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1

Leucaena leucocephala (Lam.) de Wit Leucaena, tantan Leguminosae (Mimosoideae) Legume Family.  

National Technical Information Service (NTIS)

Leucaena leucocephala commonly known as leucaena, tantan, guaje (Mexico), huaxin (Central America), zarcilla (Puerto Rico), and by many other names, is one of the most extensively cultivated leguminous trees in the world. Adapted to a wide range of lowlan...

1992-01-01

2

'Leucaena leucocephala': An Excellent Feed for Livestock.  

National Technical Information Service (NTIS)

Leucaena leucocephala, a leguminous tree native to Central America, is extremely well-suited to the seasonally dry tropics. It can be fed fresh, or as leaf meal, silage, or browse to cows, goats, chickens, and a variety of fish. This report describes char...

M. D. Benge

1980-01-01

3

The value of Leucaena leucocephala bark in leucaena-grass hay diets for Thai goats.  

PubMed

The study assessed the value of Leucaena leucocephala bark in leucaena-grass hay diets fed to Thai goats. Thai goats in metabolism pens were fed diets containing leucaena leaf (55%) + pangola grass hay (hay, 45%); leucaena leaf (48%) + leucaena bark (9%) + hay (43%); leucaena bark (57%) + hay (43%); and hay only. Feed percentages are expressed on a dry weight basis. The digestibilities of dry matter (DM) and crude protein (CP) were measured for the four diets. Leucaena bark had lower CP concentration than the leaf (11.7 vs. 25.9), and the leucaena bark + hay diet had lower DM and CP digestibility than the other diets. The calculated bark digestibilities of DM and CP of 44.1% and 38.2%, respectively, were much lower than the values for the leucaena leaf of 62.9% and 89.1%, respectively. The lower than expected CP digestibility was attributed to higher tannin levels in the bark compared to the leaves. Despite this, the bark was well accepted by the goats and was often preferred to the hay. Stripping of the bark by goats also results in stems that dry quicker and have higher calorific value as fuel. However, if leucaena branches are fed as a sole diet, the goats may consume up to 30% of bark on a DM basis and this would reduce nutritive value and animal productivity. PMID:20563643

Palmer, Brian; Jones, Raymond J; Poathong, Somsak; Chobtang, Jeerasak

2010-06-20

4

'Leucaena leucocephala': A Tree That Defies the Woodcutter.  

National Technical Information Service (NTIS)

Leucaena leucocephala, a long-ignored, versatile legume native to Central America, could offer solutions to global ecological problems of denudation, soil erosion, dwindling wood supplies, and crop production. This report documents the potential importanc...

1981-01-01

5

Some studies on anaerobic decomposition of leucaena leucocephala leaves  

SciTech Connect

Batch type anaerobic decomposition process in leucaena leucocephala plant material (leaves) has been carried out under mesophilic conditions (below 35{degrees}C). The results of studies involving variations in pH, conductivity, temperature, and optical density of digester slurry for four weeks are reported. The gas production rate was also studied which reveals that the use of leucaena leucocephala for biogas production will be helpful.

Torane, J.V.; Lokhande, C.D.; Pawar, S.H. (Energy Studies Lab., Shivaji Univ., Kolhapur (IN))

1990-01-01

6

A note on averting goats to a toxic but palatable plant, Leucaena leucocephala  

Technology Transfer Automated Retrieval System (TEKTRAN)

Conditioned taste aversions are a useful tool to reduce livestock consumption of toxic plants. The forage legume Leucaena leucocephala (leucaena) is both toxic and palatable. The objective of this study was to determine if goats could be aversively conditioned to avoid leucaena. Adult and juvenil...

7

Studies on some physicochemical properties of leucaena leucocephala bark gum.  

PubMed

Gum exudates from Leucaena Leucocephala (Family: Fabaceae) plants grown all over India were investigated for its physicochemical properties such as pH, swelling capacity and viscosities at different temperatures using standard methods. Leucaena Leucocephala bark gum appeared to be colorless to reddish brown translucent tears. 5 % w/v mucilage has pH of 7.5 at 28°C. The gum is slightly soluble in water and practically insoluble in ethanol, acetone and chloroform. It swells to about 5 times its original weight in water. A 5 %w/ v mucilage concentration gave a viscosity value which was unaffected at temperature ranges (28-40°C). At concentrations of 2 and 5 %w/v, the gum exhibited pseudo plastic flow pattern while at 10 %w/v concentration the flow behaviour was thixotropic. The results indicate that the swelling ability of Leucaena Leucocephala (LL) bark gum may provide potentials for its use as a disintegrant in tablet formulation, as a hydro gel in modified release dosage forms and the rheological flow properties may also provide potentials for its use as suspending and emulsifying agents owing to its pseudo plastic and thixotropic flow patterns. PMID:22247853

Pendyala, Vijetha; Baburao, Chandu; Chandrasekhar, K B

2010-04-01

8

STUDIES ON SOME PHYSICOCHEMICAL PROPERTIES OF LEUCAENA LEUCOCEPHALA BARK GUM  

PubMed Central

Gum exudates from Leucaena Leucocephala (Family: Fabaceae) plants grown all over India were investigated for its physicochemical properties such as pH, swelling capacity and viscosities at different temperatures using standard methods. Leucaena Leucocephala bark gum appeared to be colorless to reddish brown translucent tears. 5 % w/v mucilage has pH of 7.5 at 28°C. The gum is slightly soluble in water and practically insoluble in ethanol, acetone and chloroform. It swells to about 5 times its original weight in water. A 5 %w/ v mucilage concentration gave a viscosity value which was unaffected at temperature ranges (28-40°C). At concentrations of 2 and 5 %w/v, the gum exhibited pseudo plastic flow pattern while at 10 %w/v concentration the flow behaviour was thixotropic. The results indicate that the swelling ability of Leucaena Leucocephala (LL) bark gum may provide potentials for its use as a disintegrant in tablet formulation, as a hydro gel in modified release dosage forms and the rheological flow properties may also provide potentials for its use as suspending and emulsifying agents owing to its pseudo plastic and thixotropic flow patterns.

Pendyala, Vijetha; Baburao, Chandu; Chandrasekhar, K.B

2010-01-01

9

Alley cropping maize ( Zea mays L.) and leucaena ( Leucaena leucocephala Lam) in southern Nigeria  

Microsoft Academic Search

Summary  A maize-leucaena alley cropping system was studied on a N-deficient sandy Apomu soil series (Psammentic Usthorthent) at Ibadan\\u000a in the forest zone of southern Nigeria from 1976 to 1980. In this system maize was grown in 4 m width alleys between Leucaena\\u000a hedge rows.\\u000a \\u000a Five to six annual prunings of the leucaena hedge rows yielded between 5 to 8 tons

B. T. Kang; G. F. Wilson; L. Sipkens

1981-01-01

10

Sustain-release of various drugs from leucaena leucocephala polysaccharide.  

PubMed

This study examines the sustained release behavior of both water-soluble (acetaminophen, caffeine, theophylline and salicylic acid) and water-insoluble (indomethacin) drugs from Leucaena leucocephala seed Gum isolated from Leucaena leucocephala kernel powder. It further investigates the effect of incorporation of diluents like microcrystalline cellulose and lactose on release of caffeine and partial cross-linking of the gum (polysaccharide) on release of acetaminophen. Applying exponential equation, the mechanism of release of soluble drugs was found to be anomalous. The insoluble drug showed near case II or zero-order release mechanism. The rate of release was in the decreasing order of caffeine, acetaminophen, theophylline, salicylic acid and indomethacin. An increase in release kinetics of drug was observed on blending with diluents. However, the rate of release varied with type and amount of blend in the matrix. The mechanism of release due to effect of diluents was found to be anomalous. The rate of release of drug decreased on partial cross-linking and the mechanism of release was found to be super case II. PMID:21331185

Jeevanandham, S; Sekar, M; Dhachinamoorthi, D; Muthukumaran, M; Sriram, N; Joysaruby, J

2010-01-01

11

Influence of Antinutritional Factors of Leucaena (Leucaena leucocephala and Leucaena cunningan) and Pigeous Bean (Cajanus cajan) on the Intestinal Epithelium and Performance of Broiler Chickens  

Microsoft Academic Search

A trial was conducted to evaluate the influence of antinutritional factors in some feedstuffs on broiler chick's performance and intestinal epithelium. A total of 480 one-day old broiler chicks were allotted to a completely randomized experimental desi gn with four treatments (A= corn and soybean meal based control diet; B = diet containing Leucaena leucocephala - 6% (LL); C =

Paulo Batista de Oliveira; Alice Eiko Murakami; Elis Regina de Moraes Garcia; Marcos Macari; Cláudio Scapinello

12

Effect of feeding graded levels of Leucaena leucocephala, Leucaena pallida, Sesbania sesban and Chamaecytisus palmensis supplements to teff straw given to Ethiopian highland sheep  

Microsoft Academic Search

The effect of feeding graded levels of Leucaena leucocephala, Leucaena pallida, Sesbania sesban and Chamaecytisus palmensis supplements on intake, digestibility and live weight changes was evaluated using 102 male Ethiopian highland sheep in a 90-day trial. Teff straw (Eragrostis tef) was fed ad libitum (control diet), or supplemented with graded levels (15, 30, 45, 60% of ration dry matter intake)

R. J. Kaitho; N. N. Umunna; I. V. Nsahlai; S. Tamminga; J. Van Bruchem

1998-01-01

13

Contribution of condensed tannins and mimosine to the methane mitigation caused by feeding Leucaena leucocephala.  

PubMed

Leucaena (Leucaena leucocephala), a leguminous shrub promising to cope with feed scarcity in the tropics, may help in mitigating ruminal methane (CH4) emission in the tropics as well. Two experiments were conducted to evaluate the effect of Leucaena and major secondary compounds of this plant in ruminants. At first, effects of Leucaena tannins and mimosine on ruminal CH4 and nutrient degradability were tested in vitro. Incubations were made with Leucaena without or with polyethylene glycol (PEG) to exclude the tannins effects, as well as with Bermuda grass (Tifton) and lucerne hays, both either untreated or supplemented with mimosine at the same concentration that has been provided by the tested Leucaena (6.52 mg/g DM). Furthermore, in an in vivo experiment a control diet (per kg DM 700 g Tifton hay) and Leucaena diets (per kg DM 350 g Tifton hay and 350 g Leucaena), either with or without 20 g PEG/d per head, were evaluated in six Santa Inês sheep following a double Latin square design. In vitro, Leucaena resulted in the lowest (p < 0.05) gas and CH4 production and the highest (p < 0.05) partitioning factor, a measure for microbial efficiency, whereas the amount of truly degraded organic matter (TDOM) was lowest (p < 0.05) with Tifton among the experimental forage plants. Mimosine addition to lucerne and Tifton as well as PEG addition to Leucaena had no effect on ruminal CH4 and TDOM. In vivo Leucaena, compared to the Tifton diet, enhanced (p < 0.05) intake, faecal nitrogen excretion, body nitrogen retention and the excretion of urinary purine derivatives as an indicator for microbial protein synthesis and availability. This was independent of PEG addition. Leucaena also decreased (p < 0.001) CH4 emission per unit of digested organic matter by 14.1% and 10.8%, without and with PEG, respectively. No significant diet differences were observed in total-tract nutrient digestibility. The study demonstrated efficiency of Leucaena to mitigate in vivo methane emission of sheep, but did not reveal which constituent of Leucaena was primarily responsible for that since no clear efficiency of either tannins or mimosine could be demonstrated. PMID:23742642

Soltan, Yosra A; Morsy, Amr S; Sallam, Sobhy M A; Lucas, Ronaldo C; Louvandini, Helder; Kreuzer, Michael; Abdalla, Adibe L

2013-06-01

14

Changes in Dinitrogen Fixation in Maturing Stands of 'Casuarina equisetifolia' and 'Leucaena leucocephala'.  

National Technical Information Service (NTIS)

Biological dinitrification fixation in Casuarina equisetifolia J.R. & G. Forst, and Leucaena leucocephala (Lam.) de Wit was evaluated using the (sup 15)N-enrichment technique under field conditions in single-species and mixed-species plantings (with a non...

J. A. Parrotta D. D. Baker M. Fried

1996-01-01

15

Effect of intercrop spacing and nitrogen fertilizer on establishment of Leucaena leucocephala in alley cropping  

Microsoft Academic Search

One of the reasons for the low rate of adoption of alley cropping in the humid tropics is the problem of establishing the desired hedgerow trees. A split plot experimental design trial was set up to investigate the effects of 4 levels of nitrogen (N) fertilizer (0, 30, 60, and 120 kg N ha) on the growth of Leucaena leucocephala

J. A. Okogun; K. Mulongoy

1999-01-01

16

Improved method of in vitro regeneration in Leucaena leucocephala - a leguminous pulpwood tree species.  

PubMed

Leucaena leucocephala is a fast growing multipurpose legume tree used for forage, leaf manure, paper and pulp. Lignin in Leucaena pulp adversely influences the quality of paper produced. Developing transgenic Leucaena with altered lignin by genetic engineering demands an optimized regeneration system. The present study deals with optimization of regeneration system for L. leucocephala cv. K636. Multiple shoot induction from the cotyledonary nodes of L. leucocephala was studied in response to cytokinins, thidiazuron (TDZ) and N(6)-benzyladenine (BA) supplemented in half strength MS (½-MS) medium and also their effect on in vitro rooting of the regenerated shoots. Multiple shoots were induced from cotyledonary nodes at varied frequencies depending on the type and concentration of cytokinin used in the medium. TDZ was found to induce more number of shoots per explant than BA, with a maximum of 7 shoots at an optimum concentration of 0.23 µM. Further increase in TDZ concentration resulted in reduced shoot length and fasciation of the shoots. Liquid pulse treatment of the explants with TDZ did not improve the shoot production further but improved the subsequent rooting of the shoots that regenerated. Regenerated shoots successfully rooted on ½-MS medium supplemented with 0.54 µM ?-naphthaleneacetic acid (NAA). Rooted shoots of Leucaena were transferred to coco-peat and hardened plantlets showed ? 90 % establishment in the green house. PMID:23572941

Shaik, Noor M; Arha, Manish; Nookaraju, A; Gupta, Sushim K; Srivastava, Sameer; Yadav, Arun K; Kulkarni, Pallavi S; Abhilash, O U; Vishwakarma, Rishi K; Singh, Somesh; Tatkare, Rajeshri; Chinnathambi, Kannan; Rawal, Shuban K; Khan, Bashir M

2009-12-06

17

Development of an Agrobacterium-mediated transformation protocol for the tree-legume Leucaena leucocephala using immature zygotic embryos.  

PubMed

The tree-legume Leucaena leucocephala (leucaena) is used as a perennial fodder because of its fast-growing foliage, which is high in protein content. The use of leucaena as a fodder is however restricted due to the presence of the toxin mimosine. Improvements in the nutritional contents as well as other agronomic traits of leucaena can be accomplished through genetic transformation. The objective of this research was to develop a transformation protocol for leucaena using phosphinothricin resistance as the plant selectable marker. Explants obtained from immature zygotic embryos infected with the Agrobacterium tumefaciens strain C58C1 containing the binary plasmid pCAMBIA3201 produced four putative transformed leucaena plants. Transformation was con- firmed by PCR, RT-PCR, Southern blot, Western analyses, GUS-specific enzyme activity and herbicide leaf spraying assay. A transformation efficiency of 2% was established using this protocol. PMID:20041041

Jube, Sandro; Borthakur, Dulal

2009-01-01

18

Nitrogen cycling in degraded Leucaena leucocephala-Brachiaria decumbens pastures on an acid infertile soil in south-east Queensland, Australia  

Microsoft Academic Search

A grazing trial was conducted to quantify N cycling in degraded Leucaena leucocephala (leucaena)-Brachiaria decumbens (signal grass) pastures grown on an acid, infertile, podzolic soil in south-east Queensland. Nitrogen accumulation and cycling in leucaena-signal grass pastures were evaluated for 9 weeks until all of the leucaena on offer (mean 600 kg edible dry matter (EDM)\\/ha, 28% of total pasture EDM)

S. T. M. BURLE; H. M. SHELTON; S. A. DALZELL

19

Purification and characterization of peroxidase from Leucaena leucocephala, a tree legume  

Microsoft Academic Search

Peroxidase was purified to homogeneity from a tree legume Leucaena leucocephala. On SDS-PAGE the purified enzyme exhibited two distinct subunits each of 66 and 58kDa. Determination of native molecular weight of the purified peroxidase revealed a size of ?200kDa suggesting a heterotrimeric structure (consisting of two subunits of 66kDa and one subunit of 58kDa) for native peroxidase. Purified peroxidase was

Veda P. Pandey; Upendra N. Dwivedi

2011-01-01

20

Lime-aluminium-phosphorus interactions and the growth of Leucaena leucocephala  

Microsoft Academic Search

The effects of lime and P addition on the amounts of soil extractable P and Al, and on the growth of the tropical legume Leucaena leucocephala were investigated in a factorial experiment under controlled climate conditions using 4 (Koronivia, Nadroloulou, Batiri, and Seqaqa) highly-weathered, acid (pH initially 3.9 to 4.9) soils from Fiji. Resin-extractable P increased with lime addition and

R. Naidu; R. W. Tillman; J. K. Syers; J. H. Kirkman

1990-01-01

21

Pruning effect on nitrogen nutrient release in the root zone of Albizia lebbeck and Leucaena leucocephala  

Microsoft Academic Search

The effect of pruning on the dynamics of N release in the root zone of Albizia lebbeck and Leucaena leucocephala was studied using potted soil and minilysimeters with presterilized sand-medium supplied with N-free nutrient solution. Plants\\u000a were pruned twice at 11 and 13 months and leachates were collected weekly for 16 weeks starting from first pruning, and analysed\\u000a for mineral

B. D. Kadiata; K. Mulongoy; B. Mambani

1998-01-01

22

Evaluation of the Mineral Nutrients and Organic Food Contents of the Seeds of Lablab purpureus, Leucaena leucocephala and Mucuna utilis for Domestic Consumption and Industrial Utilization  

Microsoft Academic Search

Investigations were carried out on the mineral nutrients and organic food contents of seeds of three fodder Lablab purpureus, Leucaena leucocephala and Mucuna utilis for domestic consumption and industrial utilization. Leucaena leucocephala seeds contained the highest amount of lipids crude protein carbohydrates and ash contents. Lablab purpureus contained the lowest amount of lipid crude protein crude fibre and ash content.

D. A. Alabi; A. A. Alausa

23

The Type 3 Protein Secretion System of Cupriavidus taiwanensis Strain LMG19424 Compromises Symbiosis with Leucaena leucocephala  

PubMed Central

Cupriavidus taiwanensis forms proficient symbioses with a few Mimosa species. Inactivation of a type III protein secretion system (T3SS) had no effect on Mimosa pudica but allowed C. taiwanensis to establish chronic infections and fix nitrogen in Leucaena leucocephala. Unlike what was observed for other rhizobia, glutamate rather than plant flavonoids mediated transcriptional activation of this atypical T3SS.

Saad, Maged M.; Crevecoeur, Michele; Masson-Boivin, Catherine

2012-01-01

24

The type 3 protein secretion system of Cupriavidus taiwanensis strain LMG19424 compromises symbiosis with Leucaena leucocephala.  

PubMed

Cupriavidus taiwanensis forms proficient symbioses with a few Mimosa species. Inactivation of a type III protein secretion system (T3SS) had no effect on Mimosa pudica but allowed C. taiwanensis to establish chronic infections and fix nitrogen in Leucaena leucocephala. Unlike what was observed for other rhizobia, glutamate rather than plant flavonoids mediated transcriptional activation of this atypical T3SS. PMID:22865066

Saad, Maged M; Crèvecoeur, Michèle; Masson-Boivin, Catherine; Perret, Xavier

2012-08-03

25

Transgenic Leucaena leucocephala expressing the Rhizobium gene pydA encoding a meta-cleavage dioxygenase shows reduced mimosine content.  

PubMed

The use of the tree-legume Leucaena leucocephala (leucaena), which contains high levels of proteins in its foliage, is limited due to the presence of the toxic free amino acid mimosine. The goal of this research was to develop transgenic leucaena with reduced mimosine content. Two genes, pydA and pydB, encoding a meta-cleavage dioxygenase (EC 1.13.11.2) and a pyruvate hydrolase (EC 3.7.1.6), respectively, from the mimosine-degrading leucaena symbiont Rhizobium sp. strain TAL1145, were used to transform leucaena. These bacterial genes were sequence-optimized for expression in leucaena and cloned into the plant binary vector pCAMBIA3201 for Agrobacterium tumefaciens-mediated transformation. Using immature zygotic embryos as the start explant material, six pydA and three pydB transgenic lines were developed. The presence and expression of the bacterial genes in the transgenic lines were verified by PCR, reverse transcriptase PCR, and Southern analyses. HPLC analyses of the transgenic plants determined that the mimosine contents of the pydA-expressing lines were reduced up to 22.5% in comparison to the wild-type. No significant reduction in mimosine content was observed in the pydB-expressing lines. This is the first example of using a gene from a bacterial symbiont to reduce the toxicity of a tree-legume. PMID:20138776

Jube, Sandro L R; Borthakur, Dulal

2010-01-22

26

GROWTH OF ALBIZIA LEBBECK (L.) BENTH., AND LEUCAENA LEUCOCEPHALA (LAM.) DE-WIT, IN DIFFERENT SOIL COMPOSITIONS OF KARACHI UNIVERSITY CAMPUS SOIL  

Microsoft Academic Search

The growth of Albizia lebbeck (L.) Benth., and Leucaena leucocephala (Lam.) de-Wit, were studied in soils collected from Karachi University area under natural ecological circumstances. Various growth variables of A. lebbeck and L. leucocephala were reduced from different soil composition (25, 50 and 75%) of Karachi University soil (sandy soil) as compared to Garden soil. Growth of L. leucocephala in

Syed Atiq-ur-Rehman; Muhammad Zafar Iqbal

2010-01-01

27

Polyphasic characterization of rhizobia isolated from Leucaena leucocephala from Panxi, China.  

