metalaxyl, sedaxane thiabendazole). An aqueous leaching experiment was conducted with treated corn and soybean seeds. Leaching potential was a function of solubility and seed type. The leaching of fludioxonil, was dependent on seed type with a shorter time to equilibrium on the corn compared to the soybean seeds. Sorption experiments with the treated seeds and a solution of the AIs were conducted using three different soil types. Sorption behavior was a function of soil organic matter as well as seed type. For most AIs, a negative relationship was observed between the aqueous concentration and the log Koc. Sorption to all soils tested was limited for the hydrophilic pesticides thiamethoxam and metalaxyl. However, partitioning for the more hydrophobic fungicides was dependent on both seed type and soil properties. The mobility of fludioxonil in the sorption experiment varied by seed type indicating that the adjuvants associated with the seed coating could potentially play a role in the environmental fate of fludioxonil. This is the first study to assess, under laboratory conditions, the fate of pesticides associated with seed coatings using commercially available treated seeds. This information can be used to understand how alterations in agricultural practices (e.g., increasing use of seed treatments) can impact the exposure (concentration and duration) and potential effects of these chemicals to aquatic and terrestrial organisms.

A bioplastic-based seed coating improves seedling growth and reduces production of coated seed dust. Journal of Crop Improvement

USDA-ARS?s Scientific Manuscript database

Although recently introduced, film-coating of agronomic seeds is now widely accepted in modern agriculture as an effective technology for protecting germinating seeds and seedlings. These experiments explored the possibility of using a bioplastic-based formulation to film-coat corn (maize) and cano...

Does Ferocactus wislizeni (Cactaceae) have a between-year seed bank?

USGS Publications Warehouse

Bowers, Janice E.

2000-01-01

Field and laboratory experiments at Tumamoc Hill, Tucson, Arizona, U.S.A., demonstrated that Ferocactus wislizeni, a common perennial cactus in the northern Sonoran Desert, has a between-year seed bank. In laboratory studies, F. wislizeni seeds lost dormancy during storage at room temperature and had a light requirement for germination. Field experiments suggested that as much as 2% of the annual seed crop might escape post-dispersal predation even when unprotected; where suitable safe sites exist, a higher percentage might escape. Germination of seed recovered monthly from above- and below-ground components of an artificial seed bank showed that seeds can survive at least 18 months in and on the soil. Seed banks enable F. wislizeni to take advantage of favorable rains and temperatures throughout the growing season, thus increasing the number of opportunities for germination. Moreover, seed banks enable F. wislizeni to respond hugely when the climate seems especially favorable, thus producing the large cohorts necessary to compensate for high seedling mortality. (C) 2000 Academic Press.

Gastropod seed dispersal: an invasive slug destroys far more seeds in its gut than native gastropods.

PubMed

Blattmann, Tamara; Boch, Steffen; Türke, Manfred; Knop, Eva

2013-01-01

Seed dispersal is one of the most important mechanisms shaping biodiversity, and animals are one of the key dispersal vectors. Animal seed dispersal can directly or indirectly be altered by invasive organisms through the establishment of new or the disruption of existing seed dispersal interactions. So far it is known for a few gastropod species that they ingest and defecate viable plant seeds and consequently act as seed dispersers, referred to as gastropodochory. In a multi-species experiment, consisting of five different plant species and four different gastropod species, we tested with a fully crossed design whether gastropodochory is a general mechanism across native gastropod species, and whether it is altered by the invasive alien slug species Arion lusitanicus. Specifically, we hypothesized that a) native gastropod species consume the seeds from all tested plant species in equal numbers (have no preference), b) the voracious invasive alien slug A. lusitanicus--similarly to its herbivore behaviour--consumes a higher amount of seeds than native gastropods, and that c) seed viability is equal among different gastropod species after gut passage. As expected all tested gastropod species consumed all tested plant species. Against our expectation there was a difference in the amount of consumed seeds, with the largest and native mollusk Helix pomatia consuming most seeds, followed by the invasive slug and the other gastropods. Seed damage and germination rates did not differ after gut passage through different native species, but seed damage was significantly higher after gut passage through the invasive slug A. lusitanicus, and their germination rates were significantly reduced.

FSH: fast spaced seed hashing exploiting adjacent hashes.

PubMed

Girotto, Samuele; Comin, Matteo; Pizzi, Cinzia

2018-01-01

Patterns with wildcards in specified positions, namely spaced seeds , are increasingly used instead of k -mers in many bioinformatics applications that require indexing, querying and rapid similarity search, as they can provide better sensitivity. Many of these applications require to compute the hashing of each position in the input sequences with respect to the given spaced seed, or to multiple spaced seeds. While the hashing of k -mers can be rapidly computed by exploiting the large overlap between consecutive k -mers, spaced seeds hashing is usually computed from scratch for each position in the input sequence, thus resulting in slower processing. The method proposed in this paper, fast spaced-seed hashing (FSH), exploits the similarity of the hash values of spaced seeds computed at adjacent positions in the input sequence. In our experiments we compute the hash for each positions of metagenomics reads from several datasets, with respect to different spaced seeds. We also propose a generalized version of the algorithm for the simultaneous computation of multiple spaced seeds hashing. In the experiments, our algorithm can compute the hashing values of spaced seeds with a speedup, with respect to the traditional approach, between 1.6[Formula: see text] to 5.3[Formula: see text], depending on the structure of the spaced seed. Spaced seed hashing is a routine task for several bioinformatics application. FSH allows to perform this task efficiently and raise the question of whether other hashing can be exploited to further improve the speed up. This has the potential of major impact in the field, making spaced seed applications not only accurate, but also faster and more efficient. The software FSH is freely available for academic use at: https://bitbucket.org/samu661/fsh/overview.

Morphologic and Aerodynamic Considerations Regarding the Plumed Seeds of Tragopogon pratensis and Their Implications for Seed Dispersal.

PubMed

Casseau, Vincent; De Croon, Guido; Izzo, Dario; Pandolfi, Camilla

2015-01-01

Tragopogon pratensis is a small herbaceous plant that uses wind as the dispersal vector for its seeds. The seeds are attached to parachutes that increase the aerodynamic drag force and increase the total distance travelled. Our hypothesis is that evolution has carefully tuned the air permeability of the seeds to operate in the most convenient fluid dynamic regime. To achieve final permeability, the primary and secondary fibres of the pappus have evolved with complex weaving; this maximises the drag force (i.e., the drag coefficient), and the pappus operates in an "optimal" state. We used computational fluid dynamics (CFD) simulations to compute the seed drag coefficient and compare it with data obtained from drop experiments. The permeability of the parachute was estimated from microscope images. Our simulations reveal three flow regimes in which the parachute can operate according to its permeability. These flow regimes impact the stability of the parachute and its drag coefficient. From the permeability measurements and drop experiments, we show how the seeds operate very close to the optimal case. The porosity of the textile appears to be an appropriate solution to achieve a lightweight structure that allows a low terminal velocity, a stable flight and a very efficient parachute for the velocity at which it operates.

Morphologic and Aerodynamic Considerations Regarding the Plumed Seeds of Tragopogon pratensis and Their Implications for Seed Dispersal

PubMed Central

2015-01-01

Tragopogon pratensis is a small herbaceous plant that uses wind as the dispersal vector for its seeds. The seeds are attached to parachutes that increase the aerodynamic drag force and increase the total distance travelled. Our hypothesis is that evolution has carefully tuned the air permeability of the seeds to operate in the most convenient fluid dynamic regime. To achieve final permeability, the primary and secondary fibres of the pappus have evolved with complex weaving; this maximises the drag force (i.e., the drag coefficient), and the pappus operates in an “optimal” state. We used computational fluid dynamics (CFD) simulations to compute the seed drag coefficient and compare it with data obtained from drop experiments. The permeability of the parachute was estimated from microscope images. Our simulations reveal three flow regimes in which the parachute can operate according to its permeability. These flow regimes impact the stability of the parachute and its drag coefficient. From the permeability measurements and drop experiments, we show how the seeds operate very close to the optimal case. The porosity of the textile appears to be an appropriate solution to achieve a lightweight structure that allows a low terminal velocity, a stable flight and a very efficient parachute for the velocity at which it operates. PMID:25938765

Chickpea seeds germination rational parameters optimization

NASA Astrophysics Data System (ADS)

Safonova, Yu A.; Ivliev, M. N.; Lemeshkin, A. V.

2018-05-01

The paper presents the influence of chickpea seeds bioactivation parameters on their enzymatic activity experimental results. Optimal bioactivation process modes were obtained by regression-factor analysis: process temperature - 13.6 °C, process duration - 71.5 h. It was found that in the germination process, the proteolytic, amylolytic and lipolytic enzymes activity increased, and the urease enzyme activity is reduced. The dependences of enzyme activity on chickpea seeds germination conditions were obtained by mathematical processing of experimental data. The calculated data are in good agreement with the experimental ones. This confirms the optimization efficiency based on experiments mathematical planning in order to determine the enzymatic activity of chickpea seeds germination optimal parameters of bioactivated seeds.

The Effect of Seed-borne Mycoflora from Sorghum and Foxtail Millet Seeds on Germination and Disease Transmission.

PubMed

Yago, Jonar I; Roh, Jae-Hwan; Bae, Soon-do; Yoon, Young-Nam; Kim, Hyun-Ju; Nam, Min-Hee

2011-09-01

The seed-borne mycoflora of sorghum and foxtail millet collected from different growing areas in South Korea were isolated and taxonomically identified using dry inspection, standard blotter and the agar plate method. We investigated the in vitro and in vivo germination rates of disinfected and non-disinfected seeds of sorghum and foxtail millet using sterilized and unsterilized soil. The percent recovery of seed-borne mycoflora from the seed components of sorghum and foxtail millet seeds was determined and an infection experiment using the dominant species was evaluated for seedling emergence and mortality. A higher number of seed-borne fungi was observed in sorghum compared to that of foxtail millet. Eighteen fungal genera with 34 fungal species were identified from the seeds of sorghum and 13 genera with 22 species were identified from the seeds of foxtail millet. Five dominant species such as Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme and Phoma sp. were recorded as seed-borne mycoflora in sorghum and 4 dominant species (Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme) were observed in foxtail millet. The in vitro and in vivo germination rates were higher using disinfected seeds and sterilized soil. More seed-borne fungi were recovered from the pericarp compared to the endosperm and seed embryo. The percent recovery of seed-borne fungi ranged from 2.22% to 60.0%, and Alternaria alternata, Curvularia lunata and 4 species of Fusarium were isolated from the endosperm and embryo of sorghum and foxtail millet. Inoculation of the dominant seed-borne fungi showed considerable mortality of seedlings. All the transmitted seed-borne fungi might well be a primary source of infection of sorghum and foxtail millet crops.

Seed Transmission of Soybean vein necrosis virus: The First Tospovirus Implicated in Seed Transmission.

PubMed

Groves, Carol; German, Thomas; Dasgupta, Ranjit; Mueller, Daren; Smith, Damon L

2016-01-01

Soybean vein necrosis virus (SVNV; genus Tospovirus; Family Bunyaviridae) is a negative-sense single-stranded RNA virus that has been detected across the United States and in Ontario, Canada. In 2013, a seed lot of a commercial soybean variety (Glycine max) with a high percentage of discolored, deformed and undersized seed was obtained. A random sample of this seed was planted in a growth room under standard conditions. Germination was greater than 90% and the resulting seedlings looked normal. Four composite samples of six plants each were tested by reverse transcription polymerase chain reaction (RT-PCR) using published primers complimentary to the S genomic segment of SVNV. Two composite leaflet samples retrieved from seedlings yielded amplicons with a size and sequence predictive of SVNV. Additional testing of twelve arbitrarily selected individual plants resulted in the identification of two SVNV positive plants. Experiments were repeated by growing seedlings from the same seed lot in an isolated room inside a thrips-proof cage to further eliminate any external source of infection. Also, increased care was taken to reduce any possible PCR contamination. Three positive plants out of forty-eight were found using these measures. Published and newly designed primers for the L and M RNAs of SVNV were also used to test the extracted RNA and strengthen the diagnosis of viral infection. In experiments, by three scientists, in two different labs all three genomic RNAs of SVNV were amplified in these plant materials. RNA-seq analysis was also conducted using RNA extracted from a composite seedling sample found to be SVNV-positive and a symptomatic sample collected from the field. This analysis revealed both sense and anti-sense reads from all three gene segments in both samples. We have shown that SVNV can be transmitted in seed to seedlings from an infected seed lot at a rate of 6%. To our knowledge this is the first report of seed-transmission of a Tospovirus.

Development of 873 nm Raman Seed Pulse for Raman-seeded Laser Wakefield Acceleration

NASA Astrophysics Data System (ADS)

Grigsby, F.; Peng, D.; Downer, M. C.

2004-12-01

By using a Raman-shifted seed pulse coincident with a main driving pulse, laser wakefields can be generated with sub-relativistic intensity, coherent control and high repetition rate in the self-modulated regime. Experimentally, the generation of a chirped Stokes laser pulse by inserting a solid state Raman shifter, Ba(NO3)2, into a CPA system before the compressor (to suppress self-phase modulation) will be described. We will also report on design, modeling and experimental demonstration of a novel compressor for the Stokes pulse that uses a mismatched grating pair to achieve a near transform-limited seed pulse. Finally, we will describe the design, simulation and current status of Raman-seeded LWFA experiments that use this novel source.

CytoSEED: a Cytoscape plugin for viewing, manipulating and analyzing metabolic models created by the Model SEED

PubMed Central

DeJongh, Matthew; Bockstege, Benjamin; Frybarger, Paul; Hazekamp, Nicholas; Kammeraad, Joshua; McGeehan, Travis

2012-01-01

Summary: CytoSEED is a Cytoscape plugin for viewing, manipulating and analyzing metabolic models created using the Model SEED. The CytoSEED plugin enables users of the Model SEED to create informative visualizations of the reaction networks generated for their organisms of interest. These visualizations are useful for understanding organism-specific biochemistry and for highlighting the results of flux variability analysis experiments. Availability and Implementation: Freely available for download on the web at http://sourceforge.net/projects/cytoseed/. Implemented in Java SE 6 and supported on all platforms that support Cytoscape. Contact: dejongh@hope.edu Supplementary information: Installation instructions, a tutorial, and full-size figures are available at http://www.cs.hope.edu/cytoseed/. PMID:22210867

Soil moisture and fungi affect seed survival in California grassland annual plants.

PubMed

Mordecai, Erin A

2012-01-01

Survival of seeds in the seed bank is important for the population dynamics of many plant species, yet the environmental factors that control seed survival at a landscape level remain poorly understood. These factors may include soil moisture, vegetation cover, soil type, and soil pathogens. Because many soil fungi respond to moisture and host species, fungi may mediate environmental drivers of seed survival. Here, I measure patterns of seed survival in California annual grassland plants across 15 species in three experiments. First, I surveyed seed survival for eight species at 18 grasslands and coastal sage scrub sites ranging across coastal and inland Santa Barbara County, California. Species differed in seed survival, and soil moisture and geographic location had the strongest influence on survival. Grasslands had higher survival than coastal sage scrub sites for some species. Second, I used a fungicide addition and exotic grass thatch removal experiment in the field to tease apart the relative impact of fungi, thatch, and their interaction in an invaded grassland. Seed survival was lower in the winter (wet season) than in the summer (dry season), but fungicide improved winter survival. Seed survival varied between species but did not depend on thatch. Third, I manipulated water and fungicide in the laboratory to directly examine the relationship between water, fungi, and survival. Seed survival declined from dry to single watered to continuously watered treatments. Fungicide slightly improved seed survival when seeds were watered once but not continually. Together, these experiments demonstrate an important role of soil moisture, potentially mediated by fungal pathogens, in driving seed survival.

Oil body proteins sequentially accumulate throughout seed development in Brassica napus.

PubMed

Jolivet, Pascale; Boulard, Céline; Bellamy, Annick; Valot, Benoît; d'Andréa, Sabine; Zivy, Michel; Nesi, Nathalie; Chardot, Thierry

2011-11-15

Despite the importance of seed oil bodies (OBs) as enclosed compartments for oil storage, little is known about lipid and protein accumulation in OBs during seed formation. OBs from rapeseed (Brassica napus) consist of a triacylglycerol (TAG) core surrounded by a phospholipid monolayer embedded with integral proteins which confer high stability to OBs in the mature dry seed. In the present study, we investigated lipid and protein accumulation patterns throughout seed development (from 5 to 65 days after pollination [DAP]) both in the whole seed and in purified OBs. Deposition of the major proteins (oleosins, caleosins and steroleosins) into OBs was assessed through (i) gene expression pattern, (ii) proteomics analysis, and (iii) protein immunodetection. For the first time, a sequential deposition of integral OB proteins was established. Accumulation of oleosins and caleosins was observed starting from early stages of seed development (12-17 DAP), while steroleosins accumulated later (~25 DAP) onwards. Copyright © 2011 Elsevier GmbH. All rights reserved.

Seed removal in a tropical North American desert: an evaluation of pre- and post-dispersal seed removal in Stenocereus stellatus.

PubMed

Álvarez-Espino, R; Ríos-Casanova, L; Godínez-Álvarez, H

2017-05-01

To determine seed removal influence on seed populations, we need to quantify pre- and post-dispersal seed removal. Several studies have quantified seed removal in temperate American deserts, but few studies have been performed in tropical deserts. These studies have only quantified pre- or post-dispersal seed removal, thus underestimating the influence of seed removal. We evaluated pre- and post-dispersal seed removal in the columnar cactus Stenocereus stellatus in a Mexican tropical desert. We performed selective exclosure experiments to estimate percentage of seeds removed by ants, birds and rodents during the pre- and post-dispersal phases. We also conducted field samplings to estimate abundance of the most common seed removers. Birds (10-28%) removed a higher percentage of seeds than ants (2%) and rodents (1-4%) during pre-dispersal seed removal. Melanerpes hypopolius was probably the main bird removing seeds from fruits. Ants (62-64%) removed a higher percentage of seeds than birds (34-38%) and rodents (16-30%) during post-dispersal seed removal. Pogonomyrmex barbatus was probably the main ant removing seeds from soil. Birds and ants are the main pre- and post-dispersal seed removers in S. stellatus, respectively. Further studies in other S. stellatus populations and plants with different life forms and fruit types will contribute to evaluate seed removal in tropical American deserts. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Internal dispersal of seeds by waterfowl: effect of seed size on gut passage time and germination patterns

NASA Astrophysics Data System (ADS)

Figuerola, Jordi; Charalambidou, Iris; Santamaria, Luis; Green, Andy J.

2010-06-01

Long distance dispersal may have important consequences for gene flow and community structure. The dispersal of many plants depends on transport by vertebrate seed dispersers. The shapes of seed shadows produced by vertebrates depend both on movement patterns of the dispersers and on the dynamics and effects of passage through the disperser’s gut (i.e. the retention time, survival and germination of ingested seeds). A combination of experiments with captive waterbirds and aquatic plant seeds was used to analyse the following: (a) the effects of inter- and intra-specific variation in seed size and duck species on seed retention time in the gut and (b) the relationship between retention time and the percent germination and germination rates of seeds. Among the three Scirpus species used, those with smaller seeds showed higher survival after ingestion by birds and longer retention times inside their guts than those with larger seeds. For Potamogeton pectinatus, only seeds from the smaller size class (<8 mg) survived ingestion. Retention time affected the percent germination and germination rate of Scirpus seeds but in a manner that varied for the different plant and bird species studied. We recorded both linear and non-linear effects of retention time on percent germination. In addition, germination rate was positively correlated with retention time in Scirpus litoralis but negatively correlated in Scirpus lacustris. Small seed size can favour dispersal over larger distances. However, the effects of retention time on percent germination can modify the seed shadows produced by birds due to higher percent germination of seeds retained for short or intermediate periods. The changes in dispersal quality associated with dispersal distance (which is expected to be positively related to retention time) will affect the probability of seedling establishment over longer distances and, thus, the spatial characteristics of the effective seed shadow.

The Effect of Seed-borne Mycoflora from Sorghum and Foxtail Millet Seeds on Germination and Disease Transmission

PubMed Central

Yago, Jonar I.; Bae, Soon-do; Yoon, Young-Nam; Kim, Hyun-Ju; Nam, Min-hee

2011-01-01

The seed-borne mycoflora of sorghum and foxtail millet collected from different growing areas in South Korea were isolated and taxonomically identified using dry inspection, standard blotter and the agar plate method. We investigated the in vitro and in vivo germination rates of disinfected and non-disinfected seeds of sorghum and foxtail millet using sterilized and unsterilized soil. The percent recovery of seed-borne mycoflora from the seed components of sorghum and foxtail millet seeds was determined and an infection experiment using the dominant species was evaluated for seedling emergence and mortality. A higher number of seed-borne fungi was observed in sorghum compared to that of foxtail millet. Eighteen fungal genera with 34 fungal species were identified from the seeds of sorghum and 13 genera with 22 species were identified from the seeds of foxtail millet. Five dominant species such as Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme and Phoma sp. were recorded as seed-borne mycoflora in sorghum and 4 dominant species (Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme) were observed in foxtail millet. The in vitro and in vivo germination rates were higher using disinfected seeds and sterilized soil. More seed-borne fungi were recovered from the pericarp compared to the endosperm and seed embryo. The percent recovery of seed-borne fungi ranged from 2.22% to 60.0%, and Alternaria alternata, Curvularia lunata and 4 species of Fusarium were isolated from the endosperm and embryo of sorghum and foxtail millet. Inoculation of the dominant seed-borne fungi showed considerable mortality of seedlings. All the transmitted seed-borne fungi might well be a primary source of infection of sorghum and foxtail millet crops. PMID:22783105

The effects of Fusarium oxysporum on broomrape (Orobanche egyptiaca) seed germination.

PubMed

Hasannejad, S; Zad, S Javad; Alizade, H Mohamad; Rahymian, H

2006-01-01

Broomrape (Orobanche aegyptiaca L.), one of the most important parasitic weeds in Iran, is a root parasitic plant that can attack several crops such as tobacco, sunflower, tomato and etc. Several methods were used for Orobanche control, however these methods are inefficient and very costly. Biological control is an additional recent tool for the control of parasitic weeds. In order to study of the fungus Fusarium oxysporum (biocontrol agent) effects on broomrape seed germination, two laboratory studies were conducted in Tehran University. In the first experiment, different concentration of GR60 (0, 1, 2 and 5 ppm) as stimulation factor for Orobanche seeds germination were experimented. Results showed that concentrations of GR60 had a significant effect on seed germination. The highest seed germination percent was obtained in 1 ppm. In the second experiment, the effect of Fusarium oxysporum was tested on O. aegyptiaca seeds germination. The fungus Fusarium oxysporum were isolated from infested and juvenile O. aegyptiaca ower stalks in tomato field in karaj. Fungus spores suspension in different concentrations (0 (Control), 10(5) (T1), 10(6) (T2), 10(7) (T3) and 3 x 10(7) (T4)) from potato dextrose agar (PDA) prepared and together with 1ppm of GR60 concentration were tested on O. aegyptiaca seeds. Results show that the highest inhibition of seed germination obtained in 10(5) spores/ml. With increasing of suspension concentrations, inhibition percent was reduced and mortality of seeds germ tube was increased. In this investigation, Fusarium oxysporum can be used to inhibit seed germination, stimulate the "suicidal germination" of seeds and reduce the Orobanche seed bank.

How much Dillenia indica seed predation occurs from Asian elephant dung?

NASA Astrophysics Data System (ADS)

Sekar, Nitin; Giam, Xingli; Sharma, Netra Prasad; Sukumar, Raman

2016-01-01

Elephants are thought to be effective seed dispersers, but research on whether elephant dung effectively protects seeds from seed predation is lacking. Quantifying rates of seed predation from elephant dung will facilitate comparisons between elephants and alternative dispersers, helping us understand the functional role of megaherbivores in ecosystems. We conducted an experiment to quantify the predation of Dillenia indica seeds from elephant dung in Buxa Reserve, India from December 2012 to April 2013. Using dung boluses from the same dung pile, we compared the number of seeds in boluses that are a) opened immediately upon detection (control boluses), b) made available only to small seed predators (<3 mm wide) for 1-4 months, and c) made available to all seed predators and secondary dispersers for 1-4 months. Using a model built on this experiment, we estimated that seed predation by small seed predators (most likely ants and termites) destroys between 82.9% and 96.4% of seeds in elephant dung between the time of defecation and the median germination date for D. indica. Exposure to larger seed predators and secondary dispersers did not lead to a significant additional reduction in the number of seeds per dung bolus. Our findings suggest that post-dispersal seed predation by small insects (<3 mm) substantially reduces but does not eliminate the success of elephants as dispersers of D. indica in a tropical moist forest habitat.

Ecological Interactions Shape the Dynamics of Seed Predation in Acrocomia aculeata (Arecaceae)

PubMed Central

Pereira, Anielle C. F.; Fonseca, Francine S. A.; Mota, Gleicielle R.; Fernandes, Ane K. C.; Fagundes, Marcílio; Reis-Júnior, Ronaldo; Faria, Maurício L.

2014-01-01

Background The complex network of direct and indirect relationships determines not only the species abundances but also the community characteristics such as diversity and stability. In this context, seed predation is a direct interaction that affects the reproductive success of the plant. For Acrocomia aculeata, the seed predation by Pachymerus cardo and Speciomerus revoili in post-dispersal may destroy more than 70% of the propagules and is influenced by the herbivory of the fruits during pre-dispersal. Fruits of plants with a higher level of herbivory during pre-dispersal are less attacked by predators in post-dispersal. We proposed a hypothesis that describes this interaction as an indirect defense mediated by fungi in a multitrophic interaction. As explanations, we proposed the predictions: i) injuries caused by herbivores in the fruits of A. aculeata favor fungal colonization and ii) the colonization of A. acuelata fruit by decomposing fungi reduces the selection of the egg-laying site by predator. Methodology/Principal Findings For prediction (i), differences in the fungal colonization in fruits with an intact or damaged epicarp were evaluated in fruits exposed in the field. For prediction (ii), we performed fruit observations in the field to determine the number of eggs of P. cardo and/or S. revoili per fruit and the amount of fungal colonization in the fruits. In another experiment, in the laboratory, we use P. cardo females in a triple-choice protocol. Each insect to choose one of the three options: healthy fruits, fruits with fungus, or an empty pot. The proposed hypothesis was corroborated. Fruits with injuries in the epicarp had a higher fungal colonization, and fruits colonized by fungi were less attractive for egg-laying by seed predators. Conclusion/Significance This study emphasizes the importance of exploring the networks of interactions between multitrophic systems to understand the dynamics and maintenance of natural populations. PMID:24875386

University of Maryland MRSEC - Research: Seed 3

Science.gov Websites

MRSEC Templates Opportunities Search Home » Research » Seed 3 Seed 3: Modeling Elastic Effects on controlling parameters and variables include temperature, deposition flux, external electric field and elastic simulating the effects of these controlling factors often lead to predictions that guide future experiments

Automatic seed picking for brachytherapy postimplant validation with 3D CT images.

PubMed

Zhang, Guobin; Sun, Qiyuan; Jiang, Shan; Yang, Zhiyong; Ma, Xiaodong; Jiang, Haisong

2017-11-01

Postimplant validation is an indispensable part in the brachytherapy technique. It provides the necessary feedback to ensure the quality of operation. The ability to pick implanted seed relates directly to the accuracy of validation. To address it, an automatic approach is proposed for picking implanted brachytherapy seeds in 3D CT images. In order to pick seed configuration (location and orientation) efficiently, the approach starts with the segmentation of seed from CT images using a thresholding filter which based on gray-level histogram. Through the process of filtering and denoising, the touching seed and single seed are classified. The true novelty of this approach is found in the application of the canny edge detection and improved concave points matching algorithm to separate touching seeds. Through the computation of image moments, the seed configuration can be determined efficiently. Finally, two different experiments are designed to verify the performance of the proposed approach: (1) physical phantom with 60 model seeds, and (2) patient data with 16 cases. Through assessment of validated results by a medical physicist, the proposed method exhibited promising results. Experiment on phantom demonstrates that the error of seed location and orientation is within ([Formula: see text]) mm and ([Formula: see text])[Formula: see text], respectively. In addition, the most seed location and orientation error is controlled within 0.8 mm and 3.5[Formula: see text] in all cases, respectively. The average process time of seed picking is 8.7 s per 100 seeds. In this paper, an automatic, efficient and robust approach, performed on CT images, is proposed to determine the implanted seed location as well as orientation in a 3D workspace. Through the experiments with phantom and patient data, this approach also successfully exhibits good performance.

Sensitivity to high temperature and water stress in recalcitrant Baccaurea ramiflora seeds.

PubMed

Wen, Bin; Liu, Minghang; Tan, Yunhong; Liu, Qiang

2016-07-01

Southeast Asia experiences one of the highest rates of deforestation in the tropics due to agricultural expansion, logging, habitat fragmentation and urbanization. As tropical rainforests harbour abundant recalcitrant-seeded species, it is important to understand how recalcitrant seeds respond to deforestation and fragmentation. Baccaurea ramiflora is a recalcitrant-seeded species, widely distributed in Southeast Asian tropical rainforest. In this study, B. ramiflora seeds were sown in three plots, one in a nature reserve and two in disturbed holy hill forests, to investigate seed germination and seedling establishment in the field, while laboratory experiments were conducted to investigate the effects of high temperature and water stress on germination. It was found that seed germination and seedling establishment in B. ramiflora were clearly reduced in holy hills compared to the nature reserve, although the seeds were only moderately to minimally recalcitrant. This was potentially caused by increased temperature and decreased moisture in holy hills, for laboratory experiments showed that seed germination was greatly inhibited by temperatures ≥35 °C or water potentials ≤-0.5 MPa, and depressed by heat treatment at 40 °C when the continuous heating period lasted for 240 h or daily periodic heating exceeded 10 h. Unlike orthodox seeds, which can endure much higher temperatures in the air-dried state than in the imbibed state, both blotted and immersed B. ramiflora seeds lost viability within a narrow temperature range between 50 and 60 °C. As recalcitrant seeds can be neither air-dried nor heated, species producing recalcitrant seeds will suffer more than those producing orthodox seeds in germination and seedling establishment from increased temperature and decreased moisture in fragmented rainforests, which results in sensitivity of recalcitrant-seeded species to rainforest fragmentation.

Spatial variation in post-dispersal seed removal in an Atlantic forest: Effects of habitat, location and guilds of seed predators

NASA Astrophysics Data System (ADS)

Christianini, Alexander V.; Galetti, Mauro

2007-11-01

Studies of post-dispersal seed removal in the Neotropics have rarely examined the magnitude of seed removal by different types of granivores. The relative impact of invertebrates, small rodents, and birds on seed removal was investigated in a 2,178 ha Atlantic forest fragment in southeastern Brazil. We used popcorn kernels ( Zea mays—Poaceae) to investigate seed removal in a series of selective exclosure treatments in a replicated, paired design experiment that included forest understory, gaps, and forest edge sites. We recorded the vegetation around the experimental seed stations in detail in order to evaluate the influence of microhabitat traits on seed removal. Vertebrate granivores (rodents and birds) were surveyed to determine whether granivore abundance was correlated with seed removal levels. Seed removal varied spatially and in unpredictable ways at the study site. Seed encounter and seed use varied with treatments, but not with habitat type. However, seed removal by invertebrates was negatively correlated with gap-related traits, which suggested an avoidance of large gaps by granivorous ants. The abundance of small mammals was remarkably low, but granivorous birds (tinamous and doves) were abundant at the study site. Birds were the main seed consumers in open treatments, but there was no correlation between local granivorous bird abundance and seed removal. These results emphasize the stochastic spatial pattern of seed removal, and, contrary to previous studies, highlight the importance of birds as seed predators in forest habitats.

U.S. EPA, Pesticide Product Label, BAS 516 ST SEED TREATMENT FUNGICIDE, 05/30/2007

EPA Pesticide Factsheets

2011-04-21

... Ii: lq I JiOTectlCI[r a~Jairl,;t seeci-[x,me Tun;;11 ... Product Use Rate in oz/100 Ib Seed (Ib ai/100 Ib seed) ... t~~e~a~~~J~-~~-d-~i~~~~~see f~~'~g ...

[Isolation and characterization of polyphenols in seed of Litchi chinensis].

PubMed

Yan, Ren-Liang; Liu, Zhi-Gang

2009-04-01

To study the chemical constituents of polyphenols in seed of Litchi chinensis. The seeds of Litchi chinensis were extracted by 65% ethanol, then the compounds were separated by repeated silica gel, polyamide and preparative TLC. The structures of polyphones isolated were identified by analysis of their spectral datas and chemical properties. Four polyphones compounds were isolated as protocatechuic aldehyde (I), protocatechuic acid (II), daucosterol (III) and (-) -epicatichin (IV). Compounds I , III and IV are isolated from this plant for the first time.

Pacific Northwest forest tree seed zones: a template for native plants?

Treesearch

GR Johnson; Frank C Sorensen; J Bradley St Clair; Richard C. Cronn

2004-01-01

Seed movement guidelines for restoration activities are lacking for most native grasses, forbs, and shrubs. The forestry community has decades of experience in establishing seed zones and seed movement guidelines that may be of value to restoration managers. We review the history of seed zone development in forest trees, with emphasis on the Pacific Northwest, and make...

[Studies on chemical constituents of the seeds of Allium cepa].

PubMed

Yuan, Ling; Ji, Teng-Fei; Wang, Ai-Guo; Yang, Jian-Bo; Su, Ya-Lun

2008-02-01

To study the chemical constituents from the seeds of Allium cepa L., the constituents of the seeds of Allium cepa L. To isolate and purify by silica gel, macroporous resin HP-20, Sephadex LH-20, RP-18 column. Seven compounds were isolated from the EtOH extract of the seeds of Allium cepa., their structures were elucidated by physico-chemical properties and spectroscopic analysis as tianshic acid (I), N-trans-feruloyl tyramine (II), beta-sitosterol-3 beta-glucopyranoside-6'-palmitate (III), sitosterol (IV), daucosterol (V), tryptophane (VI), adenine riboside (VI). Compounds V-VIII are obtained from this plant for the first time, compounds I-IV are isolated from the genus Allium for the first time.

Analysis of plant soil seed banks and seed dispersal vectors: Its potential and limits for forensic investigations.

PubMed

Šumberová, Kateřina; Ducháček, Michal

2017-01-01

Plant seeds exhibit many species-specific traits, thus potentially being especially helpful for forensic investigations. Seeds of a broad range of plant species occur in soil seed banks of various habitats and may become attached in large quantities to moving objects. Although plant seeds are now routinely used as trace evidence in forensic practice, only scant information has been published on this topic in the scientific literature. Thus, the standard methods remain unknown to specialists in such botanical subjects as plant ecology and plant geography. These specialists, if made aware of the forensic uses of seeds, could help in development of new, more sophisticated approaches. We aim to bridge the gap between forensic analysts and botanists. Therefore, we explore the available literature and compare it with our own experiences to reveal both the potential and limits of soil seed bank and seed dispersal analysis in forensic investigations. We demonstrate that habitat-specific and thus relatively rare species are of the greatest forensic value. Overall species composition, in terms of species presence/absence and relative abundance can also provide important information. In particular, the ecological profiles of seeds found on any moving object can help us identify the types of environments through which the object had travelled. We discuss the applicability of this approach to various European environments, with the ability to compare seed samples with georeferenced vegetation databases being particularly promising for forensic investigations. We also explore the forensic limitations of soil seed bank and seed dispersal vector analyses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Critical phases in the seed development of common juniper (Juniperus communis).

PubMed

Gruwez, R; Leroux, O; De Frenne, P; Tack, W; Viane, R; Verheyen, K

2013-01-01

Common juniper (Juniperus communis L.) populations in northwest European lowlands are currently declining in size and number. An important cause of this decline is a lack of natural regeneration. Low seed viability seems to be one of the main bottlenecks in this process. Previous research revealed a negative relation between seed viability and both temperature and nitrogen deposition. Additionally, the seeds of common juniper have a variable ripening time, which possibly influences seed viability. However, the underlying mechanisms remain unresolved. In order to elucidate this puzzle, it is important to understand in which phases of seed production the main defects are situated, together with the influence of ripening time. In this study, we compared seed viability of populations with and without successful recruitment. We examined three seed phases: (i) gamete development; (ii) fertilisation and early-embryo development; and (iii) late-embryo development. After the first two phases, we found no difference in the percentage viable seeds between populations with or without recruitment. After late-embryo development, populations without recruitment showed a significantly lower percentage of viable seeds. These results suggest that late-embryo development is a bottleneck in seed development. However, the complex interaction between seed viability and ripening time suggest that the causes should be in the second seed phase, as the accelerated development of male and female gametophytes may disturb the male-female synchrony for successful mating. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

Differential seed handling by two African primates affects seed fate and establishment of large-seeded trees

NASA Astrophysics Data System (ADS)

Gross-Camp, Nicole D.; Kaplin, Beth A.

2011-11-01

We examined the influence of seed handling by two semi-terrestrial African forest primates, chimpanzees ( Pan troglodytes) and l'Hoest's monkeys ( Cercopithecus lhoesti), on the fate of large-seeded tree species in an afromontane forest. Chimpanzees and l'Hoest's monkeys dispersed eleven seed species over one year, with quantity and quality of dispersal varying through time. Primates differed in their seed handling behaviors with chimpanzees defecating large seeds (>0.5 cm) significantly more than l'Hoest's. Furthermore, they exhibited different oral-processing techniques with chimpanzees discarding wadges containing many seeds and l'Hoest's monkeys spitting single seeds. A PCA examined the relationship between microhabitat characteristics and the site where primates deposited seeds. The first two components explained almost half of the observed variation. Microhabitat characteristics associated with sites where seeds were defecated had little overlap with those characteristics describing where spit seeds arrived, suggesting that seed handling in part determines the location where seeds are deposited. We monitored a total of 552 seed depositions through time, recording seed persistence, germination, and establishment. Defecations were deposited significantly farther from an adult conspecific than orally-discarded seeds where they experienced the greatest persistence but poorest establishment. In contrast, spit seeds were deposited closest to an adult conspecific but experienced the highest seed establishment rates. We used experimental plots to examine the relationship between seed handling, deposition site, and seed fate. We found a significant difference in seed handling and fate, with undispersed seeds in whole fruits experiencing the lowest establishment rates. Seed germination differed by habitat type with open forest experiencing the highest rates of germination. Our results highlight the relationship between primate seed handling and deposition site and seed

A field experiment demonstrating plant life-history evolution and its eco-evolutionary feedback to seed predator populations.

PubMed

Agrawal, Anurag A; Johnson, Marc T J; Hastings, Amy P; Maron, John L

2013-05-01

The extent to which evolutionary change occurs in a predictable manner under field conditions and how evolutionary changes feed back to influence ecological dynamics are fundamental, yet unresolved, questions. To address these issues, we established eight replicate populations of native common evening primrose (Oenothera biennis). Each population was planted with 18 genotypes in identical frequency. By tracking genotype frequencies with microsatellite DNA markers over the subsequent three years (up to three generations, ≈5,000 genotyped plants), we show rapid and consistent evolution of two heritable plant life-history traits (shorter life span and later flowering time). This rapid evolution was only partially the result of differential seed production; genotypic variation in seed germination also contributed to the observed evolutionary response. Since evening primrose genotypes exhibited heritable variation for resistance to insect herbivores, which was related to flowering time, we predicted that evolutionary changes in genotype frequencies would feed back to influence populations of a seed predator moth that specializes on O. biennis. By the conclusion of the experiment, variation in the genotypic composition among our eight replicate field populations was highly predictive of moth abundance. These results demonstrate how rapid evolution in field populations of a native plant can influence ecological interactions.

[Non-thermal effect of GSM electromagnetic radiation on quality of pea seeds].

PubMed

Veselova, T V; Veselovskiĭ, V A; Deev, L I; Baĭzhumanov, A A

2012-01-01

The seeds with low level of room temperature phosphorescence (RTP) were selected from a lot of air-dry peas (Pisum sativum) with 62% germination. These strong seeds (95-97% germination percentage) in air-dry, imbibed or emerged states were exposed to 905 MHz GSM-band electromagnetic radiation (EMR). The following effects of EMR were observed. Fraction II with higher RTP level appeared in the air-dry seeds. The germination rate decreased 2-3 fold in the air-dry, swollen and sprouting seeds due to an increase in the ratio of the seedlings with morphological defects (from 3 to 38%) and suffocated seeds (from 1 to 15%). We suggest tentative mechanisms to account for the decreased fitness of peas under GSM-band EMR (905 MHz); also discussed is the role of non-enzymatic hydrolysis of carbohydrates and amino-carbonyl reaction in this process.

Physiology and biochemistry of recalcitrant Guarea guidonia (L.) Sleumer seeds

Treesearch

Kristina F. Connor; F.T. Bonner

1998-01-01

Investigations of recalcitrant, or desiccation-sensitive, seeds have as yet failed to identify the causes of this phenomenon. Experiments with Guarea guidonia (L.) Sleumer (American muskwood) were initiated to determine the effects of desiccation on the physiology and biochemistry of the seeds of this tropical tree species. Seeds were air-dried at...

Seed dormancy in alpine species

PubMed Central

Schwienbacher, Erich; Navarro-Cano, Jose Antonio; Neuner, Gilbert; Erschbamer, Brigitta

2011-01-01

In alpine species the classification of the various mechanisms underlying seed dormancy has been rather questionable and controversial. Thus, we investigated 28 alpine species to evaluate the prevailing types of dormancy. Embryo type and water impermeability of seed coats gave an indication of the potential seed dormancy class. To ascertain the actual dormancy class and level, we performed germination experiments comparing the behavior of seeds without storage, after cold-dry storage, after cold-wet storage, and scarification. We also tested the light requirement for germination in some species. Germination behavior was characterized using the final germination percentage and the mean germination time. Considering the effects of the pretreatments, a refined classification of the prevailing dormancy types was constructed based on the results of our pretreatments. Only two out of the 28 species that we evaluated had predominantly non-dormant seeds. Physiological dormancy was prevalent in 20 species, with deep physiological dormancy being the most abundant, followed by non-deep and intermediate physiological dormancy. Seeds of four species with underdeveloped embryos were assigned to the morphophysiologial dormancy class. An impermeable seed coat was identified in two species, with no additional physiological germination block. We defined these species as having physical dormancy. Light promoted the germination of seeds without storage in all but one species with physiological dormancy. In species with physical dormancy, light responses were of minor importance. We discuss our new classification in the context of former germination studies and draw implications for the timing of germination in the field. PMID:24415831

Formative Assessment Probes: Seeds in a Bag

ERIC Educational Resources Information Center

Keeley, Page

2014-01-01

Many young children come to school with prior experiences planting seeds in a garden or in a pot, watering them, and seeing them grow. These early scientific investigations are designed to help children understand that seeds need water, something to grow in (such as soil), and the right temperature to sprout--if these conditions are met, a seed…

Seed dispersal potential of Asian elephants

NASA Astrophysics Data System (ADS)

Harich, Franziska K.; Treydte, Anna C.; Ogutu, Joseph O.; Roberts, John E.; Savini, Chution; Bauer, Jan M.; Savini, Tommaso

2016-11-01

Elephants, the largest terrestrial mega-herbivores, play an important ecological role in maintaining forest ecosystem diversity. While several plant species strongly rely on African elephants (Loxodonta africana; L. cyclotis) as seed dispersers, little is known about the dispersal potential of Asian elephants (Elephas maximus). We examined the effects of elephant fruit consumption on potential seed dispersal using the example of a tree species with mega-faunal characteristics, Dillenia indica L., in Thailand. We conducted feeding trials with Asian elephants to quantify seed survival and gut passage times (GPT). In total, 1200 ingested and non-ingested control seeds were planted in soil and in elephant dung to quantify differences in germination rates in terms of GPT and dung treatment. We used survival analysis as a novel approach to account for the right-censored nature of the data obtained from germination experiments. The average seed survival rate was 79% and the mean GPT was 35 h. The minimum and maximum GPT were 20 h and 72 h, respectively. Ingested seeds were significantly more likely to germinate and to do so earlier than non-ingested control seeds (P = 0.0002). Seeds with the longest GPT displayed the highest germination success over time. Unexpectedly, seeds planted with dung had longer germination times than those planted without. We conclude that D. indica does not solely depend on but benefits from dispersal by elephants. The declining numbers of these mega-faunal seed dispersers might, therefore, have long-term negative consequences for the recruitment and dispersal dynamics of populations of certain tree species.

Infection Courts in Watermelon Plants Leading to Seed Infestation by Fusarium oxysporum f. sp. niveum.

PubMed

Petkar, Aparna; Ji, Pingsheng

2017-07-01

Fusarium wilt incited by Fusarium oxysporum f. sp. niveum is a seed-transmitted disease that causes significant yield loss in watermelon production. The pathogen may infect watermelon seeds latently, which can be an important inoculum source and contribute to severe disease outbreak. However, information regarding infection courts of F. oxysporum f. sp. niveum leading to infestation of watermelon seeds is limited. To determine how seeds in watermelon fruit can be infested by F. oxysporum f. sp. niveum during the watermelon growing season, greenhouse and field experiments were conducted in 2014 and 2015 where watermelon flowers and immature fruit were inoculated with F. oxysporum f. sp. niveum. Seeds were extracted from mature watermelon fruit, and infestation of watermelon seeds was determined by isolation of F. oxysporum f. sp. niveum and further confirmed by real-time polymerase chain reaction (PCR) analysis. Inoculation of the pericarp of immature fruit resulted in 17.8 to 54.4% of infested seeds under field conditions and 0.6 to 12.8% of infested seeds under greenhouse conditions when seeds were not surface disinfested prior to isolation. Seed infestation was also detected in 0 to 4.5% of the seeds when seeds were surface disinfested prior to isolation. Inoculation of pistil resulted in 0 to 7.2% and 0 to 18.3% of infested seeds under greenhouse and field conditions when seeds were surface disinfested or not disinfested before isolation, respectively. Inoculation of peduncle resulted in 0.6 to 6.1% and 0 to 10.0% of infested seeds in the greenhouse and field experiments when seeds were surface disinfested or not disinfested before isolation, respectively. Seed infestation was also detected in all the experiments using real-time PCR assay when pericarp or pistil was inoculated, and in three of four experiments when peduncle was inoculated, regardless of whether seeds were surface disinfested or not disinfested. Pericarp and peduncle of immature watermelon fruit

Antioxidant effects of a grape seed extract in a rat model of diabetes mellitus.

PubMed

Chis, Irina C; Ungureanu, Marius I; Marton, Adriana; Simedrea, Ramona; Muresan, Adriana; Postescu, Ion-Dan; Decea, Nicoleta

2009-07-01

In the present study we investigated the anti-hyperglycaemic and antioxidant effect of grape seed extract, a polyphenolic flavonoid, in normal and streptozotocin-induced diabetic Wistar rats. Adult male Wistar rats were divided into three groups: Group I: non-diabetic control; Group II: diabetic control; Group III: diabetic rats treated with grape seed extract, administered via an intragastric tube (0.6 ml/rat), at a dose of 100 mg/kg for 20 consecutive days after the induction of diabetes mellitus. Diabetes was induced by an i.p. injection with streptozotocin for groups II and III. TheTBARS, carbonylated proteins, were measured in the plasma and in the supernatant of liver homogenisates, and superoxide dismutase and catalase were measured in the haemolysates of RBCs and supernatant of liver homogenisates. The results showed that oral administration of grape seed extract (100 mg/kg/day) reduced the levels of lipid peroxides and carbonylated proteins and improved the antioxidant activity in plasma and hepatic tissue in rats treated with grape seed natural extract as compared with the diabetic control rats. These results suggested that the grape seed extract enhanced the antioxidant defence against reactive oxygen species produced under hyperglycaemic conditions, hence protecting the liver cells.

Analysis of cDNA libraries from developing seeds of guar (Cyamopsis tetragonoloba (L.) Taub)

PubMed Central

Naoumkina, Marina; Torres-Jerez, Ivone; Allen, Stacy; He, Ji; Zhao, Patrick X; Dixon, Richard A; May, Gregory D

2007-01-01

Background Guar, Cyamopsis tetragonoloba (L.) Taub, is a member of the Leguminosae (Fabaceae) family and is economically the most important of the four species in the genus. The endosperm of guar seed is a rich source of mucilage or gum, which forms a viscous gel in cold water, and is used as an emulsifier, thickener and stabilizer in a wide range of foods and industrial applications. Guar gum is a galactomannan, consisting of a linear (1→4)-β-linked D-mannan backbone with single-unit, (1→6)-linked, α-D-galactopyranosyl side chains. To better understand regulation of guar seed development and galactomannan metabolism we created cDNA libraries and a resulting EST dataset from different developmental stages of guar seeds. Results A database of 16,476 guar seed ESTs was constructed, with 8,163 and 8,313 ESTs derived from cDNA libraries I and II, respectively. Library I was constructed from seeds at an early developmental stage (15–25 days after flowering, DAF), and library II from seeds at 30–40 DAF. Quite different sets of genes were represented in these two libraries. Approximately 27% of the clones were not similar to known sequences, suggesting that these ESTs represent novel genes or may represent non-coding RNA. The high flux of energy into carbohydrate and storage protein synthesis in guar seeds was reflected by a high representation of genes annotated as involved in signal transduction, carbohydrate metabolism, chaperone and proteolytic processes, and translation and ribosome structure. Guar unigenes involved in galactomannan metabolism were identified. Among the seed storage proteins, the most abundant contig represented a conglutin accounting for 3.7% of the total ESTs from both libraries. Conclusion The present EST collection and its annotation provide a resource for understanding guar seed biology and galactomannan metabolism. PMID:18034910

Investigating Seed Longevity of Big Sagebrush (Artemisia tridentata)

USGS Publications Warehouse

Wijayratne, Upekala C.; Pyke, David A.

2009-01-01

The Intermountain West is dominated by big sagebrush communities (Artemisia tridentata subspecies) that provide habitat and forage for wildlife, prevent erosion, and are economically important to recreation and livestock industries. The two most prominent subspecies of big sagebrush in this region are Wyoming big sagebrush (A. t. ssp. wyomingensis) and mountain big sagebrush (A. t. ssp. vaseyana). Increased understanding of seed bank dynamics will assist with sustainable management and persistence of sagebrush communities. For example, mountain big sagebrush may be subjected to shorter fire return intervals and prescribed fire is a tool used often to rejuvenate stands and reduce tree (Juniperus sp. or Pinus sp.) encroachment into these communities. A persistent seed bank for mountain big sagebrush would be advantageous under these circumstances. Laboratory germination trials indicate that seed dormancy in big sagebrush may be habitat-specific, with collections from colder sites being more dormant. Our objective was to investigate seed longevity of both subspecies by evaluating viability of seeds in the field with a seed retrieval experiment and sampling for seeds in situ. We chose six study sites for each subspecies. These sites were dispersed across eastern Oregon, southern Idaho, northwestern Utah, and eastern Nevada. Ninety-six polyester mesh bags, each containing 100 seeds of a subspecies, were placed at each site during November 2006. Seed bags were placed in three locations: (1) at the soil surface above litter, (2) on the soil surface beneath litter, and (3) 3 cm below the soil surface to determine whether dormancy is affected by continued darkness or environmental conditions. Subsets of seeds were examined in April and November in both 2007 and 2008 to determine seed viability dynamics. Seed bank samples were taken at each site, separated into litter and soil fractions, and assessed for number of germinable seeds in a greenhouse. Community composition data

Glucosinolate pattern in Isatis tinctoria and I. indigotica seeds.

PubMed

Mohn, Tobias; Hamburger, Matthias

2008-06-01

The glucosinolate patterns in seeds of five ISATIS TINCTORIA and two ISATIS INDIGOTICA accessions were assessed with a recently developed and validated LC-MS assay for direct analysis of glucosinolates without prior desulfatation. Glucosinolate peaks were identified with in-source fragmentation and detection of the sulfate anion ( M/Z = 97), and by MS/MS experiments. The glucosinolate patterns of the seeds showed characteristic differences compared to leaves. Glucoisatisin and epiglucoisatisin were diagnostic of seed samples. Qualitative and quantitative differences in glucosinolate patterns between both ISATIS species were found for seed samples, enabling a differentiation of the two medicinal plants at the level of seed material.

Effects of Pomegranate Seed Oil on the Fertilization Potency of Rat's Sperm.

PubMed

Nikseresht, Mohsen; Fallahzadeh, Ali Reza; Toori, Mehdi Akbartabar; Mahmoudi, Reza

2015-12-01

Pomegranate has been taken great scientific attention in recent years due to its health benefits. Pomegranate seed oil is a rich source of 9-cis, and 11-trans conjugate linolenic acid. The aim of this study was to evaluate the effect of dietary pomegranate seed oil on the fertilization potency of rat's sperm. Twenty-four male Wistar rats were divided into four groups. The first group, which served as the control group, received 1 mL of corn oil for seven weeks. Groups II, III, IV served as the experimental groups received 200, 500 and 1000 mg/kg of pomegranate seed oil, for the same period of time respectively. After seven weeks, all of the rats were sacrificed, and their epididymis sperm was collected and added to IVF medium (T6) containing metaphase II oocytes. Almost 21 oocytes had been removed from every female rat oviduct. In this medium, oocyte fertilization, cleavage rates, and embryo development into blastocysts, were evaluated by inverted microscopy. Levels of LD50 in the oral route in male rats were more than 5000 mg/kg body weight. Our data showed that the rates of fertilization, cleavage and embryo development into blastocysts were higher in the groups that had received 500 and 1000 mg/kg body weight of pomegranate seed oil. This study demonstrated that pomegranate seed oil had a positive effect on the fertilization potency of male rats. These beneficial effects may be useful in assisted reproductive technology.

Commercial Seed Selection and Effectiveness of Sanitization Methods in Preparation for Plant Growth Experiments on the International Space Station

NASA Technical Reports Server (NTRS)

Boehm, Emma

2017-01-01

A closed-loop food production system will be important to gain autonomy on long duration space missions. Crop growth experiments in the Veggie plant chamber aboard the International Space Station (ISS) are helping to identify methods and limitations of food production in space. Prior to flight, seeds are surface sterilized to reduce environmental and crew contamination risks.

The numerical and functional responses of a granivorous rodent and the fate of Neotropical tree seeds

USGS Publications Warehouse

Klinger, R.; Rejmanek, M.

2009-01-01

Despite their potential to provide mechanistic explanations of rates of seed dispersal and seed fate, the functional and numerical responses of seed predators have never been explicitly examined within this context. Therefore, we investigated the numerical response of a small-mammal seed predator, Heteromys desmarestianus, to disturbance-induced changes in food availability and evaluated the degree to which removal and fate of seeds of eight tree species in a lowland tropical forest in Belize were related to the functional response of H. desmarestianus to varying seed densities. Mark-recapture trapping was used to estimate abundance of H. desmarestianus in six 0.5-ha grids from July 2000 to September 2002. Fruit availability and seed fate were estimated in each grid, and two experiments nested within the grids were used to determine (1) the form of the functional response for nine levels of fruit density (2-32 fruits/m 2), (2) the removal rate and handling times, and (3) the total proportion of fruits removed. The total proportion of fruits removed was determined primarily by the numerical response of H. desmarestianus to fruit availability, while removal rates and the proportion of seeds eaten or cached were related primarily to the form of the functional response. However, the numerical and functional responses interacted; H. desmarestianus showed strong spatial and temporal numerical responses to total fruit availability, and their density relative to fruit availability resulted in variation in the form of the functional response. Types I, II, and III functional responses were observed, as were density-independent responses, and these responses varied both among and within fruit species. The highest proportions of fruits were eaten when the Type III functional response was detected, which was when fruit availability was high relative to H. desmarestianus population density. Numerous idiosyncratic influences on seed fate have been documented, but our results

SEEDS: A Celebration of Science

NASA Technical Reports Server (NTRS)

Melton, Bob

1991-01-01

The major goal of the project of Space Exposed Experiment Developed for Students (SEEDS) was to stimulate interest in science through the active involvement of all participants. Youthful investigators utilized the basic and integrated science process skills as they conducted the research necessary to complete the data reports used in the compilation of this document. Participants described many unique activities designed to promote critical thinking and problem solving. Seeds made a significant impact toward enhancing the teaching, learning, and enjoyment of science for students worldwide.

Flavonoids of Lotus (Nelumbo nucifera) Seed Embryos and Their Antioxidant Potential.

PubMed

Zhu, Mingzhi; Liu, Ting; Zhang, Chunyun; Guo, Mingquan

2017-08-01

Flavonoids from lotus (Nelumbo nucifera) seed embryos were fractionated over a macroporous resin chromatography into 2 main fractions (I and II), and subsequently identified by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS 2 ). Sixteen flavonoids were identified in lotus seed embryos, including 8 flavonoid C-glycosides and 8 flavonoid O-glycosides, in which the flavonoid C-glycosides were the main flavonoids. Among them, 2 flavonoid O-glycosides (luteolin 7-O-neohesperidoside and kaempferol 7-O-glucoside) were identified in lotus seed embryos for the 1st time. For further elucidating the effects of flavonoid C-glycosides to the bioactivities of lotus seed embryos, we compared the differences of the flavonoids and their antioxidant activities between leaves and seed embryos of lotus using the same methods. The results showed the antioxidant activity of flavonoids in lotus seed embryos was comparable or higher than that in lotus leaves, whereas the total flavonoid content in seed embryos was lower than lotus leaves which only contained flavonoid O-glycosides. The flavonoid C-glycosides of lotus seed embryos had higher antioxidant properties than the flavonoid O-glycosides presented in lotus leaves. This study suggested that the lotus seed embryos could be promising sources with antioxidant activity and used as dietary supplements for health promotion. © 2017 Institute of Food Technologists®.

Induced Contamination Predictions for JAXA's MPAC&SEED Devices

NASA Technical Reports Server (NTRS)

Steagall, Courtney; Smith, Kendall; Huang, Alvin; Soares, Carlos; Mikatarian, Ron

2008-01-01

Externally mounted ISS payloads are exposed to the induced ISS environment, including material outgassing and thruster plume contamination. The Boeing Space Environments Team developed analytical and semiempirical models to predict material outgassing and thruster plume induced contamination. JAXA s SM/MPAC&SEED experiment provides an unique opportunity to compare induced contamination predications with measurements. Analysis results are qualitatively consistent with XPS measurements. Calculated depth of contamination within a factor of 2-3 of measured contamination. Represents extremely good agreement, especially considering long duration of experiment and number of outgassing sources. Despite XPS limitations in quantifying plume contamination, the measured and predicted results are of similar scale for the wake-facing surfaces. JAXA s JEM/MPAC&SEED experiment will also be exposed to induced contamination due to JEM and ISS hardware. Predicted material outgassing induced contamination to JEM/MPAC&SEED ranges from 44 to 262 (depending on surface temperature) for a 3 year exposure duration.

Revising the Seed Zones for Southern Pines

Treesearch

Ronald C. Schmidtling

1999-01-01

Early foresters had a sense that using local seed sources was the best for afforestation, although this was often based more on intuition than experience. Non-local planting stock has often been used in-the past. In the reforestation carried out by the Civilian Conservation Corps in the 1930's, for instance, an effort was made to use native seed sources, but...

NDCX-II target experiments and simulations

DOE PAGES

Barnard, J. J.; More, R. M.; Terry, M.; ...

2013-06-13

The ion accelerator NDCX-II is undergoing commissioning at Lawrence Berkeley National Laboratory (LBNL). Its principal mission is to explore ion-driven High Energy Density Physics (HEDP) relevant to Inertial Fusion Energy (IFE) especially in the Warm Dense Matter (WDM) regime. We have carried out hydrodynamic simulations of beam-heated targets for parameters expected for the initial configuration of NDCX-II. For metal foils of order one micron thick (thin targets), the beam is predicted to heat the target in a timescale comparable to the hydrodynamic expansion time for experiments that infer material properties from measurements of the resulting rarefaction wave. We have alsomore » carried out hydrodynamic simulations of beam heating of metallic foam targets several tens of microns thick (thick targets) in which the ion range is shorter than the areal density of the material. In this case shock waves will form and we derive simple scaling laws for the efficiency of conversion of ion energy into kinetic energy of fluid flow. Geometries with a tamping layer may also be used to study the merging of a tamper shock with the end-of-range shock. As a result, this process can occur in tamped, direct drive IFE targets.« less

Conditions Database for the Belle II Experiment

NASA Astrophysics Data System (ADS)

Wood, L.; Elsethagen, T.; Schram, M.; Stephan, E.

2017-10-01

The Belle II experiment at KEK is preparing for first collisions in 2017. Processing the large amounts of data that will be produced will require conditions data to be readily available to systems worldwide in a fast and efficient manner that is straightforward for both the user and maintainer. The Belle II conditions database was designed with a straightforward goal: make it as easily maintainable as possible. To this end, HEP-specific software tools were avoided as much as possible and industry standard tools used instead. HTTP REST services were selected as the application interface, which provide a high-level interface to users through the use of standard libraries such as curl. The application interface itself is written in Java and runs in an embedded Payara-Micro Java EE application server. Scalability at the application interface is provided by use of Hazelcast, an open source In-Memory Data Grid (IMDG) providing distributed in-memory computing and supporting the creation and clustering of new application interface instances as demand increases. The IMDG provides fast and efficient access to conditions data via in-memory caching.

The Douglas-fir seed-source movement trial yields early results

Treesearch

Constance A. Harrington; Brad St. Clair

2017-01-01

Climate change in the 21st century is likely to dramatically alter the growing conditions that Pacific Northwest tree species experience. It has been suggested that foresters plan for these changes by moving seed sources to locations where the seed-source environment and the future climate will be similar. Some people have called this type of seed-source movement “...

Liquid xenon calorimeter for MEG II experiment with VUV-sensitive MPPCs

NASA Astrophysics Data System (ADS)

Ogawa, Shinji; MEG II Collaboration

2017-02-01

The MEG II experiment is an upgrade of the MEG experiment to search for the charged lepton flavor violating decay of muon, μ+ →e+ γ . The MEG II experiment is expected to reach a branching ratio sensitivity of 4 ×10-14 , which is one order of magnitude better than the sensitivity of the current MEG experiment. The performance of the liquid xenon (LXe) γ-ray detector will be greatly improved with a highly granular scintillation readout realized by replacing 216 photomultiplier tubes (PMTs) on the γ-ray entrance face with 4092 Multi-Pixel Photon Counters (MPPCs). For this purpose, we have developed a new type of MPPC which is sensitive to the LXe scintillation light in vacuum ultraviolet (VUV) range, in collaboration with Hamamatsu Photonics K.K. We have measured the performance of the MPPC in LXe, and an excellent performance has been confirmed including high photon detection efficiency (> 15 %) for LXe scintillation light. An excellent performance of the LXe detector has been confirmed by Monte Carlo simulations based on the measured properties of the MPPC. The construction of the detector is in progress, aiming to start physics data taking in 2017.

The Life-Long Mortality Risks Of World War II Experiences

PubMed Central

Elder, Glen H.; Brown, James Scott; Martin, Leslie R.; Friedman, Howard W.