PubMed

Leucaena leucocephala was introduced into Panxi, Sichuan, China, in the 1980s and 1990s for afforestation and preventing water loss and soil erosion in this area. The co-introduction of rhizobial symbionts of introduced plants has drawn attention since they may influence local soil communities. We studied the phylogenetic position of the L. leucocephala isolates and assessed if the rhizobia were introduced together with the host to Panxi, Sichuan, China. The glnII and atpD genes of fifteen representative isolates were sequenced and analyzed, and applied multilocus sequence analyses in which the housekeeping genes recA, glnII and atpD were included. Furthermore, we estimated the within species diversity directly with 23S rDNA and IGS RFLP and indirectly through phenotypic analysis of forty L. leucocephala isolates. The isolates represented seven species and 38 diversified strains in the genera Ensifer, Mesorhizobium, Bradyrhizobium and Rhizobium. The within species diversity of the Ensifer isolates was large, proposing a potential to occupy novel niches. There was not conclusive evidence to show that any of the strains would have been co-introduced with L. leucocephala. On the contrary, we came to a conclusion that the possible introduction should not be inferred from sequence data alone. PMID:23749221

Xu, Kai Wei; Penttinen, Petri; Chen, Yuan Xue; Zou, Lan; Zhou, Tao; Zhang, Xiaoping; Hu, Chao; Liu, Fan

2013-06-01

28

Cinnamate 4-Hydroxylase (C4H) genes from Leucaena leucocephala: a pulp yielding leguminous tree.  

PubMed

Leucaena leucocephala is a leguminous tree species accounting for one-fourth of raw material supplied to paper and pulp industry in India. Cinnamate 4-Hydroxylase (C4H, EC 1.14.13.11) is the second gene of phenylpropanoid pathway and a member of cytochrome P450 family. There is currently intense interest to alter or modify lignin content of L. leucocephala. Three highly similar C4H alleles of LlC4H1 gene were isolated and characterized. The alleles shared more than 98 % sequence identity at amino acid level to each other. Binding of partial promoter of another C4H gene LlC4H2, to varying amounts of crude nuclear proteins isolated from leaf and stem tissues of L. leucocephala formed two loose and one strong complex, respectively, suggesting that the abundance of proteins that bind with the partial C4H promoter is higher in stem tissue than in leaf tissue. Quantitative Real Time PCR study suggested that among tissues of same age, root tissues had highest level of C4H transcripts. Maximum transcript level was observed in 30 day old root tissue. Among the tissues investigated, C4H activity was highest in 60 day old root tissues. Tissue specific quantitative comparison of lignin from developing seedling stage to 1 year old tree stage indicated that Klason lignin increased in tissues with age. PMID:23070917

Kumar, Santosh; Omer, Sumita; Patel, Krunal; Khan, Bashir M

2012-10-17

29

Rumen dry matter and crude protein degradability of extracted or untreated oilseeds and Leucaena leucocephala leaves.  

PubMed

A study was undertaken to determine the rumen DM and CP degradability characteristics of soyabean, canola seed, peanut, palm kernel and Leucaena leucocephala leaves. The oilseeds were either treated with n-hexane to extract the fat or left untreated. Nylon bags were incubated in each of four rumen cannulated sheep for 0, 2, 4, 6, 12, 24 and 48 h. Animals were fed on a diet consisting of meadow hay (ad libitum) and 150 g of concentrate twice daily. Fat extraction caused a decrease (P < or = 0.05) in DM disappearance of soyabean at 0, 2, 4, 6 and 12 h and of peanuts at all incubation times. CP disappearance from peanuts was reduced (P < or = 0.05) as a result of fat extraction at 0, 2, 4, 6 and 12 h. Fat extraction of canola seed increased CP disappearance at 0, 2, 4, 6 and 24 h (P < or = 0.05). However, in the case of defatted canola seed, an increase in DM disappearance (P < or = 0.05) was observed in the first 4 incubation times and a decrease (P < or = 0.05) in the later times. Fat extraction increased (P < or = 0.05) DM disappearance of palm kernel at 0 and 48 h, but reduced it at 4, 6 and 24 h. CP disappearance of palm kernel was improved by treatment (P < or = 0.05) at 0, 4, 24 and 48 h and decreased at 12 h. In the case of palm kernel the largest differences in DM and CP disappearance occurred between the 24 and 48 h incubation times. Degradability characteristics for DM and CP of full-fat soyabean, canola seed and peanut were comparable to those of the full fat samples. Effective DM degradability of soyabean, canola seed and peanuts was 72.2 and 71.9; 74.1 and 66.8; and 85.9 and 70.8 for full fat and extracted feeds, respectively. Effective CP degradability was similar in all oilseeds with the exception of the extracted canola seed. Therefore, the incorporation of full-fat soyabean, canola seed and peanut into ruminant rations can be considered as a means of increasing the energy balance. Both palm kernel DM and CP degradabilities were characterized by slow rates of degradation by negative values "b". This suggests the predominance of microbial colonization over disappearance during incubation. DM and CP disappearance of Leucaena leucocephala leaves originating from Cuba were lower than those from Nigeria. Degradability characteristics for CP and DM of Cuban leucaena leaves showed that the linear model resulted in a better fit than the exponential one. PMID:9227808

Gralak, M A; Kamalu, T; von Keyserlingk, M A; Kulasek, G W

1997-01-01

30

The role of plant growth regulators on direct and indirect plant regeneration from various organs of Leucaena leucocephala  

Microsoft Academic Search

Prolific differentiation of shoot buds of Leucaena leucocephala was induced from the different plant parts viz. cotyledon, hypocotyl and leaf. Adventitious shoot bud formation was recorded\\u000a with prudent application of N6-2- (isopentenyl) adenosine and 15% (v\\/v) coconut water. Coconut water alone was unable to produce any beneficial effect with\\u000a regard to the shoot bud proliferation but the response was augmented

Sharmistha Maity; Samit Ray; Nirmalya Banerjee

2005-01-01

31

Leucaena leucocephala seedling response to vesicular-arbuscular mycorrhizal inoculation in soils with varying levels of inherent mycorrhizal effectiveness  

Microsoft Academic Search

The symbiotic effectiveness of vesicular-arbuscular mycorrhizal (VAM) fungi present in widely differring tropical soils was evaluated in a greenhouse experiment. Small volumes of field soil, a standard inoculum (Glomus aggregatum) or both were introduced into a fumigated sand-soil medium amended with nutrients for optimum VAM activity. Leucaena leucocephala (Lam.) de Wit var. K8 was grown in the medium as an

M. Habte; R. L. Fox

1989-01-01

32

The influence of cutting height, planting density, harvesting frequency and fertilization on edible dry matter yield of leucaena leucocephala (Lam.) de wit  

Microsoft Academic Search

Leucaena leucocephala was evaluated to determine the agronomic and management requirements of this legume in Natal. The objectives were to test the effect of maintaining hedge?rows at different heights, and to investigate the effect of different densities, harvest intervals and fertilization on edible dry matter (EDM) production of L. leucocephala plants grown in the pure stand situation. Cutting plants in

A. R. Maclaurin; D. I. Bransby; N. M. Tainton

1982-01-01

33

Effects of supplementing rice straw with Leucaena (Leucaena leucocephala) and Madras thorn (Pithecellobium dulce) foliages on digestibility, microbial N supply and nitrogen balance of growing goats.  

PubMed

A total of 12 crossbred (Boer × Anglo-Nubian) goats were chosen from a commercial farm on the basis of similar body weight (25.0 ± 3.1 kg). The goats were housed in individual pens and allowed 3 weeks to adapt to experimental conditions. The goats were randomly allocated to three treatments in a 3 × 3 Latin square experiment (replicated four times). Within each period, each goat was given rice straw as roughage plus the respective treatment diet. The diets were iso-nitrogenous and iso-energetic containing cassava pulp, molasses, urea and commercial mineral and vitamin mix. The experimental treatments were (i) soybean meal (SBM), (ii) partial substitution of SBM with Leucaena (Leucaena leucocephala) foliage and (iii) partial substitution of SBM with Madras thorn (Pithecellobium dulce) foliage. Nutrient intakes, ruminal characteristics (pH, ammonia nitrogen and volatile fatty acids), nitrogen balances, plasma urea nitrogen and microbial N supply were not significantly different among treatments. The results of this study indicate that protein foliages from locally grown shrubs and trees can substitute imported feedstuff concentrates (e.g. SBM) as protein supplement for goat production. PMID:20487095

Paengkoum, P; Paengkoum, S

2010-10-01

34

[Comparison of phylogeny analysis methods for rhizobia asolated from Albizia spp., Acacia spp. and Leucaena leucocephala].  

PubMed

Multilocus house-keeping gene sequence analysis is a hotspot of taxonomy and phylogeny of prokaryotes. In this research, we used atpD and gln II gene sequences to analyze the phylogeny of nine rhizobia strains of Albizia spp., Acacia spp. and Leucaena leucocephala and compared the results to that of 16S rDNA. The phylogenetic relationships based on the sequence analysis of these three genes were congruent at the genera level. CCBAU43060 and CCBAU 61139 were located in the branch of Rhizobium-Agrobacterium. CCBAU51471, CCBAU35220, CCBAU51276 and CCBAU61158 belonged to the genera of Mesorhizobium. CCBAU35234, CCBAU61178 and CCBAU35085 were assigned to Bradyrhizobium. Differences were found for some strains, for example CCBAU 61158, CCBAU43060, CCBAU61178, at the species level. Insertion fragment and mosaic gene were also found in some isolates. These results indicated that there was recombination between species in the same genera. It is reliable to determine the taxonomy status at genera levels based on the sequence analysis of 16S rDNA. If the relationships between strains belonging to the same genera were studied using the phylogeny methods, researches should be carried out with more than one house-keeping genes. PMID:18338568

Wang, Fengqin; Zhang, Yongfa; Liu, Jie; Song, Andong; Liu, Quanjun; Chen, Wenxin

2008-01-01

35

Characterization of vine shoots, cotton stalks, Leucaena leucocephala and Chamaecytisus proliferus, and of their ethyleneglycol pulps.  

PubMed

We characterized vine shoots, cotton stalks, Leucaena leucocephala and Chamaecytisus proliferus as pulping raw materials and found C. proliferus and cotton stalks to be the best for the intended purpose on the grounds of their increased contents in holocellulose (79.73% and 72.86%) and alpha-cellulose (45.37% and 58.48%), and their decreased contents in ethanol-benzene extractables (2.64% and 1.42%), hot water solubles (2.79% and 3.33%) and 1% soda solubles (16.67% and 20.34%). These properties resulted in increased pulp yields and hence in efficient use of these two types of raw material. The previous raw materials were pulped by using an ethyleneglycol concentration of 65% at 180 degrees C for 75min, followed by beating at 1500 revolutions in a PFI refiner. The paper sheets obtained were characterized and those from C. proliferus found to be the best overall as they exhibited an increased breaking length (4644m), stretch (2.87%), burst index (2.46kN/g) tear index (0.33mNm(2)/g) and brightness (49.92% ISO); in addition C. proliferus pulp was obtained with a high-yield (62.88%). On the other hand, vine shoots provided the poorest results among the studied raw materials. PMID:17204420

Jiménez, Luis; Pérez, Antonio; de la Torre, María Jesús; Moral, Ana; Serrano, Luis

2007-01-03

36

Revegetation of lagoon ash using the legume species Acacia auriculiformis and Leucaena leucocephala.  

PubMed

A greenhouse study was conducted to evaluate the potential use of two legume species, Acacia auriculiformis and Leucaena leucocephala for growth on ameliorated lagoon ash with or without nitrogen (N(2))-fixing bacteria inoculation. Even though amendments of 30% (w/w) vermiculite or with sewage sludge compost were added to improve the chemical and physical limitations of lagoon ash, significant suppressions in biomass and plant nutrient content were found with ameliorated lagoon ash in comparison to an agricultural soil. The high proportion of clay-sized (<53 microm) ash particles limited root growth. In addition, heavy metal toxicity was a possible factor contributing to poor seedling growth. Higher plant productivity resulted from the sewage sludge compost-amended lagoon ash than with vermiculite due to a greater contribution of plant nutrients in the compost. Nodulation was inhibited in ameliorated lagoon ash but not in agricultural soil. High pH and electrical conductivity and elevated toxic metals may be important parameters that limit bacterial activity. Both species showed potential to establish on amended lagoon ash, with Acacia auriculiformis being the best adapted. PMID:15092915

Cheung, K C; Wong, J P; Zhang, Z Q; Wong, J W; Wong, M H

2000-07-01

37

Productivity of alley farming with leucaena ( Leucaena leucocephala Lam. de Wit) and Napier grass ( Pennisetum purpureum K. Schum) in coastal lowland Kenya  

Microsoft Academic Search

Inadequate supply of fodder is a serious constraint to the potentially-promising small-holder-dairy production system in coastal Kenya. Alley farming could be an approach to addressing this problem. A study of forage production based on Napier grass and leucaena in an alley cropping system was conducted on an infertile sandy soil in lowland coastal Kenya. The effects of leucaena hedgerows,Clitoria ternatea

J. G. Mureithi; R. S. Tayler; W. Thorpe

1995-01-01

38

Cloning, expression, functional validation and modeling of cinnamyl alcohol dehydrogenase isolated from xylem of Leucaena leucocephala.  

PubMed

A cDNA encoding cinnamyl alcohol dehydrogenase (CAD), catalyzing conversion of cinnamyl aldehydes to corresponding cinnamyl alcohols, was cloned from secondary xylem of Leucaena leucocephala. The cloned cDNA was expressed in Escherichia coli BL21 (DE3) pLysS cells. Temperature and Zn(2+) ion played crucial role in expression and activity of enzyme, such that, at 18°C and at 2 mM Zn(2+) the CAD was maximally expressed as active enzyme in soluble fraction. The expressed protein was purified 14.78-folds to homogeneity on Ni-NTA agarose column with specific activity of 346 nkat/mg protein. The purified enzyme exhibited lowest Km with cinnamyl alcohol (12.2 ?M) followed by coniferyl (18.1 ?M) and sinapyl alcohol (23.8 ?M). Enzyme exhibited high substrate inhibition with cinnamyl (beyond 20 ?M) and coniferyl (beyond 100 ?M) alcohols. The in silico analysis of CAD protein exhibited four characteristic consensus sequences, GHEXXGXXXXXGXXV; C(100), C(103), C(106), C(114); GXGXXG and C(47), S(49), H(69), L(95), C(163), I(300) involved in catalytic Zn(2+) binding, structural Zn(2+) binding, NADP(+) binding and substrate binding, respectively. Tertiary structure, generated using Modeller 9v5, exhibited a trilobed structure with bulged out structural Zn(2+) binding domain. The catalytic Zn(2+) binding, substrate binding and NADP(+) binding domains formed a pocket protected by two major lobes. The enzyme catalysis, sequence homology and 3-D model, all supported that the cloned CAD belongs to alcohol dehydrogenase family of plants. PMID:21708267

Pandey, Brijesh; Pandey, Veda Prakash; Dwivedi, Upendra Nath

2011-06-25

39

Competition Among Rhizobium spp. for Nodulation of Leucaena leucocephala in Two Tropical Soils †  

PubMed Central

The successful nodulation of legumes by a Rhizobium strain is determined by the competitive ability of that strain against the mixture of other native and inoculant rhizobia. Competition among six Leucaena rhizobial strains in single and multistrain inoculants were studied. Field inoculation trials were conducted in an oxisol and a mollisol soil, both of which contained indigenous Leucaena-nodulating rhizobia. Strain-specific fluorescent antibodies were used for the identification of the strains in Leucaena nodules. Mixtures of three recommended inoculum strains for Leucaena spp. (TAL82, TAL582, and TAL1145) were used in peat-based inocula either alone or with one of the three other strains isolated from the sites, B213, B214, and B215. Each of these latter three strains was also used as single-strain inocula to study their competition with the native rhizobia in the two soil systems. In the oxisol soil, strains B213 and B215, when used as single-strain inocula, outcompeted the native rhizobia and formed 92 and 62% of the nodules, respectively. Strain B214 was the least competitive in oxisol soil, where it formed 30% of the nodules, and the best in mollisol soil, where it formed 70% of the nodules. The most successful competitor for nodulation in multistrain inocula was strain TAL1145, which outcompeted native and other inoculum Leucaena rhizobia in both soils. None of the strains in single or multistrain inoculants was capable of completely overcoming the resident rhizobia, which formed 4 to 70% of the total nodules in oxisol soil and 12 to 72% in mollisol soil. No strong relationship was detected between the size of the rhizosphere population of a strain and its successful occupation of nodules.

Moawad, H.; Bohlool, B. B.

1984-01-01

40

Competition among rhizobium species for nodulation of Leucaena leucocephala in two tropical soils  

SciTech Connect

The successful nodulation of legumes by a Rhizobium strain is determined by the competitve ability of that strain against the mixture of other native and inoculant rhizobia. Competition among six Leucaena rhizobial strains in single and multistrain inoculants were studied. Field inoculation trials were conducted in an oxisol and a mollisol soil, both of which contained indigenous Leucaena-nodulating rhizobia. Strain-specific fluorescent antibodies were used for the identification of the strains in Leucaena nodules. Mixtures of three recommended inoculum strains for Leucaena species (TAL82, TAL582, and TAL1145) were used in peat-based inocula either alone or with one of the three other strains isolated from the sites, B213, B214, and B215. Each of these latter three strains was also used as single-strain inocula to study their competition with the native rhizobia in the two soil systems. In the oxisol soil, strains B213 and B215, when used as single-strain inocula, outcompeted the native rhizobia and formed 92 and 62% of the nodules, respectively. Strain B214 was the least competitive in oxisol soil, where it formed 30% of the nodules, and the best in mollisol soil, where it formed 70% of the nodules. The most successful competitor for nodulation in multistrain inocula was strain TAL1145, which outcompeted native and other inoculum Leucaena rhizobia is both soils. None of the strains in single or multistrain inoculants was capable of completely overcoming the resident rhizobia, which formed 4 to 70% of the total nodules in oxisol soil and 12 to 72% in mollisol soil. No strong relationship was detected between the size of the rhizosphere population of a strain and its successful occupation of nodules. 24 references.

Moawad, H.; Bohlool, B.B.

1984-07-01

41

Competition Among Rhizobium spp. for Nodulation of Leucaena leucocephala in Two Tropical Soils.  

PubMed

The successful nodulation of legumes by a Rhizobium strain is determined by the competitive ability of that strain against the mixture of other native and inoculant rhizobia. Competition among six Leucaena rhizobial strains in single and multistrain inoculants were studied. Field inoculation trials were conducted in an oxisol and a mollisol soil, both of which contained indigenous Leucaena-nodulating rhizobia. Strain-specific fluorescent antibodies were used for the identification of the strains in Leucaena nodules. Mixtures of three recommended inoculum strains for Leucaena spp. (TAL82, TAL582, and TAL1145) were used in peat-based inocula either alone or with one of the three other strains isolated from the sites, B213, B214, and B215. Each of these latter three strains was also used as single-strain inocula to study their competition with the native rhizobia in the two soil systems. In the oxisol soil, strains B213 and B215, when used as single-strain inocula, outcompeted the native rhizobia and formed 92 and 62% of the nodules, respectively. Strain B214 was the least competitive in oxisol soil, where it formed 30% of the nodules, and the best in mollisol soil, where it formed 70% of the nodules. The most successful competitor for nodulation in multistrain inocula was strain TAL1145, which outcompeted native and other inoculum Leucaena rhizobia in both soils. None of the strains in single or multistrain inoculants was capable of completely overcoming the resident rhizobia, which formed 4 to 70% of the total nodules in oxisol soil and 12 to 72% in mollisol soil. No strong relationship was detected between the size of the rhizosphere population of a strain and its successful occupation of nodules. PMID:16346600

Moawad, H; Bohlool, B B

1984-07-01

42

Alleu cropping sequentially cropped maize and cowpea with Leucaena on a sandy soil in Southern Nigeria  

Microsoft Academic Search

Summary The potential of alley cropping maize and cowpea with the giant Leucaena (Leucaena leucocephala (Lam) de Wit) cultivar K-28 was studied on an Entisol (Psammentic Ustorthent) in Southern Nigeria. In this trial the crops were grown in 4 m wide alleys formed by periodically pruned leucaena hedgerows. The effect of application of leucaena prunings, nitrogen fertilizer and tillage was

B. T. Kang; H. Grimme; T. L. Lawson

1985-01-01

43

Sinorhizobium morelense sp. nov., a Leucaena leucocephala-associated bacterium that is highly resistant to multiple antibiotics.  

PubMed

Sinorhizobium morelense sp. nov. is described to designate a group of bacteria isolated from root nodules of Leucaena leucocephala. S. morelense shows 98% 16S rRNA gene sequence similarity to some Sinorhizobium species and to Ensifer adhaerens. This novel species is distinguished from other Sinorhizobium species and from E. adhaerens by DNA-DNA hybridization, 165 rRNA gene restriction fragments and sequence and some distinctive phenotypic features. Strains of this species are highly resistant to some antibiotics, such as carbenicillin (1 mg ml(-1)), kanamycin (500 microg ml(-1)) and erythromycin (300 microg ml(-1)). They do not form nodules, but a nodulating strain, Lc57, is closely related to the novel species. Strain Lc04T (= LMG 21331T = CFN E1007T) is designated as the type strain of this novel species. PMID:12361275

Wang, En Tao; Tan, Zhi Yuan; Willems, Anne; Fernández-López, Manuel; Reinhold-Hurek, Barbara; Martínez-Romero, Esperanza

2002-09-01

44

PEI modified Leucaena leucocephala seed powder, a potential biosorbent for the decontamination of arsenic species from water bodies: bioremediation  

NASA Astrophysics Data System (ADS)

Environmental contamination due to anthropogenic and natural sources is increasing day by day because of increase in population, industrialization and urbanization. Arsenic species released into the environment tend to persist indefinitely, circulating and eventually accumulating throughout the food chain, thus becoming a serious threat to the environment. The present study explores the effectiveness of Leucaena leucocephala seed powder (agricultural waste) in removing arsenic ions from aqueous solution. Batch studies were carried out to characterize As (III) and As (V) removal capability of L. leucocephala seed powder. Maximum biosorption capacity for As (III) and As (V) was found to be 81.88 and 92.61 %, respectively. Amino acid-arsenic interaction has been highlighted on the basis of shifting of FTIR bands of native LLSP. Morphological changes and reduction in pore area have been observed in modified LLSP. Modification on the native LLSP results into the increase in percentage sorption of As (III) and As (V) up to 85 and 99 %, respectively. Enhancement in the percentage sorption is due the increase in the stability of the biosorbent due to increase in the final decomposition temperature of the modified LLSP. The findings showed that L. leucocephala seed powder can easily be envisaged as a new, vibrant, low-cost biosorbent for arsenic clean-up operations.

Raj, Kumar Rohit; Kardam, Abhishek; Srivastava, Shalini

2013-03-01

45

Anatomy and ultrastructure alterations of Leucaena leucocephala (Lam.) inoculated with mycorrhizal fungi in response to arsenic-contaminated soil.  