2009-01-01

Objective This longitudinal study of American veterans investigated the mortality risks of five World War II military experiences (i.e., combat exposure) and their variation among veterans in the post-war years. Methods The male subjects (N=854) are members of the Stanford-Terman study, and 38 percent served in World War II. Cox models (proportional hazards regressions) compared the relative mortality risk associated with each military experience. Results Overseas duty, service in the Pacific and exposure to combat significantly increased the mortality risks of veterans in the study. Individual differences in education, mental health in 1950, and age at entry into the military, as well as personality factors made no difference in these results. Conclusions A gradient is observable such that active duty on the home front, followed by overseas duty, service in the Pacific, and combat exposure markedly increased the risk of relatively early mortality. Potential linking mechanisms include heavy drinking. PMID:20161074

Cone and seed traits of two Juniperus species influence roles of frugivores and scatter-hoarding rodents as seed dispersal agents

NASA Astrophysics Data System (ADS)

Dimitri, Lindsay A.; Longland, William S.; Vander Wall, Stephen B.

2017-11-01

Seed dispersal in Juniperus is generally attributed to frugivores that consume the berry-like female cones. Some juniper cones are fleshy and resinous such as those of western juniper (Juniperus occidentalis), while others are dry and leathery such as those of Utah juniper (J. osteosperma). Rodents have been recorded harvesting Juniperus seeds and cones but are mostly considered seed predators. Our study sought to determine if rodents play a role in dispersal of western and Utah juniper seeds. We documented rodent harvest of cones and seeds of the locally-occurring juniper species and the alternate (non-local) juniper species in removal experiments at a western juniper site in northeastern California and a Utah juniper site in western Nevada. Characteristics of western and Utah juniper cones appeared to influence removal, as cones from the local juniper species were preferred at both sites. Conversely, removal of local and non-local seeds was similar. Piñon mice (Peromyscus truei) were responsible for most removal of cones and seeds at both sites. We used radioactively labeled seeds to follow seed fate and found many of these seeds in scattered caches (western juniper: 415 seeds in 82 caches, 63.0% of seeds found; Utah juniper: 458 seeds in 127 caches, 39.5% of seeds found) most of which were attributed to piñon mice. We found little evidence of frugivores dispersing Utah juniper seeds, thus scatter-hoarding rodents appear to be the main dispersal agents. Western juniper cones were eaten by frugivores, and scatter-hoarding is a complimentary or secondary form of seed dispersal. Our results support the notion that Utah juniper has adapted to xeric environments by conserving water through the loss of fleshy fruits that attract frugivores and instead relies on scatter-hoarding rodents as effective dispersal agents.

An invasive slug exploits an ant-seed dispersal mutualism.

PubMed

Meadley Dunphy, Shannon A; Prior, Kirsten M; Frederickson, Megan E

2016-05-01

Plant-animal mutualisms, such as seed dispersal, are often vulnerable to disruption by invasive species. Here, we show for the first time how a non-ant invasive species negatively affects seed dispersal by ants. We examined the effects of several animal species that co-occur in a temperate deciduous forest-including native and invasive seed-dispersing ants (Aphaenogaster rudis and Myrmica rubra, respectively), an invasive slug (Arion subfuscus), and native rodents-on a native myrmecochorous plant, Asarum canadense. We experimentally manipulated ant, slug, and rodent access to seed depots and measured seed removal. We also video-recorded depots to determine which other taxa interact with seeds. We found that A. rudis was the main disperser of seeds and that A. subfuscus consumed elaiosomes without dispersing seeds. Rodent visitation was rare, and rodent exclusion had no significant effect on seed or elaiosome removal. We then used data obtained from laboratory and field mesocosm experiments to determine how elaiosome robbing by A. subfuscus affects seed dispersal by A. rudis and M. rubra. We found that elaiosome robbing by slugs reduced seed dispersal by ants, especially in mesocosms with A. rudis, which picks up seeds more slowly than M. rubra. Taken together, our results show that elaiosome robbing by an invasive slug reduces seed dispersal by ants, suggesting that invasive slugs can have profound negative effects on seed dispersal mutualisms.

Efficiency of seed production in southern pine seed orchards

Treesearch

David L. Bramlett

1977-01-01

Seed production in southern pine seed orchards can be evaluated by estimating the efficiency of four separate stages of cone, seed, and seedling development. Calculated values are: cone efficiency (CE), the ratio of mature cones to the initial flower crop; seed efficiency (SE), the ratio of filled seeds per cone to the seed potential; extraction efficiency (EE), the...

Potential effects of arboreal and terrestrial avian dispersers on seed dormancy, seed germination and seedling establishment in Ormosia (Papilionoideae) species in Peru

USGS Publications Warehouse

Foster, Mercedes S.

2008-01-01

The relative effectiveness of arboreal or terrestrial birds at dispersing seeds of Ormosia macrocalyx and O. bopiensis (Fabaceae: Papilionoideae) were studied in south-eastern Peru. Seeds of both species were either scarified, to represent seed condition after dispersal by terrestrial birds, or left intact, to represent seed condition after dispersal by arboreal birds. Seeds were distributed along forest transects, and germination, seedling development and mortality were monitored to determine the successes of the two groups at producing seedlings. Scarified seeds germinated with the early rains of the dry-to-wet-season transition, when erratic rainfall was interspersed with long dry spells. Intact seeds germinated 30 d later when the rain was more plentiful and regular. Intact seeds of O. macrocalyx gave rise to significantly more seedlings (41.1% vs. 25.5%) than did scarified seeds, in part, because significantly more seedlings from scarified seeds (n = 20) than from intact seeds (n = 3) died from desiccation when their radicles failed to enter the dry ground present during the dry-to-wet-season transition. Also, seedlings from scarified seeds were neither larger nor more robust than those from intact seeds despite their longer growing period. Results are consistent with the hypothesis that dispersal effectiveness of arboreal birds, at least for O. macrocalyx, is greater than that of terrestrial birds. Screen-house experiments in which seedlings developed under different watering regimes supported this result. Numbers of seedlings developing from intact and scarified seeds of O. bopiensis did not differ significantly.

A role for seed storage proteins in Arabidopsis seed longevity

PubMed Central

Nguyen, Thu-Phuong; Cueff, Gwendal; Hegedus, Dwayne D; Rajjou, Loïc; Bentsink, Leónie

2015-01-01

Proteomics approaches have been a useful tool for determining the biological roles and functions of individual proteins and identifying the molecular mechanisms that govern seed germination, vigour and viability in response to ageing. In this work the dry seed proteome of four Arabidopsis thaliana genotypes, that carry introgression fragments at the position of seed longevity quantitative trait loci and as a result display different levels of seed longevity, was investigated. Seeds at two physiological states, after-ripened seeds that had the full germination ability and aged (stored) seeds of which the germination ability was severely reduced, were compared. Aged dry seed proteomes were markedly different from the after-ripened and reflected the seed longevity level of the four genotypes, despite the fact that dry seeds are metabolically quiescent. Results confirmed the role of antioxidant systems, notably vitamin E, and indicated that protection and maintenance of the translation machinery and energy pathways are essential for seed longevity. Moreover, a new role for seed storage proteins (SSPs) was identified in dry seeds during ageing. Cruciferins (CRUs) are the most abundant SSPs in Arabidopsis and seeds of a triple mutant for three CRU isoforms (crua crub cruc) were more sensitive to artificial ageing and their seed proteins were highly oxidized compared with wild-type seeds. These results confirm that oxidation is involved in seed deterioration and that SSPs buffer the seed from oxidative stress, thus protecting important proteins required for seed germination and seedling formation. PMID:26184996

Does solar radiation affect the growth of tomato seeds relative to their environment?

NASA Technical Reports Server (NTRS)

Holzer, Kristi

1995-01-01

The purpose of this experiment is to sequentially study and analyze the data collected from the germination and growth of irradiated Rutgers Supreme tomato seeds to adult producing plants. This experiment will not use irradiated seeds as a control as I plan to note growth in artificial verses natural environment as the basic experiment.

Seed size variability: from carob to carats

PubMed Central

Turnbull, Lindsay A; Santamaria, Luis; Martorell, Toni; Rallo, Joan; Hector, Andy

2006-01-01

The seeds of various plants were used as weights because their mass reputedly varies so little. Carob (Ceratonia siliqua), which has given its name to the carat, is particularly famous in this regard. But are carob seeds unusually constant in weight and, if not, how did the myth arise? The variability of seeds sampled from a collection of carob trees (CV=23%) was close to the average of 63 species reviewed from the literature (CV=25%). However, in a perception experiment observers could discriminate differences in carob seed weight of around 5% by eye demonstrating the potential for humans to greatly reduce natural variation. Interestingly, the variability of pre-metrication carat weight standards is also around 5% suggesting that human rather than natural selection gave rise to the carob myth. PMID:17148413

Metabolic Profiling of a Mapping Population Exposes New Insights in the Regulation of Seed Metabolism and Seed, Fruit, and Plant Relations

PubMed Central

Toubiana, David; Semel, Yaniv; Tohge, Takayuki; Beleggia, Romina; Cattivelli, Luigi; Rosental, Leah; Nikoloski, Zoran; Zamir, Dani; Fernie, Alisdair R.; Fait, Aaron

2012-01-01

To investigate the regulation of seed metabolism and to estimate the degree of metabolic natural variability, metabolite profiling and network analysis were applied to a collection of 76 different homozygous tomato introgression lines (ILs) grown in the field in two consecutive harvest seasons. Factorial ANOVA confirmed the presence of 30 metabolite quantitative trait loci (mQTL). Amino acid contents displayed a high degree of variability across the population, with similar patterns across the two seasons, while sugars exhibited significant seasonal fluctuations. Upon integration of data for tomato pericarp metabolite profiling, factorial ANOVA identified the main factor for metabolic polymorphism to be the genotypic background rather than the environment or the tissue. Analysis of the coefficient of variance indicated greater phenotypic plasticity in the ILs than in the M82 tomato cultivar. Broad-sense estimate of heritability suggested that the mode of inheritance of metabolite traits in the seed differed from that in the fruit. Correlation-based metabolic network analysis comparing metabolite data for the seed with that for the pericarp showed that the seed network displayed tighter interdependence of metabolic processes than the fruit. Amino acids in the seed metabolic network were shown to play a central hub-like role in the topology of the network, maintaining high interactions with other metabolite categories, i.e., sugars and organic acids. Network analysis identified six exceptionally highly co-regulated amino acids, Gly, Ser, Thr, Ile, Val, and Pro. The strong interdependence of this group was confirmed by the mQTL mapping. Taken together these results (i) reflect the extensive redundancy of the regulation underlying seed metabolism, (ii) demonstrate the tight co-ordination of seed metabolism with respect to fruit metabolism, and (iii) emphasize the centrality of the amino acid module in the seed metabolic network. Finally, the study highlights the added

Seed dormancy and persistent sediment seed banks of ephemeral freshwater rock pools in the Australian monsoon tropics

PubMed Central

Cross, Adam T.; Turner, Shane R.; Renton, Michael; Baskin, Jerry M.; Dixon, Kingsley W.; Merritt, David J.

2015-01-01

Background and Aims Rock pools are small, geologically stable freshwater ecosystems that are both hydrologically and biologically isolated. They harbour high levels of plant endemism and experience environmental unpredictability driven by the presence of water over variable temporal scales. This study examined the hypothesis that the sediment seed bank in monsoon tropical freshwater rock pools would persist through one or more periods of desiccation, with seed dormancy regulating germination timing in response to rock pool inundation and drying events. Methods Seeds were collected from seven dominant rock pool species, and germination biology and seed dormancy were assessed under laboratory conditions in response to light, temperature and germination stimulators (gibberellic acid, karrikinolide and ethylene). Field surveys of seedling emergence from freshwater rock pools in the Kimberley region of Western Australia were undertaken, and sediment samples were collected from 41 vegetated rock pools. Seedling emergence and seed bank persistence in response to multiple wetting and drying cycles were determined. Key Results The sediment seed bank of individual rock pools was large (13 824 ± 307 to 218 320 ± 42 412 seeds m−2 for the five species investigated) and spatially variable. Seedling density for these same species in the field ranged from 13 696 to 87 232 seedlings m−2. Seeds of rock pool taxa were physiologically dormant, with germination promoted by after-ripening and exposure to ethylene or karrikinolide. Patterns of seedling emergence varied between species and were finely tuned to seasonal temperature and moisture conditions, with the proportions of emergent seedlings differing between species through multiple inundation events. A viable seed bank persisted after ten consecutive laboratory inundation events, and seeds retained viability in dry sediments for at least 3 years. Conclusions The persistent seed bank in freshwater rock pools is likely to

Seed Experiments for Students. Tips & Demonstrations for Teachers & Parents.

ERIC Educational Resources Information Center

Tant, Carl

This book provides a short course in the mysteries of seed structure, function, and development. Chapter 1, "Backgrounds, Hints, And Tips For Teachers And Parents," provides a basis for working with the mid-years student. Chapater 2, "Where Do I Start? What Do I Do?" provides procedural tips for science research. Chapter 3,…

Ecophysiological variables influencing Aleppo pine seed and cone production: a review.

PubMed

Ayari, Abdelaziz; Khouja, Mohamed Larbi

2014-04-01

The most interesting factors associated with seed and cone production of Aleppo pine were largely reviewed to identify broad patterns and potential effectiveness of reforestation efforts and planning. Aleppo pine cone production and seed yields are relatively variable, with differences between spatial and temporal influences. These differences are considered, mainly between (i) year, (ii) stand characteristics and (iii) individual tree measurements. Annual variability among populations was recorded for cone production per tree, based on influencing factors such as genetic characteristics, wetness, nutrient availability, insect pests and disease. In addition, some factors may affect Aleppo pine tree growth directly but may be affecting seed and cone production indirectly. Therefore, reduced stand density results in less competition among Aleppo pine trees and accompanying understory flora, which subsequently increases the stem diameter and other tree dimensions, including seed production. This review suggests that reforestation planning, particularly thinning, will result in improved tree morphology that will increase Aleppo pine seed and cone crops. Wildfire intensity and stand conditions such as light and soil nutrient status are also examined.

Ammonia Volatilization from Urea-Application Influenced Germination and Early Seedling Growth of Dry Direct-Seeded Rice

PubMed Central

Qi, Xiaoli; Wu, Wei; Shah, Farooq; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Liu, Hongyan; Nie, Lixiao

2012-01-01

Poor seed germination and early seedling growth associated with urea-induced soil ammonia volatilization are major constraints in the adoption of dry direct-seeded rice. To directly examine soil ammonia volatilization and its damage to seed germination and early seedling growth of dry direct-seeded rice when urea is applied at seeding, two Petri-dish incubation experiments and a field experiment were conducted. Ammonia volatilization due to urea application significantly reduced seed germination and early seedling growth of dry direct-seedling rice. NBPT significantly reduced ammonia volatilization following urea application. The application of ammonium sulfate, instead of urea at seeding, may mitigate poor crop establishment of dry direct-seeded rice. Root growth of dry direct-seeded rice was more seriously inhibited by soil ammonia volatilization than that of shoot. Results suggest that roots are more sensitive to soil ammonia toxicity than shoots in dry direct-seeded rice system when N is applied as urea at seeding. PMID:22454611

Efficacy of Selected Insecticides Applied to Hybrid Rice Seed

PubMed Central

Adams, A.; Gore, J.; Musser, F.; Cook, D.; Walker, T.; Dobbins, C.

2016-01-01

Hybrid rice and insecticide seed treatments targeting rice water weevil, Lissorhoptrus oryzophilus Kuschel, have altered the landscape of rice production. The effect of reduced seeding rates on seed treatment efficacy in hybrid rice has not been studied. During 2011 and 2012, an experiment was conducted at seven locations to determine the relationship between low seeding rates used in hybrid rice and efficacy of selected insecticidal seed treatments as measured by rice water weevil densities and yield. Labeled rates of thiamethoxam, chlorantraniliprole, and clothianidin were compared with higher rates of these products to determine if labeled rates provide an acceptable level of control of the rice water weevil. Study locations were divided into low, moderate, and high groups based on rice water weevil larval densities. All seed treatments and seed treatment rates reduced rice water weevil densities. However, there was no observed yield or economic benefit from the use of an insecticidal seed treatment in areas of low pressure. Differences in yield were observed among seed treatments and seed treatment rates in moderate and high pressure locations, and all seed treatments yielded better than the untreated plots, but these differences were not always economical. All seed treatments showed an economic advantage in areas of high weevil pressure, and there were no differences among seed treatment products or rates, suggesting that currently labeled seed treatment rates in hybrid rice are effective for rice water weevil management. PMID:26537671

Research on tomato seed vigor based on X-ray digital image

NASA Astrophysics Data System (ADS)

Zhao, Xueguan; Gao, Yuanyuan; Wang, Xiu; Li, Cuiling; Wang, Songlin; Feng, Qinghun

2016-10-01

Seed size, interior abnormal and damage of the tomato seeds will affect the germination. The purpose of this paper was to study the relationship between the internal morphology, seed size and seed germination of tomato. The preprocessing algorithm of X-ray image of tomato seeds was studied, and the internal structure characteristics of tomato seeds were extracted by image processing algorithm. By developing the image processing software, the cavity area between embryo and endosperm and the whole seed zone were determined. According to the difference of area of embryo and endosperm and Internal structural condition, seeds were divided into six categories, Respectively for three kinds of tomato seed germination test, the relationship between seed vigor and seed size , internal free cavity was explored through germination experiment. Through seedling evaluation test found that X-ray image analysis provide a perfect view of the inside part of the seed and seed morphology research methods. The larger the area of the endosperm and the embryo, the greater the probability of healthy seedlings sprout from the same size seeds. Mechanical damage adversely effects on seed germination, deterioration of tissue prone to produce week seedlings and abnormal seedlings.

[Reason for dormancy of Cuscuta chinensis seed and solving method].

PubMed

Wang, Xuemin; He, Jiaqing; Cai, Jing; Dong, Zhenguo

2010-02-01

To study the reason for the deep dormancy of the aged Cuscuta chinensis seed and find the solving method. The separated and combined treatments were applied in the orthogonal designed experiments. The aged seed had well water-absorbency; the water and ethanol extracts of the seeds showed an inhibition effect on germination capacity of the seeds. The main reason for the deep dormancy of aged C. chinensis seed is the inhibitors existed in seed. There are two methods to solve the problem. The seeds is immersed in 98% of H2SO4 for 2 min followed by 500 mg x L(-1) of GA3 treatment for 60 min, or in 100 mg x L(-1) of NaOH for 20 min followed by 500 mg x L(-1) of GA3 treatment for 120 min.

Seed Nutrition and Quality, Seed Coat Boron and Lignin Are Influenced by Delayed Harvest in Exotically-Derived Soybean Breeding Lines under High Heat.

PubMed

Bellaloui, Nacer; Smith, James R; Mengistu, Alemu

2017-01-01

The timing of harvest is a major factor affecting seed quality in soybean, particularly in Midsouthern USA, when rain during harvest period is not uncommon. The objective of this research was to evaluate the effects of time of harvest on soybean seed quality (seed composition, germination, seed coat boron, and lignin) in high germinability (HG) breeding lines (50% exotic) developed under high heat. The hypothesis was that seeds of HG lines possess physiological and genetic traits for a better seed quality at harvest maturity and delayed harvest. A 2-year field experiment was conducted under irrigated conditions. Results showed that, at harvest maturity, the exotic HG lines had higher seed protein, oleic acid, sugars, seed coat boron, and seed coat lignin, but lower seed oil compared with the non-exotic checks (Control), confirming our hypothesis. At 28 days after harvest maturity (delayed harvest), the content of seed protein, oleic acid, sugars, seed coat boron, and seed coat lignin were higher in some of the HG lines compared with the checks, indicating a possible involvement of these seed constituents, especially seed coat boron and seed coat lignin, in maintaining seed coat integrity and protecting seed coat against physical damage. Highly significant positive correlations were found between germination and seed protein, oleic acid, sugars, and seed coat boron and seed coat lignin. Highly significant negative correlation was found between germination and oil, linoleic acid, seed coat wrinkling, shattering, and hard seed. Yields of some HG lines were competitive with checks. This research demonstrated that time of harvesting is an important factor influencing seed protein and oil production. Also, since high oleic acid is desirable for oxidative stability, shelf-life and biodiesel properties, using HG lines could positively influence these important traits. This result should suggest to breeders of some of the advantages of selecting for high seed coat boron and

Pre-dispersal predation effect on seed packaging strategies and seed viability.

PubMed

DeSoto, Lucía; Tutor, David; Torices, Rubén; Rodríguez-Echeverría, Susana; Nabais, Cristina

2016-01-01

An increased understanding of intraspecific seed packaging (i.e. seed size/number strategy) variation across different environments may improve current knowledge of the ecological forces that drive seed evolution in plants. In particular, pre-dispersal seed predation may influence seed packaging strategies, triggering a reduction of the resources allocated to undamaged seeds within the preyed fruits. Assessing plant reactions to pre-dispersal seed predation is crucial to a better understanding of predation effects, but the response of plants to arthropod attacks remains unexplored. We have assessed the effect of cone predation on the size and viability of undamaged seeds in populations of Juniperus thurifera with contrasting seed packaging strategies, namely, North African populations with single-large-seeded cones and South European populations with multi-small-seeded cones. Our results show that the incidence of predation was lower on the single-large-seeded African cones than on the multi-small-seeded European ones. Seeds from non-preyed cones were also larger and had a higher germination success than uneaten seeds from preyed cones, but only in populations with multi-seeded cones and in cones attacked by Trisetacus sp., suggesting a differential plastic response to predation. It is possible that pre-dispersal seed predation has been a strong selective pressure in European populations with high cone predation rates, being a process which maintains multi-small-seeded cones and empty seeds as a strategy to save some seeds from predation. Conversely, pre-dispersal predation might not have a strong effect in the African populations with single-large-seeded cones characterized by seed germination and filling rates higher than those in the European populations. Our results indicate that differences in pre-dispersal seed predators and predation levels may affect both selection on and intraspecific variation in seed packaging.

Latest experiences and future plans on NSLS-II insertion devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanabe, T.; Hidaka, Y.; Kitegi, C.

National Synchrotron Light Source-II (NSLS-II) is the latest storage ring of 3 GeV energy at the Brookhaven National Laboratory (BNL). The horizontal emittance of the electron beam with the currently installed six damping wigglers is 0.9 nm.rad, which could be further reduced to 0.5 nm.rad with more insertion devices (IDs). With only one RF cavity the beam current is restricted to 200 mA. Five hundred mA operation is envisaged for next year with an addition of the second cavity. Six (plus two branches) beamlines have been commissioned in the initial phase of the project. In July 2015, three NIH fundedmore » beamlines called “Advanced Beamlines for Biological Investigations with X-rays” (ABBIX) will be added for operation. This paper describes the experiences of ID development, installation, and commissioning for the NSLS-II project as well as our future plans to improve the performance of the facility in terms of source development.« less

Tillage and residue burning affects weed populations and seed banks.

PubMed

Narwal, S; Sindel, B M; Jessop, R S

2006-01-01

An integrated weed management approach requires alternative management practices to herbicide use such as tillage, crop rotations and cultural controls to reduce soil weed seed banks. The objective of this study was to examine the value of different tillage practices and stubble burning to exhaust the seed bank of common weeds from the northern grain region of Australia. Five tillage and burning treatments were incorporated in a field experiment, at Armidale (30 degrees 30'S, 151 degrees 40'E), New South Wales, Australia in July 2004 in a randomized block design replicated four times. The trial was continued and treatments repeated in July 2005 with all the mature plants from the first year being allowed to shed seed in their respective treatment plots. The treatments were (i) no tillage (NT), (ii) chisel ploughing (CP), (iii) mould board ploughing (MBP), (iv) wheat straw burning with no tillage (SBNT) and (v) wheat straw burning with chisel ploughing (SBC). Soil samples were collected before applying treatments and before the weeds flowered to establish the seed bank status of the various weeds in the soil. Wheat was sown after the tillage treatments. Burning treatments were only initiated in the second year, one month prior to tillage treatments. The major weeds present in the seed bank before initiating the trial were Polygonum aviculare, Sonchus oleraceus and Avena fatua. Tillage promoted the germination of other weeds like Hibiscus trionum, Medicago sativa, Vicia sp. and Phalaris paradoxa later in the season in 2004 and Convolvulus erubescens emerged as a new weed in 2005. The MBP treatment in 2004 reduced the weed biomass to a significantly lower level of 55 g/m2 than the other treatments of CP (118 g/m2) and NT plots (196 g/m2) (P < 0.05). However, in 2005 SBC and MBP treatments were similar in reducing the weed biomass. In 2004, the grain yield trend of wheat was significantly different between CP and NT, and MBP and NT (P < 0.05) with maximum yield of 5898

[Viability and germination of Hechtia perotensis (Bromeliaceae) seed].

PubMed

Elizalde, Violeta; García, José Rodolfo; Peña-Valdivia, Cecilia Beatriz; Ybarra, Ma Carmen; Leyva, Otto Raúl; Trejo, Carlos

2017-03-01

Endemic populations of Hechtia perotensis have been described in Puebla and Veracruz, Mexico. Good quality seed collections can be used in conservation, research and ecological restoration. To evaluate seed quality of wild and endemic species, some compounds are used as effective promoters of germination, such as potassium nitrate (KNO3) and gibberellic acid (AG3), because they increase seed germination capacity and reduce latency. The triphenyl tetrazolium chloride (tetrazolium) test correlates seed viability because it is based on the activity of dehydrogenases in live tissues that catalyze mitochondrial respiration. The objective of this study was to obtain information on size and weight of capsules and seeds and seed germination and viability of H. perotensis, collected in Veracruz in the year 2012 and 2015. The hypotheses were 1) that seed germination and viability are independent of the year of collection, 2) that there is a tetrazolium concentration that can identify seed viability better than others, and 3) that pretreatment with KNO3 or AG3 improves seed germination. Seed germination was assessed using a completely randomized design with three treatments (control and the germination promoters 0.2 % KNO3 and 500 mg/L AG3), four treatments for the viability test (control, 0.2, 0.5 and 1.0 % of tetrazolium) and six replicates for each treatment. A total of one hundred seeds for germination experiments, and 25 seeds for the viability test were used. The results between and within years were analyzed with ANOVA and multiple comparison with the Tukey test. The proportion of non-germinated seeds was quantified along with the number of normal and abnormal seedlings, seeds with viable embryo, seeds without embryo, and seeds with low or no viability. On average, for the 2012 collected sample, 36 % had viable embryos, 7 % had low viability, 24 % were not viable and 33 % had no embryo. This result was significantly different from the 2015 sample, for which 87 % of

Seed dispersal and seed fate in Joshua tree (Yucca brevifolia)

USGS Publications Warehouse

Waitman, B.A.; Vander Wall, S.B.; Esque, Todd

2012-01-01

Joshua tree (Yucca brevifolia) is a charismatic symbol of the Mojave Desert. Despite its familiarity, we know little about the reproduction of this species, including mechanisms of seed dispersal. Here we examine mechanisms of seed dispersal and resulting seed fate. We experimentally tracked fruit and seed removal and followed the fates of Joshua tree seeds using radioactive tracers. The majority of Joshua tree fruits monitored were taken directly from the tree canopy by white-tailed antelope squirrels, and seeds and fruits on the soil surface were quickly removed by animals. Rodents given seeds labeled with scandium-46 cached them between 0.1 cm and 4.1 cm deep. Seedling emergence was most common for seeds planted 1 cm deep, whereas seeds placed on the soil surface seldom germinated. Wind dispersal is unlikely because fruits and seeds lack adaptations for wind dispersal; wind speeds required to move Joshua tree seeds and fruits across the soil surface were higher than those typically found in the Mojave Desert. Further, rodents removed most seeds before abiotic burial was possible. We conclude that most Joshua tree seeds are dispersed by scatter hoarding by rodents, and that caches made by rodents are suitable sites for seedling emergence.

MADS goes genomic in conifers: towards determining the ancestral set of MADS-box genes in seed plants.

PubMed

Gramzow, Lydia; Weilandt, Lisa; Theißen, Günter

2014-11-01

MADS-box genes comprise a gene family coding for transcription factors. This gene family expanded greatly during land plant evolution such that the number of MADS-box genes ranges from one or two in green algae to around 100 in angiosperms. Given the crucial functions of MADS-box genes for nearly all aspects of plant development, the expansion of this gene family probably contributed to the increasing complexity of plants. However, the expansion of MADS-box genes during one important step of land plant evolution, namely the origin of seed plants, remains poorly understood due to the previous lack of whole-genome data for gymnosperms. The newly available genome sequences of Picea abies, Picea glauca and Pinus taeda were used to identify the complete set of MADS-box genes in these conifers. In addition, MADS-box genes were identified in the growing number of transcriptomes available for gymnosperms. With these datasets, phylogenies were constructed to determine the ancestral set of MADS-box genes of seed plants and to infer the ancestral functions of these genes. Type I MADS-box genes are under-represented in gymnosperms and only a minimum of two Type I MADS-box genes have been present in the most recent common ancestor (MRCA) of seed plants. In contrast, a large number of Type II MADS-box genes were found in gymnosperms. The MRCA of extant seed plants probably possessed at least 11-14 Type II MADS-box genes. In gymnosperms two duplications of Type II MADS-box genes were found, such that the MRCA of extant gymnosperms had at least 14-16 Type II MADS-box genes. The implied ancestral set of MADS-box genes for seed plants shows simplicity for Type I MADS-box genes and remarkable complexity for Type II MADS-box genes in terms of phylogeny and putative functions. The analysis of transcriptome data reveals that gymnosperm MADS-box genes are expressed in a great variety of tissues, indicating diverse roles of MADS-box genes for the development of gymnosperms. This study is

MADS goes genomic in conifers: towards determining the ancestral set of MADS-box genes in seed plants

PubMed Central

Gramzow, Lydia; Weilandt, Lisa; Theißen, Günter

2014-01-01

Background and Aims MADS-box genes comprise a gene family coding for transcription factors. This gene family expanded greatly during land plant evolution such that the number of MADS-box genes ranges from one or two in green algae to around 100 in angiosperms. Given the crucial functions of MADS-box genes for nearly all aspects of plant development, the expansion of this gene family probably contributed to the increasing complexity of plants. However, the expansion of MADS-box genes during one important step of land plant evolution, namely the origin of seed plants, remains poorly understood due to the previous lack of whole-genome data for gymnosperms. Methods The newly available genome sequences of Picea abies, Picea glauca and Pinus taeda were used to identify the complete set of MADS-box genes in these conifers. In addition, MADS-box genes were identified in the growing number of transcriptomes available for gymnosperms. With these datasets, phylogenies were constructed to determine the ancestral set of MADS-box genes of seed plants and to infer the ancestral functions of these genes. Key Results Type I MADS-box genes are under-represented in gymnosperms and only a minimum of two Type I MADS-box genes have been present in the most recent common ancestor (MRCA) of seed plants. In contrast, a large number of Type II MADS-box genes were found in gymnosperms. The MRCA of extant seed plants probably possessed at least 11–14 Type II MADS-box genes. In gymnosperms two duplications of Type II MADS-box genes were found, such that the MRCA of extant gymnosperms had at least 14–16 Type II MADS-box genes. Conclusions The implied ancestral set of MADS-box genes for seed plants shows simplicity for Type I MADS-box genes and remarkable complexity for Type II MADS-box genes in terms of phylogeny and putative functions. The analysis of transcriptome data reveals that gymnosperm MADS-box genes are expressed in a great variety of tissues, indicating diverse roles of MADS

Spatio-temporal variation in a seed bank of a semi-arid region in northeastern Brazil

NASA Astrophysics Data System (ADS)

da Silva, Kleber A.; dos Santos, Danielle M.; dos Santos, Josiene M. F. F.; de Albuquerque, Ulysses P.; Ferraz, Elba M. N.; Araújo, Elcida de L.

2013-01-01

This study aimed to evaluate variations in the seed bank within a 3-year temporal series in order to answer the following questions: 1) Does the seed bank's species richness and seed density differ among climatic seasons and between years? 2) Are there differences in the richness and density of seed banks between the litter and mineral soil? 3) Can the seed bank's species richness and seed density be explained by characteristics such as the previous year's precipitation and soil depth (litter or mineral soil)? The samples were collected from litter and mineral soil (0-5 cm), in 210 sub-plots, during the dry and rainy seasons of each year (August 2005 through February 2008). Overall, 79 species were recorded. On average, 1 168, 304 and 302 seeds.m-2 were recorded in the seed bank during years I, II and III, respectively. This study showed that the Caatinga's seed bank is rich in herbaceous species, yet species' density and richness are low in the litter. Furthermore, about 43% of the variation in species richness and density was explained by soil depth (litter and mineral soil) and previous years' rainfall.

Seed dormancy and persistent sediment seed banks of ephemeral freshwater rock pools in the Australian monsoon tropics.

PubMed

Cross, Adam T; Turner, Shane R; Renton, Michael; Baskin, Jerry M; Dixon, Kingsley W; Merritt, David J

2015-04-01

Rock pools are small, geologically stable freshwater ecosystems that are both hydrologically and biologically isolated. They harbour high levels of plant endemism and experience environmental unpredictability driven by the presence of water over variable temporal scales. This study examined the hypothesis that the sediment seed bank in monsoon tropical freshwater rock pools would persist through one or more periods of desiccation, with seed dormancy regulating germination timing in response to rock pool inundation and drying events. Seeds were collected from seven dominant rock pool species, and germination biology and seed dormancy were assessed under laboratory conditions in response to light, temperature and germination stimulators (gibberellic acid, karrikinolide and ethylene). Field surveys of seedling emergence from freshwater rock pools in the Kimberley region of Western Australia were undertaken, and sediment samples were collected from 41 vegetated rock pools. Seedling emergence and seed bank persistence in response to multiple wetting and drying cycles were determined. The sediment seed bank of individual rock pools was large (13 824 ± 307 to 218 320 ± 42 412 seeds m(-2) for the five species investigated) and spatially variable. Seedling density for these same species in the field ranged from 13 696 to 87 232 seedlings m(-2). Seeds of rock pool taxa were physiologically dormant, with germination promoted by after-ripening and exposure to ethylene or karrikinolide. Patterns of seedling emergence varied between species and were finely tuned to seasonal temperature and moisture conditions, with the proportions of emergent seedlings differing between species through multiple inundation events. A viable seed bank persisted after ten consecutive laboratory inundation events, and seeds retained viability in dry sediments for at least 3 years. The persistent seed bank in freshwater rock pools is likely to provide resilience to plant

Effect of weed management and seed rate on crop growth under direct dry seeded rice systems in Bangladesh.

PubMed

Ahmed, Sharif; Salim, Muhammad; Chauhan, Bhagirath S

2014-01-01

Weeds are a major constraint to the success of dry-seeded rice (DSR). The main means of managing these in a DSR system is through chemical weed control using herbicides. However, the use of herbicides alone may not be sustainable in the long term. Approaches that aim for high crop competitiveness therefore need to be exploited. One such approach is the use of high rice seeding rates. Experiments were conducted in the aman (wet) seasons of 2012 and 2013 in Bangladesh to evaluate the effect of weed infestation level (partially-weedy and weed-free) and rice seeding rate (20, 40, 60, 80, and 100 kg ha(-1)) on weed and crop growth in DSR. Under weed-free conditions, higher crop yields (5.1 and 5.2 t ha(-1) in the 2012 and 2013 seasons, respectively) were obtained at the seeding rate of 40 kg ha(-1) and thereafter, yield decreased slightly beyond 40 kg seed ha(-1). Under partially-weedy conditions, yield increased by 30 to 33% (2.0-2.2 and 2.9-3.2 t ha(-1) in the 2012 and 2013 seasons, respectively) with increase in seeding rate from 20 to 100 kg ha(-1). In the partially-weedy plots, weed biomass decreased by 41-60% and 54-56% at 35 days after sowing and at crop anthesis, respectively, when seeding rate increased from 20 to 100 kg ha(-1). Results from our study suggest that increasing seeding rates in DSR can suppress weed growth and reduce grain yield losses from weed competition.

Effect of Weed Management and Seed Rate on Crop Growth under Direct Dry Seeded Rice Systems in Bangladesh

PubMed Central

Ahmed, Sharif; Salim, Muhammad; Chauhan, Bhagirath S.

2014-01-01

Weeds are a major constraint to the success of dry-seeded rice (DSR). The main means of managing these in a DSR system is through chemical weed control using herbicides. However, the use of herbicides alone may not be sustainable in the long term. Approaches that aim for high crop competitiveness therefore need to be exploited. One such approach is the use of high rice seeding rates. Experiments were conducted in the aman (wet) seasons of 2012 and 2013 in Bangladesh to evaluate the effect of weed infestation level (partially-weedy and weed-free) and rice seeding rate (20, 40, 60, 80, and 100 kg ha−1) on weed and crop growth in DSR. Under weed-free conditions, higher crop yields (5.1 and 5.2 t ha−1 in the 2012 and 2013 seasons, respectively) were obtained at the seeding rate of 40 kg ha−1 and thereafter, yield decreased slightly beyond 40 kg seed ha−1. Under partially-weedy conditions, yield increased by 30 to 33% (2.0–2.2 and 2.9–3.2 t ha−1 in the 2012 and 2013 seasons, respectively) with increase in seeding rate from 20 to 100 kg ha−1. In the partially-weedy plots, weed biomass decreased by 41–60% and 54–56% at 35 days after sowing and at crop anthesis, respectively, when seeding rate increased from 20 to 100 kg ha−1. Results from our study suggest that increasing seeding rates in DSR can suppress weed growth and reduce grain yield losses from weed competition. PMID:25000520

Controlled cell-seeding methodologies: a first step toward clinically relevant bone tissue engineering strategies.

PubMed

Impens, Saartje; Chen, Yantian; Mullens, Steven; Luyten, Frank; Schrooten, Jan

2010-12-01

The repair of large and complex bone defects could be helped by a cell-based bone tissue engineering strategy. A reliable and consistent cell-seeding methodology is a mandatory step in bringing bone tissue engineering into the clinic. However, optimization of the cell-seeding step is only relevant when it can be reliably evaluated. The cell seeding efficiency (CSE) plays a fundamental role herein. Results showed that cell lysis and the definition used to determine the CSE played a key role in quantifying the CSE. The definition of CSE should therefore be consistent and unambiguous. The study of the influence of five drop-seeding-related parameters within the studied test conditions showed that (i) the cell density and (ii) the seeding vessel did not significantly affect the CSE, whereas (iii) the volume of seeding medium-to-free scaffold volume ratio (MFR), (iv) the seeding time, and (v) the scaffold morphology did. Prolonging the incubation time increased the CSE up to a plateau value at 4 h. Increasing the MFR or permeability by changing the morphology of the scaffolds significantly reduced the CSE. These results confirm that cell seeding optimization is needed and that an evidence-based selection of the seeding conditions is favored.

Chemical Remediation of Nickel(II) Waste: A Laboratory Experiment for General Chemistry Students

ERIC Educational Resources Information Center

Corcoran, K. Blake; Rood, Brian E.; Trogden, Bridget G.

2011-01-01

This project involved developing a method to remediate large quantities of aqueous waste from a general chemistry laboratory experiment. Aqueous Ni(II) waste from a general chemistry laboratory experiment was converted into solid nickel hydroxide hydrate with a substantial decrease in waste volume. The remediation method was developed for a…

Seed-feeding insects impacting globemallow seed production

Treesearch

Robert Hammon; Melissa Franklin

2012-01-01

Weevils (Anthonomus sphaeralciae Fall [Coleoptera: Curculionidae]), which attack flowers and developing seeds, can significantly impact globemallow Sphaeralcea spp. A. St.-Hil. (Malvaceae) seed production without a grower even noticing there was insect damage. This weevil damaged almost one-quarter of the flowers in a seed production field in Delta County, Colorado,...

Direct seeding for forestation

Treesearch

Walter H. Davidson

1980-01-01

Direct seeding, an attractive alternative to planting, is not a simple method of forestation. Past experiences show far more failures than successes. Well documented procedures must be followed to insure any degree of success. In general, conifers have given the best results. Black walnut and black locust are notable exceptions. Current research suggests that other...

Benefits of rice seed priming are offset permanently by prolonged storage and the storage conditions

PubMed Central

Hussain, Saddam; Zheng, Manman; Khan, Fahad; Khaliq, Abdul; Fahad, Shah; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Nie, Lixiao

2015-01-01

Seed priming is a commercially successful practice, but reduced longevity of primed seeds during storage may limit its application. We established a series of experiments on rice to test: (1) whether prolonged storage of primed and non-primed rice seeds for 210 days at 25°C or −4°C would alter their viability, (2) how long primed rice seed would potentially remain viable at 25°C storage, and (3) whether or not post-storage treatments (re-priming or heating) would reinstate the viability of stored primed seeds. Two different rice cultivars and three priming agents were used in all experiments. Prolonged storage of primed seeds at 25°C significantly reduced the germination (>90%) and growth attributes (>80%) of rice compared with un-stored primed seeds. However, such negative effects were not observed in primed seeds stored at −4°C. Beneficial effects of seed priming were maintained only for 15 days of storage at 25°C, beyond which the performance of primed seeds was worse even than non-primed seeds. The deteriorative effects of 25°C storage were related with hampered starch metabolism in primed rice seeds. None of the post-storage treatments could reinstate the lost viability of primed seeds suggesting that seeds become unviable by prolonged post-priming storage at 25°C. PMID:25631923

Allelopathic potential of leaf and seed of Mucuna bracteata DC. ex Kurz on Eleusine indica (L.) gaertn

NASA Astrophysics Data System (ADS)

Halimshah, Syamimi; Ismail B., S.; Ahmad, Wan Juliana Wan

2015-09-01

A study was conducted to determine the allelopathic potential of leaf and seed of Mucuna bracteata on the growth of E. indica through aqueous extract and debris (incorporated into the soil) experiment. Three concentrations of leaf and seed aqueous extract (16.7, 33.3 and 66.7 g/L) and debris (2.5, 5.0 and 10.0 g/500 g soil) of M. bracteata were used in the experiment. Complete randomized design (CRD) with three replications was applied in this experiment which was conducted twice. Results demonstrated that the leaf and seed extracts of M. bracteata exhibited higher suppression effect on the growth and germination of E. indica as the concentration increased. The leaf and seed extracts significantly reduced all measured parameters at all concentrations except for the shoot length and germination of E. indica by seed extract at 16.7 g/L which recorded insignificant reduction by 40.5% and 4% respectively. The leaf and seed debris significantly reduced the root length of E. indica at all treatments. Seed debris also showed significant reduction on the germination at all treatments and other seedling growth parameters (shoot length, fresh weight and dry weight) at 2.5 and 10.0 g/500 g soil. Meanwhile, the leaf debris demonstrated stimulation effect on the seedling growth parameters. As a whole, the leaf showed higher suppression effect in aqueous extract experiment while the seed recorded higher suppression effect in the debris experiment. Further studies need to be conducted to investigate the type of inhibition mechanism involved in both experiments.

Orchid seed removal by ants in Neotropical ant-gardens.

PubMed

Morales-Linares, J; García-Franco, J G; Flores-Palacios, A; Valenzuela-González, J E; Mata-Rosas, M; Díaz-Castelazo, C

2018-05-01

Most plants that inhabit ant-gardens (AGs) are cultivated by the ants. Some orchids occur in AGs; however, it is not known whether their seeds are dispersed by AG ants because most orchid seeds are tiny and dispersed by wind. We performed in situ seed removal experiments, in which we simultaneously provided Azteca gnava ants with seeds of three AG orchid species and three other AG epiphyte species (Bromeliaceae, Cactaceae and Gesneriaceae), as well as the non-AG orchid Catasetum integerrimum. The seeds most removed were those of the bromeliad Aechmea tillandsioides and the gesneriad Codonanthe uleana, while seeds of AG orchids Coryanthes picturata, Epidendrum flexuosum and Epidendrum pachyrachis were less removed. The non-AG orchid was not removed. Removal values were positively correlated with the frequency of the AG epiphytes in the AGs, and seeds of AG orchids were larger than those of non-AG orchids, which should favour myrmecochory. Our data show that Azt. gnava ants discriminate and preferentially remove seeds of the AG epiphytes. We report for the first time the removal of AG orchid seeds by AG ants in Neotropical AGs. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

7 CFR 201.18 - Other agricultural seeds (crop seeds).

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

Seed set in guayule (Parthenium argentatum, Asteraceae) in relation to insect pollination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mamood, A.N.; Waller, G.D.; Ray, D.T.

Guayule (Parthenium argentatum, Asteraceae) is one of two major plant species grown for natural rubber. Studies were conducted to determine the effect of honey bee (Apis mellifera) pollination and season on seed set and total seed yield/ha. The experiments involved four pollination treatments: plants caged with bees; plants caged without bees; plants open pollinated (uncovered); and plants individually covered. Seeds were harvested monthly July-September 1984, and May-September 1985. Plots with bees produced at least 150% more seeds than plots without bees, and there were no qualitative differences in the seed weights among treatments. Highest seed yield was in May andmore » September. Results indicate that (1) insect pollination in guayule increases seed yield and (2) fewer seeds are produced in the warmest months.« less

Administration Dependent Antioxidant Effect of Carica papaya Seeds Water Extract

PubMed Central

Panzarini, Elisa; Dwikat, Majdi; Mariano, Stefania; Vergallo, Cristian; Dini, Luciana

2014-01-01

Carica papaya is widely used in folk medicine as herbal remedy to prevent, protect against, and cure several diseases. These curative properties are based on the presence in different parts of the plant of phytochemical nutrients with antioxidant effect. Seeds are the less exploited part; thus this study is aimed at assessing the antioxidant activities of the C. papaya seeds water extract against hydrogen peroxide (H2O2) oxidative stress in human skin Detroit 550 fibroblasts. C. papaya seeds water extract is not toxic and acts as a potent free radical scavenger, providing protection to Detroit 550 fibroblasts that underwent H2O2 oxidative stress. Data show that (i) the maximum protective effect is achieved by the simultaneous administration of the extract with 1 mM H2O2; (ii) the extract in presence of an oxidative stress does not increase catalase activity and prevents the release of cytochrome C and the inner mitochondrial transmembrane potential (Δψ m) loss; (iii) the extract is more efficient than vitamin C to hamper the oxidative damage; (iv) the purified subfractions of the seeds water extract exert the same antioxidant effect of whole extract. In conclusion, C. papaya seeds water extract is potentially useful for protection against oxidative stress. PMID:24795765

Effect of some Evaporation Matters on Storability of Sunflower ( Helianthus annuus L.) Seed.

PubMed

El-Saidy, Aml E A; El-Hai, K M Abd

This study focuses on finding compounds that are safe to humans and environment, such as propionic and acetic acids that may provide an alternative control of seed-borne pathogens and decrease seed deterioration during storage. The objectives of this study were to reduce sunflower seed deterioration and improve the viability of sunflower seed using environmentally safe organic acids. Propionic and acetic acids were applied on sunflower seed at different concentrations under laboratory conditions during different storage periods. After 6 months storage period, the viability of sunflower seed as well as morphological and physiological characteristics of seedlings were evaluated under greenhouse conditions. Laboratory experiment was conducted in a factorial completely randomized design and randomized complete block design for greenhouse experiment. Propionic and acetic acids at different concentrations showed inhibitory effects on the presence of different fungal genera in all storage periods. Propionic acid was most effective followed by acetic acid. Increasing storage periods from 0-6 months significantly decreased germination percentage, germination energy, seedling characters, survived healthy seedlings and seed oil and protein percentages but dead and rotted seeds, as well as rotted seedlings were increased. Treating sunflower seeds with propionic acid (100%) improved germination criteria, seedling characters and seed chemical characters as well as survival seedlings and minimized the dead seeds, rotted seeds and rotted seedlings as compared with the control under all storage periods. Under greenhouse conditions, the maximum growth parameter and physiological characters (chlorophylls a, b, carotenoids and total phenols) were recorded from seed treated with 100% propionic acid after 6 months of storage. It may be concluded that propionic and acetic acids vapors can have considerable fungicidal activity against sunflower pathogens and improve seed viability

Database usage and performance for the Fermilab Run II experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonham, D.; Box, D.; Gallas, E.

2004-12-01

The Run II experiments at Fermilab, CDF and D0, have extensive database needs covering many areas of their online and offline operations. Delivering data to users and processing farms worldwide has represented major challenges to both experiments. The range of applications employing databases includes, calibration (conditions), trigger information, run configuration, run quality, luminosity, data management, and others. Oracle is the primary database product being used for these applications at Fermilab and some of its advanced features have been employed, such as table partitioning and replication. There is also experience with open source database products such as MySQL for secondary databasesmore » used, for example, in monitoring. Tools employed for monitoring the operation and diagnosing problems are also described.« less

Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds.

PubMed

Gorim, Linda; Asch, Folkard

2017-05-24

Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition.

Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds

PubMed Central

Gorim, Linda; Asch, Folkard

2017-01-01

Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition. PMID:28538658

Intercomparison of stratospheric water vapor observed by satellite experiments - Stratospheric Aerosol and Gas Experiment II versus Limb Infrared Monitor of the Stratosphere and Atmospheric Trace Molecule Spectroscopy

NASA Technical Reports Server (NTRS)

Chiou, E. W.; Mccormick, M. P.; Mcmaster, L. R.; Chu, W. P.; Larsen, J. C.; Rind, D.; Oltmans, S.

1993-01-01

A comparison is made of the stratospheric water vapor measurements made by the satellite sensors of the Stratospheric Aerosol and Gas Experiment II (SAGE II), the Nimbus-7 LIMS, and the Spacelab 3 Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment. It was found that, despite differences in the measurement techniques, sampling bias, and observational periods, the three experiments have disclosed a generally consistent pattern of stratospheric water vapor distribution. The only significant difference occurs at high southern altitudes in May below 18 km, where LIMS measurements were 2-3 ppmv greater than those of SAGE II and ATMOS.

Influence of microgravity on ultrastructure and storage reserves in seeds of Brassica rapa L

NASA Technical Reports Server (NTRS)

Kuang, A.; Xiao, Y.; McClure, G.; Musgrave, M. E.

2000-01-01

Successful plant reproduction under spaceflight conditions has been problematic in the past. During a 122 d opportunity on the Mir space station, full life cycles of Brassica rapa L. were completed in microgravity in a series of three experiments in the Svet greenhouse. Ultrastructural and cytochemical analyses of storage reserves in mature dry seeds produced in these experiments were compared with those of seeds produced during a high-fidelity ground control. Additional analyses were performed on developing Brassica embryos, 15 d post pollination, which were produced during a separate experiment on the Shuttle (STS-87). Seeds produced on Mir had less than 20% of the cotyledon cell number found in seeds harvested from the ground control. Cytochemical localization of storage reserves in mature cotyledons showed that starch was retained in the spaceflight material, whereas protein and lipid were the primary storage reserves in ground control seeds. Protein bodies in mature cotyledons produced in space were 44% smaller than those in the ground control seeds. Fifteen days after pollination, cotyledon cells from mature embryos formed in space had large numbers of starch grains, and protein bodies were absent, while in developing ground control seeds at the same stage, protein bodies had already formed and fewer starch grains were evident. These data suggest that both the late stage of seed development and maturation are changed in Brassica by growth in a microgravity environment. While gravity is not absolutely required for any step in the plant life cycle, seed quality in Brassica is compromised by development in microgravity.

How-to-Do-It: A Practical Method for Teaching Seed Stratification.

ERIC Educational Resources Information Center

Englert, Karen M.; Shontz, Nancy N.

1989-01-01

Described is a laboratory procedure for teaching seed stratification. Materials, methods, results, and applicability of the experiment are explained. Diagrams showing the percent of total germination as a function of stratification time and the germination rate of stratified seeds are included. (RT)

Isac Sc-Linac Phase-II Helium Refrigerator Commissioning and First Operational Experience at Triumf

NASA Astrophysics Data System (ADS)

Sekachev, I.; Kishi, D.; Laxdal, R. E.

2010-04-01

ISAC Phase-II is an upgrade of the radioactive isotope superconducting linear accelerator, SC-linac, at TRIUMF. The Phase-I section of the accelerator, medium-beta, is operational and is cooled with a 600 W helium refrigerator, commissioned in March 2005. An identical refrigerator is being used with the Phase-II segment of the accelerator; which is now under construction. The second refrigerator has been commissioned and tested with the Phase-I section of the linac and is used for Phase-II linac development, including new SC-cavity performance tests. The commissioning of the Phase-II refrigeration system and recent operational experience is presented.

Standardized Method for High-throughput Sterilization of Arabidopsis Seeds.

PubMed

Lindsey, Benson E; Rivero, Luz; Calhoun, Chistopher S; Grotewold, Erich; Brkljacic, Jelena

2017-10-17

Arabidopsis thaliana (Arabidopsis) seedlings often need to be grown on sterile media. This requires prior seed sterilization to prevent the growth of microbial contaminants present on the seed surface. Currently, Arabidopsis seeds are sterilized using two distinct sterilization techniques in conditions that differ slightly between labs and have not been standardized, often resulting in only partially effective sterilization or in excessive seed mortality. Most of these methods are also not easily scalable to a large number of seed lines of diverse genotypes. As technologies for high-throughput analysis of Arabidopsis continue to proliferate, standardized techniques for sterilizing large numbers of seeds of different genotypes are becoming essential for conducting these types of experiments. The response of a number of Arabidopsis lines to two different sterilization techniques was evaluated based on seed germination rate and the level of seed contamination with microbes and other pathogens. The treatments included different concentrations of sterilizing agents and times of exposure, combined to determine optimal conditions for Arabidopsis seed sterilization. Optimized protocols have been developed for two different sterilization methods: bleach (liquid-phase) and chlorine (Cl2) gas (vapor-phase), both resulting in high seed germination rates and minimal microbial contamination. The utility of these protocols was illustrated through the testing of both wild type and mutant seeds with a range of germination potentials. Our results show that seeds can be effectively sterilized using either method without excessive seed mortality, although detrimental effects of sterilization were observed for seeds with lower than optimal germination potential. In addition, an equation was developed to enable researchers to apply the standardized chlorine gas sterilization conditions to airtight containers of different sizes. The protocols described here allow easy, efficient, and

Standardized Method for High-throughput Sterilization of Arabidopsis Seeds

PubMed Central

Calhoun, Chistopher S.; Grotewold, Erich; Brkljacic, Jelena

2017-01-01

Arabidopsis thaliana (Arabidopsis) seedlings often need to be grown on sterile media. This requires prior seed sterilization to prevent the growth of microbial contaminants present on the seed surface. Currently, Arabidopsis seeds are sterilized using two distinct sterilization techniques in conditions that differ slightly between labs and have not been standardized, often resulting in only partially effective sterilization or in excessive seed mortality. Most of these methods are also not easily scalable to a large number of seed lines of diverse genotypes. As technologies for high-throughput analysis of Arabidopsis continue to proliferate, standardized techniques for sterilizing large numbers of seeds of different genotypes are becoming essential for conducting these types of experiments. The response of a number of Arabidopsis lines to two different sterilization techniques was evaluated based on seed germination rate and the level of seed contamination with microbes and other pathogens. The treatments included different concentrations of sterilizing agents and times of exposure, combined to determine optimal conditions for Arabidopsis seed sterilization. Optimized protocols have been developed for two different sterilization methods: bleach (liquid-phase) and chlorine (Cl2) gas (vapor-phase), both resulting in high seed germination rates and minimal microbial contamination. The utility of these protocols was illustrated through the testing of both wild type and mutant seeds with a range of germination potentials. Our results show that seeds can be effectively sterilized using either method without excessive seed mortality, although detrimental effects of sterilization were observed for seeds with lower than optimal germination potential. In addition, an equation was developed to enable researchers to apply the standardized chlorine gas sterilization conditions to airtight containers of different sizes. The protocols described here allow easy, efficient, and

[Dynamics of seed rain of Tripterygium hypoglaucum and soil seed bank].

PubMed

Zhang, Zhi-Wei; Wei, Yong-Sheng; Liu, Xiang; Su, Shu; Qu, Xian-You; Wang, Chang-Hua

2017-11-01

Tripterygium hypoglaucum is an endangered species in arid areas of Xiannvshan Chongqing, China. The dynamic characteristics of seed rain and soil seed bank of T. hypoglaucum were studied in this paper．Results showed that T. hypoglaucum years of mature seeds distribution number up to October; the seed rain occurred from the last ten-day of September to in the first ten-day of November and the peak of scattered seed rain concentrated in the October．The numbers of soil seed bank at 2-5 cm soil layer,mainly concentrated in the 1.5-3.5 m range. T. hypoglaucum seeds to the wind as a force for transmission, the transmission ability is strong, but in the process of natural reproduction, full mature seed rate is low, the soil seed bank seeds seed short-lived factors these were unfavorable for the natural reproduction of T. hypoglaucum population. Copyright© by the Chinese Pharmaceutical Association.

[Procedure of seed quality testing and seed grading standard of Prunus humilis].

PubMed

Wen, Hao; Ren, Guang-Xi; Gao, Ya; Luo, Jun; Liu, Chun-Sheng; Li, Wei-Dong

2014-11-01

So far there exists no corresponding quality test procedures and grading standards for the seed of Prunus humilis, which is one of the important source of base of semen pruni. Therefor we set up test procedures that are adapt to characteristics of the P. humilis seed through the study of the test of sampling, seed purity, thousand-grain weight, seed moisture, seed viability and germination percentage. 50 cases of seed specimens of P. humilis tested. The related data were analyzed by cluster analysis. Through this research, the seed quality test procedure was developed, and the seed quality grading standard was formulated. The seed quality of each grade should meet the following requirements: for first grade seeds, germination percentage ≥ 68%, thousand-grain weight 383 g, purity ≥ 93%, seed moisture ≤ 5%; for second grade seeds, germination percentage ≥ 26%, thousand-grain weight ≥ 266 g, purity ≥ 73%, seed moisture ≤9%; for third grade seeds, germination percentage ≥ 10%, purity ≥ 50%, thousand-grain weight ≥ 08 g, seed moisture ≤ 13%.

Effect of Seed Density on Splash Cup Seed Dispersal

NASA Astrophysics Data System (ADS)

Wigger, Patrick; Pepper, Rachel

2017-11-01

Splash cup plants are plants that utilize a small, mm-sized cup filled with seeds as a method of seed dispersal. The cup uses kinetic energy of an incident raindrop in order to project the seeds away from the plant up to 1 meter. The dispersal distance is important to ensure the offspring are not clustered too tightly to the parent plant. It has previously been found that a cup angle of 40 degrees to the horizontal is optimal for maximum dispersal of water from cups with no seeds. In this study we examine if the 40 degree cup is optimal for cups containing seeds with varying densities. We released uniform water drops above 5.0 mm 3D printed models of splash cups, using 1.0 mm plastic and glass microspheres of varying densities to simulate seeds. We observed the dispersal characteristics of each bead type by measuring the final seed locations after each splash, and by recording high speed video to determine the angle and velocity of the seeds as they exited the cup.

Small-mammal seed predation limits the recruitment and abundance of two perennial grassland forbs.

PubMed

Bricker, Mary; Pearson, Dean; Maron, John

2010-01-01

Although post-dispersal seed predators are common and often reduce seed density, their influence on plant population abundance remains unclear. On the one hand, increasing evidence suggests that many plant populations are seed limited, implying that seed predators could reduce plant abundance. On the other hand,.it is generally uncertain whether the magnitude of seed limitation imposed by granivores is strong enough to overcome density-dependent processes that could compensate for seed loss at later stages. We examined the impact of seed predation by small mammals, primarily deer mice (Peromyscus maniculatus), on seedling recruitment and subsequent plant establishment of two perennial grassland forbs in western Montana, USA: Lupinus sericeus (Fabaceae) and Lithospermum ruderale (Boraginaceae). The experiment combined graded densities of seed addition for each species with a small-mammal exclusion treatment. Seedling recruitment and plant establishment were monitored in the experimental plots for up to three years. For both species, small-mammal exclusion increased the total number of seedlings that emerged, and these effects were still significant three years after seed addition, resulting in greater numbers of established plants inside exclosures than in control plots. We also found evidence of seed limitation, with increasing density of seeds added leading to increased numbers of seedlings. Results from seed addition and small-mammal exclusion experiments in later years also revealed significant impacts of small mammals on seedling emergence. These results suggest that granivores can have potentially important impacts in limiting forb abundance in grasslands communities.

Joshua tree (Yucca brevifolia) seeds are dispersed by seed-caching rodents

USGS Publications Warehouse

Vander Wall, S.B.; Esque, T.; Haines, D.; Garnett, M.; Waitman, B.A.

2006-01-01

Joshua tree (Yucca brevifolia) is a distinctive and charismatic plant of the Mojave Desert. Although floral biology and seed production of Joshua tree and other yuccas are well understood, the fate of Joshua tree seeds has never been studied. We tested the hypothesis that Joshua tree seeds are dispersed by seed-caching rodents. We radioactively labelled Joshua tree seeds and followed their fates at five source plants in Potosi Wash, Clark County, Nevada, USA. Rodents made a mean of 30.6 caches, usually within 30 m of the base of source plants. Caches contained a mean of 5.2 seeds buried 3-30 nun deep. A variety of rodent species appears to have prepared the caches. Three of the 836 Joshua tree seeds (0.4%) cached germinated the following spring. Seed germination using rodent exclosures was nearly 15%. More than 82% of seeds in open plots were removed by granivores, and neither microsite nor supplemental water significantly affected germination. Joshua tree produces seeds in indehiscent pods or capsules, which rodents dismantle to harvest seeds. Because there is no other known means of seed dispersal, it is possible that the Joshua tree-rodent seed dispersal interaction is an obligate mutualism for the plant.

Direct seeding

Treesearch

Richard M. Godman; G. A. Mattson

1992-01-01

At present, direct seeding of hardwoods in the Lake States is more of a supplemental than a primary means of artificial regeneration. Direct seeding may be used to augment a poor seed crop or increase the proportion of a preferred species. In the future, it will no doubt play a bigger role-in anticipation of this we need to collect and store the amounts of seed needed...

Logistics support of the Japanese Experiment Module by the H-II rocket

NASA Astrophysics Data System (ADS)

Shibato, Yoji; Eto, Takao; Fukushima, Yukio; Takatsuka, Hitoshi

1988-10-01

This paper describes salient design features of the Japanese Experiment Module (JEM), which will be attached to the Space Station. Special attention is given to the logistic support of the JEM (which is planned to become operational in 1990s) by the HOPE orbiter, which will be used for the resupply and the retrieval of the JEM, and the H-II rocket, which will be used to launch the HOPE. The concepts of HOPE and the H-II rocket are discussed together with the estimated logistics requirements of this system. Configuration diagrams are included.

Value of neonicotinoid seed treatments to US soybean farmers.