PubMed

Many studies demonstrate the potential application of arbuscular mycorrhizal fungi (AMF) for remediation purposes, but little is known on AMF potential to enhance plant tolerance to arsenic (As) and the mechanisms involved in this process. We carried anatomical and ultrastructural studies to examine this symbiotic association and the characteristics of shoots and roots of Leucaena leucocephala in As-amended soils (35 and 75mgAsdm(-3)). The experiment used 3 AMF isolates from uncontaminated soils: Acaulospora morrowiae, Glomus clarum, and Gigaspora albida; a mixed inoculum derived from combining these 3 isolates (named Mix AMF); and, 3 AMF isolates from As-contaminated areas: A. morrowiae, G. clarum and Paraglomus occultum. Phytotoxicity symptoms due to arsenic contamination appeared during plant growth, especially in treatments without AMF application. Inoculation with G. clarum and the mixture of species (A. morrowiae, G. albida, and G. clarum) resulted in better growth of L. leucocephala in soils with high As concentrations, as well as significant As removal from the soil, showing a potential for using AMF in phytoextraction. Light microscopy (LS), transmission (TEM) and scanning electron microscopies (SEM) studies showed the colonization of the AMF in plant tissues and damage in all treatments, with ultrastructural changes being observed in leaves and roots of L. leucocephala, especially with the addition of 75mgdm(-3) of As. PMID:22704769

Schneider, Jerusa; Labory, Claudia Regina Gontijo; Rangel, Wesley Melo; Alves, Eduardo; Guilherme, Luiz Roberto Guimarães

2012-06-01

46

Reproductive performance, colostrum and milk constituents of mimosine-adapted South African Nguni goats on Leucaena leucocephala-grass or natural pastures  

Microsoft Academic Search

The study evaluates the cause of the high pre-weaning kid mortality rate in South African Nguni goat (SANG) kids maintained on Leucaena leucocephala-grass pasture (LGP) as feed sources during gestation via reproductive performance, colostrum and milk constituents of mimosine-adapted South African Nguni dams. Does grazing LGP plots gained 2.9 (P<0.05) and 5.2kg (P<0.01) more in body weight between gestation and

A. A Akingbade; I. V Nsahlai; C. D Morris

2004-01-01

47

Site factors associated with the performance of Leucaena leucocephala (Lam.) de Wit and Sesbania sesban (L.) Merill in pure and mixed stands in the northern highlands of Rwanda  

Microsoft Academic Search

Alley cropping with leguminous tree hedgerows planted on contours is an emerging practice in the northern highlands of Rwanda\\u000a where field slopes range from 4 to 76% and loss of soil fertility due to erosion is the principal impediment to food production.\\u000a Sesbania sesban and Leucaena Leucocephala, the two woody species recommended for alley cropping in the region, do not

J. R. Burleigh; C. F. Yamoah

1997-01-01

48

Plant growth, leaf water potential, nitrogenase activity and nodule anatomy in Leucaena leucocephala as affected by water stress and nitrogen availability  

Microsoft Academic Search

The effects of water stress and nitrogen availability on leaf water potential, nitrogenase activity, and growth was studied\\u000a in a pot experiment with Leucaena leucocephala seedlings. Water stress was imposed on fertilized and unfertilized plants after inoculation with Rhizobium. Non-inoculated seedlings were used as control plants. Water stress lowered leaf water potential in all seedlings after 14\\u000a days of treatment.

A. F. Mrema; U. Granhall; L. Sennerby-Forsse

1997-01-01

49

Productive performance and urinary excretion of mimosine metabolites by hair sheep grazing in a silvopastoral system with high densities of Leucaena leucocephala.  

PubMed

The aim of this study was to evaluate daily weight gain (DWG), total dry matter (DM) intake, rumen degradability of forage, and urinary excretion of mimosine metabolites by hair sheep in a silvopastoral system with high densities of Leucaena leucocephala. A completely randomized design was carried out with two treatments: treatment 1 (T1) silvopastoral system with leucaena at a density of 35,000 plants/ha and treatment 2 (T2), leucaena at a density of 55,000 plants/ha. Leucaena was associated with tropical grasses Panicum maximum and Cynodon nlemfluensis. Twenty-four male Pelibuey lambs of 23.2 ± 3.4 kg live weight (LW) were used (12 lambs per treatment). Results showed differences (P < 0.05) in DWG of T1 (106.41 ± 11.66 g(-1) sheep(-1)) with respect to that of T2 (81.33 ± 11.81 g(-1) sheep). Voluntary intake was higher in lambs from T1 (83.81 ± 04.07 g DM/kg LW(0.75)) with respect to that from T2 (71.67 ± 8.12 g DM/kg LW(0.75)). There was a difference in color of urine between sheep of T1 and T2, the latter giving positive results for the presence of metabolites derived from mimosine (3-4 dihydroxypyridine and 2-3 dihydroxy pyridone). Rumen degradability of DM of L. leucocephala was higher (P < 0.05) compared to that of P. maximum and C. nlemfluensis (72.94 ± 0.40 vs. 67.06?±?1.50 and 63.25 ± 1.51 %, respectively). It is concluded that grazing at high densities of L. leucocephala affects daily weight gain of hair sheep, possibly due to ingestion of high amounts of mimosine which may exert an adverse effect on voluntary intake. PMID:22528536

Barros-Rodríguez, Marcos; Solorio-Sánchez, Javier; Ku-Vera, Juan; Ayala-Burgos, Armín; Sandoval-Castro, Carlos; Solís-Pérez, Georgina

2012-04-19

50

Within-country variation in the ability of ruminants to degrade DHP following the ingestion of Leucaena leucocephala--a Thailand experience.  

PubMed

Goats fed Leucaena leucocephala (leucaena) at an experimental site in Thailand were shown to be excreting DHP in their urine. This was unexpected as earlier results from another site had shown that goats and cattle fed leucaena did not excrete DHP and so possessed DHP-degrading bacteria. Goats sampled near the earlier sample site excreted no DHP in their urine. Rumen fluid taken from these goats was successfully used to transfer DHP--degrading ability to the goats at the Experimental site some 350 km away that did not show the presence of DHP-degrading bacteria. Degradation of mimosine in-vitro and excretion of DHP in the urine ceased 72 hr after addition of rumen fluid and infusion with rumen fluid from protected goats, respectively. The situation in Thailand may not be unique. Countries where leucaena is fed should check that animals are protected. Fortunately, the ferric chloride urine test is simple to use and effective in detecting the problem and also the recovery after transfer of rumen fluid from protected animals. PMID:19544003

Palmer, Brian; Jones, Raymond J; Poathong, Somsak; Chobtang, Jeerasak

2009-06-20

51

Wood and biomass production of Leucaena in subtropical Australia  

Microsoft Academic Search

Although only Leucaena leucocephala is widely used, most members of the Leucaena genus have potential as multipurpose species for tropical agroforestry systems. To investigate the wood and biomass production\\u000a potential of the Leucaena genus, 116 accessions covering the 22 species were evaluated over a two-year period at Brisbane, southeast Queensland, Australia.\\u000a Trees were planted into replicated line plots 5 m

B. F. Mullen; R. C. Gutteridge

2002-01-01

52

Chemically-modified polysaccharide extract derived from Leucaena leucocephala alters Raw 264.7 murine macrophage functions.  

PubMed

In this study, a chemical modification of the polysaccharides extract (E) derived from Leucaena leucocephala seeds was performed to prepare C-glycosidic 2-propanol derivative (PE), and its sulphated derivative (SPE). This study aimed to characterize immunomodulatory activities of the original extract and its derivatives by exploring their effects on Raw macrophage 264.7 functions and their antioxidant activity. Our results indicated that PE was an effective radical scavenger to hydroxyl, peroxyl, and superoxide anion radicals, and SPE was a peroxyl radical scavenger. PE and SPE were found to influence the macrophage functions. Both of PE and SPE enhanced the macrophage proliferation and phagocytosis of FITC-zymosan; PE inhibited nitric oxide (NO) generation and tumor necrosis factor-alpha (TNF-alpha) secretion in lipopolysaccharide (LPS)-stimulated Raw macrophage 264.7. In contrast, SPE over-induced NO generation and TNF-alpha secretion. Moreover, PE strongly inhibited the binding affinity of FITC-LPS to Raw 264.7, as indicated by flow cytometry analysis. These findings revealed that PE may act as a potent anti-inflammatory agent; however SPE may act as an inducer of macrophage functions against pathogens. PMID:17466921

Gamal-Eldeen, Amira M; Amer, Hassan; Helmy, Wafaa A; Talaat, Roba M; Ragab, Halla

2007-03-05

53

Biochemical characterization of recombinant cinnamoyl CoA reductase 1 (Ll-CCRH1) from Leucaena leucocephala.  

PubMed

Recombinant cinnamoyl CoA reductase 1 (Ll-CCRH1) protein from Leucaena leucocephala was overexpressed in Escherichia coli BL21 (DE3) strain and purified to apparent homogeneity. Optimum pH for forward and reverse reaction was found to be 6.5 and 7.8 respectively. The enzyme was most stable around pH 6.5 at 25°C for 90 min. The enzyme showed Kcat/Km for feruloyl, caffeoyl, sinapoyl, coumaroyl CoA, coniferaldehyde and sinapaldehyde as 4.6, 2.4, 2.3, 1.7, 1.9 and 1.2 (×10(6) M(-1) s(-1)), respectively, indicating affinity of enzyme for feruloyl CoA over other substrates and preference of reduction reaction over oxidation. Activation energy, Ea for various substrates was found to be in the range of 20-50 kJ/mol. Involvement of probable carboxylate ion, histidine, lysine or tyrosine at the active site of enzyme was predicted by pH activity profile. SAXS studies of protein showed radius 3.04 nm and volume 49.25 nm(3) with oblate ellipsoid shape. Finally, metal ion inhibition studies revealed that Ll-CCRH1 is a metal independent enzyme. PMID:23541561

Sonawane, Prashant; Vishwakarma, Rishi Kishore; Khan, Bashir M

2013-03-26

54

Antioxidant activity and inhibitory effects of lead (Leucaena leucocephala) seed extracts against lipid oxidation in model systems.  

PubMed

Antioxidant activity of brown lead (Leucaena leucocephala) seed extracts with and without prior chlorophyll removal was studied in comparison with mimosine. Both extracts showed similar hydroxyl radical (HO(•)) scavenging activity, hydrogen peroxide (H2O2) scavenging activity, singlet oxygen inhibition and hypochlorous acid (HOCl) scavenging capacity (p?>?0.05). Nevertheless, the extract without prior chlorophyll removal had higher oxygen radical absorbance capacity than that with prior chlorophyll removal (p?

Benjakul, Soottawat; Kittiphattanabawon, Phanat; Shahidi, Fereidoon; Maqsood, Sajid

2013-05-31

55

Leucaena: New Forage and Tree Crop for the Tropics.  

National Technical Information Service (NTIS)

The report describes Leucaena leucocephala, a little-known Mexican plant with bushy and tree-type varieties that produce nutritious forage, firewood, timber, paper pulp, and organic fertilizer. Its diverse uses also include revegetating hillslopes and pro...

1977-01-01

56

Symbiotic efficiency and phylogeny of the rhizobia isolated from Leucaena leucocephala in arid-hot river valley area in Panxi, Sichuan, China.  

PubMed

In search of effective nitrogen-fixing strains for inoculating Leucaena leucocephala, we assessed the symbiotic efficiency of 41 rhizobial isolates from root nodules of L. leucocephala growing in the arid-hot river valley area in Panxi, China. The genetic diversity of the isolates was studied by analyzing the housekeeping genes 16S rRNA and recA, and the symbiotic genes nifH and nodC. In the nodulation and symbiotic efficiency assay, only 11 of the 41 isolates promoted the growth of L. leucocephala while the majority of the isolates were ineffective in symbiotic nitrogen fixation. Furthermore, one fourth of the isolates had a growth slowing effect on the host. According to the 16S rRNA and recA gene analyses, most of the isolates were Ensifer spp. The remaining isolates were assigned to Rhizobium, Mesorhizobium and Bradyrhizobium. The sequence analyses indicated that the L. leucocephala rhizobia had undergone gene recombination. In contrast to the promiscuity observed as a wide species distribution of the isolates, the results implied that L. leucocephala is preferentially nodulated by strains that share common symbiosis genes. The symbiotic efficiency was not connected to chromosomal background of the symbionts and isolates carrying a similar nifH or nodC showed totally different nitrogen fixation efficiency. PMID:22767181

Xu, Kai Wei; Penttinen, Petri; Chen, Yuan Xue; Chen, Qiang; Zhang, Xiaoping

2012-07-06

57

Over-expression of a subgroup 4 R2R3 type MYB transcription factor gene from Leucaena leucocephala reduces lignin content in transgenic tobacco.  

PubMed

KEY MESSAGE : LlMYB1 , a subgroup 4 R2R3-type MYB transcription factor gene from Leucaena leucocephala appears to be a repressor of lignin biosynthesis pathway by regulating the transcription of general phenylpropanoid pathway genes. R2R3MYB transcription factors are known to play a wide role in regulating the phenylpropanoid pathway in plants. In this study, we report isolation, cloning and characterization of an R2R3MYB transcription factor gene (LlMYB1) from an economically important tree species, Leucaena leucocephala. LlMYB1 consists of 705 bp coding sequence corresponding to 235 amino acids. Sequence alignment revealed that the N-terminal (MYB) domain of the gene shares up to 95 % similarity with subgroup 4 (Sg4) members of R2R3Myb gene family functionally known to be lignin repressors. Highly divergent C-terminal region of the gene carried an ERF-associated amphiphilic repression (EAR) motif, another characteristic of the Sg4. The gene was phylogenetically grouped closest with AmMYB308, a known repressor of monolignol biosynthetic pathway genes. Spatio-temporal expression studies at different ages of seedlings using quantitative real-time PCR (QRT-PCR) showed highest transcript level of the gene in 10 day old stem tissues. Over-expression of the gene in transgenic tobacco showed statistically significant decline in the transcript levels of the general phenylpropanoid pathway genes and reduction in lignin content. Our study suggests that LlMYB1 might be playing the role of a repressor of lignin biosynthesis in L. leucocephala. PMID:23052594

Omer, Sumita; Kumar, Santosh; Khan, Bashir M

2012-10-06

58

Manual harvesting of high population Leucaena stands  

Microsoft Academic Search

Five-year-old giant Leucaena leucocephala, planted at spacing 1x0.5 m, were harvested using bolos (Filipino machetes) and chainsaws. For felling alone, chainsaws took 35% less time than bolos. For the total harvest including delimbing and hauling an average 20 m to the edge of the stand, chainsaws took 20% less time than bolos. Assuming chainsaws are economically viable, it may be

R. D. Pecson; R. J. Van Den Beldt

1983-01-01

59

Anaerobic cellulolytic rumen fungal populations in goats fed with and without Leucaena leucocephala hybrid, as determined by real-time PCR.  

PubMed

The effect of Leucaena leucocephala hybrid-Bahru (LLB), which contains a high concentration of condensed tannins, on cellulolytic rumen fungal population in goats was investigated using real-time PCR. The fungal population in goats fed LLB was inhibited during the first 10 days of feeding, but after 15 days of feeding, there was a tremendous increase of fungal population (157.0 ?g/ml), which was about fourfold more than that in control goats (39.7 ?g/ml). However, after this period, the fungal population decreased continuously, and at 30 days of feeding, the fungal population (50.6 ?g/ml) was not significantly different from that in control goats (55.4 ?g/ml). PMID:24173648

Kok, Ching Mun; Sieo, Chin Chin; Tan, Hui Yin; Saad, Wan Zuhainis; Liang, Juan Boo; Ho, Yin Wan

2013-10-31

60

The cloned 1-aminocyclopropane-1-carboxylate (ACC) deaminase gene from Sinorhizobium sp. strain BL3 in Rhizobium sp. strain TAL1145 promotes nodulation and growth of Leucaena leucocephala.  

PubMed

The objective of this study was to determine the role of 1-aminocyclopropane-1-carboxylate (ACC) deaminase of symbionts in nodulation and growth of Leucaena leucocephala. The acdS genes encoding ACC deaminase were cloned from Rhizobium sp. strain TAL1145 and Sinorhizobium sp. BL3 in multicopy plasmids, and transferred to TAL1145. The BL3-acdS gene greatly enhanced ACC deaminase activity in TAL1145 compared to the native acdS gene. The transconjugants of TAL1145 containing the native or BL3 acdS gene could grow in minimal media containing 1.5mM ACC, whereas BL3 could tolerate up to 3mM ACC. The TAL1145 acdS gene was inducible by mimosine and not by ACC, while the BL3 acdS gene was highly inducible by ACC and not by mimosine. The transconjugants of TAL1145 containing the native- and BL3-acdS genes formed nodules with greater number and sizes, and produced higher root mass on L. leucocephala than by TAL1145. This study shows that the introduction of multiple copies of the acdS gene increased ACC deaminase activities of TAL1145 and enhanced its symbiotic efficiency on L. leucocephala. PMID:18406559

Tittabutr, Panlada; Awaya, Jonathan D; Li, Qing X; Borthakur, Dulal

2008-04-11

61

Feeding potential of cassava (Manihot esculenta Crantz) peels ensiled with Leucaena leucocephala and Gliricidia sepium assessed with West African dwarf goats.  

PubMed

Cassava peels (CaPe) were ensiled in mixtures with Gliricidia sepium and Leucaena leucocephala, and the utilization of the mixed silages by West African dwarf (WAD) goats was assessed. Five silages were composed, comprising of 100% ensiled CaPe (control), CaPe + G. sepium 2:1 (w/w; 2CGS), CaPe + G. sepium 1:1 (w/w; CGS), CaPe + L. leucocephala 2:1 (w/w; 2CLL) and CaPe + L. leucocephala 1:1 (w/w; CLL). All diets were supplemented with molasses (40 g/kg) before ensiling which lasted 3 months. Fifteen WAD goats (8.01 ± 0.12 kg body weight) were fed one of the experimental diets (50 g/kg body weight) for 8 weeks. The control had the lowest hydrocyanic acid content (0.05 mg/kg DM), while others ranged from 6.2 to 81.3 mg/kg. Condensed tannin concentration ranged from 1.7 to 8.4 mg/kg DM, while mimosine levels were 11.6 and 12.4 mg/kg DM in 2CLL and CLL, respectively. After fermentation, all silages showed low pH (<4.5) and were different (P < 0.05) in the lactic, acetic and butyric acid concentrations. Ratio of foliage supplementation influenced DM intake (P < 0.05). Daily weight gains ranged from 17 (CLL) to 24 g/day in control. The digestibility coefficients of nutrients and fibre fractions differed (P < 0.05) among diets. The values for packed cell volume, haemoglobin, red blood cells, neutrophils, lymphocytes and monocytes were also different (P < 0.05) across the dietary treatments. Ensiling CaPe with foliages of G. sepium and L. leucocephala can be recommended for feeding WAD goats especially during the dry spells when there is little or no available forage for the animals. PMID:23397521

Oduguwa, Bamidele Omonuwa; Oni, Adebayo Olusoji; Arigbede, Oluwasanmi Moses; Adesunbola, Julius Olukunle; Sudekum, Karl Heinz

2013-02-10

62

Intercropping of two Leucaena spp. with sweet potato: yield, growth rate and biomass  

SciTech Connect

Results of trials with Leucaena leucocephala and Leucaena diversifolia at Wau, Papua New Guinea, showed potential benefits of the agroforestry cropping system. The total biomass yield (sweet potato plus firewood and green manure) was considerably greater than the yield per unit area of sweet potato alone. 3 references.

Swift, J.F.

1982-01-01

63

Down-regulation of Leucaena leucocephala cinnamoyl CoA reductase (LlCCR) gene induces significant changes in phenotype, soluble phenolic pools and lignin in transgenic tobacco.  

PubMed

cDNA and genomic clones of cinnamoyl CoA reductase measuring 1011 and 2992 bp were isolated from a leguminous pulpwood tree Leucaena leucocephala, named as LlCCR. The cDNA exhibited 80-85% homology both at the nucleotide and amino acid levels with other known sequences. The genomic sequence contained five exons and four introns. Sense and antisense constructs of LlCCR were introduced in tobacco plants to up and down-regulate this key enzyme of lignification. The primary transformants showed a good correlation between CCR transcript levels and its activity. Most of the CCR down-regulated lines displayed stunted growth and development, wrinkled leaves and delayed senescence. These lines accumulated unusual phenolics like ferulic and sinapic acids in cell wall. Histochemical staining suggested reduction in aldehyde units and increased syringyl over guaiacyl (S/G) ratio of lignin. Anatomical studies showed thin walled, elongated xylem fibres, collapsed vessels with drastic reduction of secondary xylem. The transmission electron microscopic studies revealed modification of ultrastructure and topochemical distribution of wall polysaccharides and lignin in the xylem fibres. CCR down-regulated lines showed increased thickness of secondary wall layers and poor lignification of S2 and S3 wall layers. The severely down-regulated line AS17 exhibited 24.7% reduction of Klason lignin with an increase of 15% holocellulose content. Contrarily, the CCR up-regulated lines exhibited robust growth, development and significant increase in lignin content. The altered lignin profiles observed in transgenic tobacco lines support a role for CCR down-regulation in improving wood properties of L. leucocephala exclusively used in the pulp and paper industry of India. PMID:21847621

Prashant, S; Srilakshmi Sunita, M; Pramod, S; Gupta, Ranadheer K; Anil Kumar, S; Rao Karumanchi, S; Rawal, S K; Kavi Kishor, P B

2011-08-17

64

Effect of Fly-Ash on Metal Composition and Physiological Responses in Leucaena Leucocephala (Lamk.) de. Wit  

Microsoft Academic Search

Plants of L. leucocephala were grown in 100%soil (as control), 100% fly-ash and fly-ash amendedwith 50% press mud for 80 days, and analysed withrespect to plant growth, elemental composition andphysiological changes in different parts of the plant.The results revealed that amending fly-ash with pressmud enhanced plant growth as well as otherphysiological responses such as chlorophyll, protein,in vivo nitrate reductase activity

Meetu Gupta; Avanish Kumar; M. Yunus

2000-01-01

65

Rhizobium grahamii sp. nov., from nodules of Dalea leporina, Leucaena leucocephala and Clitoria ternatea, and Rhizobium mesoamericanum sp. nov., from nodules of Phaseolus vulgaris, siratro, cowpea and Mimosa pudica.  

PubMed

Two novel related Rhizobium species, Rhizobium grahamii sp. nov. and Rhizobium mesoamericanum sp. nov., were identified by a polyphasic approach using DNA-DNA hybridization, whole-genome sequencing and phylogenetic and phenotypic characterization including nodulation of Leucaena leucocephala and Phaseolus vulgaris (bean). As similar bacteria were found in the Los Tuxtlas rainforest in Mexico and in Central America, we suggest the existence of a Mesoamerican microbiological corridor. The type strain of Rhizobium grahamii sp. nov. is CCGE 502(T) (= ATCC BAA-2124(T) = CFN 242(T) = Dal4(T) = HAMBI 3152(T)) and that of Rhizobium mesoamericanum sp. nov. is CCGE 501(T) (= ATCC BAA-2123(T) = HAMBI 3151(T) = CIP 110148(T) = 1847(T)). PMID:22081714

López-López, Aline; Rogel-Hernández, Marco A; Barois, Isabelle; Ortiz Ceballos, Angel I; Martínez, Julio; Ormeño-Orrillo, Ernesto; Martínez-Romero, Esperanza

2011-11-11

66

Partial replacement of dried Leucaena leucocephala (Lam.) de Wit leaves for noug (Guizotia abyssinica) (L.f.) Cass. seed cake in the diet of highland sheep fed on wheat straw.  