PubMed

Hurley, Terrance; Mitchell, Paul

2017-01-01

The benefits of neonicotinoid seed treatment to soybean farmers have received increased scrutiny. Rather than use data from small-plot experiments, this research uses survey data from 500 US farmers to estimate the benefit of neonicotinoid seed treatments to them. As seed treatment users, farmers are familiar with their benefits in the field and have economic incentives to only use them if they provide value. Of the surveyed farmers, 51% used insecticide seed treatments, averaging 87% of their soybean area. Farmers indicated that human and environmental safety is an important consideration affecting their pest management decisions and reported aphids as the most managed and important soybean pest. Asking farmers who used seed treatments to state how much value they provided gives an estimate of $US 28.04 ha -1 treated in 2013, net of seed treatment costs. Farmer-reported average yields provided an estimated average yield gain of 128.0 kg ha -1 treated in 2013, or about $US 42.20 ha -1 treated, net of seed treatment costs. These estimates using different data and methods are consistent and suggest the value of insecticide seed treatments to the US soybean farmers who used them in 2013 was around $US 28-42 ha -1 treated, net of seed treatment costs. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

SMBH Seeds: Model Discrimination with High-energy Emission Based on Scaling Relation Evolution

NASA Astrophysics Data System (ADS)

Ben-Ami, Sagi; Vikhlinin, Alexey; Loeb, Abraham

2018-02-01

We explore the expected X-ray (0.5–2 keV) signatures from supermassive black holes (SMBHs) at high redshifts (z∼ 5{--}12) assuming various models for their seeding mechanism and evolution. Seeding models are approximated through deviations from the {M}{BH}{--}σ relation observed in the local universe, while N-body simulations of the large-scale structure are used to estimate the density of observable SMBHs. We focus on two seeding model families: (i) light seed BHs from remnants of Pop-III stars and (ii) heavy seeds from the direct collapse of gas clouds. We investigate several models for the accretion history, such as sub-Eddington accretion, slim disk models, and torque-limited growth models. We consider observations with two instruments: (i) the Chandra X-ray Observatory and (ii) the proposed Lynx. We find that all of the simulated models are in agreement with the current results from the Chandra Deep Field South, i.e., consistent with zero SMBHs in the field of view. In deep Lynx exposures, the number of observed objects is expected to become statistically significant. We demonstrate the capability to limit the phase space of plausible scenarios of the birth and evolution of SMBHs by performing deep observations at a flux limit of 1× {10}-19 {erg} {{cm}}-2 {{{s}}}-1. Finally, we show that our models are in agreement with current limits on the cosmic X-ray background (CXRB) and the expected contribution from unresolved quasars. We find that an analysis of CXRB contributions down to the Lynx confusion limit yields valuable information that can help identify the correct scenario for the birth and evolution of SMBHs.

On the role of abscisic acid in seed dormancy of red rice.

PubMed

Gianinetti, Alberto; Vernieri, Paolo

2007-01-01

Abscisic acid (ABA) is commonly assumed to be the primary effector of seed dormancy, but conclusive evidence for this role is lacking. This paper reports on the relationships occurring in red rice between ABA and seed dormancy. Content of free ABA in dry and imbibed caryopses, both dormant and after-ripened, the effects of inhibitors, and the ability of applied ABA to revert dormancy breakage were considered. The results indicate: (i) no direct correlation of ABA content with the dormancy status of the seed, either dry or imbibed; (ii) different sensitivity to ABA of non-dormant seed and seed that was forced to germinate by fluridone; and (iii) an inability of exogenous ABA to reinstate dormancy in fluridone-treated seed, even though applied at a pH which favoured high ABA accumulation. These considerations suggest that ABA is involved in regulating the first steps of germination, but unidentified developmental effectors that are specific to dormancy appear to stimulate ABA synthesis and to enforce the responsiveness to this phytohormone. These primary effectors appear physiologically to modulate dormancy and via ABA they effect the growth of the embryo. Therefore, it is suggested that ABA plays a key role in integrating the dormancy-specific developmental signals with the control of growth.

Persistence of seeds from crops of conventional and herbicide tolerant oilseed rape (Brassica napus).

PubMed

Lutman, Peter J W; Berry, Kate; Payne, Roger W; Simpson, Euan; Sweet, Jeremy B; Champion, Gillian T; May, Mike J; Wightman, Pat; Walker, Kerr; Lainsbury, Martin

2005-09-22

A series of rotation experiments at five sites over four years has explored the environmental and agronomic implications of growing herbicide tolerant oilseed rape and sugar beet. This paper reports on the population dynamics of volunteer rape (Brassica napus). The experiments compared four winter oilseed rape (WOSR) cultivars: a conventional cultivar (Apex) and three developmental cultivars either genetically modified (GM) to be tolerant to glyphosate or glufosinate, or conventionally bred to be tolerant to herbicides of the imidazolinone group. Seed losses at harvest averaged 3575 seeds m(-2) but ranged from less than 2000 up to more than 10000 seeds m(-2). There was a rapid decline in seed numbers during the first few months after harvest, resulting in a mean loss of seeds of 60%. In subsequent seasons, the seedbank declined much more slowly at four of the five sites (ca 20% per year) and the models predicted 95% seed loss after approximately 9 years. Seed decline was much faster at the fifth site. There were no clear differences between the four cultivars in either the numbers of seeds shed at harvest or in their subsequent persistence. The importance of the persistence of GM rape seeds, in the context of the coexistence of GM and non-GM crops and the role of good management practices that minimize seed persistence, are discussed.

A Survey of Optometry Graduates to Determine Practice Patterns: Part II: Licensure and Practice Establishment Experiences.

ERIC Educational Resources Information Center

Bleimann, Robert L.; Smith, Lee W.

1985-01-01

A summary of Part II of a two-volume study of optometry graduates conducted by the Association of Schools and Colleges of Optometry is presented. Part II includes the analysis of the graduates' licensure and practice establishment experiences. (MLW)

β-sheet propensity controls the kinetic pathways and morphologies of seeded peptide aggregation

NASA Astrophysics Data System (ADS)

Morriss-Andrews, Alex; Bellesia, Giovanni; Shea, Joan-Emma

2012-10-01

The effect of seeds in templating the morphology of peptide aggregates is examined using molecular dynamics simulations and a coarse-grained peptide representation. Varying the nature of the aggregate seed between β-sheet, amorphous, and β-barrel seeds leads to different aggregation pathways and to morphologically different aggregates. Similar effects are seen by varying the β-sheet propensity of the free peptides. For a fibrillar seed and free peptides of high β-sheet propensity, fibrillar growth occurred by means of direct attachment (without structural rearrangement) of free individual peptides and small ordered oligomers onto the seed. For a fibrillar seed and free peptides of low β-sheet propensity, fibrillar growth occurred through a dock-lock mechanism, in which the free peptides first docked onto the seed, and then locked on, extending and aligning to join the fibril. Amorphous seeds absorbed free peptides into themselves indiscriminately, with any fibrillar rearrangement subsequent to this absorption by means of a condensation-ordering transition. Although the mechanisms observed by varying peptide β-sheet propensity are diverse, the initial pathways can always be broken down into the following steps: (i) the free peptides diffuse in the bulk and attach individually to the seed; (ii) the free peptides diffuse and aggregate among themselves; (iii) the free peptide oligomers collide with the seed; and (iv) the free oligomers merge with the seed and rearrange in a manner dependent on the backbone flexibility of both the free and seed peptides. Our simulations indicate that it is possible to sequester peptides from amorphous aggregates into fibrils, and also that aggregate morphology (and thus cytoxicity) can be controlled by introducing seeds of aggregate-compatible peptides with differing β-sheet propensities into the system.

High precipitation and seeded species competition reduce seeded shrub establishment during dryland restoration.

PubMed

Rinella, Matthew J; Hammond, Darcy H; Bryant, Ana-Elisa M; Kozar, Brian J

2015-06-01

Drylands comprise 40% of Earth's land mass and are critical to food security, carbon sequestration, and threatened and endangered wildlife. Exotic weed invasions, overgrazing, energy extraction, and other factors have degraded many drylands, and this has placed an increased emphasis on dryland restoration. The increased restoration focus has generated a wealth of experience, innovations and empirical data, yet the goal of restoring diverse, native, dryland plant assemblages composed of grasses, forbs, and shrubs has generally proven beyond reach. Of particular concern are shrubs, which often fail to establish or establish at trivially low densities. We used data from two Great Plains, USA coal mines to explore factors regulating shrub establishment. Our predictor data related to weather and restoration (e.g., seed rates, rock cover) variables, and our response data described shrub abundances on fields of the mines. We found that seeded non-shrubs, especially grasses, formed an important competitive barrier to shrub establishment: With every one standard deviation increase in non-shrub seed rate, the probability shrubs were present decreased ~0.1 and shrub cover decreased ~35%. Since new fields were seeded almost every year for > 20 years, the data also provided a unique opportunity to explore effects of stochastic drivers (i.e., precipitation, year effects). With every one standard deviation increase in precipitation the first growing season following seeding, the probability shrubs were present decreased ~0.07 and shrub cover decreased ~47%. High precipitation appeared to harm shrubs by increasing grass growth/competition. Also, weak evidence suggested shrub establishment was better in rockier fields where grass abundance/competition was lower. Multiple lines of evidence suggest reducing grass seed rates below levels typically used in Great Plains restoration would benefit shrubs without substantially impacting grass stand development over the long term. We used

Algorithms and sensitivity analyses for Stratospheric Aerosol and Gas Experiment II water vapor retrieval

NASA Technical Reports Server (NTRS)

Chu, W. P.; Chiou, E. W.; Larsen, J. C.; Thomason, L. W.; Rind, D.; Buglia, J. J.; Oltmans, S.; Mccormick, M. P.; Mcmaster, L. M.

1993-01-01

The operational inversion algorithm used for the retrieval of the water-vapor vertical profiles from the Stratospheric Aerosol and Gas Experiment II (SAGE II) occultation data is presented. Unlike the algorithm used for the retrieval of aerosol, O3, and NO2, the water-vapor retrieval algorithm accounts for the nonlinear relationship between the concentration versus the broad-band absorption characteristics of water vapor. Problems related to the accuracy of the computational scheme, the accuracy of the removal of other interfering species, and the expected uncertainty of the retrieved profile are examined. Results are presented on the error analysis of the SAGE II water vapor retrieval, indicating that the SAGE II instrument produced good quality water vapor data.

Dense understory dwarf bamboo alters the retention of canopy tree seeds

NASA Astrophysics Data System (ADS)

Qian, Feng; Zhang, Tengda; Guo, Qinxue; Tao, Jianping

2016-05-01

Tree seed retention is thought to be an important factor in the process of forest community regeneration. Although dense understory dwarf bamboo has been considered to have serious negative effects on the regeneration of forest community species, little attention has been paid to the relationship between dwarf bamboo and seed retention. In a field experiment we manipulated the density of Fargesia decurvata, a common understory dwarf bamboo, to investigate the retention of seeds from five canopy tree species in an evergreen and deciduous broad-leaved mixed forest in Jinfoshan National Nature Reserve, SW China. We found that the median survival time and retention ratio of seeds increased with the increase in bamboo density. Fauna discriminately altered seed retention in bamboo groves of different densities. Arthropods reduced seed survival the most, and seeds removed decreased with increasing bamboo density. Birds removed or ate more seeds in groves of medium bamboo density and consumed fewer seeds in dense or sparse bamboo habitats. Rodents removed a greater number of large and highly profitable seeds in dense bamboo groves but more small and thin-husked seeds in sparse bamboo groves. Seed characteristics, including seed size, seed mass and seed profitability, were important factors affecting seed retention. The results suggested that dense understory dwarf bamboo not only increased seeds concealment and reduced the probability and speed of seed removal but also influenced the trade-off between predation and risk of animal predatory strategies, thereby impacting the quantity and composition of surviving seeds. Our results also indicated that dense understory dwarf bamboo and various seed characteristics can provide good opportunities for seed storage and seed germination and has a potential positive effect on canopy tree regeneration.

Agricultural Extension Messages Using Video on Portable Devices Increased Knowledge about Seed Selection, Storage and Handling among Smallholder Potato Farmers in Southwestern Uganda

PubMed Central

Van Campenhout, Bjorn; Vandevelde, Senne; Walukano, Wilberforce; Van Asten, Piet

2017-01-01

To feed a growing population, agricultural productivity needs to increase dramatically. Agricultural extension information, with its public, non-rival nature, is generally undersupplied, and public provision remains challenging. In this study, simple agricultural extension video messages, delivered through Android tablets, were tested in the field to determine if they increased farmers’ knowledge of recommended practices on (i) potato seed selection and (ii) seed storage and handling among a sample of potato farmers in southwestern Uganda. Using a field experiment with ex ante matching in a factorial design, it was established that showing agricultural extension videos significantly increased farmers’ knowledge. However, results suggested impact pathways that went beyond simply replicating what was shown in the video. Video messages may have triggered a process of abstraction, whereby farmers applied insights gained in one context to a different context. PMID:28122005

A role for fruit structure in seed survival and germination of Swartzia langsdorffii Raddi beyond dispersal.

PubMed

Vaz, T A A; Rodrigues-Junior, A G; Davide, A C; Nakamura, A T; Toorop, P E

2018-03-01

Diaspore structure has been hypothesised to play a role in seed viability and/or germination of recalcitrant seeds, especially for Swartzia langsdorffii. Thus, this work aims to (i) investigate the in situ contribution of pericarp and aril on seed viability and germination, and (ii) identify morphoanatomical traits of S. langsdorffii diaspores that allow its desiccation-sensitive seeds to remain viable. The role of the pericarp and aril in seed survival and germination was investigated by placing the whole fruit, whole seeds (arillate seed) and bare seeds (without aril) in soil in the forest understorey, assessing germination, emergence, dead, firm and predated seeds, and water content of pericarps, arils and seeds. Correlation analysis was performed between environmental variables and physiological parameters. Histochemical features of diaspores were also investigated. Pericarp water content fell after several months, while the aril maintained its water content. Seeds did not lose water even without the presence of the pericarp and aril. However, presence of the pericarp promoted seed water content, viability and germination long after dispersal. The embryo had a thickened outer periclinal cell wall. Pericarp and aril are not essential to prevent water loss in seeds, but do help to retain seed moisture, favouring viability maintenance and promoting germination during the rainy season. Morphoanatomical features of seeds are suggested as main factors that reduce water loss. Survival of these desiccation-sensitive seeds upon dispersal during the dry season appears to be facilitated by multiple diaspore features that prevent viability loss. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

Ozone exposure of a weed community produces adaptive changes in seed populations of Spergula arvensis.

PubMed

Landesmann, Jennifer B; Gundel, Pedro E; Martínez-Ghersa, M Alejandra; Ghersa, Claudio M

2013-01-01

Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergulaarvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5% RH and 25 ºC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production.

Ozone Exposure of a Weed Community Produces Adaptive Changes in Seed Populations of Spergula arvensis

PubMed Central

Landesmann, Jennifer B.; Gundel, Pedro E.; Martínez-Ghersa, M. Alejandra; Ghersa, Claudio M.

2013-01-01

Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergula arvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5% RH and 25 ºC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production. PMID:24086640

Validation of Helicopter Gear Condition Indicators Using Seeded Fault Tests

NASA Technical Reports Server (NTRS)

Dempsey, Paula; Brandon, E. Bruce

2013-01-01

A "seeded fault test" in support of a rotorcraft condition based maintenance program (CBM), is an experiment in which a component is tested with a known fault while health monitoring data is collected. These tests are performed at operating conditions comparable to operating conditions the component would be exposed to while installed on the aircraft. Performance of seeded fault tests is one method used to provide evidence that a Health Usage Monitoring System (HUMS) can replace current maintenance practices required for aircraft airworthiness. Actual in-service experience of the HUMS detecting a component fault is another validation method. This paper will discuss a hybrid validation approach that combines in service-data with seeded fault tests. For this approach, existing in-service HUMS flight data from a naturally occurring component fault will be used to define a component seeded fault test. An example, using spiral bevel gears as the targeted component, will be presented. Since the U.S. Army has begun to develop standards for using seeded fault tests for HUMS validation, the hybrid approach will be mapped to the steps defined within their Aeronautical Design Standard Handbook for CBM. This paper will step through their defined processes, and identify additional steps that may be required when using component test rig fault tests to demonstrate helicopter CI performance. The discussion within this paper will provide the reader with a better appreciation for the challenges faced when defining a seeded fault test for HUMS validation.

Producing the target seed: Seed collection, treatment, and storage

Treesearch

Robert P. Karrfalt

2011-01-01

The role of high quality seeds in producing target seedlings is reviewed. Basic seed handling and upgrading techniques are summarized. Current advances in seed science and technology as well as those on the horizon are discussed.

Converting standard seeding rates for grasses to actual seeding rates per acre.

Treesearch

Joseph F. Pechanec

1950-01-01

Standard rates specifying the amount of grass seed to sow per acre are stated in most of the more recent publications as pounds of live pure seed (lps) to be used. For a seeding project these rates must be converted to the actual amount of seed to sow because seed as purchased from the dealer or grower is never all live pure seed. Even the best lots of seed contain...

Precipitation formation from orographic cloud seeding.

PubMed

French, Jeffrey R; Friedrich, Katja; Tessendorf, Sarah A; Rauber, Robert M; Geerts, Bart; Rasmussen, Roy M; Xue, Lulin; Kunkel, Melvin L; Blestrud, Derek R

2018-02-06

Throughout the western United States and other semiarid mountainous regions across the globe, water supplies are fed primarily through the melting of snowpack. Growing populations place higher demands on water, while warmer winters and earlier springs reduce its supply. Water managers are tantalized by the prospect of cloud seeding as a way to increase winter snowfall, thereby shifting the balance between water supply and demand. Little direct scientific evidence exists that confirms even the basic physical hypothesis upon which cloud seeding relies. The intent of glaciogenic seeding of orographic clouds is to introduce aerosol into a cloud to alter the natural development of cloud particles and enhance wintertime precipitation in a targeted region. The hypothesized chain of events begins with the introduction of silver iodide aerosol into cloud regions containing supercooled liquid water, leading to the nucleation of ice crystals, followed by ice particle growth to sizes sufficiently large such that snow falls to the ground. Despite numerous experiments spanning several decades, no direct observations of this process exist. Here, measurements from radars and aircraft-mounted cloud physics probes are presented that together show the initiation, growth, and fallout to the mountain surface of ice crystals resulting from glaciogenic seeding. These data, by themselves, do not address the question of cloud seeding efficacy, but rather form a critical set of observations necessary for such investigations. These observations are unambiguous and provide details of the physical chain of events following the introduction of glaciogenic cloud seeding aerosol into supercooled liquid orographic clouds.

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 1 2011-04-01 2011-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 19 Customs Duties 1 2014-04-01 2014-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 19 Customs Duties 1 2013-04-01 2013-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 1 2012-04-01 2012-04-01 false Certified seed potatoes, and seed corn or maize... Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification as seed potatoes under subheading 0701.10.00, as seed corn (maize) under subheading 1005.10...

Ant-seed mutualisms: Can red imported fire ants sour the relationship?

USGS Publications Warehouse

Zettler, J.A.; Spira, T.P.; Allen, Craig R.

2001-01-01

Invasion by the red imported fire ant, Solenopsis invicta, has had negative impacts on individual animal and plant species, but little is known about how S. invicta affects complex mutualistic relationships. In some eastern forests of North America, 30% of herbaceous species have ant-dispersed seeds. We conducted experiments to determine if fire ants are attracted to seeds of these plant species and assessed the amount of scarification or damage that results from handling by fire ants. Fire ants removed nearly 100% of seeds of the ant-dispersed plants Trillium undulatum, T. discolor, T. catesbaei, Viola rotundifolia, and Sanguinaria canadensis. In recovered seeds fed to ant colonies, fire ants scarified 80% of S. canadensis seeds and destroyed 86% of V. rotundifolia seeds. Our study is the first to document that red imported fire ants are attracted to and remove seeds of species adapted for ant dispersal. Moreover, fire ants might damage these seeds and discard them in sites unfavorable for germination and seedling establishment. ?? 2001 Elsevier Science Ltd. All rights reserved.

Seed weight - seedling size correlation in coastal Douglas-fir: genetic and environmental components.

Treesearch

Frank C. Sorensen; Robert K. Campbell

1992-01-01

The effect of seed weight on nursery seedling height was analyzed in two experiments. In expt. 1, 16 seeds per family from 111 families were individually weighed and sown in autumn. In expt. 2, a second group of 16 seeds were individually weighed and stratified and sown in spring. Four-tree noncontiguous family plots were randomly assigned to two densities in two...

Consistent individual differences in seed disperser quality in a seed-eating fish.

PubMed

Pollux, Bart J A

2017-01-01

Animal-mediated seed dispersal (zoochory) is considered to be an important mechanism regulating biological processes at larger spatial scales. To date, intra-specific variation in seed disperser quality within seed-dispersing animals has not been studied. Here, I employed seed feeding trials to quantify individual differences in disperser quality within the common carp (Cyprinus carpio) using seeds of two aquatic plants: unbranched bur-reed (Sparganium emersum, Sparganiaceae) and arrowhead (Sagittaria sagittifolia, Alismataceae). I found substantial variation among carp individuals in their propensity to ingest seeds and their ability to digest them, resulting in up to 31-fold differences in the probability of seed dispersal. In addition, there were significant differences in the time that seeds are retained in their digestive systems, generating a twofold difference in the maximum distance over which they can potentially disperse seeds. I propose that seed-eating animal species consist of individuals that display continuous variation in disperser quality, with at one end of the continuum individuals that are likely to eat seeds, pass them unharmed through their digestive tract and transport them over large distances to new locations (i.e. high-quality seed dispersers) and at the other end individuals that rarely eat seeds, destroy most of the ones they ingest and transport the few surviving seeds over relatively short distances (low-quality seed dispersers). Although individual differences in seed dispersal quality could be the result of a variety of factors, these results underline the ecological and evolutionary potential of such variation for both plants and animals.

Measuring effects of music, noise, and healing energy using a seed germination bioassay.

PubMed

Creath, Katherine; Schwartz, Gary E

2004-02-01

To measure biologic effects of music, noise, and healing energy without human preferences or placebo effects using seed germination as an objective biomarker. A series of five experiments were performed utilizing okra and zucchini seeds germinated in acoustically shielded, thermally insulated, dark, humid growth chambers. Conditions compared were an untreated control, musical sound, pink noise, and healing energy. Healing energy was administered for 15-20 minutes every 12 hours with the intention that the treated seeds would germinate faster than the untreated seeds. The objective marker was the number of seeds sprouted out of groups of 25 seeds counted at 12-hour intervals over a 72-hour growing period. Temperature and relative humidity were monitored every 15 minutes inside the seed germination containers. A total of 14 trials were run testing a total of 4600 seeds. Musical sound had a highly statistically significant effect on the number of seeds sprouted compared to the untreated control over all five experiments for the main condition (p < 0.002) and over time (p < 0.000002). This effect was independent of temperature, seed type, position in room, specific petri dish, and person doing the scoring. Musical sound had a significant effect compared to noise and an untreated control as a function of time (p < 0.03) while there was no significant difference between seeds exposed to noise and an untreated control. Healing energy also had a significant effect compared to an untreated control (main condition, p < 0.0006) and over time (p < 0.0001) with a magnitude of effect comparable to that of musical sound. This study suggests that sound vibrations (music and noise) as well as biofields (bioelectromagnetic and healing intention) both directly affect living biologic systems, and that a seed germination bioassay has the sensitivity to enable detection of effects caused by various applied energetic conditions.

Commissioning and Early Operation Experience of the NSLS-II Storage Ring RF System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, F.; Rose, J.; Cupolo, J.

2015-05-03

The National Synchrotron Light Source II (NSLS-II) is a 3 GeV electron X-ray user facility commissioned in 2014. The storage ring RF system, essential for replenishing energy loss per turn of the electrons, consists of digital low level RF controllers, 310 kW CW klystron transmitters, CESR-B type superconducting cavities, as well as a supporting cryogenic system. Here we will report on RF commissioning and early operation experience of the system for beam current up to 200mA.

A feature-based inference model of numerical estimation: the split-seed effect.

PubMed

Murray, Kyle B; Brown, Norman R

2009-07-01

Prior research has identified two modes of quantitative estimation: numerical retrieval and ordinal conversion. In this paper we introduce a third mode, which operates by a feature-based inference process. In contrast to prior research, the results of three experiments demonstrate that people estimate automobile prices by combining metric information associated with two critical features: product class and brand status. In addition, Experiments 2 and 3 demonstrated that when participants are seeded with the actual current base price of one of the to-be-estimated vehicles, they respond by revising the general metric and splitting the information carried by the seed between the two critical features. As a result, the degree of post-seeding revision is directly related to the number of these features that the seed and the transfer items have in common. The paper concludes with a general discussion of the practical and theoretical implications of our findings.

[Determination of Hard Rate of Alfalfa (Medicago sativa L.) Seeds with Near Infrared Spectroscopy].

PubMed

Wang, Xin-xun; Chen, Ling-ling; Zhang, Yun-wei; Mao, Pei-sheng

2016-03-01

Alfalfa (Medicago sativa L.) is the most commonly grown forage crop due to its better quality characteristics and high adaptability in China. However, there was 20%-80% hard seeds in alfalfa which could not be identified easily from non hard seeds which would cause the loss of seed utilization value and plant production. This experiment was designed for 121 samples of alfalfa. Seeds were collected according to different regions, harvested year and varieties. 31 samples were artificial matched as hard rates ranging from 20% to 80% to establish a model for hard seed rate by near infrared spectroscopy (NIRS) with Partial Least Square (PLS). The objective of this study was to establish a model and to estimate the efficiency of NIRS for determining hard rate of alfalfa seeds. The results showed that the correlation coefficient (R2(cal)) of calibration model was 0.981 6, root mean square error of cross validation (RMSECV) was 5.32, and the ratio of prediction to deviation (RPD) was 3.58. The forecast model in this experiment presented the satisfied precision. The proposed method using NIRS technology is feasible for identification and classification of hard seed in alfalfa. A new method, as nondestructive testing of hard seed rate, was provided to theoretical basis for fast nondestructive detection of hard seed rates in alfalfa.

Growth characteristics of maize seeds exposed to magnetic field.

PubMed

Vashisth, Ananta; Joshi, Devendra Kumar

2017-02-01

Standardization of magnetic field was done for maximum enhancement in germination characteristics of maize seeds. Seeds of maize were exposed to static magnetic fields of strength 50, 100, 150, 200, and 250 for 1, 2, 3, and 4 h for all field strengths. Results indicate that magnetic field application enhanced seed performance in terms of percentage germination, speed of germination, seedling length, and seedling dry weight significantly compared to unexposed control. Among the various combinations of field strength and duration, 200 mT for 1 h exposure gave best results. Exposure of seeds to magnetic fields improved seed coat membrane integrity as it reduced cellular leakage and, consequently, electrical conductivity. Experiments conducted at a research farm as well as farmer's field showed that plants raised from seeds exposed to 200 mT for 1 h had higher values of leaf area index, shoot length, number of leaves, chlorophyll content, shoot/root dry weight, and root characteristics as compared to corresponding values in untreated control. From the studies, it may be concluded that exposure of dry seeds to static magnetic field of 200 mT for 1 h improved shoot and root growth. Improved root system and biomass led to increased seed yield. Improved functional root parameters suggested that magnetically treated maize seeds could be used under moisture stress conditions. Bioelectromagnetics. 38:151-157, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

GERMINATOR: a software package for high-throughput scoring and curve fitting of Arabidopsis seed germination.

PubMed

Joosen, Ronny V L; Kodde, Jan; Willems, Leo A J; Ligterink, Wilco; van der Plas, Linus H W; Hilhorst, Henk W M

2010-04-01

Over the past few decades seed physiology research has contributed to many important scientific discoveries and has provided valuable tools for the production of high quality seeds. An important instrument for this type of research is the accurate quantification of germination; however gathering cumulative germination data is a very laborious task that is often prohibitive to the execution of large experiments. In this paper we present the germinator package: a simple, highly cost-efficient and flexible procedure for high-throughput automatic scoring and evaluation of germination that can be implemented without the use of complex robotics. The germinator package contains three modules: (i) design of experimental setup with various options to replicate and randomize samples; (ii) automatic scoring of germination based on the color contrast between the protruding radicle and seed coat on a single image; and (iii) curve fitting of cumulative germination data and the extraction, recap and visualization of the various germination parameters. The curve-fitting module enables analysis of general cumulative germination data and can be used for all plant species. We show that the automatic scoring system works for Arabidopsis thaliana and Brassica spp. seeds, but is likely to be applicable to other species, as well. In this paper we show the accuracy, reproducibility and flexibility of the germinator package. We have successfully applied it to evaluate natural variation for salt tolerance in a large population of recombinant inbred lines and were able to identify several quantitative trait loci for salt tolerance. Germinator is a low-cost package that allows the monitoring of several thousands of germination tests, several times a day by a single person.

A new device to estimate abundance of moist-soil plant seeds

USGS Publications Warehouse

Penny, E.J.; Kaminski, R.M.; Reinecke, K.J.

2006-01-01

Methods to sample the abundance of moist-soil seeds efficiently and accurately are critical for evaluating management practices and determining food availability. We adapted a portable, gasoline-powered vacuum to estimate abundance of seeds on the surface of a moist-soil wetland in east-central Mississippi and evaluated the sampler by simulating conditions that researchers and managers may experience when sampling moist-soil areas for seeds. We measured the percent recovery of known masses of seeds by the vacuum sampler in relation to 4 experimentally controlled factors (i.e., seed-size class, sample mass, soil moisture class, and vacuum time) with 2-4 levels per factor. We also measured processing time of samples in the laboratory. Across all experimental factors, seed recovery averaged 88.4% and varied little (CV = 0.68%, n = 474). Overall, mean time to process a sample was 30.3 ? 2.5 min (SE, n = 417). Our estimate of seed recovery rate (88%) may be used to adjust estimates for incomplete seed recovery, or project-specific correction factors may be developed by investigators. Our device was effective for estimating surface abundance of moist-soil plant seeds after dehiscence and before habitats were flooded.

A comparison of the Stratospheric Aerosol and Gas Experiment II tropospheric water vapor to radiosonde measurements

NASA Technical Reports Server (NTRS)

Larsen, J. C.; Chiou, E. W.; Chu, W. P.; Mccormick, M. P.; Mcmaster, L. R.; Oltmans, S.; Rind, D.

1993-01-01

Results are presented of a comparison beteen observations of the upper-tropospheric water vapor data obtained from the Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument and radiosonde observations for 1987 and radiosonde-based climatologies. Colocated SAGE II-radiosonde measurement pairs are compared individually and in a zonal mean sense. A straight comparison of monthly zonal means between SAGE II and radiosondes for 1987 and Global Atmospheric Statistics (1963-1973) indicates that the clear-sky SAGE II climatology is approximately half the level of clear/cloudy sky of both radiosonde climatologies. Annual zonal means calculated from the set of profile pairs again showed SAGE II to be significantly drier in many altitude bands.

Effects of rodent species, seed species, and predator cues on seed fate

NASA Astrophysics Data System (ADS)

Sivy, Kelly J.; Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan

2011-07-01

Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord's kangaroo rat ( Dipodomys ordii) and the Great Basin pocket mouse ( Perognathus parvus). The indirect cue was shrub cover, a feature of the environment. Direct cues, presented individually, were (1) control, (2) coyote ( Canis latrans) vocalization, (3) coyote scent, (4) red fox ( Vulpes vulpes) scent, or (5) short-eared owl ( Asio flammeus) vocalization. We offered seeds of three sizes: two native grasses, Indian ricegrass ( Achnatherum hymenoides) and bluebunch wheatgrass ( Pseudoroegneria spicata), and the non-native cereal rye ( Secale cereale), each in separate trays. Kangaroo rats preferentially harvested Indian ricegrass while pocket mice predominately harvested Indian ricegrass and cereal rye. Pocket mice were more likely to scatter hoard preferred seeds, whereas kangaroo rats mostly consumed and/or larder hoarded preferred seeds. No predator cue significantly affected seed preferences. However, both species altered seed handling behavior in response to direct predation cues by leaving more seeds available in the seed pool, though they responded to different predator cues. If these results translate to natural dynamics on the landscape, the two rodents are expected to have different impacts on seed survival and plant recruitment via their different seed selection and seed handling behaviors.

Effects of rodent species, seed species, and predator cues on seed fate

USGS Publications Warehouse

Sivy, Kelly J.; Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan

2011-01-01

Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord's kangaroo rat (Dipodomys ordii) and the Great Basin pocket mouse (Perognathus parvus). The indirect cue was shrub cover, a feature of the environment. Direct cues, presented individually, were (1) control, (2) coyote (Canis latrans) vocalization, (3) coyote scent, (4) red fox (Vulpes vulpes) scent, or (5) short-eared owl (Asio flammeus) vocalization. We offered seeds of three sizes: two native grasses, Indian ricegrass (Achnatherum hymenoides) and bluebunch wheatgrass (Pseudoroegneria spicata), and the non-native cereal rye (Secale cereale), each in separate trays. Kangaroo rats preferentially harvested Indian ricegrass while pocket mice predominately harvested Indian ricegrass and cereal rye. Pocket mice were more likely to scatter hoard preferred seeds, whereas kangaroo rats mostly consumed and/or larder hoarded preferred seeds. No predator cue significantly affected seed preferences. However, both species altered seed handling behavior in response to direct predation cues by leaving more seeds available in the seed pool, though they responded to different predator cues. If these results translate to natural dynamics on the landscape, the two rodents are expected to have different impacts on seed survival and plant recruitment via their different seed selection and seed handling behaviors.

An analysis of the development of cauliflower seed as a model to improve the molecular mechanism of abiotic stress tolerance in cauliflower artificial seeds.

PubMed

Rihan, Hail Z; Al-Issawi, Mohammed; Fuller, Michael P

2017-07-01

The development stages of conventional cauliflower seeds were studied and the accumulation of dehydrin proteins through the maturation stages was investigated with the aim of identifying methods to improve the viability of artificial seeds of cauliflower. While carbohydrate, ash and lipids increased throughout the development of cauliflower traditional seeds, proteins increased with the development of seed and reached the maximum level after 75 days of pollination, however, the level of protein started to decrease after that. A significant increase in the accumulation of small size dehydrin proteins (12, 17, 26 KDa) was observed during the development of cauliflower seeds. Several experiments were conducted in order to increase the accumulation of important dehydrin proteins in cauliflower microshoots (artificial seeds). Mannitol and ABA (Absisic acid) increased the accumulation of dehydrins in cauliflower microshoots while cold acclimation did not have a significant impact on the accumulation of these proteins. Molybdenum treatments had a negative impact on dehydrin accumulation. Dehydrins have an important role in the drought tolerance of seeds and, therefore, the current research helps to improve the accumulation of these proteins in cauliflower artificial seeds. This in turns improves the quality of these artificial seeds. The current results suggest that dehydrins do not play an important role in cold tolerance of cauliflower artificial seeds. This study could have an important role in improving the understanding of the molecular mechanism of abiotic stress tolerance in plants. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Biochemical Changes after Short-term Oral Exposure of Jatropha curcas Seeds in Wistar Rats

PubMed Central

Awasthy, Vijeyta; Vadlamudi, V. P.; Koley, K. M.; Awasthy, B. K.; Singh, P. K.

2010-01-01

Jatropha curcas (Euphorbiaceae) is a multipurpose shrub with varied medicinal uses and is of significant economic importance. In addition to being the source of biodiesel, its seeds are also considered highly nutritious and could be exploited as a rich and economical protein supplement in animal feeds. However, the inherent phytotoxins present in the seed is the hindrance. The toxicity nature of the seeds of the local variety of J. curcas is not known. Therefore, investigations were undertaken to evaluate the short-term oral toxicity of the seeds of locally grown J. curcas. Short-term toxicity was conducted in rats by daily feeding the basal diet (Group I), and the diet in which the crude protein requirement was supplemented at 25% (Group II) and 50% (Group III) levels through Jatropha seed powder. The adverse effects of Jatropha seed protein supplementation (JSPS) were evaluated by observing alterations in biochemical profiles. The biochemical profile of rats fed on diet with JSPS at both the levels revealed significant reduction in plasma glucose and total protein and increase in plasma creatinine, transaminases (Plasma glutamic pyruvic transaminase and Plasma glutamic oxaloacetic transaminase), and alkaline phosphatase. PMID:21170248

Timing of seed dispersal generates a bimodal seed bank depth distribution

USGS Publications Warehouse

Espinar, J.L.; Thompson, K.; Garcia, L.V.

2005-01-01

The density of soil seed banks is normally highest at the soil surface and declines monotonically with depth. Sometimes, for a variety of reasons, peak density occurs below the surface but, except in severely disturbed soils, it is generally true that deeper seeds are older. In seasonally dry habitats that develop deep soil cracks during the dry season, it is possible that some seeds fall down cracks and rapidly become deeply buried. We investigated this possibility for three dominant clonal perennials (Scirpus maritimus, S. litoralis, and Juncus subulatus) in the Don??ana salt marsh, a nontidal marsh with a Mediterranean climate located in southwest Spain. Two species, which shed most of their seed during the dry season and have seeds with low buoyancy, had bimodal viable seed depth distributions, with peak densities at the surface and at 16-20 cm. A third species, which shed most seeds after soil cracks had closed and had seeds with high buoyancy, had viable seeds only in surface soil. Bimodal seed bank depth distributions may be relatively common in seasonally dry habitats with fine-textured soils, but their ecological significance has not been investigated.

The Biostack Experiments I and II aboard Apollo 16 and 17.

PubMed

Bucker, H

1974-01-01

The concept of the Biostack experiment has become practicable through European scientific collaboration and with help of NASA. The objectives of this experiment flown aboard Apollo 16 and 17 are to study the biological effects of individual heavy cosmic particles of high-energy loss (HZE) not available on earth; to study the influence of additional spaceflight factors; to get some knowledge on the mechanism by which HZE particles damage biological materials; to get information on the spectrum of charge and energy of the cosmic ions in the spacecraft; to estimate the radiation hazards for man in space. For this purpose the Biostack experiment comprises a widespread spectrum of biological objects, and various radiobiological end-points are under investigation. Bacterial spores, protozoa cysts, plant seeds, shrimp eggs, and insect eggs were included in the Biostack experiment packages together with different physical radiation detectors (nuclear emulsions, plastics, AgCl crystals, and LiF thermoluminescence dosimeters). By using special arrangements of biological objects and physical track detectors, individual evaluation of tracks was obtained allowing the identification of each penetrating particle in relation to the possible biological effects on its path. The response of the different biological objects to space flight and HZE ions bombardment was of different degree, presumably depending on the ability of the organism to replace the cells damaged by a hit. The results help to estimate the radiation hazard for astronauts during space missions of long duration.

Metabolic and structural changes during early maturation of Inga vera seeds are consistent with the lack of a desiccation phase.

PubMed

Caccere, Rodrigo; Teixeira, Simone P; Centeno, Danilo C; Figueiredo-Ribeiro, Rita de Cássia L; Braga, Márcia R

2013-06-15

Inga vera, native to South America, is an important leguminous species used for ecological restoration of riparian forests and its seeds are among the most recalcitrant ones described up to date. In this work, we analysed the metabolic profile, cell ultrastructure as well as cell wall polysaccharides of I. vera seeds in order to better understand its maturation, which allows embryo germination without a quiescent phase. Increased amounts of citric, glutamic, pyroglutamic, and aspartic acids from stages I to II (120 and 129 days after flowering (DAF)) corroborate the hypothesis of high metabolism, shifting from fermentative to aerobic respiration at seed maturity. This phase was characterized by an extensive vacuolization of embryonic cells, which also indicate high metabolic activity. The proportion of arabinose in the cell walls of embryonic axis (approx. 20%) was lower than those found in some orthodox seeds (nearly 40%), suggesting that arabinose-containing polysaccharides, which are thought to provide more flexibility to the cell wall during natural drying, are less abundant in I. vera seeds. Taken together, our results provide evidence that the major changes occurred during early stages of seed maturation of I. vera, indicating that the rapid temporary metabolic shift observed between stages I and II may be related to the lack of desiccation phase, moving directly to germination. Copyright © 2013 Elsevier GmbH. All rights reserved.

Stability Study of Algerian Nigella sativa Seeds Stored under Different Conditions

PubMed Central

Ahamad Bustamam, Muhammad Safwan; Hadithon, Kamarul Arifin; Rukayadi, Yaya; Lajis, Nordin

2017-01-01

In a study to determine the stability of the main volatile constituents of Nigella sativa seeds stored under several conditions, eight storage conditions were established, based on the ecological abiotic effects of air, heat, and light. Six replicates each were prepared and analyzed with Headspace-Gas Chromatography-Mass Spectrometry (HS-GC-MS) for three time points at the initial (1st day (0)), 14th (1), and 28th (2) day of storage. A targeted multivariate analysis of Principal Component Analysis revealed that the stability of the main volatile constituents of the whole seeds was better than that of the ground seeds. Exposed seeds, whole or ground, were observed to experience higher decrement of the volatile composition. These ecofactors of air, heat, and light are suggested to be directly responsible for the loss of volatiles in N. sativa seeds, particularly of the ground seeds. PMID:28255502

Relationships of red pine seed source, seed weight, seedling weight, and height growth in Kane test plantation

Treesearch

A. F. Hough

1952-01-01

In 1928 the Lake States Forest Experiment Station of the U. S. Forest Service began studies of various races or strains of red pine (Pinus resinosa Ait.), to find out how well red pine is adapted to climatic regions distant from its natural seed sources.

[Study on procedure of seed quality testing and seed grading scale of Phellodendron amurense].

PubMed

Liu, Yanlu; Zhang, Zhao; Dai, Lingchao; Zhang, Bengang; Zhang, Xiaoling; Wang, Han

2011-12-01

To study the procedure of seed quality testing and seed grading scale of Phellodendron amurense. Seed quality testing methods were developed, which included the test of sampling, seed purity, weight per 1 000 seeds, seed moisture, seed viability and germination rate. The related data from 62 cases of seed specimens of P. amurense were analyzed by cluster analysis. The seed quality test procedure was developed, and the seed quality grading scale was formulated.

High-efficiency microchip laser with self-injection seeding.

PubMed

Wang, Sha; Wang, Yan-biao; Yang, Xian-heng; Feng, Guo-ying; Zhou, Shou-huan

2015-12-10

In this paper, we use a small bandwidth 808 nm cw Ti:sapphire laser as a pump source to pump a picosecond microchip laser. Different focal length pump focus lenses have been tested to improve laser efficiency. A maximum slope efficiency of around 20% is obtained by a 30 mm focal length lens. The pump threshold is only 13 mW. In order to reduce the timing jitter, we explored the self-injection seeding method by adding a seeding cavity to the microchip laser. A reduction factor in the timing jitter of up to a factor of 23 relative to the unseeded laser is obtained. From the experiments, we also found that higher seeding pulse energy will help to reduce the jitter more.

Pine seed germination under weightlessness (a study of the Kosmos 782 satellite)

NASA Technical Reports Server (NTRS)

Platonova, R. N.; Parfenov, G. P.; Olkhovenko, V. P.; Karpova, N. I.; Pichugov, M. Y.

1977-01-01

Orientation of the above and underground organs of pine plants, grown from seeds under weightlessness, was found to be determined by seed position on the substrate. Normal plant growth was observed only if the seed embryos were oriented toward the substrate. Some differences were noted between the experimental and control plants concerning the amount of nucleoli in the root meristematic cells and the cell shape in cotyledonous leaves. No complete similarity was found in experimental results obtained with plants under weightlessness and under compensated gravity. The seeds were obtained from Pinus silvestris, considered to be particularly suitable for this experiment.

Improvements in and actual performance of the Plant Experiment Unit onboard Kibo, the Japanese experiment module on the international space station

NASA Astrophysics Data System (ADS)

Yano, Sachiko; Kasahara, Haruo; Masuda, Daisuke; Tanigaki, Fumiaki; Shimazu, Toru; Suzuki, Hiromi; Karahara, Ichirou; Soga, Kouichi; Hoson, Takayuki; Tayama, Ichiro; Tsuchiya, Yoshikazu; Kamisaka, Seiichiro

2013-03-01

In 2004, Japan Aerospace Exploration Agency developed the engineered model of the Plant Experiment Unit and the Cell Biology Experiment Facility. The Plant Experiment Unit was designed to be installed in the Cell Biology Experiment Facility and to support the seed-to-seed life cycle experiment of Arabidopsis plants in space in the project named Space Seed. Ground-based experiments to test the Plant Experiment Unit showed that the unit needed further improvement of a system to control the water content of a seedbed using an infrared moisture analyzer and that it was difficult to keep the relative humidity inside the Plant Experiment Unit between 70 and 80% because the Cell Biology Experiment Facility had neither a ventilation system nor a dehumidifying system. Therefore, excess moisture inside the Cell Biology Experiment Facility was removed with desiccant bags containing calcium chloride. Eight flight models of the Plant Experiment Unit in which dry Arabidopsis seeds were fixed to the seedbed with gum arabic were launched to the International Space Station in the space shuttle STS-128 (17A) on August 28, 2009. Plant Experiment Unit were installed in the Cell Biology Experiment Facility with desiccant boxes, and then the Space Seed experiment was started in the Japanese Experiment Module, named Kibo, which was part of the International Space Station, on September 10, 2009 by watering the seedbed and terminated 2 months later on November 11, 2009. On April 19, 2010, the Arabidopsis plants harvested in Kibo were retrieved and brought back to Earth by the space shuttle mission STS-131 (19A). The present paper describes the Space Seed experiment with particular reference to the development of the Plant Experiment Unit and its actual performance in Kibo onboard the International Space Station. Downlinked images from Kibo showed that the seeds had started germinating 3 days after the initial watering. The plants continued growing, producing rosette leaves, inflorescence

Myrmecochory and short-term seed fate in Rhamnus alaternus: Ant species and seed characteristics

NASA Astrophysics Data System (ADS)

Bas, J. M.; Oliveras, J.; Gómez, C.

2009-05-01

Benefits conferred on plants in ant-mediated seed dispersal mutualisms (myrmecochory) depend on the fate of transported seeds. We studied the effects of elaiosome presence, seed size and seed treatment (with and without passage through a bird's digestive tract) on short-term seed fate in Rhamnus alaternus. In our study, we define short-term seed, or initial, seed fate, as the location where ants release the seeds after ant contact with it. The elaiosomes had the most influence on short-term fate, i.e. whether or not seeds were transported to the nest. The workers usually transported big seeds more often than small ones, but small ants did not transport large seeds. Effect of seed size on transport depended on the ant species and on the treatment of the seed (manual extraction simulating a direct fall from the parent plant vs. bird deposition corresponding to preliminary primary dispersal). Probability of removal of elaiosome-bearing seeds to the nest by Aphaenogaster senilis increased with increasing seed weight.

Environmental factors influencing Pyrenophora semeniperda-caused seed mortality in Bromus tectorum

Treesearch

Heather Finch; Phil S. Allen; Susan E. Meyer

2013-01-01

Temperature and water potential strongly influence seed dormancy status and germination of Bromus tectorum. As seeds of this plant can be killed by the ascomycete fungus Pyrenophora semeniperda, this study was conducted to learn how water potential and temperature influence mortality levels in this pathosystem. Separate experiments were conducted to determine: (1) if P...

[Changes in Properties of Water during Germination of Zucchini Seed in Water Used].

PubMed

Novikov, S N; Novikov, L N; Ermolaeva, A I; Timoshenkov, S P; Goryunova, E P

2015-01-01

In this research the changes in the supramolecular structure of distilled water during germination of the seed in this water were studied. We used three methods: gravimetry, precision thermal analysis, electron work function measurements. In the first stage of seed germination--seed swelling--the seed extracts coherent domains in the water, herewith due to the transition of coherent domains adsorbed in nanofields into a stable state the flow of electromagnetic energy appears. In the second stage of the experiment--germ growing--the flow of biophotons occurs. This is evidenced by the increased water electron work function. A hypothetical model of the process of zucchini seed germination is suggested.

Practical considerations for maximizing heat production in a novel thermobrachytherapy seed prototype

PubMed Central

Gautam, Bhoj; Warrell, Gregory; Shvydka, Diana; Subramanian, Manny; Ishmael Parsai, E.

2014-01-01

, and a preliminary experiment demonstrates thermal self-regulation and adequate heating of a tissue-mimicking phantom by seed prototypes. The effect of self-shielding of the seed against the external magnetic field is small, and only minor thermal stress is induced in heating of the seeds from room temperature to well above the seed operating temperature. With proper selection of magnetic field parameters, the thermal dose distribution of an arrangement of TB and hyperthermia-only seeds may be made to match with its radiation dose distribution. Conclusions: The presented analyses address several practical considerations for manufacturing of the proposed TB seeds and identify critical issues for the prototype implementation. The authors’ preliminary experiments demonstrate close agreement with the modeling results, confirming the feasibility of combining sources of heat and radiation into a single thermobrachytherapy seed. PMID:24506651

Practical considerations for maximizing heat production in a novel thermobrachytherapy seed prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gautam, Bhoj; Warrell, Gregory; Shvydka, Diana

2014-02-15

CT images, and a preliminary experiment demonstrates thermal self-regulation and adequate heating of a tissue-mimicking phantom by seed prototypes. The effect of self-shielding of the seed against the external magnetic field is small, and only minor thermal stress is induced in heating of the seeds from room temperature to well above the seed operating temperature. With proper selection of magnetic field parameters, the thermal dose distribution of an arrangement of TB and hyperthermia-only seeds may be made to match with its radiation dose distribution. Conclusions: The presented analyses address several practical considerations for manufacturing of the proposed TB seeds and identify critical issues for the prototype implementation. The authors’ preliminary experiments demonstrate close agreement with the modeling results, confirming the feasibility of combining sources of heat and radiation into a single thermobrachytherapy seed.« less

Practical considerations for maximizing heat production in a novel thermobrachytherapy seed prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gautam, Bhoj; Warrell, Gregory; Shvydka, Diana

CT images, and a preliminary experiment demonstrates thermal self-regulation and adequate heating of a tissue-mimicking phantom by seed prototypes. The effect of self-shielding of the seed against the external magnetic field is small, and only minor thermal stress is induced in heating of the seeds from room temperature to well above the seed operating temperature. With proper selection of magnetic field parameters, the thermal dose distribution of an arrangement of TB and hyperthermia-only seeds may be made to match with its radiation dose distribution. Conclusions: The presented analyses address several practical considerations for manufacturing of the proposed TB seeds and identify critical issues for the prototype implementation. The authors’ preliminary experiments demonstrate close agreement with the modeling results, confirming the feasibility of combining sources of heat and radiation into a single thermobrachytherapy seed.« less

Seed proteomics.

PubMed

Miernyk, Ján A; Hajduch, Martin

2011-04-01

Seeds comprise a protective covering, a small embryonic plant, and a nutrient-storage organ. Seeds are protein-rich, and have been the subject of many mass spectrometry-based analyses. Seed storage proteins (SSP), which are transient depots for reduced nitrogen, have been studied for decades by cell biologists, and many of the complicated aspects of their processing, assembly, and compartmentation are now well understood. Unfortunately, the abundance and complexity of the SSP requires that they be avoided or removed prior to gel-based analysis of non-SSP. While much of the extant data from MS-based proteomic analysis of seeds is descriptive, it has nevertheless provided a preliminary metabolic picture explaining much of their biology. Contemporary studies are moving more toward analysis of protein interactions and posttranslational modifications, and functions of metabolic networks. Many aspects of the biology of seeds make then an attractive platform for heterologous protein expression. Herein we present a broad review of the results from the proteomic studies of seeds, and speculate on a potential future research directions. Copyright © 2010 Elsevier B.V. All rights reserved.

Involvement of Alternative Splicing in Barley Seed Germination

PubMed Central

Zhang, Qisen; Zhang, Xiaoqi; Wang, Songbo; Tan, Cong; Zhou, Gaofeng; Li, Chengdao

2016-01-01

Seed germination activates many new biological processes including DNA, membrane and mitochondrial repairs and requires active protein synthesis and sufficient energy supply. Alternative splicing (AS) regulates many cellular processes including cell differentiation and environmental adaptations. However, limited information is available on the regulation of seed germination at post-transcriptional levels. We have conducted RNA-sequencing experiments to dissect AS events in barley seed germination. We identified between 552 and 669 common AS transcripts in germinating barley embryos from four barley varieties (Hordeum vulgare L. Bass, Baudin, Harrington and Stirling). Alternative 3’ splicing (34%-45%), intron retention (32%-34%) and alternative 5’ splicing (16%-21%) were three major AS events in germinating embryos. The AS transcripts were predominantly mapped onto ribosome, RNA transport machineries, spliceosome, plant hormone signal transduction, glycolysis, sugar and carbon metabolism pathways. Transcripts of these genes were also very abundant in the early stage of seed germination. Correlation analysis of gene expression showed that AS hormone responsive transcripts could also be co-expressed with genes responsible for protein biosynthesis and sugar metabolisms. Our RNA-sequencing data revealed that AS could play important roles in barley seed germination. PMID:27031341

Can seed removal through soil erosion explain the scarcity of vegetation in the Chinese Loess Plateau?

NASA Astrophysics Data System (ADS)

Jiao, Juying; Han, Luyan; Jia, Yanfeng; Wang, Ning; Lei, Dong; Li, Linyu

2011-09-01

Seed removal by water erosion may explain the sparse vegetation cover in systems like the Chinese Loess Plateau, which is characterized by severe soil erosion. The seeds from 16 species found on the plateau were examined in relation to the likelihood of their removal by erosion, as tested by rainfall simulation experiments. The experiments were performed over 1-m 2 plots with slopes of 10°, 15°, 20° and 25° for 60 min at intensities of 50 mm h -1, 100 mm h -1 and 150 mm h -1, respectively. Seed loss occurred at simulated rainfall intensities of 100 mm h -1 and 150 mm h -1, with total seed loss rates of 26-33% and 59-67%, respectively. Most seeds were displaced, even at 50 mm h -1. The degrees of seed loss and displacement varied among species. These data, in combination with data from our former research on propagule, seedling and population development in these species, indicate that the species with high seed loss rates either compensate by having a soil seed bank that produces seedlings during the growing season or reproduce by vegetative propagation; the species with no seed loss are still sparsely distributed. Seed germination and seedling survival seem to be more important than seed loss in determining establishment in these regions of the Loess Plateau. Seed translocation by water erosion, however, contributes to the observed distribution of vegetation in this geographic region.

A new method to track seed dispersal and recruitment using 15N isotope enrichment.

PubMed

Carlo, Tomás A; Tewksbury, Joshua J; Martínez Del Río, Carlos

2009-12-01

Seed dispersal has a powerful influence on population dynamics, genetic structuring, evolutionary rates, and community ecology. Yet, patterns of seed dispersal are difficult to measure due to methodological shortcomings in tracking dispersed seeds from sources of interest. Here we introduce a new method to track seed dispersal: stable isotope enrichment. It consists of leaf-feeding plants with sprays of 15N-urea during the flowering stage such that seeds developed after applications are isotopically enriched. We conducted a greenhouse experiment with Solanum americanum and two field experiments with wild Capsicum annuum in southern Arizona, USA, to field-validate the method. First, we show that plants sprayed with 15N-urea reliably produce isotopically enriched progeny, and that delta 15N (i.e., the isotopic ratio) of seeds and seedlings is a linear function of the 15N-urea concentration sprayed on mothers. We demonstrate that three urea dosages can be used to distinctly enrich plants and unambiguously differentiate their offspring after seeds are dispersed by birds. We found that, with high urea dosages, the resulting delta 15N values in seedlings are 10(3) - 10(4) times higher than the delta 15N values of normal plants. This feature allows tracking not only where seeds arrive, but in locations where seeds germinate and recruit, because delta 15N enrichment is detectable in seedlings that have increased in mass by at least two orders of magnitude before fading to normal delta 15N values. Last, we tested a mixing model to analyze seed samples in bulk. We used the delta 15N values of batches (i.e., combined seedlings or seeds captured in seed traps) to estimate the number of enriched seeds coming from isotopically enriched plants in the field. We confirm that isotope enrichment, combined with batch-sampling, is a cheap, reliable, and user-friendly method for bulk-processing seeds and is thus excellent for the detection of rare dispersal events. This method could

Persistence of seeds from crops of conventional and herbicide tolerant oilseed rape (Brassica napus)

PubMed Central

Lutman, Peter J.W; Berry, Kate; Payne, Roger W; Simpson, Euan; Sweet, Jeremy B; Champion, Gillian T; May, Mike J; Wightman, Pat; Walker, Kerr; Lainsbury, Martin

2005-01-01

A series of rotation experiments at five sites over four years has explored the environmental and agronomic implications of growing herbicide tolerant oilseed rape and sugar beet. This paper reports on the population dynamics of volunteer rape (Brassica napus). The experiments compared four winter oilseed rape (WOSR) cultivars: a conventional cultivar (Apex) and three developmental cultivars either genetically modified (GM) to be tolerant to glyphosate or glufosinate, or conventionally bred to be tolerant to herbicides of the imidazolinone group. Seed losses at harvest averaged 3575 seeds m−2 but ranged from less than 2000 up to more than 10 000 seeds m−2. There was a rapid decline in seed numbers during the first few months after harvest, resulting in a mean loss of seeds of 60%. In subsequent seasons, the seedbank declined much more slowly at four of the five sites (ca 20% per year) and the models predicted 95% seed loss after approximately 9 years. Seed decline was much faster at the fifth site. There were no clear differences between the four cultivars in either the numbers of seeds shed at harvest or in their subsequent persistence. The importance of the persistence of GM rape seeds, in the context of the coexistence of GM and non-GM crops and the role of good management practices that minimize seed persistence, are discussed. PMID:16191596

Seed Pubescence and Shape Modulate Adaptive Responses to Fire Cues

PubMed Central

Gómez-González, Susana; Ojeda, Fernando; Torres-Morales, Patricio; Palma, Jazmín E.

2016-01-01

Post-fire recruitment by seeds is regarded as an adaptive response in fire-prone ecosystems. Nevertheless, little is known about which heritable seed traits are functional to the main signals of fire (heat and smoke), thus having the potential to evolve. Here, we explored whether three seed traits (pubescence, dormancy and shape) and fire regime modulate seed response to fire cues(heat and smoke). As a model study system, we used Helenium aromaticum (Asteraceae), a native annual forb from the Chilean matorral, where fires are anthropogenic. We related seed trait values with fitness responses (germination and survival) after exposure to heat-shock and smoke experimental treatments on seeds from 10 H. aromaticum wild populations. We performed a phenotypic selection experiment to examine the relationship of seed traits with post-treatment fitness within a population (adaptive hypothesis). We then explored whether fire frequency in natural habitats was associated with trait expression across populations, and with germination and survival responses to experimental fire-cues. We found that populations subjected to higher fire frequency had, in average, more rounded and pubescent seeds than populations from rarely burned areas. Populations with more rounded and pubescent seeds were more resistant to 80°C heat-shock and smoke treatments.There was correlated selection on seed traits: pubescent-rounded or glabrouscent-elongated seeds had the highest probability of germinating after heat-shock treatments. Seed pubescence and shape in H. aromaticum are heritable traits that modulate adaptive responses to fire. Our results provide new insights into the process of plant adaptation to fire and highlight the relevance of human-made fires as a strong evolutionary agent in the Anthropocene. PMID:27438267

Seed Pubescence and Shape Modulate Adaptive Responses to Fire Cues.

PubMed

Gómez-González, Susana; Ojeda, Fernando; Torres-Morales, Patricio; Palma, Jazmín E

2016-01-01

Post-fire recruitment by seeds is regarded as an adaptive response in fire-prone ecosystems. Nevertheless, little is known about which heritable seed traits are functional to the main signals of fire (heat and smoke), thus having the potential to evolve. Here, we explored whether three seed traits (pubescence, dormancy and shape) and fire regime modulate seed response to fire cues(heat and smoke). As a model study system, we used Helenium aromaticum (Asteraceae), a native annual forb from the Chilean matorral, where fires are anthropogenic. We related seed trait values with fitness responses (germination and survival) after exposure to heat-shock and smoke experimental treatments on seeds from 10 H. aromaticum wild populations. We performed a phenotypic selection experiment to examine the relationship of seed traits with post-treatment fitness within a population (adaptive hypothesis). We then explored whether fire frequency in natural habitats was associated with trait expression across populations, and with germination and survival responses to experimental fire-cues. We found that populations subjected to higher fire frequency had, in average, more rounded and pubescent seeds than populations from rarely burned areas. Populations with more rounded and pubescent seeds were more resistant to 80°C heat-shock and smoke treatments.There was correlated selection on seed traits: pubescent-rounded or glabrouscent-elongated seeds had the highest probability of germinating after heat-shock treatments. Seed pubescence and shape in H. aromaticum are heritable traits that modulate adaptive responses to fire. Our results provide new insights into the process of plant adaptation to fire and highlight the relevance of human-made fires as a strong evolutionary agent in the Anthropocene.

Brassica napus seed endosperm - metabolism and signaling in a dead end tissue.

PubMed

Lorenz, Christin; Rolletschek, Hardy; Sunderhaus, Stephanie; Braun, Hans-Peter

2014-08-28

Oilseeds are an important element of human nutrition and of increasing significance for the production of industrial materials. The development of the seeds is based on a coordinated interplay of the embryo and its surrounding tissue, the endosperm. This study aims to give insights into the physiological role of endosperm for seed development in the oilseed crop Brassica napus. Using protein separation by two-dimensional (2D) isoelectric focusing (IEF)/SDS polyacrylamide gel electrophoresis (PAGE) and protein identification by mass spectrometry three proteome projects were carried out: (i) establishment of an endosperm proteome reference map, (ii) proteomic characterization of endosperm development and (iii) comparison of endosperm and embryo proteomes. The endosperm proteome reference map comprises 930 distinct proteins, including enzymes involved in genetic information processing, carbohydrate metabolism, environmental information processing, energy metabolism, cellular processes and amino acid metabolism. To investigate dynamic changes in protein abundance during seed development, total soluble proteins were extracted from embryo and endosperm fractions at defined time points. Proteins involved in sugar converting and recycling processes, ascorbate metabolism, amino acid biosynthesis and redox balancing were found to be of special importance for seed development in B. napus. Implications for the seed filling process and the function of the endosperm for seed development are discussed. The endosperm is of key importance for embryo development during seed formation in plants. We present a broad study for characterizing endosperm proteins in the oilseed plant B. napus. Furthermore, a project on the biochemical interplay between the embryo and the endosperm during seed development is presented. We provide evidence that the endosperm includes a complete set of enzymes necessary for plant primary metabolism. Combination of our results with metabolome data will further

Does retained-seed priming drive the evolution of serotiny in drylands? An assessment using the cactus Mammillaria hernandezii.

PubMed

Santini, Bianca A; Martorell, Carlos

2013-02-01

Serotinous plants retain their seeds for a long time. In deserts, retained seeds undergo hydration-dehydration cycles and thus may become primed. Priming enhances germination and seedling vigor. We test the hypothesis that serotiny evolves because it provides a site protected from predators in which seeds can become primed. Rainfall-cued dispersal of primed seeds may enhance this effect. We tested this hypothesis with Mammillaria hernandezii through protein-content analyses; field and laboratory germination experiments with primed, unprimed, and retained seeds; and fitness estimations from demographic models. Hydration-dehydration cycles induced priming, enhancing germination. Artificial priming and retention in the parent plant for 1 yr induced similar changes in seed protein patterns, suggesting that priming occurs naturally while seeds are retained. Under field conditions, germination of seeds retained for 1 yr more than doubled that of seeds of the same cohort that were not primed or that remained buried for 1 yr. The first seeds to germinate died rapidly. Serotinous plants whose seeds underwent priming had higher fitness than those whose seeds were in the soil seed bank or that did not experience priming. Priming in soil seed banks may be costly because of high predation, so seed protection during priming is sufficient to promote the evolution of serotiny. Bet hedging contributes to this process. Rapid germination of primed seeds that respond to brief rainfall events is disadvantageous because such rainfall is insufficient for seedling survival. Serotinous species counteract this cost by cueing dispersal with heavy precipitation.