PubMed

This study investigated the effect of replacing noug (Guizotia abyssinica) (L.f.) Cass. seed cake by dried Leucaena leucocephala (Lam.) de Wit leaves on feed intake, live weight gain, nutrient digestibility, and nitrogen balance of highland sheep in Tigray Region in northern Ethiopia. Twenty intact yearling male highland sheep weighing 16.9 ± 1.62 kg were used in a randomized complete block design and included the following four treatments: T1 (control, wheat straw ad libitum + 200 g noug seed cake (NSC) + 150 g wheat bran (WB)); T2 (wheat straw ad libitum + 170 g NSC + 44.3 g dried L. leucocephala (DLL) + 150 g WB); T3 (wheat straw ad libitum + 140 g NSC + 87.3 g DLL + 150 g WB); and T4 (wheat straw ad libitum + 110 g NSC + 130.2 g DLL + 150 g WB). Sheep fed on T4 diet consumed higher total dry matter (658 g/head/day) and recorded the highest average daily weight gain (59 g/head/day). Sheep fed on T4 diet had higher dry matter (61 %), organic matter (63 %), and crude protein (75 %) digestibility values than the other treatments. Sheep fed on T3 diet demonstrated higher feed conversion ratio (11.93) than sheep kept on the other treatments. All sheep exhibited positive nitrogen balance, with the highest nitrogen retention being measured in T4 (12 g/head/day). It is concluded that partially replacing NSC by DLL can improve total dry matter intake, digestibility of nutrients, and body weight gain in highland sheep fed on wheat straw as the basal diet. PMID:22820996

Tesfay, Temesgen; Tesfay, Yayneshet

2012-07-23

67

Reclassification of Rhizobium tropici type A strains as Rhizobium leucaenae sp. nov.  

PubMed

Rhizobium tropici is a well-studied legume symbiont characterized by high genetic stability of the symbiotic plasmid and tolerance to tropical environmental stresses such as high temperature and low soil pH. However, high phenetic and genetic variabilities among R. tropici strains have been largely reported, with two subgroups, designated type A and B, already defined within the species. A polyphasic study comprising multilocus sequence analysis, phenotypic and genotypic characterizations, including DNA-DNA hybridization, strongly supported the reclassification of R. tropici type A strains as a novel species. Type A strains formed a well-differentiated clade that grouped with R. tropici, Rhizobium multihospitium, Rhizobium miluonense, Rhizobium lusitanum and Rhizobium rhizogenes in the phylogenies of the 16S rRNA, recA, gltA, rpoA, glnII and rpoB genes. Several phenotypic traits differentiated type A strains from all related taxa. The novel species, for which the name Rhizobium leucaenae sp. nov. is proposed, is a broad host range rhizobium being able to establish effective root-nodule symbioses with Leucaena leucocephala, Leucaena esculenta, common beans (Phaseolus vulgaris) and Gliricidia sepium. Strain CFN 299(T) (?=?USDA 9039(T)?=?LMG 9517(T)?=?CECT 4844(T)?=?JCM 21088(T)?=?IAM 14230(T)?=?SEMIA 4083(T)?=?CENA 183(T)?=?UMR1026(T)?=?CNPSo 141(T)) is designated the type strain of Rhizobium leucaenae sp. nov. PMID:21742822

Ribeiro, Renan Augusto; Rogel, Marco A; López-López, Aline; Ormeño-Orrillo, Ernesto; Barcellos, Fernando Gomes; Martínez, Julio; Thompson, Fabiano Lopes; Martínez-Romero, Esperanza; Hungria, Mariangela

2011-07-08

68

Potential contribution of leucaena hedgerows intercropped with maize to the production of organic nitrogen and fuelwood in the lowland tropics. [L. leucocephala  

SciTech Connect

Data from the literature was analysed. Annual N-production by L. leucocephala hedgerows planted more than 150 cm apart and cut every 8 weeks to 15-30 cm was estimated to be 45 g/linear m of hedgerow. The system is thought to be useful where soil-N availability is a limiting factor and where maize productivity is less than 1000 kg/ha (when increases of 112% for 1.5 m hedge spacings to 28% for 6 m spacings are predicted).

Torres, F.

1983-01-01

69

Coat condition of ringtailed lemurs, Lemur catta, at Berenty Reserve, Madagascar: II. Coat and tail alopecia associated with Leucaena leucocepahala, 2001-2006.  

PubMed

Fur condition in wild ringtailed lemurs, Lemur catta, was recorded during September-November birth seasons 2001-2006 at Berenty Reserve, Madagascar. Body coat condition was scored on a scale from BS 0: full, smooth coat with guard hairs, to BS5: half or more of back and limbs hairless. Tail condition was scored from TS 0: full, to TS 5: half or more hairless. Where troop core areas included stands of Leucaena leucocephala, alopecia was dramatically more frequent than in similar areas without leucaena, including many animals with score BS5 or TS5, "bald lemur syndrome." Females' coats were worse than males', possibly related to female dominance and access to this preferred food. Tails in non-leucaena-feeding females tend to remain full, even if coats deteriorate, but with leucaena-feeding female tails are highly correlated with coat condition and equally bare. Coat and tail condition in L. catta reflected not only the dietary toxin but individual differences as well as differences between adjacent troops that may result from territorially mediated access to the environment. Leucaena contains the non-protein amino acid mimosine, a known cause of alopecia, wasting, and organ damage in livestock, although the effects are usually reversible. This is the first case of its effect in wildlife. Leucaena is an agroforestry tree introduced throughout the tropics. In high dietary concentrations leucaena might potentially affect any browsing mammal. PMID:19051314

Jolly, Alison

2009-03-01

70

Leucaena + maize alley cropping in Malawi. Part 1: Effects of N, P, and leaf application on maize yields and soil properties  

Microsoft Academic Search

Yields under alley cropping might be improved if the most limiting nutrients not adequately supplied or cycled by the leaves\\u000a could be added as an inorganic fertilizer supplement. Three historic leaf management strategies had been in effect for 3 years\\u000a ina Leucaena leucocephala alley cropping trial on the Lilongwe Plain of central Malawi : 1) leaves returned; 2) leaves removed;

R. B. Jones; J. W. Wendt; W. T. Bunderson; O. A. Itimu

1996-01-01

71

Leucaena: Promising Forage and Tree Crop for the Tropics. Second Edition.  

National Technical Information Service (NTIS)

In 1976 the National Research Council and the Philippine Council for Agriculture and Resources research convened a meeting to review the available information on leucaena, a versatile, nitrogen-fixing tree for tropical and subtropical countries. Since tha...

1984-01-01

72

Biomass resource potential for selected crops in Hawaii. [Koa haole (giant leucaena); napier and guinea grass  

SciTech Connect

The biomass crops selected for review were koa haole (giant leucaena), napier and guinea grass, and eucalyptus (saligna, grandis, and globulus). The islands examined were Hawaii, Kauai, Maui, and Molokai. The potential land acreage for growing these crops was estimated grossly. As anticipated, the island of Hawaii had the largest land potential with eucalyptus having the greatest potential land acreage.

Seki, A.

1982-06-01

73

Isolation of Insertion Sequence ISRLdTAL1145-1 from a Rhizobium sp. (Leucaena diversifolia) and Distribution of Homologous Sequences Identifying Cross-Inoculation Group Relationships †  

PubMed Central

Insertion sequence (IS) element ISRLdTAL1145-1 from Rhizobium sp. (Leucaena diversifolia) strain TAL 1145 was entrapped in the sacB gene of the positive selection vector pUCD800 by insertional inactivation. A hybridization probe prepared from the whole 2.5-kb element was used to determine the distribution of homologous sequences in a diverse collection of 135 Rhizobium and Bradyrhizobium strains. The IS probe hybridized strongly to Southern blots of genomic DNAs from 10 rhizobial strains that nodulate both Phaseolus vulgaris (beans) and Leucaena leucocephala (leguminous trees), 1 Rhizobium sp. that nodulates Leucaena spp., 9 R. meliloti (alfalfa) strains, 4 Rhizobium spp. that nodulate Sophora chrysophylla (leguminous trees), and 1 nonnodulating bacterium associated with the nodules of Pithecellobium dulce from the Leucaena cross-inoculation group, producing distinguishing IS patterns for each strain. Hybridization analysis revealed that ISRLdTAL1145-1 was strongly homologous with and closely related to a previously isolated element, ISRm USDA1024-1 from R. meliloti, while restriction enzyme analysis found structural similarities and differences between the two IS homologs. Two internal segments of these IS elements were used to construct hybridization probes of 1.2 kb and 380 bp that delineate a structural similarity and a difference, respectively, of the two IS homologs. The internal segment probes were used to analyze the structures of homologous IS elements in other strains. Five types of structural variation in homolog IS elements were found. The predominate IS structural type naturally occurring in a strain can reasonably identify the strain's cross-inoculation group relationships. Three IS structural types were found in Rhizobium species that nodulate beans and Leucaena species, one of which included the designated type IIB strain of R. tropici (CIAT 899). Weak homology to the whole IS probe, but not with the internal segments, was found with two Bradyrhizobium japonicum strains. The taxonomic and ecological implications of the distribution of ISRLdTAL1145-1 are discussed. Images

Rice, Douglas J.; Somasegaran, Padma; MacGlashan, Kathryn; Bohlool, B. Ben

1994-01-01

74

Isolation of Insertion Sequence ISRLdTAL1145-1 from a Rhizobium sp. (Leucaena diversifolia) and Distribution of Homologous Sequences Identifying Cross-Inoculation Group Relationships.  

PubMed

Insertion sequence (IS) element ISRLdTAL1145-1 from Rhizobium sp. (Leucaena diversifolia) strain TAL 1145 was entrapped in the sacB gene of the positive selection vector pUCD800 by insertional inactivation. A hybridization probe prepared from the whole 2.5-kb element was used to determine the distribution of homologous sequences in a diverse collection of 135 Rhizobium and Bradyrhizobium strains. The IS probe hybridized strongly to Southern blots of genomic DNAs from 10 rhizobial strains that nodulate both Phaseolus vulgaris (beans) and Leucaena leucocephala (leguminous trees), 1 Rhizobium sp. that nodulates Leucaena spp., 9 R. meliloti (alfalfa) strains, 4 Rhizobium spp. that nodulate Sophora chrysophylla (leguminous trees), and 1 nonnodulating bacterium associated with the nodules of Pithecellobium dulce from the Leucaena cross-inoculation group, producing distinguishing IS patterns for each strain. Hybridization analysis revealed that ISRLdTAL1145-1 was strongly homologous with and closely related to a previously isolated element, ISRm USDA1024-1 from R. meliloti, while restriction enzyme analysis found structural similarities and differences between the two IS homologs. Two internal segments of these IS elements were used to construct hybridization probes of 1.2 kb and 380 bp that delineate a structural similarity and a difference, respectively, of the two IS homologs. The internal segment probes were used to analyze the structures of homologous IS elements in other strains. Five types of structural variation in homolog IS elements were found. The predominate IS structural type naturally occurring in a strain can reasonably identify the strain's cross-inoculation group relationships. Three IS structural types were found in Rhizobium species that nodulate beans and Leucaena species, one of which included the designated type IIB strain of R. tropici (CIAT 899). Weak homology to the whole IS probe, but not with the internal segments, was found with two Bradyrhizobium japonicum strains. The taxonomic and ecological implications of the distribution of ISRLdTAL1145-1 are discussed. PMID:16349459

Rice, D J; Somasegaran, P; Macglashan, K; Bohlool, B B

1994-12-01

75

Role of Leucaena glauca Leaf litter on the Growth and Reproduction of Earthworms Eisenia fetida Savigny  

Microsoft Academic Search

The growth (biomass) and reproduction (cocoon production and hatch- lings) of earthworms Eisenia fetida Savigny were observed in leguminous tree Leucaena glauca leaf litter, clay loam soil and cowdung mixture (w\\/w) in dif- ferent proportions. They were T1 ferent proportions. They were T1 ferent proportions. They were T (cowdung alone), T2 (cowdung alone), T2 (cowdung alone), T (1 leaf litter:

Govindarajan Manimegala; Senguttuvan Sarojini; Govindarajan Gunasekaran; Mani Prakash; Kasi Parthasarathi; Sriramulu Ananthakrishnasamy

76

Leucaena and dried poultry waste improve the performance of West African Dwarf sheep on a grass diet.  

PubMed

This study investigated the effects on digestibility and growth when West African Dwarf (WAD) sheep were fed a basal diet of Tripsacum laxum with Leucaena leucocephala or dried poultry waste as supplement. Fifteen WAD sheep (12 rams and 3 ewes) were randomly allocated to three dietary treatments of 5 animals each, namely T1-basal diet of chopped T. laxum (control), T2-basal diet plus dried poultry waste, and T3-basal diet plus L. leucocephala. Animals had access to drinking water and a mineral mix ad libitum. They were weighed weekly after a 2-week adaptation period, for a duration of 12 weeks. At the end of the feeding trial, three rams randomly selected from each treatment group were used for the digestibility study. Results revealed that average daily intake of L. leucocephala (350.0 ± 0.3 g/animal) was higher than that of dried poultry waste (260.0 ± 0.1 g/animal). The supplemented groups, T2 and T3, gained 21.4 and 31.0 g daily respectively, while animals of the control group (T1) lost 6.0 g daily. There was a significant difference (P<0.01) in dry matter intake between the control and supplemented groups, with T2 recording the highest intake. Organic matter intake of treatment 3 was significantly (P<0.01) higher than that of T1 and T2. The differences in crude fibre (CF) ingestion between T2 and T1 as well as T3 and T1 were significant (P<0.01), with the highest ingestion of CF occurring in T1. The dry matter digestibility of the supplemented groups was significantly higher (P<0.05) than that of the control. The organic matter digestibility of T2 and T3, as well as T1 and T3 were significantly different (P<0.05), being highest in T3 (77.0 ± 2.1 %) and lowest in T2 (58.1 ± 1.0 %) It was concluded from the study that T. laxum can be better utilized in West African Dwarf sheep when supplemented with dried poultry waste or L. leucocephala. PMID:23224820

Agbor, Euphresia Besongtakor; Ndamukong, Kenneth Jacob Ngoh; Pamo, Etienne Tendonkeng

2012-12-06

77

Prevention of leucaena toxicosis of cattle in Florida by ruminal inoculation with 3-hydroxy-4-(1H)-pyridone-degrading bacteria.  

PubMed

Ruminal microorganisms in cattle at a Florida agriculture research station did not have the ability to detoxify leucaena by degradation of 3-hydroxy-4(1H)-pyridone (3,4,-DHP), but a DHP isomer (2,3-DHP) was degraded in some cattle. Cattle with microorganisms that degraded 2,3-DHP were mostly Senepol cattle imported from St. Croix, US Virgin Islands, where leucaena is an indigenous species. Hereford cattle at the research station in Florida generally did not degrade 3,4-DHP or 2,3-DHP. An experiment was conducted in which a pure culture of 3,4-DHP-degrading bacteria was inoculated into Hereford cattle (with ruminal fistula) grazing leucaena. The bacteria successfully colonized the rumen of recipient cattle and persisted through the following winter when there was no leucaena in the diet. PMID:2610447

Hammond, A C; Allison, M J; Williams, M J; Prine, G M; Bates, D B

1989-12-01

78

Exploiting unique germplasm resources of leguminous trees: Prosopis, leucaena and acacia. Final report, August 31, 1982-August 30, 1992  

SciTech Connect

In Haiti, and other semiarid regions of the world, the need for fuelwood and forage is critical. The report summarizes research conducted over a ten year period on developing replicable plantations of leguminous trees in semiarid lands, especially in areas near seawater salinity levels. Research included greenhouse and laboratory work followed by field trials in Haiti and focused on two species: Prosopis and Leucaena. (Acacia is mentioned in the report's title but not in the report itself.) Results were as follows. (1) Greenhouse experiments identified leaf diagnostic criteria indicating mineral nutrient deficiencies in field trees. It also established the importance of micronutrients, especially zinc, in permitting growth in high pH (9.0) soils.

Felker, P.

1992-01-01

79

Structural and docking studies of Leucaena leucocephala Cinnamoyl CoA reductase.  

PubMed

Lignin, a major constituent of plant call wall, is a phenolic heteropolymer. It plays a major role in the development of plants and their defense mechanism against pathogens. Therefore Lignin biosynthesis is one of the critical metabolic pathways. In lignin biosynthesis, the Cinnamoyl CoA reductase is a key enzyme which catalyzes the first step in the pathway. Cinnamoyl CoA reductase provides the substrates which represent the main transitional molecules of lignin biosynthesis pathway, exhibits a high in vitro kinetic preference for feruloyl CoA. In present study, the three-dimensional model of cinnamoyl CoA reductase was constructed based on the crystal structure of Grape Dihydroflavonol 4-Reductase. Furthermore, the docking studies were performed to understand the substrate interactions to the active site of CCR. It showed that residues ARG51, ASN52, ASP54 and ASN58 were involved in substrate binding. We also suggest that residue ARG51 in CCR is the determinant residue in competitive inhibition of other substrates. This structural and docking information have prospective implications to understand the mechanism of CCR enzymatic reaction with feruloyl CoA, however the approach will be applicable in prediction of substrates and engineering 3D structures of other enzymes as well. PMID:20512516

Prasad, Nirmal K; Vindal, Vaibhav; Kumar, Vikash; Kabra, Ashish; Phogat, Navneet; Kumar, Manoj

2010-05-29

80

LEUCAENA LEUCOCEPHALA AS A SOURCE OF PROTEIN FOR CALVES REARED IN A RESTRICTED SUCKLING SYSTEM  

Microsoft Academic Search

In milk production systems in the tropical regions of Mexico, Zebu and Zebu crosses using larger breeds such as Brown Swiss and Holstein are generally used in dual-purpose systems. Thus the incomes from the sale of milk and of calves for fattening are equally important. One of the principal problems found in such systems is related to the growth of

G Saucedo; F J Alvarez; A Arriaga; N Jimenez

81

Production of rhizobia biofertilizers using baker's yeast effluent and their application to Leucaena leucocephala  

Microsoft Academic Search

Industrial baker's yeast effluent (BYE) was experimented on as a culture medium for growth and biomass production of six fast-growing rhizobia strains. Diluting the effluent with distilled water was necessary to maximize bacterial biomass production. The addition of phosphate buffer, ammonium chloride or trace-elements did not improve the final biomass yield of tested micro-organisms. Rhizobial growth and biomass on the

Sayeda M. Ali; Gamil Amin; Mohammed Fayez; Mahmoud El-Tahan; Mohammed Monib; Nabil A. Hegazi

2005-01-01

82

Feed intake, live weight gain and reproductive performance of Menz ewes supplemented with Lablab purpureus, graded levels of Leucaena pallida 14203 and Sesbania sesban 1198  

Microsoft Academic Search

The research was conducted at the International Livestock Research Institute's Debre Zeit Research Station in Ethiopia. Leucaena pallida 14203, Sesbania sesban 1198 and Lablab purpureus were grown, harvested and dried at the research station. Seventy individually penned Menz ewes with a mean initial weight of 18.6±0.41 kg (mean±S.D.) were used in a randomized block design experiment that lasted for 6

Solomon Melaku; Kurt J Peters; Azage Tegegne

2004-01-01

83

Equi-protein Replacement of Fishmeal with Leucaena Leaf Protein Concentrate: An Assessment of Performance Characteristics and Muscle Development in the Chicken  

Microsoft Academic Search

A batch of three hundred 7- day old Shaver broiler-chicks was used to assess the equi-protein replacement of fishmeal (FM) protein with Leucaena leaf protein concentrates (LLPC) in broiler-starter mash. Before the feeding trial, the LLPC was analyzed for its protein, amino acids, phytin and tannin contents. Thereafter, five diets were tested. The control (diet 1) had 5% FM protein

2003-01-01

84

Supplementation of Menz ewes with dried leaves of Lablab purpureus or graded levels of Leucaena pallida 14203 and Sesbania sesban 1198: effects on feed intake, live weight gain and estrous cycle  

Microsoft Academic Search

The research was conducted at the International Livestock Research Institute, Debre Zeit Research Station, which is situated in the central highlands of Ethiopia. Leaves of Lablab purpureus and the multipurpose trees (MPT), namely, Leucaena pallida 14203 and Sesbania sesban 1198 were harvested and dried in a shade at the research station. Seventy individually penned Menz ewes with a mean initial

Solomon Melaku; Kurt J Peters; Azage Tegegne

2004-01-01

85

Vegetation Response to Grazing and Planting of Leucaena leucocephala in a Urochloa maximum-dominated Grassland in Puerto Rico  

Microsoft Academic Search

A considerable portion of the former dry and dry-transition-to-moist forests of Puerto Rico dominated by Bucida buceras L. was transformed by land clearing and periodic fires to tall grasslands dominated by Urochloa maximum Jacq. and savannas with scattered small trees and shrubs. These commu- nities, maintained by fires, are relatively stable and difficult to reforest. A study was carried out

John K. Francis; John A. Parrotta

86

Effects of Acacia nilotica, A. polyacantha and Leucaena leucocephala leaf meal supplementation on performance of Small East African goats fed native pasture hay basal forages  

Microsoft Academic Search

Optimal utilisation of tannin-rich browse tree fodders including Acacia spp. foliages as crude protein (CP) supplements to ruminants in the tropics is limited by less available information on their feed nutritive potential. Two studies were conducted to: (1) determine rate and extent of ruminal dry matter (DM) degradability (DMD) and (2) investigate effect of sun-dried Acacia nilotica (NLM), A. polyacantha

C. D. K. Rubanza; M. N. Shem; S. S. Bakengesa; T. Ichinohe; T. Fujihara

2007-01-01

87

Molecular mechanism of enzyme inhibition: prediction of the three-dimensional structure of the dimeric trypsin inhibitor from Leucaena leucocephala by homology modelling  

Microsoft Academic Search

Serine proteinase inhibitors are widely distributed in nature and inhibit the activity of enzymes like trypsin and chymotrypsin. These proteins interfere with the physiological processes such as germination, maturation and form the first line of defense against the attack of seed predator. The most thoroughly examined plant serine proteinase inhibitors are found in the species of the families Leguminosae, Graminae,

Rabia Sattar; Syed Abid Ali; Mustafa Kamal; Aftab Ahmed Khan; Atiya Abbasi

2004-01-01

88

Phylogenetic analysis, homology modelling, molecular dynamics and docking studies of caffeoyl-CoA-O- methyl transferase (CCoAOMT 1 and 2) isoforms isolated from subabul (Leucaena leucocephala).  