Towards a better monitoring of seed ageing under ex situ seed conservation

PubMed Central

Fu, Yong-Bi; Ahmed, Zaheer; Diederichsen, Axel

2015-01-01

Long-term conservation of 7.4 million ex situ seed accessions held in agricultural genebanks and botanic gardens worldwide is a challenging mission for human food security and ecosystem services. Recent advances in seed biology and genomics may have opened new opportunities for effective management of seed germplasm under long-term storage. Here, we review the current development of tools for assessing seed ageing and research advances in seed biology and genomics, with a focus on exploring their potential as better tools for monitoring of seed ageing. Seed ageing is found to be associated with the changes reflected in reactive oxygen species and mitochondria-triggered programmed cell deaths, expression of antioxidative genes and DNA and protein repair genes, chromosome telomere lengths, epigenetic regulation of related genes (microRNA and methylation) and altered organelle and nuclear genomes. Among these changes, the signals from mitochondrial and nuclear genomes may show the most promise for use in the development of tools to predict seed ageing. Non-destructive and non-invasive analyses of stored seeds through calorimetry or imaging techniques are also promising. It is clear that research into developing advanced tools for monitoring seed ageing to supplement traditional germination tests will be fruitful for effective conservation of ex situ seed germplasm. PMID:27293711

Environmental regulation of dormancy loss in seeds of Lomatium dissectum (Apiaceae)

PubMed Central

Scholten, Melissa; Donahue, Jacklyn; Shaw, Nancy L.; Serpe, Marcelo D.

2009-01-01

Background and Aims Lomatium dissectum (Apiaceae) is a perennial, herbaceous plant of wide distribution in Western North America. At the time of dispersal, L. dissectum seeds are dormant and have under-developed embryos. The aims of this work were to determine the requirements for dormancy break and germination, to characterize the type of seed dormancy, and to determine the effect of dehydration after embryo growth on seed viability and secondary dormancy. Methods The temperature requirements for embryo growth and germination were investigated under growth chamber and field conditions. The effect of GA3 on embryo growth was also analysed to determine the specific type of seed dormancy. The effect of dehydration on seed viability and induction of secondary dormancy were tested in seeds where embryos had elongated about 4-fold their initial length. Most experiments examining the nature of seed dormancy were conducted with seeds collected at one site in two different years. To characterize the degree of variation in dormancy-breaking requirements among seed populations, the stratification requirements of seeds collected at eight different sites were compared. Key Results Embryo growth prior to and during germination occurred at temperatures between 3 and 6 °C and was negligible at stratification temperatures of 0·5 and 9·1 °C. Seeds buried in the field and exposed to natural winter conditions showed similar trends. Interruption of the cold stratification period by 8 weeks of dehydration decreased seed viability by about 30 % and induced secondary dormancy in the remaining viable seeds. Comparison of the cold stratification requirements of different seed populations indicates that seeds collected from moist habitats have longer cold stratification requirements that those from semiarid environments. Conclusions Seeds of L. dissectum have deep complex morphophysiological dormancy. The requirements for dormancy break and germination reflect an adaptation to trigger

The effect of hydrostatic vs. shock pressure treatment of plant seeds

NASA Astrophysics Data System (ADS)

Mustey, A.; Leighs, J. A.; Appleby-Thomas, G. J.; Wood, D. C.; Hazael, R.; McMillan, P. F.; Hazell, P. J.

2014-05-01

The hydrostatic pressure and shock response of plant seeds has been investigated antecedently, primarily driven by interest in reducing bacterial contamination of crops and the theory of panspermia, respectively. However, comparisons have not previously been made between these two methods ofapplying pressure to plant seeds. Here such a comparison has been undertaken based on the premise that any correlations in collected data may provide a route to inform understanding of damage mechanisms in the seeds under test. In this work two varieties of plant seeds were subjected to hydrostatic pressure via a non-end-loaded piston cylinder setup and shock compression via employment of a 50 mm bore, single stage gas gun using the flyer plate technique. Results from germination tests of recovered seed samples have been compared and contrasted, and initial conclusions made regarding causes of trends in the resultant data-set. Data collected has shown that cress seeds are extremely resilient to static loading, whereas the difference in the two forms of loading is negligible for lettuce seeds. Germination time has been seen to extend dramatically following static loading of cress seeds to greater than 0.4 GPa. In addition, the cut-off pressure previously seen to cause 0% germination in dynamic experiments performed on cress seeds has now also been seen in lettuce seeds.

Effects of inorganic seeds on secondary organic aerosol formation from photochemical oxidation of acetone in a chamber

NASA Astrophysics Data System (ADS)

Ge, Shuangshuang; Xu, Yongfu; Jia, Long

2017-12-01

Photochemical oxidations of acetone were studied under different inorganic seed (NaCl, (NH4)2SO4 and NaNO3) conditions in a self-made chamber. The results show that no secondary organic aerosol (SOA) can be formed in the experiments either in the absence of artificially added seed particles or in the presence of solid status of the added particles. Liquid water content is the key factor for the formation of SOA in the experiments with seeds. The amount of SOA was only about 4-7 μg m-3 in the experiments with the initial acetone of ∼15 ppm under different seed conditions. The analysis of SOA compositions by Exactive-Orbitrap mass spectrometer equipped with electro-spray interface (ESI-MS) shows that chlorine-containing and sulfur-containing compounds were detected in SOA formed from the experiments with NaCl and (NH4)2SO4 seeds, respectively, which were not identified in SOA from those with NaNO3. The compositions of SOA were mainly esters, organonitrates, hydroperoxides, etc. It is concluded that inorganic seed particles participated into the formation of SOA. Acetone SOA was mainly formed in the aqueous phase in which dissolved SOA precursors underwent further oxidation reactions, esterification reactions and/or radical-radical reactions. Our experiments further demonstrate that low-molecular-weight VOCs, such as acetone, can form SOA under certain conditions in the atmosphere, although their contributions to SOA may not be large.

Online Data Reduction for the Belle II Experiment using DATCON

NASA Astrophysics Data System (ADS)

Bernlochner, Florian; Deschamps, Bruno; Dingfelder, Jochen; Marinas, Carlos; Wessel, Christian

2017-08-01

The new Belle II experiment at the asymmetric e+e-accelerator SuperKEKB at KEK in Japan is designed to deliver a peak luminosity of 8 × 1035cm-2s-1. To perform high-precision track reconstruction, e.g. for measurements of time-dependent CP-violating decays and secondary vertices, the Belle II detector is equipped with a highly segmented pixel detector (PXD). The high instantaneous luminosity and short bunch crossing times result in a large stream of data in the PXD, which needs to be significantly reduced for offline storage. The data reduction is performed using an FPGA-based Data Acquisition Tracking and Concentrator Online Node (DATCON), which uses information from the Belle II silicon strip vertex detector (SVD) surrounding the PXD to carry out online track reconstruction, extrapolation to the PXD, and Region of Interest (ROI) determination on the PXD. The data stream is reduced by a factor of ten with an ROI finding efficiency of >90% for PXD hits inside the ROI down to 50MeV in pT of the stable particles. We will present the current status of the implementation of the track reconstruction using Hough transformations, and the results obtained for simulated ϒ(4S) → BB¯ events.

Reduction of Salmonella on alfalfa seeds using peroxyacetic acid and a commercial seed washer is as effective as treatment with 20 000 ppm of Ca(OCl)2.

PubMed

Buchholz, A; Matthews, K R

2010-10-01

The efficacy of a commercial seed washer and 1 and 3% peroxyacetic acid or 20 000 ppm calcium hypochlorite for reducing Salmonella on alfalfa seeds was investigated. Alfalfa seeds were inoculated with Salmonella Stanley to achieve c. 5 log CFU g(-1). Seeds were then treated with 1 or 3% peroxyacetic acid or 20 000 ppm calcium hypochlorite for 15 min in a commercial seed washer that uses air to enhance contact of the sanitizer with the seed. Experiments were also conducted using industry and laboratory methods. An c. 1-log reduction in number of Salm. Stanley was demonstrated regardless of the chemical treatment or method of treatment. Although this 1-log reduction was significant (P < 0.05), differences among the treatments were not significant. Treating the seed with 1 and 3% peroxyacetic acid resulted in similar Salm. Stanley reductions of 1.77 and 1.34 log, respectively, not being statistically significant (P > 0.05). These results suggest that under conditions tested, 1 or 3% peroxyacetic acid solutions are equally effective as 20 000 ppm of Ca(OCl)2 in the reduction of Salm. Stanley on alfalfa seed when used in conjunction with a commercial seed washer. A 1% peroxyacetic acid solution could potentially be used in place of 20 000 ppm of Ca(OCl)2 for treatment of seeds used for sprouting. The commercial seed washer did not enhance removal of Salm. Stanley from alfalfa seeds, but did facilitate removal of excess soil from seeds. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Influence of Light Intensity and Photoperiod on the Seed Germination of Four Rhododendron Species in Taiwan.

PubMed

Lin, Lei-Chen; Wang, Chang-Sheng

2017-01-01

There are 15 native Rhododendron species in Taiwan, among which 11 species are endemic and compose 73% of these native species. Although researchers predominantly use cuttings to propagate Rhododendron shrubs, there are no studies on the seed germination of Rhododendron species. The objective of this study was to evaluate the seed germination of four Rhododendron species in Taiwan under different light intensities and photoperiods. Two experiments on the seed germination percentage of R. breviperulatum, R. kanehirai, R. ovatum and R. simsii were conducted in this study. The first experiment was to identify the seed germination percentage of these four Rhododendron species using different light intensities (0, 700, 1400 and 3200 lux). The second experiment was to clarify the seed germination percentage of these four Rhododendron species using different photoperiods (0, 1, 4 and 16 h). All statistical analyses were performed using Statistical Package for the Social Science (SPSS12.0) for Windows software program. The data were analyzed using Tukey's multiple range test at the p<0.05 significance level. After 30 days, no seed germination occurred in darkness. The highest average seed germination percentages were all observed at 700 lux: R. breviperulatum (83.3%), R. kanehirai (68.9%), R. ovatum (85.6%) and R. simsii (92.2%). The highest average germination percentages of seeds were observed in R. breviperulatum at 16 h (83.3%), R. kanehirai at 1 h (60.0%), R. ovatum at 16 h (84.4%) and R. simsii at 16 h (85.6%). According to the results, these four Rhododendron species required light for germination. There were significant differences (p<0.05) in the seed germination of these four Rhododendron species for light intensity greater than 700 lux. Similar results were observed with photoperiods. The seed germination percentage of R. breviperulatum, R. ovatum and R. simsii increased with increasing photoperiod.

Seed Treatment. Manual 92.

ERIC Educational Resources Information Center

Missouri Univ., Columbia. Agricultural Experiment Station.

This training manual provides information needed to meet minimum EPA standards for certification as a commercial applicator of pesticides in the seed treatment category. The text discusses pests commonly associated with seeds; seed treatment pesticides; labels; chemicals and seed treatment equipment; requirements of federal and state seed laws;…

Seed Treatment. Bulletin 760.

ERIC Educational Resources Information Center

Lowery, Harvey C.

This manual gives a definition of seed treatment, the types of seeds normally treated, diseases and insects commonly associated with seeds, fungicides and insecticides used, types of equipment used for seed treatment, and information on labeling and coloring of treated seed, pesticide carriers, binders, stickers, and safety precautions. (BB)

Adenylate and Nicotinamide Nucleotides in Developing Soybean Seeds During Seed-Fill 1

PubMed Central

Quebedeaux, Bruno

1981-01-01

Profiles of adenylate and nicotinamide nucleotides in soybean seeds were determined during seed-fill. The ATP content per seed increased during the early seed-filling stages to a level of 10 to 12 micrograms per seed. Seed ATP decreased after 40 days of development and reached its lowest level of less than 1 microgram at maturity. The ATP:ADP ratios were relatively constant at all seed development stages. Sharp increases in AMP levels during the late seed-fill stages were paralleled with a disappearance of ATP and ADP pools resulting in a reduced seed energy charge. Energy charge varied from the highest value of 0.78 at mid-seed-fill to less than 0.10 at maturity. Of the oxidized (NAD, NADP) and reduced (NADH, NADPH) nicotinamide nucleotide forms, NAD was the most abundant. Levels as high as 17.5 micrograms per seed were observed during the mid-seed-filling stages. NADP was found almost exclusively in the reduced form with a NADP: NADPH ratio of less than 0.35, whereas the reverse was noted for NAD which was found mainly in the oxidized form with a NAD:NADH ratio in the range of 5 to 25. NADP was detected in low concentrations compared to the other adenylate and nicotinamide nucleotides. The nicotinamide redox charge defined as (NADH + NADPH)/(NAD + NADH) + (NADP + NADPH) was calculated to express the state of the energy balance between the oxidized and reduced nicotinamide nucleotide forms. The nicotinamide redox charge varied between 0.15 and 0.30 during seed development and was significantly lower than that found for the adenylate energy charge. PMID:16661875

Vertebrate seed dispersers maintain the composition of tropical forest seedbanks

PubMed Central

Wandrag, E. M.; Dunham, A. E.; Miller, R. H.; Rogers, H. S.

2015-01-01

The accumulation of seeds in the soil (the seedbank) can set the template for the early regeneration of habitats following disturbance. Seed dispersal is an important factor determining the pattern of seed rain, which affects the interactions those seeds experience. For this reason, seed dispersal should play an important role in structuring forest seedbanks, yet we know little about how that happens. Using the functional extirpation of frugivorous vertebrates from the island of Guam, together with two nearby islands (Saipan and Rota) that each support relatively intact disperser assemblages, we aimed to identify the role of vertebrate dispersers in structuring forest seedbanks. We sampled the seedbank on Guam where dispersers are absent, and compared this with the seedbank on Saipan and Rota where they are present. Almost twice as many species found in the seedbank on Guam, when compared with Saipan and Rota, had a conspecific adult within 2 m. This indicates a strong role of vertebrate dispersal in determining the identity of seeds in the seedbank. In addition, on Guam, a greater proportion of samples contained no seeds and overall species richness was lower than on Saipan. Differences in seed abundance and richness between Guam and Rota were less clear, as seedbanks on Rota also contained fewer species than Saipan, possibly due to increased post-dispersal seed predation. Our findings suggest that vertebrate seed dispersers can have a strong influence on the species composition of seedbanks. Regardless of post-dispersal processes, without dispersal, seedbanks no longer serve to increase the species pool of recruits during regeneration. PMID:26578741

Chloroxyanion Residue on Seeds and Sprouts after Chlorine Dioxide Sanitation of Alfalfa Seed.

PubMed

Smith, David J; Herges, Grant R

2018-02-28

The effects of a 6-h chlorine dioxide sanitation of alfalfa seed (0, 50, 100, and 200 mg/kg seed) on total coliform bacteria, seed germination, and the presence of chlorate and perchlorate residues in seed rinse, seed soak, and alfalfa sprouts was determined. Chlorate residues in 20,000 mg/L calcium hypochlorite, commonly used to disinfect seed, were quantified. Chlorine dioxide treatment reduced (P < 0.05) total coliforms on seeds with no effect (P > 0.05) on germination. Dose-dependent sodium chlorate residues were present in seed rinse (4.1 to 31.2 μg/g seed) and soak (0.7 to 8.3 μg/g seed) waters, whereas chlorate residues were absent (LOQ 5 ng/g) in sprouts, except for 2 of 5 replicates from the high chlorine dioxide treatment. Copious chlorate residues were present (168 to 1260 mg/L) in freshly prepared 20,000 mg/L calcium hypochlorite solution, and storage at room temperature increased chlorate residues significantly (P < 0.01).

Seed Placement in Permanent Breast Seed Implant Brachytherapy: Are Concerns Over Accuracy Valid?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morton, Daniel, E-mail: dmorton@bccancer.bc.ca; Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia; Hilts, Michelle

Purpose: To evaluate seed placement accuracy in permanent breast seed implant brachytherapy (PBSI), to identify any systematic errors and evaluate their effect on dosimetry. Methods and Materials: Treatment plans and postimplant computed tomography scans for 20 PBSI patients were spatially registered and used to evaluate differences between planned and implanted seed positions, termed seed displacements. For each patient, the mean total and directional seed displacements were determined in both standard room coordinates and in needle coordinates relative to needle insertion angle. Seeds were labeled according to their proximity to the anatomy within the breast, to evaluate the influence of anatomicmore » regions on seed placement. Dosimetry within an evaluative target volume (seroma + 5 mm), skin, breast, and ribs was evaluated to determine the impact of seed placement on the treatment. Results: The overall mean (±SD) difference between implanted and planned positions was 9 ± 5 mm for the aggregate seed population. No significant systematic directional displacements were observed for this whole population. However, for individual patients, systematic displacements were observed, implying that intrapatient offsets occur during the procedure. Mean displacements for seeds in the different anatomic areas were not found to be significantly different from the mean for the entire seed population. However, small directional trends were observed within the anatomy, potentially indicating some bias in the delivery. Despite observed differences between the planned and implanted seed positions, the median (range) V{sub 90} for the 20 patients was 97% (66%-100%), and acceptable dosimetry was achieved for critical structures. Conclusions: No significant trends or systematic errors were observed in the placement of seeds in PBSI, including seeds implanted directly into the seroma. Recorded seed displacements may be related to intrapatient setup adjustments. Despite

Effect of Gold Marker Seeds on Magnetic Resonance Spectroscopy of the Prostate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hossain, Murshed, E-mail: Murshed.Hossain@fccc.edu; Schirmer, Timo; Richardson, Theresa

2012-05-01

Purpose: Magnetic resonance stereoscopic imaging (MRSI) of the prostate is an emerging technique that may enhance targeting and assessment in radiotherapy. Current practices in radiotherapy invariably involve image guidance. Gold seed fiducial markers are often used to perform daily prostate localization. If MRSI is to be used in targeting prostate cancer and therapy assessment, the impact of gold seeds on MRSI must be investigated. The purpose of this study was to quantify the effects of gold seeds on the quality of MRSI data acquired in phantom experiments. Methods and Materials: A cylindrical plastic phantom with a spherical cavity 10 centimetersmore » in diameter wss filled with water solution containing choline, creatine, and citrate. A gold seed fiducial marker was put near the center of the phantom mounted on a plastic stem. Spectra were acquired at 1.5 Tesla by use of a clinical MRSI sequence. The ratios of choline + creatine to citrate (CC/Ci) were compared in the presence and absence of gold seeds. Spectra in the vicinity of the gold seed were analyzed. Results: The maximum coefficient of variation of CC/Ci induced by the gold seed was found to be 10% in phantom experiments at 1.5 T. Conclusion: MRSI can be used in prostate radiotherapy in the presence of gold seed markers. Gold seeds cause small effects (in the order of the standard deviation) on the ratio of the metabolite's CC/Ci in the phantom study done on a 1.5-T scanner. It is expected that gold seed markers will have similar negligible effect on spectra from prostate patients. The maximum of 10% of variation in CC/Ci found in the phantom study also sets a limit on the threshold accuracy of CC/Ci values for deciding whether the tissue characterized by a local spectrum is considered malignant and whether it is a candidate for local boost in radiotherapy dose.« less

Effects of fungicide seed treatments on germination, population, and yield of maize grown from seed infected with fungal pathogens

USDA-ARS?s Scientific Manuscript database

Seedborne fungi can reduce survival, growth, and yield of maize (Zea mays L.). Laboratory, field, and growth chamber experiments were conducted to determine the effects of the seed treatment fungicides fludioxonil, mefenoxam, and azoxystrobin on germination, plant population, and grain yield of maiz...

Interactions between seed traits and digestive processes determine the germinability of bird-dispersed seeds

PubMed Central

Soons, Merel B.

2018-01-01

Waterbirds disperse a wide range of plant seeds via their guts, promoting biotic connectivity between isolated habitat patches. However, the intensity of digestive forces encountered by seeds, and therefore their potential to survive digestive tract passage, varies within and between waterbird species. Here, we investigate under controlled conditions how the interaction between seed traits and digestive strategies affect the germinability of seeds following waterbird-mediated dispersal. We exposed seeds of 30 wetland plant species to the main digestive processes in the dabbling duck digestive system: mechanical, chemical and intestinal digestion. These were simulated by 1) a pressure test and scarification treatment, 2) incubation in simulated gastric juice, and 3) incubation in intestinal contents of culled mallards (Anas platyrhynchos). We evaluated their separate and combined effects on seed germination, and identified the role of seed size and seed coat traits in resisting the digestive forces. Seeds were generally resistant to separate digestive processes, but highly sensitive to a combination. Resistance to mechanical break-down was reduced by up to 80% by chemical pre-treatment, especially for seeds with permeable coats. Scarified seeds were 12–17% more vulnerable to chemical and intestinal digestive processes than undamaged seeds. Large seeds and seeds with thin, permeable coats were particularly sensitive to chemical and intestinal digestion. These results indicate that efficient digestion of seeds requires multiple digestive processes. The gizzard, responsible for mechanical digestion, plays a key role in seed survival. Omnivorous birds, which have relatively light gizzards compared to pure herbivores or granivores, are thus most likely to disperse seeds successfully. Regardless of digestive strategy, small seeds with tough seed coats are most resistant to digestion and may be adapted to endozoochorous dispersal by waterbirds. PMID:29614085

Interactions between seed traits and digestive processes determine the germinability of bird-dispersed seeds.

PubMed

Kleyheeg, Erik; Claessens, Mascha; Soons, Merel B

2018-01-01

Waterbirds disperse a wide range of plant seeds via their guts, promoting biotic connectivity between isolated habitat patches. However, the intensity of digestive forces encountered by seeds, and therefore their potential to survive digestive tract passage, varies within and between waterbird species. Here, we investigate under controlled conditions how the interaction between seed traits and digestive strategies affect the germinability of seeds following waterbird-mediated dispersal. We exposed seeds of 30 wetland plant species to the main digestive processes in the dabbling duck digestive system: mechanical, chemical and intestinal digestion. These were simulated by 1) a pressure test and scarification treatment, 2) incubation in simulated gastric juice, and 3) incubation in intestinal contents of culled mallards (Anas platyrhynchos). We evaluated their separate and combined effects on seed germination, and identified the role of seed size and seed coat traits in resisting the digestive forces. Seeds were generally resistant to separate digestive processes, but highly sensitive to a combination. Resistance to mechanical break-down was reduced by up to 80% by chemical pre-treatment, especially for seeds with permeable coats. Scarified seeds were 12-17% more vulnerable to chemical and intestinal digestive processes than undamaged seeds. Large seeds and seeds with thin, permeable coats were particularly sensitive to chemical and intestinal digestion. These results indicate that efficient digestion of seeds requires multiple digestive processes. The gizzard, responsible for mechanical digestion, plays a key role in seed survival. Omnivorous birds, which have relatively light gizzards compared to pure herbivores or granivores, are thus most likely to disperse seeds successfully. Regardless of digestive strategy, small seeds with tough seed coats are most resistant to digestion and may be adapted to endozoochorous dispersal by waterbirds.

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2014 CFR

2014-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2012 CFR

2012-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2011 CFR

2011-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2010 CFR

2010-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

Code of Federal Regulations, 2013 CFR

2013-01-01

... quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required under... seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for... pertaining to such seed show that it is “Seed for processing,” or, if the seed is in containers and in...

Germination of pine seed in weightlessness (investigation in Kosmos 782)

NASA Technical Reports Server (NTRS)

Platonova, R. N.; Parfenov, G. P.; Olkhovenko, V. P.; Karpova, N. I.; Pichugov, M. Y.

1978-01-01

An investigation was made of the orientation of aboveground and underground organs of pine plants grown from seed in weightlessness. Orientation was found to be caused by the position of the seeds relative to the substrate surface. Normal growth was manifest only for the plants grown from seed oriented with embryo toward the substrate. Differences were noted between experiment and control as to the quantitative content of nucleoli in the meristematic cells of the rootlets and the shape of cells in the cotyledonous leaflets. No complete agreement was found between data obtained in weightlessness and when gravity was compensated (clinostat treatment with horizontal rotation).

Weeding volatiles reduce leaf and seed damage to field-grown soybeans and increase seed isoflavones.

PubMed

Shiojiri, Kaori; Ozawa, Rika; Yamashita, Ken-Ichi; Uefune, Masayoshi; Matsui, Kenji; Tsukamoto, Chigen; Tokumaru, Susumu; Takabayashi, Junji

2017-01-30

Field experiments were conducted over 3 years (2012, 2013, and 2015), in which half of the young stage soybean plants were exposed to volatiles from cut goldenrods three times over 2-3 weeks, while the other half remained unexposed. There was a significant reduction in the level of the total leaf damage on exposed soybean plants compared with unexposed ones. In 2015, the proportion of damage to plants by Spodoptera litura larvae, a dominant herbivore, was significantly less in the exposed field plots than in the unexposed plots. Under laboratory conditions, cut goldenrod volatiles induced the direct defenses of soybean plants against S. litura larvae and at least three major compounds, α-pinene, β-myrcene, and limonene, of cut goldenrod volatiles were involved in the induction. The number of undamaged seeds from the exposed plants was significantly higher than that from unexposed ones. Concentrations of isoflavones in the seeds were significantly higher in seeds from the exposed plants than in those from the unexposed plants. Future research evaluating the utility of weeding volatiles, as a form of plant-plant communications, in pest management programs is necessary.

The Florida Harvester Ant, Pogonomyrmex badius, Relies on Germination to Consume Large Seeds

PubMed Central

Kwapich, Christina L.

2016-01-01

The Florida harvester ant, Pogonomyrmex badius, is one of many ant species and genera that stores large numbers of seeds in damp, underground chambers for later consumption. A comparison of the sizes of seeds recovered from storage chambers with those of seed husks discarded following consumption revealed that the used seeds are far smaller than stored seeds. This difference in use-rate was confirmed in field and laboratory colonies by offering marked seeds of various sizes and monitoring the appearance of size-specific chaff. Because foragers collect a range of seed sizes but only open small seeds, large seeds accumulate, forming 70% or more of the weight of seed stores. Major workers increase the rates at which small and medium seeds are opened, but do not increase the size range of opened seeds. Experiments limiting ant access to portions of natural seed chambers showed that seeds germinate during storage, but that the ants rapidly remove them. When offered alongside non germinating seeds, germinating seeds were preferentially fed to larvae. The rate of germination during the annual cycle was determined by both burial in artificial chambers at various depths and under four laboratory temperatures. The germination rate depends upon the species of seed, the soil/laboratory temperature and/or the elapsed time. The seasonal soil temperature cycle generated germination patterns that vary with the mix of locally-available seeds. Taken together, exploitation of germination greatly increases the resources available to the ants in space and time. While the largest seeds may have the nutritional value of 15 small seeds, the inability of workers to open large seeds at will precludes them from rapid use during catastrophic events. The harvester ant’s approach to seed harvesting is therefore two-pronged, with both immediate and delayed payoffs arising from the tendency to forage for a wide variety of seeds sizes. PMID:27893844

The Florida Harvester Ant, Pogonomyrmex badius, Relies on Germination to Consume Large Seeds.

PubMed

Tschinkel, Walter R; Kwapich, Christina L

2016-01-01

The Florida harvester ant, Pogonomyrmex badius, is one of many ant species and genera that stores large numbers of seeds in damp, underground chambers for later consumption. A comparison of the sizes of seeds recovered from storage chambers with those of seed husks discarded following consumption revealed that the used seeds are far smaller than stored seeds. This difference in use-rate was confirmed in field and laboratory colonies by offering marked seeds of various sizes and monitoring the appearance of size-specific chaff. Because foragers collect a range of seed sizes but only open small seeds, large seeds accumulate, forming 70% or more of the weight of seed stores. Major workers increase the rates at which small and medium seeds are opened, but do not increase the size range of opened seeds. Experiments limiting ant access to portions of natural seed chambers showed that seeds germinate during storage, but that the ants rapidly remove them. When offered alongside non germinating seeds, germinating seeds were preferentially fed to larvae. The rate of germination during the annual cycle was determined by both burial in artificial chambers at various depths and under four laboratory temperatures. The germination rate depends upon the species of seed, the soil/laboratory temperature and/or the elapsed time. The seasonal soil temperature cycle generated germination patterns that vary with the mix of locally-available seeds. Taken together, exploitation of germination greatly increases the resources available to the ants in space and time. While the largest seeds may have the nutritional value of 15 small seeds, the inability of workers to open large seeds at will precludes them from rapid use during catastrophic events. The harvester ant's approach to seed harvesting is therefore two-pronged, with both immediate and delayed payoffs arising from the tendency to forage for a wide variety of seeds sizes.

Development of a wavelength stabilized seed laser system for an airborne water vapour lidar experiment

NASA Astrophysics Data System (ADS)

Schwarzer, H.; Börner, A.; Fix, A.; Günther, B.; Hübers, H.-W.; Raugust, M.; Schrandt, F.; Wirth, M.

2007-09-01

At the German Aerospace Center an airborne multi-wavelength differential absorption LIDAR for the measurement of atmospheric water vapour is currently under development. This instrument will enable the retrieval of the complete humidity profile from the surface up to the lowermost stratosphere with high vertical and horizontal resolution at a systematic error below 5%. The LIDAR will work in the wavelength region around 935 nm at three different water vapour absorption lines and one reference wavelength. A major sub-system of this instrument is a highly frequency stabilized seed laser system for the optical parametrical oscillators which generate the narrowband high energy light pulses. The development of the seed laser system includes the control software, the electronic control unit and the opto-mechanical layout. The seed lasers are Peltier-cooled distributed feedback laser diodes with bandwidths of about 30 MHz, each one operating for 200 μs before switching to the next one. The required frequency stability is +/- 30 MHz ≅ +/- 10 -4 nm under the rough environmental conditions aboard an aircraft. It is achieved by locking the laser wavelength to a water vapour absorption line. The paper describes the opto-mechanical layout of the seed laser system, the stabilization procedure and the results obtained with this equipment.

Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

Treesearch

Xiaojun Du; Qinfeng Guo; Xianming Gao; Keping Na

2007-01-01

Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms.We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan,...

Seed birth to death: dual functions of reactive oxygen species in seed physiology.

PubMed

Jeevan Kumar, S P; Rajendra Prasad, S; Banerjee, Rintu; Thammineni, Chakradhar

2015-09-01

Reactive oxygen species (ROS) are considered to be detrimental to seed viability. However, recent studies have demonstrated that ROS have key roles in seed germination particularly in the release of seed dormancy and embryogenesis, as well as in protection from pathogens. This review considers the functions of ROS in seed physiology. ROS are present in all cells and at all phases of the seed life cycle. ROS accumulation is important in breaking seed dormancy, and stimulating seed germination and protection from pathogens. However, excessive ROS accumulation can be detrimental. Therefore, knowledge of the mechanisms by which ROS influence seed physiology will provide insights that may not only allow the development of seed quality markers but also help us understand how dormancy can be broken in several recalcitrant species. Reactive oxygen species have a dual role in seed physiology. Understanding the relative importance of beneficial and detrimental effects of ROS provides great scope for the improvement and maintenance of seed vigour and quality, factors that may ultimately increase crop yields. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Amphibious Landing Operations in World War II: Personal Experience in Applying and Developing Doctrine

DTIC Science & Technology

2015-05-21

the forefront of the Army’s effort to gain experience planning and conducting amphibious landings was Lucian K . Truscott, Jr, a Cavalry officer by...Landing Operations, Lucian K . Truscott, Jr., Operation Torch, Operation Husky, 3rd Infantry Division, World War II 16. SECURITY CLASSIFICATION OF: 17...gain experience planning and conducting amphibious landings was Lucian K . Truscott, Jr., a Cavalry officer by training. Following his assignment to

Chloroxyanion residue on seeds and sprouts after chlorine dioxide sanitation of alfalfa seed

USDA-ARS?s Scientific Manuscript database

The effects of a 6-h chlorine dioxide sanitation of alfalfa seed (0, 50, 100, and 200 mg/kg seed) on total coliform bacteria, seed germination, and on the presence of chlorate and perchlorate residues in seed rinse, seed soak, and in alfalfa sprouts was determined. Chlorate residues in 20000 ppm cal...

Cryopreservation of human spermatozoa. I. Effects of holding procedure and seeding on motility, fertilizability, and acrosome reaction.

PubMed

Critser, J K; Huse-Benda, A R; Aaker, D V; Arneson, B W; Ball, G D

1987-04-01

Three experiments were conducted to evaluate effects of holding semen at +5.0 degrees C for 30 minutes or -5.0 degrees C for 10 minutes and ice crystal induction (seeding) on frozen-thawed human spermatozoa. In experiment 1, spermatozoa were frozen, and postthaw motility was evaluated immediately (0 hour) and 24 hours later. At both 0 and 24 hours, nonfrozen control samples had higher motility than all other treatment groups. At 0 hour postthaw, motility was higher in samples held at -5.0 degrees C for 10 minutes with no significant effect of seeding. At 24 hours, samples held at -5.0 degrees C for 10 minutes and seeded, but not samples held at -5.0 degrees C and not seeded, had higher motility than samples held at +5.0 degrees C. In experiment 2, semen samples were frozen, and fertilizability was evaluated in a zona-free hamster egg penetration assay. Seeded samples had a higher frequency of sperm penetration than either nonfrozen or nonseeded samples. In experiment 3, nonfrozen controls and frozen treatment groups were evaluated for the frequency of survival and acrosomal integrity. Seeded samples had higher frequencies of survival and loss of acrosomal integrity than nonseeded samples. All frozen-thawed samples had a lower frequency of survival and a higher frequency of loss of acrosomal integrity than nonfrozen controls. Although altered patterns of fertilizability and acrosomal integrity are induced, collectively these data suggest that incorporating a holding temperature of -5.0 degrees C for 10 minutes and seeding may result in a superior protocol for freezing human spermatozoa.

Phase II Upgrade of the GERDA Experiment for the Search of Neutrinoless Double Beta Decay

NASA Astrophysics Data System (ADS)

Majorovits, B.

Observation of neutrinoless double beta decay could answer the question regarding the Majorana or Dirac nature of neutrinos. The GERDA experiment utilizes HPGe detectors enriched with the isotope 76Ge to search for this process. Recently the GERDA collaboration has unblinded data of Phase I of the experiment. In order to further improve the sensitivity of the experiment, additionally to the coaxial detectors used, 30 BEGe detectors made from germanium enriched in 76Ge will be deployed in GERDA Phase II. BEGe detectors have superior PSD capability, thus the background can be further reduced. The liquid argon surrounding the detector array will be instrumented in order to reject background by detecting scintillation light induced in the liquid argon by radiation. After a short introduction the hardware preparations for GERDA Phase II as well as the processing and characterization of the 30 BEGe detectors are discussed.

Extraction and the Fatty Acid Profile of Rosa acicularis Seed Oil.

PubMed

Du, Huanan; Zhang, Xu; Zhang, Ruchun; Zhang, Lu; Yu, Dianyu; Jiang, Lianzhou

2017-12-01

Rosa acicularis seed oil was extracted from Rosa acicularis seeds by the ultrasonic-assisted aqueous enzymatic method using cellulase and protease. Based on a single experiment, Plackett-Burman design was applied to ultrasonic-assisted aqueous enzymatic extraction of wild rose seed oil. The effects of enzyme amount, hydrolysis temperature and initial pH on total extraction rate of wild rose seed oil was studied by using Box-Behnken optimize methodology. Chemical characteristics of a sample of Rosa acicularis seeds and Rosa acicularis seed oil were characterized in this work. The tocopherol content was 200.6±0.3 mg/100 g oil. The Rosa acicularis seed oil was rich in linoleic acid (56.5%) and oleic acid (34.2%). The saturated fatty acids included palmitic acid (4%) and stearic acid (2.9%). The major fatty acids in the sn-2 position of triacylglycerol in Rosa acicularis oil were linoleic acid (60.6%), oleic acid (33.6%) and linolenic acid (3.2%). According to the 1,3-random-2-random hypothesis, the dominant triacylglycerols were LLL (18%), LLnL (1%), LLP (2%), LOL (10%), LLSt (1.2%), PLP (0.2%), LLnP (0.1%), LLnO (0.6%) and LOP (1.1%). This work could be useful for developing applications for Rosa acicularis seed oil.

Plant recruitment in a northern Arizona ponderosa pine forest: Testing seed- and leaf litter-limitation hypotheses

Treesearch

Scott R. Abella

2008-01-01

Seed availability and leaf litter limit plant establishment in some ecosystems. To evaluate the hypothesis that these factors limit understory plant recruitment in Pinus ponderosa forests, I conducted a seeding and litter removal experiment at six thinned sites in the Fort Valley Experimental Forest, northern Arizona. Experimental seeding of four native species (

Tree Seed Technology Training Course

Treesearch

F.T. Bonner; James A. Vozzo; W.W. Elam; S.B. Land

1994-01-01

This manual is intended primarily to train seed collectors, seed-plant managers, seed analysts, and nursery managers, but it can serve as a resource for any training course in forest regeneration. It includes both temperate and tropical tree species of all intended uses. The manual covers the following topics: seed biology, seed collection, seed handling, seed-quality...

Survival and growth of seed trees 20 years after a natural regeneration cut in the piedmont of Georgia

Treesearch

Stephen R. Logan; M. Boyd Edwards; Barry D. Shiver

2005-01-01

An experiment was installed in 1982 to compare six methods of natural regeneration in the Piedmont of Georgia. These methods include (1) clearcut with seed in place; (2) clearcut with seed in place and preharvest burn; (3) seed tree; (4) seed tree with preharvest burn; (5) shelterwood; and (6) shelterwood with preharvest burn. Because of endangered species regulations...

Effectiveness of calcium hypochlorite on viral and bacterial contamination of alfalfa seeds.

PubMed

Wang, Qing; Kniel, Kalmia E

2014-10-01

Alfalfa sprouts have been involved in numerous foodborne outbreaks, which has increased the awareness for seed and sprout safety. This study compared the effectiveness of calcium hypochlorite (Ca(OCl)2) on the inactivation of bacteria and viruses on alfalfa seeds and in the presence of a simulated organic load. Alfalfa seeds were inoculated with human norovirus (huNoV) genogroup II (GII), murine norovirus (MNV), Tulane virus (TV), Escherichia coli O104:H4, and Salmonella enterica serovar Agona. Seeds were treated with Ca(OCl)2 (2000 ppm or 20,000 ppm with the average of free chlorine 1388 ± 117 mg/L and 11,472 ± 1500 mg/L, respectively, pH adjusted to 7.00). The reduction of huNoV genomic copies indicated that huNoV was relatively resistant to Ca(OCl)2 regardless of concentrations. Significant reductions were observed in the order of TV < Salmonella Agona < MNV < E. coli O104:H4 at 20,000 ppm Ca(OCl)2. A similar trend was found at 2000 ppm Ca(OCl)2 in the order of TV, Salmonella Agona, MNV < E. coli O104:H4. Ca(OCl)2 at 20,000 ppm was more effective than 2000 ppm for all the organisms tested. This trend was also observed in samples containing an artificial organic material load. Ca(OCl)2 activity on virus inactivation decreased as the organic load increased. Reduction was greater in fetal bovine serum-containing samples compared to alfalfa seeds, indicating a close relationship between the organisms and alfalfa seeds. Ca(OCl)2 could not completely inactivate bacteria or viruses inoculated on seeds, and high levels of E. coli O104:H4 and Salmonella Agona were present on sprouts from sanitized seed samples following a 7-day germination period.

Increasing seed size and quality by manipulating BIG SEEDS1 in legume species

PubMed Central

Ge, Liangfa; Yu, Jianbin; Wang, Hongliang; Luth, Diane; Bai, Guihua; Wang, Kan

2016-01-01

Plant organs, such as seeds, are primary sources of food for both humans and animals. Seed size is one of the major agronomic traits that have been selected in crop plants during their domestication. Legume seeds are a major source of dietary proteins and oils. Here, we report a conserved role for the BIG SEEDS1 (BS1) gene in the control of seed size and weight in the model legume Medicago truncatula and the grain legume soybean (Glycine max). BS1 encodes a plant-specific transcription regulator and plays a key role in the control of the size of plant organs, including seeds, seed pods, and leaves, through a regulatory module that targets primary cell proliferation. Importantly, down-regulation of BS1 orthologs in soybean by an artificial microRNA significantly increased soybean seed size, weight, and amino acid content. Our results provide a strategy for the increase in yield and seed quality in legumes. PMID:27791139

Surrogate Seeds For Growth Of Crystals

NASA Technical Reports Server (NTRS)

Shlichta, Paul J.

1989-01-01

Larger crystals of higher quality grown. Alternative method for starting growth of crystal involves use of seed crystal of different material instead of same material as solution. Intended for growing single-crystal proteins for experiments but applicable in general to growth of crystals from solutions and to growth of semiconductor or other crystals from melts.

Conference Proceedings: Seed Ecology III - The Third International Society for Seed Science Meeting on Seeds and the Environment - "Seeds and Change"; June 20-June 24, 2010; Salt Lake City, Utah, USA

Treesearch

Rosemary Pendleton; Susan Meyer; Bitsy Schultz

2010-01-01

Seed Ecology III was held in Salt Lake City, Utah in June 2010, sharing the latest research on all aspects of seed ecology. Our meeting was organized around the theme "Seeds and Change." We welcomed contributions in any area of seed ecology. Our agenda also aimed to create bridges between seed ecology and plant conservation, restoration ecology, and global...

Establishment of three permanent cover crop seed mixtures in Hungarian vineyards

NASA Astrophysics Data System (ADS)

Miglécz, Tamas; Valkó, Orsolya; Donkó, Ádám; Deák, Balázs; Török, Péter; Kelemen, András; Drexler, Dóra; Tóthmérész, Béla

2015-04-01

In organic vineyard farming sowing high diversity cover crop seed mixtures offers a great opportunity to overcome high-priority problems mitigating vineyard cultivation, such as gain erosion control, save soil fertility, improve soil microbial activity and control weeds. Furthermore, we can also improve the biodiversity and ecosystem services of vineyards. Mainly non-native or low diversity seed mixtures are used for cover cropping containing some grass, grain or Fabaceae species. We studied vegetation development after sowing native high-diversity seed mixtures in four vineyards in an on farm field trial. We compared the effects of 4 treatments: (i) Biocont-Ecowin mixture (12 species), (ii) Fabaceae mixture (9 species), (iii) Grass-forb mixture (16 species) and control (no seed sowing). Study sites were located in Tokaj wine region, East Hungary. Seed mixtures were sown in March, 2012. After sowing, we recorded the percentage cover of vascular plant species in the end of June 2012, 2013 and 2014 in altogether 80 permanent plots. In the first year the establishment and weed control of Biocont-Ecowin and Legume seed mixture was the best. For the second year in inter-rows sown with Grass-herb and Legume seed mixtures we detected decreasing weed cover scores, while in inter-rows sown with Biocont-Ecowin seed mixture and in control inter-rows we detected higher weed cover scores. In the third year we still detected lower weed cover scores in inter-rows sown with Grass-forb and Legume seed mixtures, however on several sites we also detected decreasing cover of sown species. All sown species were detected in our plots during the time of the study, however some species were present only with low cover scores or only in a few plots. Out of the sown species Lotus corniculatus, Medicago lupulina, Plantago lanceolata, Trifolium repens, T. pratense and Coronilla varia established the most successfully, and had high cover scores on most sites even in the second and third year

Lychee seed extract protects against neuronal injury and improves cognitive function in rats with type II diabetes mellitus with cognitive impairment

PubMed Central

Wu, Jianming; Chen, Haixia; Zeng, Yuan; Wang, Xiuling; Yang, Le; Mei, Qibing; Cao, Shousong; Qin, Dalian

2018-01-01

Lychee seed is a traditional Chinese medicine and has many beneficial effects such as modulation of blood sugar and lipids, antioxidation, antivirus and antitumor. Studies have indicated that type II diabetes mellitus (T2DM) and Alzheimer's disease (AD) share common biological mechanisms including insulin resistance, impaired glucose metabolism, β-amyloid (Aβ) formation, oxidative stress and presence of advanced glycation end products (AGEs). The present study investigated the effects of lychee seed extract (LSE) on neuroprotection, cognitive function improvement and possible underlying mechanisms in a rat model of T2DM with cognitive impairment. We analyzed the chemical profile of LSE using a UHPLC-SPD chromatogram and evaluated its effect on the improvement of spatial learning and memory of rats by a Morris water maze. The levels of glucose, insulin, Aβ, AGEs, Tau protein and acetylcholinesterase in the blood and/or hippocampus of rats were determined by blood-glucose meter, radioimmunoassay, chemical chromatometry, enzyme-linked immunosorbent assay (ELISA) and immunohistochemical analysis, respectively. Results demonstrated that LSE consists of eight major and around 20 minor ingredients, and it remarkably prevents neuronal injury and improves cognitive functions in T2DM rats. The levels of glucose, insulin, Aβ, AGEs and Tau protein were significantly increased in the blood and/or hippocampus of T2DM rats, while LSE remarkably decreased their levels compared to vehicle treatment (P<0.01). The possible mechanisms may be associated with IR improvement and decreased formations of Aβ, AGEs and Tau protein in the hippocampus of T2DM rats. LSE may be developed as the agent for the treatment of T2DM and/or AD clinically. PMID:29138799

Insect Seed Predators in Erythrina falcata (Fabaceae): Identification of Predatory Species and Ecological Consequences of Asynchronous Flowering.

PubMed

Pereira, C M; Moura, M O; Da-Silva, P R

2014-06-01

Seed predation by insects exerts negative effects on plant reproduction by limiting the supply of seeds and preventing germination. Seed predators of the family Fabaceae are usually generalists, which increases the rate of predation. One strategy to minimize seed predation, developed by plants from temperate regions, is "escape in time," i.e., flowering before or after the peak of predation. For tropical species, few studies have investigated the strategies used by plants to minimize seed predation. Here, using Erythrina falcata, a tropical species of Fabaceae, we test three main hypotheses: (i) escape in time is a mechanism used by E. falcata to minimize seed predation, (ii) the predators of E. falcata seeds are generalists, and (iii) the biometric variables of the pods can influence seed predation. In order to test these hypotheses, we determined the flowering time of E. falcata, rate of seed predation, the predators insects, and biometric variables of the pods. The analyzed trees were grouped into three classes: "early," "peak," and "late" flowering. The average seed predation rates on trees in the early and late classes were 65% and 50%, respectively, and in the peak class, 80%; thus, our first hypothesis can be accepted. Three species of Lepidoptera and two of Coleoptera were found preying on E. falcata seeds. These species were observed to be generalist predators; thus, our second hypothesis can be accepted. The biometric variables of the pods cannot influence seed predation rate. The ecological consequences of asynchronous flowering on plants and insects are discussed.

Genetic relatedness among developing seeds and intra fruit seed abortion in Dalbergia sissoo (Fabaceae).

PubMed

Mohana, G S; Shaanker, R U; Ganeshaiah, K N; Dayanandan, S

2001-07-01

Dalbergia sissoo, a wind-dispersed tropical tree, exhibits high intrafruit seed abortion. Of the four to five ovules in the flower, generally one and occasionally two or three develop to maturity. It has been proposed that the seed abortion is a consequence of intense sibling competition for maternal resources and that this competition occurs as an inverse function of the genetic relatedness among the developing seeds. Accordingly, developing seeds compete intensely when they are genetically less related but tend to develop together when genetically more related. We tested this hypothesis by comparing the genetic similarity among the pairs of seeds developing within a pod with that among (a) random pairs from the pool of all seeds, (b) random pairs from single-seeded pods, and (c) random pairs from two-seeded pods, using both randomly amplified polymorphic DNA (RAPD) and isozymes in five trees. We found that the pairs of seeds developing within a pod are genetically more similar than any random pairs of seeds in a tree. Thus the formation of two-seeded pods appear to be associated with increased genetic relatedness among the developing seeds. We discuss the results in the context of possible fitness advantages and then discuss the possible mechanisms that promote tolerance among related seeds.

Vertebrate seed dispersers maintain the composition of tropical forest seedbanks.

PubMed

Wandrag, E M; Dunham, A E; Miller, R H; Rogers, H S

2015-11-16

The accumulation of seeds in the soil (the seedbank) can set the template for the early regeneration of habitats following disturbance. Seed dispersal is an important factor determining the pattern of seed rain, which affects the interactions those seeds experience. For this reason, seed dispersal should play an important role in structuring forest seedbanks, yet we know little about how that happens. Using the functional extirpation of frugivorous vertebrates from the island of Guam, together with two nearby islands (Saipan and Rota) that each support relatively intact disperser assemblages, we aimed to identify the role of vertebrate dispersers in structuring forest seedbanks. We sampled the seedbank on Guam where dispersers are absent, and compared this with the seedbank on Saipan and Rota where they are present. Almost twice as many species found in the seedbank on Guam, when compared with Saipan and Rota, had a conspecific adult within 2 m. This indicates a strong role of vertebrate dispersal in determining the identity of seeds in the seedbank. In addition, on Guam, a greater proportion of samples contained no seeds and overall species richness was lower than on Saipan. Differences in seed abundance and richness between Guam and Rota were less clear, as seedbanks on Rota also contained fewer species than Saipan, possibly due to increased post-dispersal seed predation. Our findings suggest that vertebrate seed dispersers can have a strong influence on the species composition of seedbanks. Regardless of post-dispersal processes, without dispersal, seedbanks no longer serve to increase the species pool of recruits during regeneration. Published by Oxford University Press on behalf of the Annals of Botany Company.

Non-native earthworms promote plant invasion by ingesting seeds and modifying soil properties

NASA Astrophysics Data System (ADS)

Clause, Julia; Forey, Estelle; Lortie, Christopher J.; Lambert, Adam M.; Barot, Sébastien

2015-04-01

Earthworms can have strong direct effects on plant communities through consumption and digestion of seeds, however it is unclear how earthworms may influence the relative abundance and composition of plant communities invaded by non-native species. In this study, earthworms, seed banks, and the standing vegetation were sampled in a grassland of central California. Our objectives were i) to examine whether the abundances of non-native, invasive earthworm species and non-native grassland plant species are correlated, and ii) to test whether seed ingestion by these worms alters the soil seed bank by evaluating the composition of seeds in casts relative to uningested soil. Sampling locations were selected based on historical land-use practices, including presence or absence of tilling, and revegetation by seed using Phalaris aquatica. Only non-native earthworm species were found, dominated by the invasive European species Aporrectodea trapezoides. Earthworm abundance was significantly higher in the grassland blocks dominated by non-native plant species, and these sites had higher carbon and moisture contents. Earthworm abundance was also positively related to increased emergence of non-native seedlings, but had no effect on that of native seedlings. Plant species richness and total seedling emergence were higher in casts than in uningested soils. This study suggests that there is a potential effect of non-native earthworms in promoting non-native and likely invasive plant species within grasslands, due to seed-plant-earthworm interactions via soil modification or to seed ingestion by earthworms and subsequent cast effects on grassland dynamics. This study supports a growing body of literature for earthworms as ecosystem engineers but highlights the relative importance of considering non-native-native interactions with the associated plant community.

Seed fates in crop-wild hybrid sunflower: crop allele and maternal effects.

PubMed

Pace, Brian A; Alexander, Helen M; Emry, Jason D; Mercer, Kristin L

2015-02-01

Domestication has resulted in selection upon seed traits found in wild populations, yet crop-wild hybrids retain some aspects of both parental phenotypes. Seed fates of germination, dormancy, and mortality can influence the success of crop allele introgression in crop-wild hybrid zones, especially if crop alleles or crop-imparted seed coverings result in out-of-season germination. We performed a seed burial experiment using crop, wild, and diverse hybrid sunflower (Helianthus annuus) cross types to test how a cross type's maternal parent and nuclear genetic composition might affect its fate under field conditions. We observed higher maladaptive fall germination in the crop- and F1- produced seeds than wild-produced seeds and, due to an interaction with percent crop alleles, fall germination was higher for cross types with more crop-like nuclear genetics. By spring, crop-produced cross types had the highest overwintering mortality, primarily due to higher fall germination. Early spring germination was identical across maternal types, but germination continued for F1-produced seeds. In conclusion, the more wild-like the maternal parent or the less proportion of the cross type's genome contributed by the crop, the greater likelihood a seed will remain ungerminated than die. Wild-like dormancy may facilitate introgression through future recruitment from the soil seed bank.

Restoration seed reserves for assisted gene flow within seed orchards

Treesearch

C.S. Echt; B.S. Crane

2017-01-01

Changing climate and declining forest populations imperil the future of certain forest tree species. To complement forest management and genetic conservation plans, we propose a new paradigm for seedling seed orchards: foster genetic mixing among a variety of seed sources to increase genetic diversity and adaptive potential of seed supplies used for forest restoration...

Automated seed manipulation and planting

NASA Technical Reports Server (NTRS)

Garcia, Ray; Herrera, Javier; Holcomb, Scott; Kelly, Paul; Myers, Scott; Rosendo, Manny; Sivitz, Herbert; Wolsefer, Dave

1988-01-01

The Mechanical Division fabricated three seed separators utilizing pressure gradients to move and separate wheat seeds. These separators are called minnow buckets and use air, water, or a combination of both to generate the pressure gradient. Electrostatic fields were employed in the seed separator constructed by the Electrical Division. This separator operates by forcing a temporary electric dipole on the wheat seeds and using charged electrodes to attract and move the seeds. Seed delivery to the hydroponic growth tray is accomplished by the seed cassette. The cassette is compatible with all the seed separators, and it consists of a plastic tube threaded with millipore filter paper. During planting operations, the seeds are placed in an empty cassette. The loaded cassette is then placed in the growth tray and nutrient solution provided. The solution wets the filter paper and capillary action draws the nutrients up to feed the seeds. These seeding systems were tested and showed encouraging results. Seeds were effectively separated and the cassette can support the growth of wheat plants. Problems remaining to be investigated include improving the success of delivering the seeds to the cassette and providing adequate spacing between seeds for the electric separator.

Wrinkled alfalfa seeds harbor more aerobic bacteria and are more difficult to sanitize than smooth seeds.

PubMed

Charkowski, A O; Sarreal, C Z; Mandrell, R E

2001-09-01

At least 14 separate outbreaks of food poisoning attributed to either Salmonella enterica or Escherichia coli O157:H7 have been traced to sprouts in the past decade. Seeds contaminated with human pathogens caused most of these outbreaks, thus many sprout growers are now treating alfalfa seeds with the sanitizing agent, calcium hypochlorite (Ca[OCl]2), prior to sprouting. The efficacy of alfalfa seed sanitation varies between seed lots and between seeds within each lot. Alfalfa seeds from different seed lots were sorted by type in an effort to determine if certain seed types carry more aerobic bacteria than other seed types. Seeds with a wrinkled type, characteristic of lygus bug damage, had significantly higher levels of culturable aerobic bacteria and were more difficult to sanitize than smooth, healthy seeds. After sanitation, wrinkled alfalfa seeds that had been inoculated with S. enterica ser. Newport carried significantly higher levels of Salmonella Newport than smooth seeds. If S. enterica is present on wrinkled seeds in naturally contaminated seed lots, it may be difficult to chemically sanitize the seed lot. Removal of the wrinkled alfalfa seeds from the seed lots, perhaps by adapting color sorting equipment similar to that used to sort rice grains and other seeds, should reduce the level of aerobic bacteria in seed lots and may result in lower levels of human pathogens on contaminated alfalfa seeds.

Infrared radiation from hot cones on cool conifers attracts seed-feeding insects.

PubMed

Takács, Stephen; Bottomley, Hannah; Andreller, Iisak; Zaradnik, Tracy; Schwarz, Joseph; Bennett, Robb; Strong, Ward; Gries, Gerhard

2009-02-22

Foraging animals use diverse cues to locate resources. Common foraging cues have visual, auditory, olfactory, tactile or gustatory characteristics. Here, we show a foraging herbivore using infrared (IR) radiation from living plants as a host-finding cue. We present data revealing that (i) conifer cones are warmer and emit more near-, mid- and long-range IR radiation than needles, (ii) cone-feeding western conifer seed bugs, Leptoglossus occidentalis (Hemiptera: Coreidae), possess IR receptive organs and orient towards experimental IR cues, and (iii) occlusion of the insects' IR receptors impairs IR perception. The conifers' cost of attracting cone-feeding insects may be offset by occasional mast seeding resulting in cone crops too large to be effectively exploited by herbivores.

Seed coat import and unloading in pisum. [Pisum sativum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grusak, M.A.; Minchin, P.E.H.

1987-08-01

Experiments were undertaken with empty, attached ovules of Pisum sativum to observe the effects of osmotic solution changes on seed coat import and unloading into the apoplast. Through the use of /sup 11/CO/sub 2/ pulse labelling along with collimated monitoring of plant sections, the authors were able to continuously and simultaneously measure total pod import, import into a single ovule, and washout from the ovule into a flow-through bathing solution. The authors results indicated that changes in bathing solution sucrose concentration had no immediate effect on tracer washout in Pisum, but did affect ovule import. Lowering the sucrose concentration decreasedmore » import and raising the concentration increased import. Furthermore, these import changes were only gradually reflected in the seed coat washout profile, suggesting a buffering capability of the non-phloem seed coat tissues. Additional results have also led them to propose that the terminal site of seed coat unloading in Pisum is the plasmalemma of an non-phloem seed coat cell type, that unloading from this site occurs via a passive membrane transport process, and that solutes move symplastically to this compartment from the phloem.« less

Seed-specific overexpression of AtFAX1 increases seed oil content in Arabidopsis.

PubMed

Tian, Yinshuai; Lv, Xueyan; Xie, Guilan; Zhang, Jing; Xu, Ying; Chen, Fang

2018-06-02

Biosynthesis of plant seed oil is accomplished through the coordinate action of multiple enzymes in multiple subcellular compartments. Fatty acid (FA) has to be transported from plastid to endoplasmic reticulum (ER) for TAG synthesis. However, the role of plastid FA transportation during seed oil accumulation has not been evaluated. AtFAX1 (Arabidopsis fatty acid export1) mediated the FA export from plastid. In this study, we overexpressed AtFAX1 under the control of a seed specific promoter in Arabidopsis. The resultant overexpression lines (OEs) produced seeds which contained 21-33% more oil and 24-30% more protein per seed than those of the wild type (WT). The increased oil content was probably because of the enhanced FA and TAG synthetic activity. The seed size and weight were both increased accordingly. In addition, the seed number per silique and silique number per plant had no changes in transgenic plants. Taken together, our results demonstrated that seed specific overexpression of AtFAX1 could promote oil accumulation in Arabidopsis seeds and manipulating FA transportation is a feasible strategy for increasing the seed oil content. Copyright © 2018 Elsevier Inc. All rights reserved.

An automated, fast and accurate registration method to link stranded seeds in permanent prostate implants

NASA Astrophysics Data System (ADS)

Westendorp, Hendrik; Nuver, Tonnis T.; Moerland, Marinus A.; Minken, André W.

2015-10-01

The geometry of a permanent prostate implant varies over time. Seeds can migrate and edema of the prostate affects the position of seeds. Seed movements directly influence dosimetry which relates to treatment quality. We present a method that tracks all individual seeds over time allowing quantification of seed movements. This linking procedure was tested on transrectal ultrasound (TRUS) and cone-beam CT (CBCT) datasets of 699 patients. These datasets were acquired intraoperatively during a dynamic implantation procedure, that combines both imaging modalities. The procedure was subdivided in four automatic linking steps. (I) The Hungarian Algorithm was applied to initially link seeds in CBCT and the corresponding TRUS datasets. (II) Strands were identified and optimized based on curvature and linefits: non optimal links were removed. (III) The positions of unlinked seeds were reviewed and were linked to incomplete strands if within curvature- and distance-thresholds. (IV) Finally, seeds close to strands were linked, also if the curvature-threshold was violated. After linking the seeds an affine transformation was applied. The procedure was repeated until the results were stable or the 6th iteration ended. All results were visually reviewed for mismatches and uncertainties. Eleven implants showed a mismatch and in 12 cases an uncertainty was identified. On average the linking procedure took 42 ms per case. This accurate and fast method has the potential to be used for other time spans, like Day 30, and other imaging modalities. It can potentially be used during a dynamic implantation procedure to faster and better evaluate the quality of the permanent prostate implant.

Laser shock compression experiments on precompressed water in ``SG-II'' laser facility

NASA Astrophysics Data System (ADS)

Shu, Hua; Huang, Xiuguang; Ye, Junjian; Fu, Sizu

2017-06-01

Laser shock compression experiments on precompressed samples offer the possibility to obtain new hugoniot data over a significantly broader range of density-temperature phase than was previously achievable. This technique was developed in ``SG-II'' laser facility. Hugoniot data were obtained for water in 300 GPa pressure range by laser-driven shock compression of samples statically precompressed in diamond-anvil cells.

Efficient color-tunable multiexcitonic dual wavelength emission from Type II semiconductor tetrapods.

PubMed

Wu, Wen-Ya; Li, Mingjie; Lian, Jie; Wu, Xiangyang; Yeow, Edwin K L; Jhon, Mark H; Chan, Yinthai

2014-09-23

We synthesized colloidal InP/ZnS seeded CdS tetrapods by harnessing the structural stability of the InP/ZnS seed nanocrystals at the high reaction temperatures needed to grow the CdS arms. Because of an unexpected Type II band alignment at the interface of the InP/ZnS core and CdS arms that enhanced the occurrence of radiative excitonic recombination in CdS, these tetrapods were found to be capable of exhibiting highly efficient multiexcitonic dual wavelength emission of equal intensity at spectrally distinct wavelengths of ∼485 and ∼675 nm. Additionally, the Type II InP/ZnS seeded CdS tetrapods displayed a wider range of pump-dependent emission color-tunability (from red to white to blue) within the context of a CIE 1931 chromaticity diagram and possessed higher photostability due to suppressed multiexcitonic Auger recombination when compared to conventional Type I CdSe seeded CdS tetrapods. By employing time-resolved spectroscopy measurements, we were able to attribute the wide emission color-tunability to the large valence band offset between InP and CdS. This work highlights the importance of band alignment in the synthetic design of semiconductor nanoheterostructures, which can exhibit color-tunable multiwavelength emission with high efficiency and photostability.

Seed potato production system in Japan, starting from foundation seed of potato

PubMed Central

Kawakami, Tsukasa; Oohori, Hidemiki; Tajima, Kazuyuki

2015-01-01

Potato is one of the staple crops cultivated in upland farming in Japan and is propagated vegetatively by means of tubers. However once infected with diseases, potato yield decreases significantly. And one seed potato can produce approximately only 10 potato tubers. To improve the production system of seed potatoes in Japan, Japanese government established a three-stage propagation system for the production and distribution of healthy and disease-free seed potatoes. The National Center for Seeds and Seedlings (NCSS) has a role for the production of foundation seed potatoes and strictly manages the production in isolated fields that are treated thoroughly to control pests and diseases. Recently though the distribution of foundation seed potatoes is decreasing, the number of varieties of foundation seed potatoes has increased steadily. And new varieties of potato adapted various requirements, including resistance of the golden potato cyst nematode, have been increasing. Therefore, NCSS is introducing a new method of producing minitubers (MnTs) by using hydroponic cultivation greenhouse to increase the efficiency of propagation and to rapidly disseminate these new potato varieties. In this review, we describe a seed potato production system in Japan and the production of foundation seed potatoes as an important role of NCSS. PMID:25931977