PubMed

Caffeoyl coenzyme A O-methyltransferase (CCoAOMT) is an important enzyme that participates in lignin biosynthesis especially in the formation of cell wall ferulic esters of plants. It plays a pivotal role in the methylation of the 3-hydroxyl group of caffeoyl CoA. Two cDNA clones that code CCoAOMT were isolated earlier from subabul and in the present study; 3D models of CCoAOMT1 and CCoAOMT2 enzymes were built using the MODELLER7v7 software to find out the substrate binding sites. These two proteins differed only in two amino acids and may have little or no functional redundancy. Refined models of the proteins were obtained after energy minimization and molecular dynamics in a solvated water layer. The models were further assessed by PROCHECK, WHATCHECK, Verify_3D and ERRAT programs and the results indicated that these models are reliable for further active site and docking analysis. The refined models showed that the two proteins have 9 and 10 alpha-helices, 6 and 7 beta-sheets respectively. The models were used for docking the substrates CoA, SAM, SAH, caffeoyl CoA, feruloyl CoA, 5-hydroxy feruloyl CoA and sinapyl CoA which showed that CoA and caffeoyl CoA are binding with high affinity with the enzymes in the presence and absence of SAM. It appears therefore that caffeoyl CoA is the substrate for both the isoenzymes. The results also indicated that CoA and caffeoyl CoA are binding with higher affinity to CCoAOMT2 than CCoAOMT1. Therefore, CCoAOMT2 conformation is thought to be the active form that exists in subabul. Docking studies indicated that conserved active site residues Met58, Thr60, Val63, Glu82, Gly84, Ser90, Asp160, Asp162, Thr169, Asn191 and Arg203 in CCoAOMT1 and CCoAOMT2 enzymes create the positive charge to balance the negatively charged caffeoyl CoA and play an important role in maintaining a functional conformation and are directly involved in donor-substrate binding. PMID:19048314

Sekhar Pagadala, Nataraj; Arha, Manish; Reddy, P S; Kumar, Ranadheer; Sirisha, V L; Prashant, S; Janardhan Reddy, K; Khan, Bashir; Rawal, S K; Kavi Kishor, P B

2008-12-02

89

Optimization the soda-AQ process for cellulose pulp production and energy content of black liquor from L. leucocephala K360.  

PubMed

A commercial variety of Leucaena leucocephala K360 was used for pulp production and papermaking employing the soda-anthraquinone process. Also, the chemical and energy contents of the resultant black liquors were determined to simultaneously optimize: pulp and paper production and energy generation. A process temperature of (185°C), an operating time of (120 min) and an active alkali concentration of (21%) provided sheets of paper with good strength (tensile index of 12.12 Nm/g, burst index of 0.38 kPa m(2)/g, tear index of 1.29 mN m(2)/g and a Kappa number of 20.5) and black liquor with a greater calorific value (14.1 MJ/kg) than that obtained with higher active alkali concentrations. However, reducing the active alkali concentration to a level in the low operation range led to less marked degradation of cellulose and allowed paper sheets with good properties to be obtained and energy to be optimally produced from the black liquor. PMID:22789829

Feria, M J; García, J C; Díaz, M J; Garrote, G; López, F

2012-06-23

90

Leucaena— A promising soil-erosion-control plant  

Microsoft Academic Search

This woody legume, originally native to Mexico but now naturalized in Arizona, Florida and Texas, has been extensively used\\u000a in Indonesia for soil erosion control and should be similarly employed in our Southern States.

M. J. Dijkman

1950-01-01

91

Grazing and Rangeland Development for Livestock Production: A Handbook for Volunteers.  

National Technical Information Service (NTIS)

Three technical papers from AID's Agriculture Technology for Development series, covering basic rangeland management, leucaena leucocephala as livestock feed and combined crop/livestock farming systems in the tropics and subtropics. Illustrated with chart...

1982-01-01

92

The relations of stomatal closure and reopening to xylem ABA concentration and leaf water potential during soil drying and rewatering  

Microsoft Academic Search

Two tropical tree species, Acacia confusa and Leucaena leucocephala, were used to study the relationships among stomatal conductance, xylem ABA concentration and leaf water potential during a soil drying and rewatering cycle. Stomatal conductance of both A. confusa and L. leucocephala steadily decreased with the decreases in soil water content and pre-dawn leaf water potential. Upon rewatering, soil water content

Jiansheng Liang; Jianhua Zhang

1999-01-01

93

The nitrogen mineralization rate of legume residues in soil as influenced by their polyphenol, lignin, and nitrogen contents  

Microsoft Academic Search

A 12-week greenhouse experiment was conducted to determine the effect of the polyphenol, lignin and N contents of six legumes on their N mineralization rate in soil and to compare estimates of legume-N release by the difference and 15N-recovery methods. Mature tops of alfalfa (Medicago sativa L.), round leaf cassia (Cassia rotundifolia Pers., var. Wynn), leucaena (Leucaena leucocephala Lam., deWit),

R. H. Fox; R. J. K. Myers; I. Vallis

1990-01-01

94

Agroforestry for soil and water conservation in the western Himalayan Valley Region of India 2. Crop and tree production  

Microsoft Academic Search

A ten-year-study (1983 to 1992) conducted on nine 15 90 m runoff plots at 4% slope compared production efficiency of Leucaena\\u000a leucocephala and Eucalyptus hybrid based agroforestry as well as monocropping landuse systems in the warm, subhumid climate\\u000a of the western Himalayan region of India. Treatments for the first sequence were: monocropping systems of leucaena, eucalyptus,\\u000a Chrysopogon fulvus grass and

Pratap Narain; R. K. Singh; N. S. Sindhwal; P. Joshie

1997-01-01

95

Nitrogen recovery by alley-cropped maize and treesfrom 15N-labeled tree biomass in the subhumid highlands of Kenya  

Microsoft Academic Search

The effectiveness of tree-leaf biomass as a source of N to crops in agroforestry systems depends on the rate at which crops\\u000a can obtain N from the biomass. A study was conducted to determine the fate of 15N labeled, soil-applied biomass of two hedgerow species, Calliandra calothyrsus Meissner (calliandra) and Leucaena leucocephala (Lam.) de Wit (leucaena), in the subhumid highlands

D. N. Mugendi; P. K. R. Nair; D. A. Graetz; J. N. Mugwee; M. K. O'Neill

2000-01-01

96

Performance of Eleven Multipurpose Tree Legume Seedlings Grown in the Hill Soils under Nursery Conditions in Bangladesh  

Microsoft Academic Search

Seedlings of Acacia auriculiformis, A. catechu, A. mangium, Albizia lebbeck, A. procera, A. saman, Cassia fistula, C. siamea, Gliricidia sepium, Dalbergia sissoo and Leucaena leucocephala were raised in polybags containing the soil of barren hilly areas of Chittagong University campus situated at the south-eastern part of Bangladesh. The study was conducted to evaluate comparative germination, growth, leaf' pigments and nodulation

B. M. KHAN; M. A. HOSSAIN; M. K. HOSSAIN

97

PHYTOSTABILIZATION OF A Pb-CONTAMINATED MINE TAILING BY VARIOUS TREE SPECIES IN POT AND FIELD TRIAL EXPERIMENTS  

Microsoft Academic Search

The potential of 6 tree species (Leucaena leucocephala, Acacia mangium, Peltophorum pterocarpum, Pterocarpus macrocarpus, Lagerstroemia floribunda, Eucalyptus camaldulensis) for phytoremediation of Pb in sand tailings (total Pb>9850 mg kg) from KEMCO Pb mine in Kanchanaburi province, Thailand, were investigated employing a pot experiment (3 months) and field trial experiment (12 months). In pot study E. camaldulensis treated with Osmocote fertilizer

Weeradej Meeinkuirt; Phanwimol Tanhan; Prayad Pokethitiyook; Maleeya Kruatrachue; Rattanawat Chaiyarat

2012-01-01

98

Recent work on the production and utilization of tree fodder in East Africa  

Microsoft Academic Search

Most of the work discussed in the paper is part of the Agroforestry Research Network for Africa (AFRENA). In the sub-humid highlands the most common form of livestock management is a mixture of grazing, tethering and stall feeding. In the arid and semi-arid lowlands of Kenya the normal livestock management practice is grazing. Leucaena leucocephala was a popular fodder species

R. L. Roothaert; R. T. Paterson

1997-01-01

99

Trees and shrubs as sources of fodder in Australia  

Microsoft Academic Search

Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used

E. C. Lefroy; P. R. Dann; J. H. Wildin; R. N. Wesley-Smith; A. A. McGowan

1992-01-01

100

PREFERENCIA DE ÁRBOLES FORRAJEROS POR CABRAS EN LA ZONA BAJA DE LOS ANDES VENEZOLANOS. Goats Preference of Fodder Tree in the Venezuelan Andes Low Zone  

Microsoft Academic Search

In order to know the preference of twelve fodder species (Chlo- rophora tinctoria, Morus alba, Pithecellobium pedicellare, Gliri- cidia sepium, Guazuma ulmifolia, Cordia alba, Trichantera gi- gantea, Tithonia diversifolia, Leucaena leucocephala, Moringa oleifera, Azadirachta indica and Samanea saman) a cafeteria trial was carried out in goats at Trujillo State, Venezuela. An ex- perimental square latin design with evaluation period of

Danny Eugenio García; María Gabriela Medina; Tyrone Clavero; Johny Humbría; Alfredo Baldizán; Carlos Domínguez

2008-01-01

101

Performance of growing indigenous goats fed diets based on urban market crop wastes  

Microsoft Academic Search

The effect of feeding diets including market crop wastes (sweet potato vines (Ipomoea batatas) and scarlet eggplant (Solanum aethiopicum)) on growth and digestibility was studied using 32 indigenous intact growing male goats. Adding elephant grass (Pennisetum purpureum), maize bran and Leucaena leucocephala leaves, four isocaloric and isonitrogenous diets (Sweet potato vines, Solanum, Mixed and Control) were formulated. After\\u000a the growth

C. B. Katongole; E. N. Sabiiti; F. B. Bareeba; I. Ledin

2009-01-01

102

AMUKA, Issue Number 26, May-August 1983.  

National Technical Information Service (NTIS)

This issue of AMUKA contains reports on: Rural education; reintroduction of wheat culture to the zones of Beni and Lubero in North Kivu, Zaire; conservation of leguminous grains; Leucaena leucocephala; eight myths of hunger; study of a project of agro-pas...

K. Mpongo K. Mwitirwa K. Tabaro G. Defour K. Kabusa

1983-01-01

103

Economic analysis of a simulated alley cropping system for semi-arid conditions, using micro computers  

SciTech Connect

Returns were simulated for the semi-arid areas in Mackakos District, Kenya (bimodal rainfall distribution, 600 mm/yr) comparing the present system (maize and beans intercropped twice a year) with a Leucaena leucocephala hedgerow system. Although some of the assumptions contain a large element of uncertainty, the results were promising enough for the system to be considered further. 4 references.

Hoekstra, D.A.

1983-01-01

104

Growth and yield of eight agroforestry tree species in line plantings in Western Kenya and their effect on maize yields and soil properties  

Microsoft Academic Search

Between October 1988 and August 1992, field experiments were carried out in West Kenya to evaluate the suitability of Leucaena leucocephala, L. collinsii, Gliricidia sepium, Calliandra calothyrsus, Sesbania sesban, S. grandiflora, Senna siamea and S. spectabilis to provide a range of agroforestry products and services. The initial objective was to establish the growth rates and wood and leaf yields of

A. M Heineman; H. J. O Otieno; E. K Mengich; B. A Amadalo

1997-01-01

105

Potential of Trees, Grasses, and Turf Legumes for Restoring Eroded Soils  

Microsoft Academic Search

The performance and development potential of seven trees, two grasses and five turf legumes were evaluated in three highly eroded landscapes of Puerto Rico. Species development during the first year of establishment was adequate at the Corozal site, intermediate in Vega Baja and poor at the Orocovis location. Tree species Albicia procera and Leucaena leucocephala K 636 grew particularly well

Rafael Ramos Santana; Gustavo Martínez; Raúl Macchiavelli; José E. Rodríguez; José L. Guzmán

2003-01-01

106

Fuel farming  

Microsoft Academic Search

Plantations of fast-growing hardwoods, such as the Leucaena leucocephala giant strains which are leguminous, reproduce by coppicing and are hardy, could serve as renewable, self-perpetuating sources of energy. These energy plantations or fuel farms would produce fuelwood for household use, for the manufacture of charcoal for household and industrial purposes, and for the generation of electricity, either by direct combustion

J. A. Semana

1979-01-01

107

The Potential of Albizia lebbeck as a Supplementary Feed for Goats in Tanzania  

Microsoft Academic Search

Forty growing goats (20 males and 20 females) were used in a 90-day growth and intake study to evaluate the potential of Albizia lebbeck (ABC) based concentrate as compared with Gliricidia sepium (GBC), Leucaena leucocephala (LBC), and Moringa oleifera (MBC) based concentrates with cotton seed cake (CSC) as a control. The animals were fed a basal diet of maize stover

E. E. Ndemanisho; B. N. Kimoro; E. J. Mtengeti; V. R. M. Muhikambele

2006-01-01

108

Spatial and temporal effects in drying biomass for energy  

Microsoft Academic Search

This study evaluates the impact of the moisture content of biomass on thermal efficiency and relative boiler size which directly represent the economic merits of biomass drying. A model for predicting the moisture content of bundled Leucaena (Leucocephala) trees under open environment was validated for tropical Hawaii. Cumulative precipitation and evapotranspiration (ET) are the major factors affecting the biomass moisture

T. Liang; M. A. Khan; Q. Meng

1996-01-01

109

In vitro flowering of Kniphofia leucocephala : influence of cytokinins  

Microsoft Academic Search

The role of cytokinins in the promotion of flowering in the endangered species Kniphofia leucocephala Baijnath. was investigated using shoots maintained in culture for 3 years. The highest percentage flowering (65%) was obtained on media containing 20 ?M benzyladenine (BA). The inclusion of isopentenyladenine and zeatin in the media also resulted in flowering, but these treatments were less effective than BA

N. J. Taylor; M. E. Light; J. Van Staden

2005-01-01

110

Using RAPDs to Identify DNA Sequence Loci for Species Level Phylogeny Reconstruction: an Example from Leucaena (Fabaceae)  

Microsoft Academic Search

Resolving phylogenies among closely related species remains a perplexing problem in plant systematics. All too often cpDNA and nrDNA ITS are insufciently variable to provide desired resolution or support. In the present study, we have adopted a RAPD-based approach to develop sequence-characterized regions, from the nuclear genome, with levels of DNA sequence variation appropriate for resolving relationships within subclades of

C. Donovan Bailey; Colin E. Hughes; Stephen A. Harris

2004-01-01

111

Nitrogen fixation by trees in relation to soil nitrogen economy  

Microsoft Academic Search

The N2-fixing potential (NFP) (i.e. the amount of fixed N2 in a constraint-free environment) of N2-fixing trees (NFTs) varies with the genotype. The NFP can be higher than 30-50 g N2 fixed tree-1 year-1 in the most active species, be they leguminous trees such asAlbizia lebbeck, Gliricidia sepium andLeucaena leucocephala, or actinorhizal trees such asCasuarina equisetifolia. The actual amount of

Y. R. Dommergues

1995-01-01

112

The effects of drying temperature on chemical composition and nutritive value of some tropical fodder shrubs  

Microsoft Academic Search

The effects of drying temperature on chemical composition and nutritive value of leaves of the shrub legumes Acacia angustissima (Miller) Kuntze, Calliandra calothyrsus Meissn and Leucaena leucocephala (Lam.) de Wit were determined in two studies in Zimbabwe. In the first study, the effects of shade-, sun- and oven-drying\\u000a leaves on chemical composition and protein precipitation capacity of tannin extracts were

L. Hove; L. R. Ndlovu; S. Sibanda

2003-01-01

113

Do all tannins have similar nutritional effects? A comparison of three Brazilian fodder legumes  

Microsoft Academic Search

Three tropical legumes, namely Leucaena leucocephala, Sesbania sesban and Cajanus cajan, were subjected to chemical analysis plus in vitro, in situ and in vivo evaluations. Three different assays were used to determine total tannins: adsorption to polyvinyl pyrrolidine (PVPP-tannins), radial diffusion (RD-tannins) and protein precipitation capacity (BSA-tannins). Total phenols, total tannins and condensed tannins were highest for Sesbania. RD-tannins were

D. M. S. S. Vitti; A. L. Abdalla; I. C. S. Bueno; J. C. Silva Filho; C. Costa; M. S. Bueno; E. F. Nozella; C. Longo; E. Q. Vieira; S. L. S. Cabral Filho; P. B. Godoy; I. Mueller-Harvey

2005-01-01

114

Crop-tree interactions in alley cropping systems on alluvial soils of the Upper Amazon Basin  

Microsoft Academic Search

A crop\\/hedgerow interface design was used to test three leguminous species,Inga edulis, Leucaena leucocephala andErythrina sp., for their potential use for alley cropping on alluvial soils in the upper Amazon Basin. Prunings were applied as mulch at three rates 0, 3.3 and 6.7 Mg dry matter\\/ha\\/crop. Competition, crop yields, nutrient budgets, and weed control were monitored for three consecutive crops

A. Salazar; L. T. Szott; C. A. Palm

1993-01-01

115

Beneficial effect of aluminum on growth of plants adapted to low pH soils  

Microsoft Academic Search

Plants in which growth was reduced by low and high Al applications were designated as Al-sensitive plant (Hordeum vulgare) and Al-medium tolerant plants (Leucaena leucocephala, Ischaemum barbatum, Stylosanthes guianensis, and Fagopyrum esculentum), respectively, while plants in which growth was not affected or was stimulated by Al application were designated as Al-tolerant plant (Brachiaria ruziziensis) and Al-stimulated plants (Melastoma malabathricum, Melaleuca

Mitsuru Osaki; Toshihiro Watanabe; Toshiaki Tadano

1997-01-01

116

Ecology of Heteropsylla cubana (Homoptera: Psyllidae): Psyllid Damage, Tree Phenology, Thermal Relations, and Parasitism in the Field  

Microsoft Academic Search

The fast-growing Central American tree Leucaena leucocephala (Lam.) de Wit (Le- guminosae: Mimosoidaeae) has been widely planted in the tropics since the 1970s for agro-forestry, reforestation, and fodder. Since the mid-1980s the tree has suffered serious damage throughout its exotic range from the psyllid Heteropsylla cubana Crawford, which is also native to Central America. This article summarizes field studies on

Chris A. Geiger; Andrew P. Gutierrez

2000-01-01

117

Moisture conservation and nitrogen recycling through legume mulching in rainfed maize ( Zea mays )–wheat ( Triticum aestivum ) cropping system  

Microsoft Academic Search

Mulching with vegetative materials is a highly beneficial and widely-investigated agro-technique in rainfed areas but the\\u000a adoption of this practice has been constrained due to non-availability of mulch biomass locally. Live mulching with fast-growing\\u000a annual green manure legumes like sunnhemp (Crotalaria juncea) or prunings of Leucaena leucocephala grown as hedge rows can be done for moisture conservation as well as

A. R. Sharma; Ratan Singh; S. K. Dhyani; R. K. Dube

2010-01-01

118

Planted legume fallows reduce weeds and increase soil N and P contents but not upland rice yields  

Microsoft Academic Search

Shortened fallows have resulted in declining upland rice yields in slash-and-burn upland rice systems in northern Laos. We\\u000a studied the benefit of planted legume fallows for rice productivity, weeds, and soil nitrogen and phosphorus availability.\\u000a Four systems were evaluated over a 5-year period: 1-year fallow with native species, 1-year Cajanus cajan fallow, 1-year Leucaena leucocephala fallow, and continuous annual rice

K. Saito; B. Linquist; D. E. Johnson; S. Phengchanh; T. Shiraiwa; T. Horie

2008-01-01

119

Effect of replacement of concentrate mixture with isonitrogenous leaf meal mixture on growth, nutrient utilization and rumen fermentation in goats  

Microsoft Academic Search

This study was conducted to examine the effect of replacing concentrate mixture with leaf meal mixture of Leucaena leucocephala–Melia azedarach–Morus alba in equal proportion on growth, nutrient utilization, blood and rumen metabolites in growing goats using completely randomized design. Twelve male non-descript goats were divided into two groups, control and experimental, consisting of six animals in each group. The control

Ajit Pal; R. K. Sharma; Ravindra Kumar; K. Barman

2010-01-01

120

Effect of perennial mulches on moisture conservation and soil-building properties through agroforestry  

Microsoft Academic Search

The effect of perennial mulches on moisture status, soil characteristics and on crop yields (maize-wheat rotation) was evaluated from 1986 through 1989 in a silty loam acidic soil (pH 5.6, PWP 11.4 & FC 25.6%) at the Research Farm of the Central Soil & Water Conservation Research & Training Institute, Dahra Dun. Mulch materials, comprised of leaves of Leucaena leucocephala,

V. P. S. Tomar; P. Narain; K. S. Dadhwal

1992-01-01

121

Genetic selection and improvement of hard wood tree species for fuelwood production on sodic soil with particular reference to Prosopis juliflora  

Microsoft Academic Search

This study is a part of a research programme on selection and improvement of fast growing tree species suitable for wood fuel production on sodic wastelands (pH 8.6–10.5). Field trials of nine legumes (Acacia auriculiformis, A. nilotica, Albizia lebbeck, A. procera, Dalbergia sissoo, Leucaena leucocephala, Pongamia pinnata, Prosopis juliflora, Pithecellobium dulce) and three other tree species (Azadirachta indica, Eucalyptus tereticornis

V. L Goel; H. M Behl

2001-01-01

122

Alley cropping on an Ultisol in subhumid Benin. Part 2: Changes in crop physiology and tree crop competition  

Microsoft Academic Search

From 1986–92 alley cropping with Leucaena leucocephala (Lam.) de Wit and Cajanus cajan (L.) Millsp. was compared to a no-tree control, and fertilisation with 90, 39 and 75 kg ha–1 N, P and K vs. no fertilisation were studied in maize and cassava grown intercropped or in rotation. Light transmission measurements and row position effects on food crop yield did

D. E. Leihner; R. Ernst-Schaeben; T. P. Akondé; N. Steinmüller

1996-01-01

123

Nutrient composition and in vitro ruminal fermentation of tropical legume mixtures with contrasting tannin contents  

Microsoft Academic Search

Various combinations of a low-tannin herbaceous legume (Vigna unguiculata) and foliage of tanniniferous shrub legumes (Calliandra calothyrsus, Flemingia macrophylla and Leucaena leucocephala) or a low-tannin shrub legume (Cratylia argentea), all mixed together with a low-quality tropical grass (Brachiaria humidicola), were tested in vitro for differences in the effects on ruminal fermentation. Two experiments with the gas transducer technique were carried

C. D. Stürm; T. T. Tiemann; C. E. Lascano; M. Kreuzer; H. D. Hess

2007-01-01

124

Nitrogen fixation ability of exopolysaccharide synthesis mutants of Rhizobium sp. strain NGR234 and Rhizobium trifolii is restored by the addition of homologous exopolysaccharides.  

PubMed Central

Several transposon Tn5-induced mutants of the broad-host-range Rhizobium sp. strain NGR234 produce little or no detectable acidic exopolysaccharide (EPS) and are unable to induce nitrogen-fixing nodules on Leucaena leucocephala var. Peru or siratro plants. The ability of these Exo- mutants to induce functioning nodules on Leucaena plants was restored by coinoculation with a Sym plasmid-cured (Nod- Exo+) derivative of parent strain NGR234, purified EPS from the parent strain, or the oligosaccharide from the EPS. Coinoculation with EPS or related oligosaccharide also resulted in formation of nitrogen-fixing nodules on siratro plants. In addition, an Exo- mutant (ANU437) of Rhizobium trifolii ANU794 was able to form nitrogen-fixing nodules on white clover in the presence of added EPS or related oligosaccharide from R. trifolii ANU843. These results demonstrate that the absence of Rhizobium EPSs can result in failure of effective symbiosis with both temperate and subtropical legumes. Images

Djordjevic, S P; Chen, H; Batley, M; Redmond, J W; Rolfe, B G

1987-01-01

125

Feed intake, digestion kinetics and rumen volatile fatty acids in Menz rams supplemented with Lablab purpureus or graded levels of Leucaena pallida 14203 and Sesbania sesban 1198  

Microsoft Academic Search

35 Menz rams weighing 19.3 ± 0.87kg (mean ± S.D.) were used in a randomized block design experiment that was conducted for 35 days at Debre Zeit Research Station of the International Livestock Research Institute, Ethiopia. The objectives of the study were to determine feed intake, apparent digestibility, passage rate and level of rumen volatile fatty acids (VFA) in Menz

Solomon Melaku

2004-01-01

126

Effect of condensed tannins on bovine rumen protist diversity based on 18S rRNA gene sequences.  

PubMed

Molecular diversity of protists from bovine rumen fluid incubated with condensed tannins of Leucaena leucocephala hybrid-Rendang at 20 mg/500 mg dry matter (treatment) or without condensed tannins (control) was investigated using 18S rRNA gene library. Clones from the control library were distributed within nine genera, but clones from the condensed tannin treatment clone library were related to only six genera. Diversity estimators such as abundance-based coverage estimation and Chao1 showed significant differences between the two libraries, although no differences were found based on Shannon-Weaver index and Libshuff. PMID:23205499

Tan, Hui Yin; Sieo, Chin Chin; Abdullah, Norhani; Liang, Juan Boo; Huang, Xiao Dan; Ho, Yin Wan

2012-12-03

127

Nitrogen-Fixing Nodules with Ensifer adhaerens Harboring Rhizobium tropici Symbiotic Plasmids  

PubMed Central

Ensifer adhaerens is a soil bacterium that attaches to other bacteria and may cause lysis of these other bacteria. Based on the sequence of its small-subunit rRNA gene, E. adhaerens is related to Sinorhizobium spp. E. adhaerens ATCC 33499 did not nodulate Phaseolus vulgaris (bean) or Leucaena leucocephala, but with symbiotic plasmids from Rhizobium tropici CFN299 it formed nitrogen-fixing nodules on both hosts. The nodule isolates were identified as E. adhaerens isolates by growth on selective media.

Rogel, M. Antonio; Hernandez-Lucas, Ismael; Kuykendall, L. David; Balkwill, David L.; Martinez-Romero, Esperanza

2001-01-01

128

Nitrogen-fixing nodules with Ensifer adhaerens harboring Rhizobium tropici symbiotic plasmids.  

PubMed

Ensifer adhaerens is a soil bacterium that attaches to other bacteria and may cause lysis of these other bacteria. Based on the sequence of its small-subunit rRNA gene, E. adhaerens is related to Sinorhizobium spp. E. adhaerens ATCC 33499 did not nodulate Phaseolus vulgaris (bean) or Leucaena leucocephala, but with symbiotic plasmids from Rhizobium tropici CFN299 it formed nitrogen-fixing nodules on both hosts. The nodule isolates were identified as E. adhaerens isolates by growth on selective media. PMID:11425750

Rogel, M A; Hernández-Lucas, I; Kuykendall, L D; Balkwill, D L; Martinez-Romero, E

2001-07-01

129

Role of bioinoculants and organic fertilizers in fodder production and quality of leguminous tree species.  

PubMed

The comparative effect of dual inoculation of native N fixer (Rhizobium) and AM fungi consortia with different organic fertilizers (vermicompost and farm yard manure) on fodder production and quality of two leguminous tree species (Leucaena leucocephala (Lam) de. Wit. and Sesbania sesban (L.) Merr.) in silvopastoral system and their impact on the fodder production of un-inoculated Panicum maximum Jacq. under cut and carry system. After three years of plantation maximum tree survival was in L. leucocephala in all the treatments in comparison to S. sesban while fodder production was more in S. sesban for initial two years and in third year it accelerated in L. leucocephala. Dual inoculation with vermicompost significantly improved fodder production, fodder quality and rhizosphere microflora in L. leucocephala but in S. sesban dual inoculation was at par with single inoculation of N fixer, AM fungi and control (without inoculation). The grass production was higher with L. leucocephala for two years while in third year it was more with S. sesban. The association of Rhizobium with AM fungi in L. leucocephala was better than in S. sesban. PMID:21888233

Mishra, Seema; Sharma, Satyawati; Vasudevan, Padma

2011-01-01

130

[Vegetation biomass allocation and its spatial distribution after 20 years ecological restoration in a dry-hot valley in Yuanmou, Yunnan Province of Southwest China].  

PubMed

By using layering harvest method, a comparative study was conducted on the biomass allocation and its spatial distribution of 20-year-old Eucalyptus camaldulensis plantation, Leucaena leucocephala plantation, and E. camaldulensis-L. leucocephala plantation in Yuanmou dry-hot valley of Yunnan Province, Southwest China. The stand biomass in the mixed E. camaldulensis-L. leucocephala plantation (82.99 t x hm(-2)) was between that of monoculture E. camaldulensis plantation (60.64 t x hm(-2)) and L. leucocephala plantation (127.79 t x hm(-2)). The individual tree biomass of E. camaldulensis in the mixed plantation (44.32 kg) was 49.8% higher than that in monoculture plantation (29.58 kg). The branch and leaf biomass of L. leucocephala (25.4%) in monoculture plantation was larger than that of E. camaldulensis (8.9%) in monoculture plantation, and the aboveground biomass distribution ratio (78.0%) of L. leucocephala (25.4%) was also higher than that of E. camaldulensis (73.4%). The roots of L. leucocephala in both monoculture and mixed plantations were mainly distributed in 0-40 cm soil layer, while those of E. camaldulensis in monoculture and mixed plantations were mainly found in 0-80 cm and 0-60 cm, respectively. The proportion of biomass allocated to roots including medium roots, small roots, and fine roots of L. leucocephala in mixed plantation was higher than that in monoculture plantation, but it was contrary for E. camaldulensis. It was suggested that introducing L. leucocephala in E. camaldulensis plantation promoted the growth of E. camaldulensis, especially for its aboveground biomass, and increased the amount of lateral roots in 0-20 cm soil layer, which had significance in soil and water conservation in the study area. PMID:24066529

Li, Bin; Tang, Guo-Yong; Li, Kun; Gao, Cheng-Jie; Liu, Fang-Yan; Wang, Xiao-Fei

2013-06-01

131

Leguminous plants nodulated by selected strains of Cupriavidus necator grow in heavy metal contaminated soils amended with calcium silicate.  

PubMed

Increasing concern regarding mining area environmental contamination with heavy metals has resulted in an emphasis of current research on phytoremediation. The aim of the present study was to assess the efficiency of symbiotic Cupriavidus necator strains on different leguminous plants in soil contaminated with heavy metals following the application of inorganic materials. The application of limestone and calcium silicate induced a significant increase in soil pH, with reductions in zinc and cadmium availability of 99 and 94 %, respectively. In addition, improved nodulation of Mimosa caesalpiniaefolia, Leucaena leucocephala and Mimosa pudica in soil with different levels of contamination was observed. Significant increases in the nitrogen content of the aerial parts of the plant were observed upon nodulation of the root system of Leucaena leucocephala and Mimosa pudica by strain UFLA01-659 (36 and 40 g kg(-1)) and by strain UFLA02-71 in Mimosa caesalpiniaefolia (39 g kg(-1)). The alleviating effect of calcium silicate resulted in higher production of dry matter from the aerial part of the plant, an increase in nodule number and an increase in the nitrogen fixation rate. The results of the present study demonstrate that the combination of rhizobia, leguminous plants and calcium silicate may represent a key factor in the remediation of areas contaminated by heavy metals. PMID:23670312

Avelar Ferreira, Paulo Ademar; Lopes, Guilherme; Bomfeti, Cleide Aparecida; de Oliveira Longatti, Silvia Maria; de Sousa Soares, Cláudio Roberto Fonseca; Guimarães Guilherme, Luiz Roberto; de Souza Moreira, Fatima Maria

2013-05-14

132

Combining napier grass with leguminous shrubs in contour hedgerows controls soil erosion without competing with crops  

Microsoft Academic Search

We established hedges\\/barriers of calliandra (Calliandra calothyrsus Meissner), leucaena (Leucaena trichandra (Zucc.) Urban)) and napier grass (Pennisetum purpureum Schumach) and combination hedges of either calliandra or leucaena with napier grass on slopes exceeding 5% to study the effect\\u000a of vegetative barriers on productivity of arable steep-lands in central Kenya. Hedges\\/barriers were pruned regularly and biomass\\u000a incorporated into the plots. Hedge

James K. Mutegi; Daniel N. Mugendi; Louis V. Verchot; James B. Kung’u

2008-01-01

133

Rare or remarkable microfungi from Oaxaca (south Mexico)--Part II.  

PubMed

Microfungi were collected in southern Mexico in the vicinity of Puerto Escondido, Oaxaca in 2007. In 2006, samples were gathered from Acacia myrmecophytes [(Remarkable microfungi from Oaxaca of Acacia species) Part I]. In the present investigation [Part II], we collected microfungi from different parts of a variety of wild and cultivated higher plants belonging to the families Anacardiaceae, Caricaceae, Fabaceae, Moraceae, and Nyctaginacae. The microfungi found here live as parasites or saprophytes. Interestingly, the species Colletotrichum lindemuthianum (Sacc. and Magn.) Briosi and Cavara has repeatedly been used to cause fungal infections of Phaseolus lunatus leaves in laboratory experiments. We could now find the same fungus as parasite on the same host plants under field conditions showing that results obtained in the laboratory are also relevant in nature. Most of the fungal species collected belong to the classes Ascomycotina, Basidiomycotina and Deuteromycotina. Until now, some of the microfungi identified in this study have been rarely observed before or have been reported for the first time in Mexico, for example: Pestalotia acaciae Thüm. on Acacia collinsii Safford; Corynespora cassiicola (Berk. and M.A. Curtis) C.T. Wei on Carica papaya L.; Botryosphaeria ribis Grossenb. and Duggar and Cercosporella leucaenae (Raghu Ram and Mallaiah) U. Braun (new for Mexico) and Camptomeris leucaenae (F. Stevens and Dalbey) Syd. (new for Mexico) on Leucaena leucocephala (Lam.) de Wit.; Oidium clitoriae Narayanas. and K. Ramakr. and Phakopsora cf. pachyrhizi Sydow and Sydow (new for Mexico) on Clitoria ternatea L.; Botryosphaeria obtusa (Schw.) Shoemaker on Prosopis juliflora (Sw.) DC.; Cylindrocladium scoparium Morg. on Ficus benjamina L.; Acremonium sp. on Bougainvillea sp. All specimens are located in the herbarium ESS. Mycotheca Parva collection G.B. Feige and N. Ale-Agha. PMID:19226752

Ale-Agha, N; Jensen, M; Brassmann, M; Kautz, S; Eilmus, S; Ballhorn, D J

2008-01-01

134

Neural fuzzy model applied to ethylene-glycol pulping of non-wood raw materials.  

PubMed

We studied the influence of the operational variables (viz. ethylene-glycol concentrations of 50-70%, temperatures of 155-185 degrees C, times of 30-90 min and numbers of PFI beating revolutions of 500-1500) on pulp yield and various paper properties (breaking length, stretch, burst index, tear index and brightness) obtained in the ethylene-glycol pulping of vine shoots, cotton stalks, leucaena (Leucaena leucocephala) and tagasaste (Chamaecytisus proliferus). The fuzzy neural network models used reproduced the experimental results with errors less than 15% and smaller than those provided by second-order polynomial models in all cases. An ethylene-glycol concentration of 65% at 180 degrees C for 75 min and 1500 PFI beating revolutions were found to provide substantial savings in energy, chemicals and facility investments as a result of operating under milder conditions than the strongest ones studied in this work. Tagasaste was found to be the most suitable raw material among those tested as it provided the paper sheets with the highest breaking length (4644 m), stretch (2.87%), burst index (2.46 kN/g), tear index (0.33 m Nm(2)/g) and brightness (40.92%); its pulp yield was also high (62.88%), which reflects efficient use of this raw material. PMID:17462885

Rodríguez, Alejandro; Pérez, Antonio; de la Torre, María Jesús; Ramos, Enrique; Jiménez, Luis

2007-04-25

135

Methane emissions from grazing cattle using point-source dispersion.  

PubMed

The ability to accurately measure greenhouse gas (GHG) emissions is essential to gauge our ability to reduce these emissions. Enteric methane from ruminants is an important but often difficult source to quantify since it depends on the amount and type of feed intake. Unfortunately, many of the available measurement techniques for estimating enteric methane emissions can impose a change in feed intake. Our study evaluates a nonintrusive technique that uses a novel approach (point-source dispersion with multiple open-path concentrations) to calculate enteric methane emissions from grazing cattle, reported as the major source of GHG in many countries, particularly Australia. A scanner with a mounted open-path laser was used to measure methane concentration across five paths above a paddock containing 18 grazing cattle over 16 d. These data were used along with wind statistics in a dispersion model (WindTrax) to estimate an average herd methane emission rate over 10-mm intervals. Enteric methane emissions from the herd grazing a combination of Rhodes grass (Chlotis gayana Kunth) and Leucaena [Leucaena leucocephala (Lam.)] averaged (+/- SD) 141 (+/- 147) g animal(-1) d(-1). In a release-recovery experiment, the technique accounted for 77% of the released methane at a single point. Our study shows the technique generates more reliable methane emissions during daytime (unstable stratification). PMID:21488489

McGinn, S M; Turner, D; Tomkins, N; Charmley, E; Bishop-Hurley, G; Chen, D

136

Effects of Streblus asper Lour foliage on digestibility, rumen fermentation, and nitrogen balance of growing goats.  

PubMed

Eighteen crossbred (Thai native x Anglo-Nubian) goats were chosen from a Suranaree University of Technology's farm on the basis of similar bodyweight (15.5 ± 3.5 kg). The goats were randomly allocated to three treatments in randomized complete block design. Each goat was given urea-treated rice straw as roughage plus the respective treatment diets. The diets were iso-nitrogenous and iso-energetic containing cassava pulp, molasses, urea, and commercial mineral and vitamin mix. The experimental treatments were (1) soybean meal (SBM), (2) partial substitution of SBM with Streblus aspe Lour foliage, or (3) partial substitution of SBM with Leucaena (Leucaena leucocephala) foliage. Nutrient intakes, ruminal characteristics (pH, ammonia nitrogen, and volatile fatty acids), nitrogen balances, and plasma urea nitrogen were not significantly different among treatments. The present results indicate that protein foliages from locally grown shrubs and trees can substitute imported feedstuffs concentrate (e.g., SBM) as protein supplement for goat production. PMID:21088895

Paengkoum, Pramote

2010-11-19

137

Preparative scale isolation, purification and derivatization of mimosine, a non-proteinogenic amino acid.  

PubMed

Focusing on drug discovery non-proteinogenic amino acids have often been used as important building blocks for construction of compound libraries in the filed of combinatorial chemistry and chemical biology. Highly homogeneous L: -mimosine, ?-amino-?-(3-hydoxy-4-oxo-1,4-dihydropyridin-1-yl)-propanoic acid, a non-proteinogenic amino acid, has been successfully isolated and purified on an industrial scale from wild leaves of Leucaena (Leucaena leucocephala de Wit) which is a widely distributed legume in Okinawa, a sub-tropical island in Japan. Optical purity determinations used for quality control have been established through diastereomer formation. Physico-chemical properties and biological properties of purified mimosine have been clarified. Mimosine is sparingly soluble in water and organic solvents but can be dissolved in aqueous alkaline solution. The tyrosinase pathway is of particular interest in the cosmetic field, since mimosine is an analog of tyrosine. Thus the present purified mimosine have been tested in tyrosinase inhibitory assays. The IC50 for tyrosinase inhibitory activity of purified Mim was compared with kojic acid. Mimosine shows significant inhibition of melanin production in murine melanoma cells. The derivatization of mimosine has been investigated with a focus on its use in conventional peptide syntheses to generate mimosyl peptides. N-(9-Fluorenylmethoxycarbonyloxy)-mimosine and resin-bound mimosine for solid-phase syntheses have also been performed. Highly homogeneous Mim is a useful material for the development of functional cosmetics or active pharmaceutical ingredients. PMID:21993536

Nokihara, Kiyoshi; Hirata, Akiyoshi; Sogon, Tetsuya; Ohyama, Takafumi

2011-10-13

138

Lactational performance of Jersey cows given Napier fodder (Pennisetum purpureum) with and without protein concentrates in the semi-humid tropics.  

PubMed

Two experiments with 12 and 18 lactating Jersey cows respectively were carried out in the coastal semi-humid zone of Kenya to assess the performance arising from the feeding of chopped Napier fodder (Pennisetum purpureum) given ad libitum with and without one of three sources of protein; fishmeal, copra cake and freshly cut Leucaena (Leucaena leucocephala). Each source supplied approximately 300 g crude protein daily. Dry matter intakes of Napier fodder fed alone averaged 7.1 and 5.5 kg in Experiments 1 and 2 respectively. Additional protein did not affect Napier fodder intake, but total intakes of dry matter were higher for the cows receiving the protein supplements, differences which were significant (P < 0.05) in Experiment 2. Average daily milk production from cows fed Napier fodder alone was 6.4 and 4.2 kg in Experiments 1 and 2 respectively. The additional 300 g crude protein increased milk production by 1.0 to 1.6 kg/day, increases which, except that for fishmeal, were significant (P < 0.05). Weight losses of the cows were either reduced or changed to weight gains by the provision of protein. The results are assessed in relation to the energy and protein requirements for milk production. PMID:8236479

Muinga, R W; Thorpe, W; Topps, J H

1993-05-01

139

Equilibrium and kinetic studies on biosorption of 2,4,6-trichlorophenol from aqueous solutions by Acacia leucocephala bark.  

PubMed

Biosorption of 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solution by biomass prepared from Acacia leucocephala bark, an agricultural solid waste has been investigated in the present study. All the experiments are carried out by batch mode technique. The resulting biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The effect of experimental parameters such as contact time, effect of pH (2-10), initial concentration of adsorbate (50-200 mg L(-1)) and amount of biosorbent dosage was evaluated. The removal was found to be pH dependent, and maximum removal was found to be at pH 5.0. The equilibrium time was found to be 3h. The biosorbent dose was increased, and the percentage removal of 2,4,6-TCP was increased, while the adsorption capacity at equilibrium q(e) (mg g(-1)) (amount of 2,4,6-TCP loaded per unit weight of adsorbent) decreased. Biosorption kinetic and isotherm studies showed the pseudo-second-order kinetics with a good correlation coefficient (R(2)=0.999), and both Langmuir and Freundlich isotherms were the best choices to describe the adsorption behaviors. The maximum monolayer biosorption capacity of A. leucocephala bark for 2,4,6-TCP was found to be 256.4 mg g(-1), at 30±1°C according to Langmuir model. This study demonstrated for the first time that the A. leucocephala bark could be an alternative for more costly adsorbents used for removal of 2,4,6-TCP from aqueous media. PMID:22365378

Kumar, Nadavala Siva; Woo, Heung-Sik; Min, Kim

2012-02-07

140

Mutual reproductive dependence of distylic Cordia leucocephala (Cordiaceae) and oligolectic Ceblurgus longipalpis (Halictidae, Rophitinae) in the Caatinga  

PubMed Central

Background and Aims The close relationship between distylic Cordia leucocephala and the bee Ceblurgus longipalpis, both endemic to the Caatinga, north-east Brazil, was investigated, emphasizing reproductive dependence, morphological adaptations of the partners, and pollen flow. Methods In the municipality of Pedra, in the Caatinga of Pernambuco, the breeding system and reproductive success of C. leucocephala, its interaction with flower visitors and inter- and intramorph pollen flow were determined. Key Results The bee Ceblurgus longipalpis, the unique flower visitor and effective pollinator of self-incompatible Cordia leucocephala, presents morphological features adapted to exploit hidden pollen and nectar in the long and narrow corolla tubes. Pollen of low-level anthers is collected with hairs on prolonged mouthparts and pollen of high-level anthers with clypeus, mandibles, and labrum, showing pollen removal from both levels with the same effectiveness. In both morphs, this results in similar legitimate, i.e. intermorph cross-pollen flow. Illegitimate pollen flow to stigmas of pin flowers, however, was much higher than to stigmas of thrum flowers. Moreover, more illegitimate pollen was transported to stigmas of pin and less to those of thrum flowers when compared with legitimate pollen flow. Conclusions The study reveals a one-to-one reproductive inter-dependence between both partners. Data indicate that this relationship between bee species and plant species is one of the rare cases of monolecty among bees. Monotypic Ceblurgus longipalpis, the only rophitine species of Brazil, evolved prolonged mouthparts rare among short-tongued bees that enable them to access pollen from flowers with short-level anthers hidden for bees of other species, and nectar at the base of the flower tube.

Milet-Pinheiro, Paulo; Schlindwein, Clemens

2010-01-01

141

Phylogenetic relationships and host range of Rhizobium spp. that nodulate Phaseolus vulgaris L.  

PubMed Central

We determined the nucleotide sequences of 16S rRNA gene segments from five Rhizobium strains that have been isolated from tropical legume species. All share the capacity to nodulate Phaseolus vulgaris L., the common bean. Phylogenetic analysis confirmed that these strains are of two different chromosomal lineages. We defined the host ranges of two strains of Rhizobium etli and three strains of R. tropici, comparing them with those of the two most divergently related new strains. Twenty-two of the 43 tested legume species were nodulated by three or more of these strains. All seven strains have broad host ranges that include woody species such as Albizia lebbeck, Gliricidia maculata, and Leucaena leucocephala.

Hernandez-Lucas, I; Segovia, L; Martinez-Romero, E; Pueppke, S G

1995-01-01

142

The role of nurse trees in mitigating fire effects on tropical dry forest restoration: a case study.  

PubMed

The threat of fire is always a consideration when establishing a forest restoration program. Two wildfires occurred in 2006 and 2007 in an established dry forest restoration project in Puerto Rico. The original goal of the project was to determine differential growth responses of native trees under the nurse tree Leucaena leucocephala versus in open sites. Tree species growth, mortality and response to the fires were evaluated according to their leaf habit, successional status, and prefire tolerance to environmental conditions. Results showed that regardless of a species' leaf habit and successional status, trees attained greater height and lower mortality under nurse trees. In open sites, sprouting was the most common fire response and mature-forest and evergreen species had greater postfire survival than pioneers and deciduous species. Although nurse trees are typically used to help manage nutrient or light environments in reforestation projects, these trees also appear to provide a secondary benefit of limiting fire damage by reducing fuel load. PMID:19205184

Santiago-García, Ricardo J; Colón, Sandra Molina; Sollins, Phillip; Van Bloem, Skip J

2008-12-01

143

[Effects of different planting modes on the soil permeability of sloping farmlands in purple soil area].  

PubMed

Taking bare land as the control, this paper studied the effects of different planting modes on the soil permeability of sloping farmlands in purple soil area. For the test six planting modes, the soil permeability was in the order of Eriobotrya japonica > Citrus limon > Vetiveria zizanioides hedgerows +corn >Leucaena leucocephala hedgerows + corn> Hemerocallis fulva > corn> bare land, and decreased with increasing depth. The eigenvalues of soil infiltration were in the order of initial infiltration rate> average infiltration rate> stable infiltration rate. The soil permeability had significant positive linear correlations with soil total porosity, non-capillary porosity, initial moisture content, water holding capacity, and organic matter content, and significant negative linear correlation with soil bulk density. The common empirical infiltration model could well fit the soil moisture infiltration processes under the six planting modes, while the Kostiakov equation could not. PMID:23755487

Li, Jian-Xing; He, Bing-Hui; Mei, Xue-Mei; Liang, Yan-Ling; Xiong, Jian

2013-03-01

144

Cyclic-?-glucans of Rhizobium (Sinorhizobium) sp. strain NGR234 are required for hypo-osmotic adaptation, motility, and efficient symbiosis with host plants.  

PubMed

Cyclic-?-glucans (C?G) consist of cyclic homo-polymers of glucose that are present in the periplasmic space of many Gram-negative bacteria. A number of studies have demonstrated their importance for bacterial infection of plant and animal cells. In this study, a mutant of Rhizobium (Sinorhizobium) sp. strain NGR234 (NGR234) was generated in the cyclic glucan synthase (ndvB)-encoding gene. The great majority of C?G produced by wild-type NGR234 are negatively charged and substituted. The ndvB mutation abolished C?G biosynthesis. We found that, in NGR234, a functional ndvB gene is essential for hypo-osmotic adaptation and swimming, attachment to the roots, and efficient infection of Vigna unguiculata and Leucaena leucocephala. PMID:22583376

Gay-Fraret, Jérémie; Ardissone, Silvia; Kambara, Kumiko; Broughton, William J; Deakin, William J; Le Quéré, Antoine

2012-06-01

145

Voltammetric trace determination of mercury using plant refuse modified carbon paste electrodes.  

PubMed

Citrus limon peel (kitchen waste) and Leucaena leucocephala seeds (agricultural waste) were used as a modifier for fabrication of modified carbon paste electrode for determination of mercury in aqueous sample using differential pulse anodic stripping voltammetry. Mercury was adsorbed on electrode surface at open circuit and anodic stripping voltammetric scan was run from -0.5 to 0.5 V. Various electrochemical parameters including amount of modifier, supporting electrolyte, accumulating solvent, pH of the accumulating solvent, and accumulation time were investigated. The effect of presence of other metal ions and surfactants was also studied. In comparison C. limon peel proved to be a better modifier than L. leucocephala seed biomass. This was justified by electrode characterization using cyclic voltammetry that indicated decrease in resistance of electrode when C. limon peel was used as modifier and increase when modifier was L. leucocephala seeds. Maximum current response was obtained using 5 % C. limon peel biomass, hydrochloric acid as supporting electrolyte, acetate buffer of pH 6 as an accumulating solvent, 10-min accumulation time, and scan rate of 50 mV/s. Linear calibration curves were obtained in the concentration range 100 to 1,000 ?g L(-1) of mercury for accumulation time of 10 min with limit of detection of 57.75 ?g L(-1) and limit of quantification of 192.48 ?g L(-1). This technique does not use mercury as electrode material and, therefore, has a positive environmental benefit. PMID:23709264

Devnani, Harsha; Satsangee, Soami Piara

2013-05-25

146

Effect of six tropical tanniferous plant extracts on larval exsheathment of Haemonchus contortus.  

PubMed

Tanniferous plants represent a promising alternative for controlling gastrointestinal nematodes of small ruminants. This experiment evaluated the effects of extracts from the leaf and stem of Anadenanthera colubrina, Leucaena leucocephala and Mimosa tenuiflora on larval exsheathment of Haemonchus contortus in vitro and verified the role of tannins in this process. Third-stage larvae of H. contortus were incubated with extracts for 3 hours and were exposed to sodium hypochlorite solution. The extracts were tested at 300 ?g.mL(-1) and accompanied by controls: phosphate buffer solution (PBS) and polyvinyl polypyrrolidone (PVPP). The larval exsheathment was evaluated for 60 minutes, and the results were subjected to the Kruskal-Wallis test (p < 0.05). The six extracts blocked larval exsheathment. After PVPP addition, a tannin inhibitor, the exsheathment percentage was similar to the PBS (p > 0.05), except for L. leucocephala and M. tenuiflora leaf extracts. However, pre-incubation with PVPP of these two extracts significantly changed larval exsheathment when compared to the non-treated extracts (p < 0.05). These results suggest that A. colubrina, L. leucocephala and M. tenuiflora could be useful in gastrointestinal nematode control and that tannins are probably the main compounds involved in the observed effects. However, in vivo and toxicological studies should be conducted. PMID:21722491

Oliveira, Lorena Mayana Beserra de; Bevilaqua, Claudia Maria Leal; Macedo, Iara Tersia Freitas; Morais, Selene Maia de; Monteiro, Maria Vivina Barros; Campello, Claudio Cabral; Ribeiro, Wesley Lyeverton Correia; Batista, Emanuelle Karine Frota

147

A comparative study on mimosine, 3,4-dihydroxy pyridone (3,4-DHP) and 2,3-dihydroxy pyridone (2,3-DHP), purine derivatives (PD) excretion in the urine, thyroid hormone and blood metabolites profiles of Thai swamp buffalo (Bubalus bubalis) and Murrah buffalo (Bubalus bubalis).  

PubMed

Four Thai swamp buffaloes (SB) and four Murrah buffaloes (MB) fed a based diet of fresh ruzi grass (Bachiaria ruziziensis) with an increased proportion of fresh leucaena leaves. Intake of nutrients in animals increased when ruzi grass was mixed with leucaena. Digestibility of nutrients were the highest in SB and MB fed diets containing 25% and 50% of leucaena, respectively, and nitrogen (N) balances in both animal breeds were varied among diets. The regression equation coefficient of mimosine + DHP in the urine was twice as high in SB than in MB. Urinary purine derivatives excretion rate in SB was higher than that in MB. Plasma triiodothyronine and thyroxine declined in both animal breeds fed a diet containing >1 g mimosine intake/kg BW(0.75)/day. Plasma urea-N was the lowest in SB, but the highest in MB when fed a diet containing 84% of leucaena. Plasma ?-HBA in SB have declined when diets contained >50% of leucaena but that in MB was not affected by any diet. In conclusion, the effect of leucaena in diet upon buffalo breeds depends on the proportion of leucaena in the diet, mimosine contents and condensed tannins components. PMID:21928129

Jetana, Thongsuk; Thongruay, Sirima; Uswang, Sawong; Hengtrakulsin, Runchuan

2011-09-18

148

Nutritive value and qualitative assessment of secondary compounds in seeds of eight tropical browse, shrub and pulse legumes.  

PubMed

Seeds of four tropical multipurpose trees (Albizia saman, Albizia lebbeck, Albizia rhizonse, Leucaena leucocephala), two shrubs (Tephrosia candida, Tephrosia bracteolata) and two pulse legume (Lablab purpureus, Canavalia ensiformis) were chemically analysed for dry matter (DM), ash, crude protein (CP), neutral detergent fibre (NDF) and ether extract (EE). Qualitative evaluation of secondary metabolites (saponins, phenols, steroids, and alkaloids) was elucidated. The DM, ash, CP, NDF and EE ranged between 88.9-93.6 %, 3.0-5.4 %, 24.8-38.2 %, 22.1-46.9 % and 2.0-17.0 % respectively. All seed species contained at least one group of secondary plant metabolites and steroids were common to all except C. ensiformis that was not implicated for any. A. lebbeck and A. rhizonse showed low saponin content. Indications for water soluble tannins were reported for L. leucocephala while the two species of Tephrosia contained flavonoids or condensed tannins. The study suggested the potentials of the legumes seed species as a feed source for ruminants. PMID:15560266

Babayemi, O J; Demeyer, D; Fievez, V

2004-01-01

149

[Soil labile organic carbon contents and their allocation characteristics under different land uses at dry-hot valley].  

PubMed

Soil organic carbon (SOC), readily oxidation organic carbon (ROC), microbial biomass carbon (MBC)and dissolved organic carbon (DOC) contents and their allocation ratios were comparatively investigated under Leucaena leucocephala woodland, Acacia auriculiformis woodland, dry cropland and wasteland in dry-hot valley. Results showed that SOC contents were not significant differences among the four land uses with the range of 4.22-5.19 g x kg(-1). ROC contents under L. leucocephala (2.14 g x kg(-1)) and A. auriculiformis woodland (2.03 g x kg(-1)) were both significantly higher than those under dry cropland (1.38 g x kg(-1)) and wasteland (1.34 g x kg(-1)). The highest MBC and DOC contents both presented under dry cropland among the four land uses, whereas the lowest occurred under wasteland. ROC allocation ratios under woodlands were 1.3 to 1.6 times to those under dry cropland and wasteland. MBC and DOC allocation ratios under cropland were higher than those under other three land uses, and the ratios were closely among woodlands and wasteland. Plant residue amounts and management were primarily determined ROC contents, and soil water content and plant residue quantity were mainly affected the variation of MBC and DOC contents under the four land uses. The change of ROC contents could sensitively indicate SOC dynamics in dry-hot valley, but the change of MBC or DOC could not. PMID:20623878

Tang, Guo-yong; Li, Kun; Sun, Yong-yu; Zhang, Chun-hua

2010-05-01

150

Effects of four tropical tanniniferous plant extracts on the inhibition of larval migration and the exsheathment process of Trichostrongylus colubriformis infective stage.  

PubMed

The anthelmintic (AH) effect of Acacia pennatula, Leucaena leucocephala, Lisyloma latisiliquum and Piscidia piscipula was evaluated in the infective larvae (L(3)) of Trichostrongylus colubriformis. Different concentrations of lyophilized extracts were tested using the larval migration inhibition (LMI) test. An inhibitor of tannins (the polyvinyl polypyrrolidone [PVPP]) was used to verify whether these compounds were responsible for the AH effects. Then, the effect of extracts on larval exsheathment was examined by observing the exsheathment process at 10-min intervals for 70 min. The LMI test showed a dose-dependant AH effect for A. pennatula, L. leucocephala and L. latisiliquum (P<0.01), but not for P. piscipula. The restoration of L(3) migration to values similar to those of controls after the addition of PVPP, indicates that tannins are involved in AH effects. Trichostrongylus colubriformis exsheathment was partially or totally blocked by the four plants extracts. Tropical tanniniferous plants evaluated in the current study may have potential as AH for the control of T. colubriformis if in vivo investigations indicate useful effects. PMID:18304736

Alonso-Díaz, M A; Torres-Acosta, J F J; Sandoval-Castro, C A; Capetillo-Leal, C; Brunet, S; Hoste, H

2008-01-17

151

The pydA-pydB fusion gene produces an active dioxygenase-hydrolase that degrades 3-hydroxy-4-pyridone, an intermediate of mimosine metabolism.  

PubMed

The objective of this research was to construct a pydA-pydB hybrid gene that encodes a functional dioxygenase-hydrolase (PydA-PydB) fusion protein for degradation of 3-hydroxy-4-pyridone (HP). HP is an intermediate in both synthesis and degradation of mimosine, a toxic amino acid produced by the tree legume Leucaena leucocephala. Computer-generated models of the fusion proteins suggested that joining of PydA and PydB with 0, 3, or 7 glycine residues as a linker should produce a functional PydA-PydB fusion protein. Accordingly, three hybrid genes, G0, G3, and G7, were constructed in which pydA and pydB were connected with 0, 9, and 21 nucleotides, respectively, encoding the glycine residues of the linker region. When these hybrid genes were expressed in Rhizobium and Escherichia coli, only one of them, G3, produced a functional PydA-PydB fusion protein, having both the dioxygenase and hydrolase activities. The G3 hybrid gene could complement both pydA and pydB mutants of Rhizobium, and E. coli lysate containing the overexpressed G3 protein was able to degrade HP. This hybrid gene may be useful for developing mimosine-free L. leucocephala plants in the future. PMID:17390132

Awaya, Jonathan D; Walton, Chad; Borthakur, Dulal

2007-03-28

152

Cupriavidus necator isolates are able to fix nitrogen in symbiosis with different legume species.  

PubMed

The aim of the present study was to identify a collection of 35 Cupriavidus isolates at the species level and to examine their capacity to nodulate and fix N(2). These isolates were previously obtained from the root nodules of two promiscuous trap species, Phaseolus vulgaris and Leucaena leucocephala, inoculated with soil samples collected near Sesbania virgata plants growing in Minas Gerais (Brazil) pastures. Phenotypic and genotypic methods applied for this study were SDS-PAGE of whole-cell proteins, and 16S rRNA and gyrB gene sequencing. To confirm the ability to nodulate and fix N(2), the presence of the nodC and nifH genes was also determined, and an experiment was carried out with two representative isolates in order to authenticate them as legume nodule symbionts. All 35 isolates belonged to the betaproteobacterium Cupriavidus necator, they possessed the nodC and nifH genes, and two representative isolates were able to nodulate five different promiscuous legume species: Mimosa caesalpiniaefolia, L. leucocephala, Macroptilium atropurpureum, P. vulgaris and Vigna unguiculata. This is the first study to demonstrate that C. necator can nodulate legume species. PMID:22361568

da Silva, Krisle; Florentino, Ligiane Aparecida; da Silva, Karina Barroso; de Brandt, Evie; Vandamme, Peter; de Souza Moreira, Fatima Maria

2012-02-22

153

International Consultation on Ipil-Ipil Research.  

National Technical Information Service (NTIS)

Discoveries on the multi-uses of ipil-ipil (Leucaena spp.) generated worldwide interest in the production of this versatile plant. Originating from Mexico, this species was introduced to various tropical countries especially in Southeast Asia. Undoubtedly...

1978-01-01

154

In vitro larval migration and kinetics of exsheathment of Haemonchus contortus larvae exposed to four tropical tanniniferous plant extracts.  

PubMed

As for some temperate forage, some tropical tanniniferous plants (TTP) from browsing might represent an alternative to chemical anthelmintic. The anthelmintic effect of four TTP (Acacia pennatula, Lysiloma latisiliquum, Piscidia piscipula, Leucaena leucocephala) on Haemonchus contortus was measured using two in vitro assays. First, the effects of increasing concentrations of lyophilized extracts (150, 300, 600, 1200 microg/ml PBS) were tested on H. contortus larvae (L(3)) using the larval migration inhibition (LMI) test. An inhibitor of tannin, polyvinyl polypyrrolidone (PVPP), was used to verify whether tannins were responsible for the AH effect. Secondly, the effects of extracts on larval exsheathment were examined. Larvae (L(3)) were in contact with extracts (1200 microg/ml) for 3h, and then were exposed to an artificial exsheathment procedure with observations of the process at 10 min intervals. A general lineal model (GLM) test was used to determine the dose effect in the LMI test and the difference of the percentage of exsheathed larvae between the control and the treatment groups. A Kruskal Wallis test was used to determine the effect of PVPP on LMI results. The LMI test showed a dose-dependent anthelmintic effect for A. pennatula, L. latisiliquum and L. leucocephala (P<0.01), which disappeared after PVPP addition, confirming the role of tannins. No effect was found for P. piscipula on H. contortus in the LMI test. However, all four plant extracts interfered with the process of L(3) exsheathment which might be involved as a mechanism of action of tannins on H. contortus larvae. A. pennatula, L. latisiliquum and L. leucocephala could be used as an anthelmintic for the control of H. contortus after confirmation based on in vivo studies. PMID:18378085

Alonso-Díaz, M A; Torres-Acosta, J F J; Sandoval-Castro, C A; Aguilar-Caballero, A J; Hoste, H

2008-02-08

155

Impacts of vegetative contour hedges on soil inorganic-N cycling and erosional losses in Arable Steep-lands of the Central Highlands of Kenya  

Microsoft Academic Search

Moderate to steep landscapes and severe soil, water and nutrient losses characterize over 40% of arable land in the central\\u000a highlands of Kenya. To study the effectiveness of biological methods in management and enhancement of productivity of these\\u000a arable steep-lands, we established contour double row hedges of sole Calliandra, Leucaena and napier and combination hedges of either Calliandra or Leucaena

James K. Mutegi; Daniel N. Mugendi; Louis V. Verchot; James B. Kungu

156

Reliability of the Most-Probable-Number Technique for Enumerating Rhizobia in Tropical Soils †  

PubMed Central

We used six rhizobium-legume systems to test the reliability of the most-probable-number (MPN) technique for enumerating rhizobia introduced into 14 sites representing four soil orders. The range-of-transition values (the number of dilution steps between the first not-entirely-positive and the last not-entirely-negative growth units) were compared for each species and for each soil. The probability that the observed data were significantly different from theoretical values varied with the species. The acceptability of MPN codes (P > 0.99) was the highest (97 to 99%) with Vicia sativa, Trifolium repens, and Glycine max and lowest (72%) with Leucaena leucocephala. Medicago sativa and Macroptilium atropurpureum yielded 87 and 75% acceptable MPN codes, respectively. The acceptability of the MPN data obtained for a host species was related to rooting habit and time to nodulation. Comparison of data for each soil indicated that, despite large differences in characteristics, the soil was not a major source of variability in the MPN counts. There was no significant interaction of the range of transition of rhizobium-legume plant infection count data between species and site.

Woomer, Paul L.; Singleton, Paul W.; Bohlool, B. Ben

1988-01-01

157

Diversity of Rhizobia Nodulating Phaseolus vulgaris L. in Two Kenyan Soils with Contrasting pHs  

PubMed Central

Rhizobia were isolated from two Kenyan soils with pHs of 4.5 and 6.8 and characterized on the basis of their host ranges for nodulation and nitrogen fixation, colony morphologies, restriction fragment fingerprints, and hybridization with a nifH probe. The populations of rhizobia nodulating Phaseolus vulgaris in the two soils were similar in numbers and in effectiveness of N(inf2) fixation but were markedly different in composition. The population in the Naivasha soil (pH 6.8) was dominated by isolates specific in host range for nodulation to P. vulgaris; these all had multiple copies, in most cases four, of the structural nitrogenase gene nifH. Only one of the isolates from this soil formed effective nodules on Leucaena leucocephala, and this isolate had only a single copy of nifH. By contrast, the population in the acid Daka-ini soil (pH 4.5) was composed largely of broad-host-range isolates which had single copies of nifH. The isolates from the Daka-ini soil which were specific to P. vulgaris generally had three copies of nifH, although one isolate had only two copies. These rhizobial isolates are indigenous to Kenyan soils and yet have marked similarities to previously described Rhizobium species from other continents.

Anyango, B.; Wilson, K. J.; Beynon, J. L.; Giller, K. E.

1995-01-01

158

Ecological Indicators of Native Rhizobia in Tropical Soils †  

PubMed Central

The relationship between environment and abundance of rhizobia was described by determining the populations of root nodule bacteria at 14 diverse sites on the island of Maui. Mean annual rainfall at the sites ranged from 320 to 1,875 mm, elevation from 37 to 1,650 m, and soil pH from 4.6 to 7.9. Four different soil orders were represented in this study: inceptisols, mollisols, ultisols, and an oxisol. The rhizobial populations were determined by plant infection counts of five legumes (Trifolium repens, Medicago sativa, Vicia sativa, Leucaena leucocephala, and Macroptilium atropurpureum). Populations varied from 1.1 to 4.8 log10 cells per g of soil. The most frequently occurring rhizobia were Bradyrhizobium spp., which were present at 13 of 14 sites with a maximum of 4.8 log10 cells per g of soil. Rhizobium trifolii and R. leguminosarum occurred only at higher elevations. The presence of a particular Rhizobium or Bradyrhizobium sp. was correlated with the occurrence of its appropriate host legume. Total rhizobial populations were significantly correlated with mean annual rainfall, legume cover and shoot biomass, soil temperature, soil pH, and phosphorus retention. Regression models are presented which describe the relationship of legume hosts, soil climate, and soil fertility on native rhizobial populations.

Woomer, Paul; Singleton, Paul W.; Bohlool, B. Ben

1988-01-01

159

Reclamation of tannery polluted soil through phytoremediation.  

PubMed

The huge volume of sludge emanating from the tannery effluent treatment plants poses a serious environmental problem. Phytoremediation is an emerging technology in which the plants are employed to reclamate the contaminated soil strewn with heavy metals (metalloids) and toxic compounds. This work focuses the impact of application of tannery sludge on biochemical properties of 6 months old tree saplings of Azadirachta indica A. Juss. (Neem), Melia azedarach Linn. (Wild Neem) and Leucaena leucocephala (Lam) de Wit (Subabool) raised over the tannery sludge in an attempt to use these plants for phytoremediation. The plants raised over the garden soil served as the control. The porosity and water holding capacity of the tannery sludge were higher. The plant growth supporting elements such as Ca, total N2, NO3 and Mg were higher in the sludge. The plants raised over the sludge were found to be dark green with increased morphometric parameters. Electrophoretic profile revealed amplification of a few polypeptides (100, 105, 49 and 55 KDa). The levels of biomolecules and the CO2 absorption increased in 6 months old plants. There was a significant uptake and transport of chromium in all the three tree species suggesting that these plants could be employed in phytoremediation of soils contaminated with heavy metals. PMID:23572927

Sakthivel, V; Vivekanandan, M

2009-06-28

160

Symbiosis-induced cascade regulation of the Mesorhizobium loti R7A VirB/D4 type IV secretion system.  

PubMed

The Mesorhizobium loti R7A symbiosis island contains genes encoding a VirB/D4 type IV secretion system (T4SS) similar to that of Agrobacterium tumefaciens. This system has host-dependent effects on symbiosis that probably are due to translocation of two effector proteins, Msi059 and Msi061, into host cells. Here we report that, as in A. tumefaciens, the M. loti vir genes are transcriptionally regulated by a VirA/VirG two-component regulatory system. A virGN54D mutant gene of M. loti caused constitutive expression of lacZ reporter gene fusions to virB1, virD4, msi059, and msi061. Expression of these gene fusions also was activated by a NodD gene product from Rhizobium leguminosarum in the presence of the inducer naringenin, as was a virA::lacZ fusion. This activation was dependent on a nod box present 851 bp upstream of virA, and a mutant with the nod box deleted formed effective nodules on Leucaena leucocephala, the same symbiotic phenotype as other M. loti vir mutants. In contrast, the wild-type strain formed small, empty nodules whereas a nodD1 mutant was completely Nod-. These results indicate that the M. loti vir genes are induced in a symbiosis-specific manner that involves a two-tiered regulatory cascade, and that the vir effectors act after Nod factor during infection thread formation. PMID:17378428

Hubber, Andree M; Sullivan, John T; Ronson, Clive W

2007-03-01

161

Phytotoxicity of volatile oil from Eucalyptus citriodora against some weedy species.  

PubMed

A study was undertaken to explore the phytotoxicity of volatile essential oil from Eucalyptus citriodora Hook. against some weeds viz. Bidens pilosa, Amaranthus viridis, Rumex nepalensis, and Leucaena leucocephala in order to assess its herbicidal activity. Dose-response studies conducted under laboratory conditions revealed that eucalypt oils (in concentration ranging from 0.0012 to 0.06%) greatly suppress the germination and seedling height of test weeds. At 0.06% eucalypt oil concentration, none of the seed of test weeds germinated. Among the weed species tested, A. viridis was found to be the most sensitive and its germination was completed inhibited even at 0.03%. Not only the germination and seedling growth, even the chlorophyll content and respiratory activity in leaves of emerged seedlings were severely affected. In A. viridis chlorophyll content and respiratory activity were reduced by over 51% and 71%, respectively, even at a very low concentration of 0.06%. These results indicated an adverse effect of eucalypt oils on the photosynthetic and energy metabolism of the test weeds. A strong negative correlation was observed between the observed effect and the concentration of eucalypt oil. Based on the study, it can be concluded that oil from E. citriodora possess strong inhibitory potential against weeds that could be exploited for weed management. PMID:17717987

Setia, N; Batish, D R; Singh, H P; Kohli, R K

2007-01-01

162

Mesorhizobium albiziae sp. nov., a novel bacterium that nodulates Albizia kalkora in a subtropical region of China.  

PubMed

A novel Mesorhizobium group associated with Albizia kalkora [Wang et al. (2006), Syst Appl Microbiol 29, 502-517] was further characterized. The seven strains in this group showed similar protein patterns and were different from defined Mesorhizobium species in SDS-PAGE of whole-cell proteins. The representative strain CCBAU 61158(T) formed a novel Mesorhizobium lineage in phylogenetic analyses of 16S rRNA, atpD, glnII and nifH genes. However, its nodC gene sequence was more similar to that of Rhizobium gallicum R602sp(T) than to those of Mesorhizobium species. DNA-DNA relatedness between CCBAU 61158(T) and reference strains of defined Mesorhizobium species was lower than 34.1 %. These results indicated that this Mesorhizobium group was a unique genomic species. The subtropical distribution, host origin, PCR-RFLP patterns of 16S rRNA genes, fatty acid profile and a series of phenotypic characteristics could be used as distinctive features of this group. This group is therefore proposed as a novel species, Mesorhizobium albiziae sp. nov., with CCBAU 61158(T) (=LMG 23507(T)=USDA 4964(T)) as the type strain. Strain CCBAU 61158(T) could form effective nodules on Albizia julibrissin, Glycine max, Leucaena leucocephala and Phaseolus vulgaris. PMID:17551028

Wang, Feng Qin; Wang, En Tao; Liu, Jie; Chen, Qiang; Sui, Xin Hua; Chen, Wen Feng; Chen, Wen Xin

2007-06-01

163

Temporal changes of selected chemical properties in three manure - amended soils of Hawaii.  

PubMed

Soil amendment with organic materials (crop residues animal manure, and green manure) reportedly has positive effects on soil properties, from acidity to plant-nutrient availability. To examine that hypothesis, an incubation study was conducted to assess the changes in some chemical properties of three different tropical soils (Andisol, Ultisol, and Oxisol) amended with chicken manure and green manure (Leucaena leucocephala) at the rate of 10tha(-1). The results showed that organic amendments raised soil pH and EC, regardless of the type of manure used. Manuring lowered the concentrations of Mehlich-3 extractable Ca, P, Mn and Si in all soils and decreased the concentration of Mg in the Ultisol and Oxisol. However, manure amendment led to increases in the concentrations of Mg and K in the Andisol. Organic amendments caused a decrease in KCl extractable Al. Initial soluble C levels were highest in the Oxisol (60micromolg(-1)) and lowest in the Andisol (20micromolg(-1)). The concentration of soluble C decreased exponentially with duration of incubation. Three low molecular weight organic molecules (acetic acid, catechol and oxalic acid) out of the eight tested were found in all manure-amended soils. This study quantified the release of some Al chelating organic acids, the reduction of exchangeable Al, and the changes in major plant-nutrients when organic materials were added to nutrient poor, tropical acid soils. PMID:18550367

Ortiz Escobar, M E; Hue, N V

2008-06-11

164

Preventing establishment: an inventory of introduced plants in Puerto Villamil, Isabela Island, Galapagos.  

PubMed

As part of an island-wide project to identify and eradicate potentially invasive plant species before they become established, a program of inventories is being carried out in the urban and agricultural zones of the four inhabited islands in Galapagos. This study reports the results of the inventory from Puerto Villamil, a coastal village representing the urban zone of Isabela Island. We visited all 1193 village properties to record the presence of the introduced plants. In addition, information was collected from half of the properties to determine evidence for potential invasiveness of the plant species. We recorded 261 vascular taxa, 13 of which were new records for Galapagos. Most of the species were intentionally grown (cultivated) (73.3%) and used principally as ornamentals. The most frequent taxa we encountered were Cocos nucifera (coconut tree) (22.1%) as a cultivated plant and Paspalum vaginatum (salt water couch) (13.2%) as a non cultivated plant. In addition 39 taxa were naturalized. On the basis of the invasiveness study, we recommend five species for eradication (Abutilon dianthum, Datura inoxia, Datura metel, Senna alata and Solanum capsicoides), one species for hybridization studies (Opuntia ficus-indica) and three species for control (Furcraea hexapetala, Leucaena leucocephala and Paspalum vaginatum). PMID:17940606

Guézou, Anne; Pozo, Paola; Buddenhagen, Christopher

2007-10-17

165

in Silico mutagenesis and docking studies of active site residues suggest altered substrate specificity and possible physiological role of Cinnamoyl CoA Reductase 1 (Ll-CCRH1)  

PubMed Central

Cinnamoyl CoA reductase (CCR) carries out the first committed step in monolignol biosynthesis and acts as a first regulatory point in lignin formation. CCR shows multiple substrate specificity towards various cinnamoyl CoA esters. Here, in Silico mutagenesis studies of active site residues of Ll-CCRH1 were carried out. Homology modeling based modeled 3D structure of Ll-CCRH1 was used as template for in Silico mutant preparations. Docking simulations of Ll-CCRH1 mutants with CoA esters by AutoDock Vina tools showed altered substrate specificity as compared to wild type. The study evidences that conformational changes, and change in geometry or architecture of active site pocket occurred following mutations. The altered substrate specificity for active site mutants suggests the possible physiological role of CCR either in lignin formation or in defense system in plants. Abbreviations Ll-CCRH1 - Leucaena leucocephala cinnamoyl CoA reductase 1, OPLS - Optimized Potentials for Liquid Simulations, RMSD - Root Mean Square Deviation.

Sonawane, Prashant; Patel, Krunal; Vishwakarma, Rishi Kishore; Singh, Somesh; Khan, Bashir Mohammad

2013-01-01

166

Effects of species and season on chemical composition and ruminal crude protein and organic matter degradability of some multi-purpose tree species by West African dwarf rams.  

PubMed

Seasonal chemical composition and ruminal organic matter (OM) and crude protein (CP) degradabilities were determined in four tropical multi-purpose tree species (MPTS) namely; Pterocarpus santalinoides, Grewia pubescens, Enterolobium cyclocarpum and Leucaena leucocephala. Three West African dwarf (WAD) rams fitted with permanent rumen cannula were used for the degradability trials. Foliage samples were collected four times to represent seasonal variations as follows: January--mid dry; April--late dry; July--mid rainy and October--late rainy seasons. Leaf samples were randomly collected from the trees for estimation of dry matter (DM) and chemical composition. Ruminal in sacco OM and CP degradabilities were estimated from residues in nylon bags. All samples had high CP (161-259 g/kg DM) and moderate fibre concentrations [neutral detergent fibre (without residual ash], 300-501 g/kg DM; acid detergent fibre (without residual ash), 225-409 g/kg DM and acid detergent lignin, 87-179 g/kg DM across seasons. Interaction effects of species and season on chemical composition were highly significant (p = 0.001) except for trypsin inhibitor (p = 0.614). The MPTS recorded more than 60% OM and CP degradability at 24 h, which implied that they were all highly degradable in the rumen. Their incorporation into ruminant feeding systems as dry season forage supplements is therefore recommended. PMID:21535229

Arigbede, O M; Anele, U Y; Südekum, K-H; Hummel, J; Oni, A O; Olanite, J A; Isah, A O

2011-05-02

167

Development of feeding systems and strategies of supplementation to enhance rumen fermentation and ruminant production in the tropics  

PubMed Central

The availability of local feed resources in various seasons can contribute as essential sources of carbohydrate and protein which significantly impact rumen fermentation and the subsequent productivity of the ruminant. Recent developments, based on enriching protein in cassava chips, have yielded yeast fermented cassava chip protein (YEFECAP) providing up to 47.5% crude protein (CP), which can be used to replace soybean meal. The use of fodder trees has been developed through the process of pelleting; Leucaena leucocephala leaf pellets (LLP), mulberry leaf pellets (MUP) and mangosteen peel and/or garlic pellets, can be used as good sources of protein to supplement ruminant feeding. Apart from producing volatile fatty acids and microbial proteins, greenhouse gases such as methane are also produced in the rumen. Several methods have been used to reduce rumen methane. However, among many approaches, nutritional manipulation using feed formulation and feeding management, especially the use of plant extracts or plants containing secondary compounds (condensed tannins and saponins) and plant oils, has been reported. This approach could help todecrease rumen protozoa and methanogens and thus mitigate the production of methane. At present, more research concerning this burning issue - the role of livestock in global warming - warrants undertaking further research with regard to economic viability and practical feasibility.

2013-01-01

168

Heterologous exopolysaccharide production in Rhizobium sp. strain NGR234 and consequences for nodule development.  

PubMed Central

Rhizobium sp. strain NGR234 produces large amounts of acidic exopolysaccharide. Mutants that fail to synthesize this exopolysaccharide are also unable to nodulate the host plant Leucaena leucocephala. A hybrid strain of Rhizobium sp. strain NGR234 containing exo genes from Rhizobium meliloti was constructed. The background genetics and nod genes of Rhizobium sp. strain NGR234 are retained, but the cluster of genes involved in exopolysaccharide biosynthesis was deleted. These exo genes were replaced with genes required for the synthesis of succinoglycan exopolysaccharide from R. meliloti. As a result of the genetic manipulation, the ability of these hybrids to synthesize exopolysaccharide was restored, but the structure was that of succinoglycan and not that of Rhizobium sp. strain NGR234. The replacement genes were contained on a cosmid which encoded the entire known R. meliloti exo gene cluster, with the exception of exoB. Cosmids containing smaller portions of this exo gene cluster did not restore exopolysaccharide production. The presence of succinoglycan was indicated by staining with the fluorescent dye Calcofluor, proton nuclear magnetic resonance spectroscopy, and monosaccharide analysis. Although an NGR234 exoY mutant containing the R. meliloti exo genes produced multimers of the succinoglycan repeat unit, as does the wild-type R. meliloti, the deletion mutant of Rhizobium sp. strain NGR234 containing the R. meliloti exo genes produced only the monomer. The deletion mutant therefore appeared to lack a function that affects the multiplicity of succinoglycan produced in the Rhizobium sp. strain NGR234 background. Although these hybrid strains produced succinoglycan, they were still able to induce the development of an organized nodule structure on L. leucocephala. The resulting nodules did not fix nitrogen, but they did contain infection threads and bacteroids within plant cells. This clearly demonstrated that a heterologous acidic exopolysaccharide structure was sufficient to enable nodule development to proceed beyond the developmental barrier imposed on mutants of Rhizobium sp. strain NGR234 that are unable to synthesize any acidic exopolysaccharide. Images

Gray, J X; Zhan, H J; Levery, S B; Battisti, L; Rolfe, B G; Leigh, J A

1991-01-01

169

Evidence of an American origin for symbiosis-related genes in Rhizobium lusitanum.  

PubMed

Randomly amplified polymorphic DNA (RAPD) analysis was used to investigate the diversity of 179 bean isolates recovered from six field sites in the Arcos de Valdevez region of northwestern Portugal. The isolates were divided into 6 groups based on the fingerprint patterns that were obtained. Representatives for each group were selected for sequence analysis of 4 chromosomal DNA regions. Five of the groups were placed within Rhizobium lusitanum, and the other group was placed within R. tropici type IIA. Therefore, the collection of Portuguese bean isolates was shown to include the two species R. lusitanum and R. tropici. In plant tests, the strains P1-7, P1-1, P1-2, and P1-16 of R. lusitanum nodulated and formed nitrogen-fixing symbioses both with Phaseolus vulgaris and Leucaena leucocephala. A methyltransferase-encoding nodS gene identical with the R. tropici locus that confers wide host range was detected in the strain P1-7 as well as 24 others identified as R. lusitanum. A methyltransferase-encoding nodS gene also was detected in the remaining isolates of R. lusitanum, but in this case the locus was that identified with the narrow-host-range R. etli. Representatives of isolates with the nodS of R. etli formed effective nitrogen-fixing symbioses with P. vulgaris and did not nodulate L. leucocephala. From sequence data of nodS, the R. lusitanum genes for symbiosis were placed within those of either R. tropici or R. etli. These results would support the suggestion that R. lusitanum was the recipient of the genes for symbiosis with beans from both R. tropici and R. etli. PMID:21705533

Valverde, Angel; Velázquez, Encarna; Cervantes, Emilio; Igual, José M; van Berkum, Peter

2011-06-24

170

Tropical tanniniferous legumes used as an option to mitigate sheep enteric methane emission.  

PubMed

This study presents the first results from Brazil using SF(6) tracer technique adapted from cattle to evaluate the capability of condensed tannin (CT) present in three tropical legume forages, Leucaena leucocephala (LEU), Styzolobium aterrimum (STA), and Mimosa caesalpiniaefolia Benth (MIM) to reduce enteric CH(4) production in Santa Inês sheep. Twelve male lambs [27.88?±?2.85 kg body weight (BW)] were allocated in individual metabolic cages for 20-day adaptation followed by 6 days for measuring dry matter intake (DMI) and CH(4) emission. All lambs received water, mineral supplement, and Cynodon dactylon v. coast-cross hay ad libitum. The treatments consisted of soybean meal (710 g/kg) and ground corn (290 g/kg) [control (CON)]; soybean meal (150 g/kg), ground corn (30 g/kg), and Leucaena hay (820 g/kg) (LEU); soybean meal (160 g/kg), ground corn (150 g/kg), and Mucuna hay (690 g/kg) (STA); and soybean meal (280 g/kg), ground corn (190 g/kg), and Mimosa hay (530 g/kg) (MIM); all calculated to provide 40 g/kg CT (except for CON). DMI (in grams of DMI per kilogram BW per day) was lower for LEU (22.0) than CON (29.3), STA (31.2), and MIM (31.6). The LEU group showed emission of 7.8 g CH(4)/day, significantly lower than CON (10.5 g CH(4)/day), STA (10.4 g CH(4)/day), and MIM (11.3 g CH(4)/day). However, when the CH(4) emission per DMI was considered, there were no significant differences among treatments (0.37, 0.36, 0.33, and 0.35 g CH(4)/g DMI/kg BW/day, respectively, for CON, LEU, STA, and MIM). The sheep receiving STA had shown a tendency (p?=?0.15) to reduce methane emission when compared to the CON group. Therefore, it is suggested that tropical tanniniferous legumes may have potential to reduce CH(4) emission in sheep, but more research is warranted to confirm these results. PMID:23054809

Moreira, Guilherme Dias; Lima, Paulo de Mello Tavares; Borges, Bárbara Oliveira; Primavesi, Odo; Longo, Cibele; McManus, Concepta; Abdalla, Adibe; Louvandini, Helder

2012-10-07

171

midD-encoded 'rhizomimosinase' from Rhizobium sp. strain TAL1145 is a C-N lyase that catabolizes L-mimosine into 3-hydroxy-4-pyridone, pyruvate and ammonia.  

PubMed

Rhizobium sp. strain TAL1145 catabolizes mimosine, which is a toxic non-protein amino acid present in Leucaena leucocephala (leucaena). The objective of this investigation was to study the biochemical and catalytic properties of the enzyme encoded by midD, one of the TAL1145 genes involved in mimosine degradation. The midD-encoded enzyme, MidD, was expressed in Escherichia coli, purified and used for biochemical and catalytic studies using mimosine as the substrate. The reaction products in the enzyme assay were analyzed by HPLC and mass spectrometry. MidD has a molecular mass of ~45 kDa and its catalytic activity was found to be optimal at 37 °C and pH 8.5. The major product formed in the reaction had the same retention time as that of synthetic 3-hydroxy-4-pyridone (3H4P). It was confirmed to be 3H4P by MS/MS analysis of the HPLC-purified product. The K m, V max and K cat of MidD were 1.27 × 10(-4) mol, 4.96 × 10(-5) mol s(-1) mg(-1), and 2,256.05 s(-1), respectively. Although MidD has sequence similarities with aminotransferases, it is not an aminotransferase because it does not require a keto acid as the co-substrate in the degradation reaction. It is a pyridoxal-5'-phosphate (PLP)-dependent enzyme and the addition of 50 ?M hydroxylamine completely inhibited the reaction. However, the supplementation of the reaction with 0.1 ?M PLP restored the catalytic activity of MidD in the reaction containing 50 ?M hydroxylamine. The catalytic activity of MidD was found to be specific to mimosine, and the presence of its structural analogs including L-tyrosine, L-tryptophan and L-phenylalanine did not show any competitive inhibition. In addition to 3H4P, we also identified pyruvate and ammonia as other degradation products in equimolar quantities of the substrate used. The degradation of mimosine into a ring compound, 3H4P with the release of ammonia indicates that MidD of Rhizobium sp. strain TAL1145 is a C-N lyase. PMID:23462928

Negi, Vishal Singh; Bingham, Jon-Paul; Li, Qing X; Borthakur, Dulal

2013-03-06

172

Reproductive Capacities and Development of a Seed Bruchid Beetle, Acanthoscelides macrophthalmus, a Potential Host for the Mass Rearing of the Parasitoid, Dinarmus basalis  

PubMed Central

The reproductive capacities and development of the seed beetle Acanthoscelides macrophthalmus (Schaeffer) (Coleoptera: Bruchidae), found in Togo, were determined under natural conditions in a Guinean zone for its use as a substitute host for the mass rearing of the parasitoid Dinarmus basalts Rond (Hymenoptera: Pteromalidae), a biological agent for the control of beetles that are pests of cowpea, Vigna unguiculata (L.) Walpers (Fabales: Fabaceae). Population dynamics at the field level; and survival, fecundity and offspring production by A. macrophthalmus under laboratory conditions were measured when fed on its natural plant-host Leucaena leucocephala (Lamark) deWit (Fabales: Mimosaceae). The data resulting from the laboratory study were used to calculate the demographic parameters of A. macrophthalmus by establishing its fertility and life tables. Contrary to cultivated leguminous food plants, L. leucocephala is a perennial sub-spontaneous leguminous plant whose pods are available year round. Although A. macrophthalmus was present in nature throughout the year, its infestation rate of the pods fluctuated according to the phenology of the plant. The maximum infestation of L. leucocephala pods was observed between August and December. Four larval stages and one pupal stage of A. macrophthalmus were identified in the laboratory. The total mean development time varied on average 33.75 ± 2.87 days on the mature pods and 33.39 ± 2.02 days on seeds. The adult female lived from one to two weeks. During its life time, the female laid an average of 62.3 ± 19 and 43.1 ± 13 eggs on the mature pods and seeds respectively and produced an average of 36.7 ± 11.3 offspring on the mature pods and 21.8 ± 8.4 offspring on seeds. On seeds, the net reproduction rate was 5.88 females per female and the intrinsic rate of population increase 0.051 per day. The generation time was 34.59 days and the doubling time 13.59 days. The demographic parameters of A. macrophthalmus in this study are close to those of Callobruchus maculatus F. (Bruchidae), the natural host of D. basalts in a previous study. A. macrophthalmus could therefore be used as substitute host for the mass rearing of D. basalts and subsequently its release in farmers' storage containers. The data presented in this study provide some baseline information regarding the reproductive capacities of A. macrophthalmus that may be useful for its promotion as a substitute host for mass rearing of D. basalts.

TQ, Effowe; K, Amevoin; Y, Nuto; D, Mondedji; IA, Glitho

2010-01-01

173

Reproductive capacities and development of a seed Bruchid beetle, Acanthoscelides macrophthalmus, a potential host for the mass rearing of the parasitoid, Dinarmus basalis.  

PubMed

The reproductive capacities and development of the seed beetle Acanthoscelides macrophthalmus (Schaeffer) (Coleoptera: Bruchidae), found in Togo, were determined under natural conditions in a Guinean zone for its use as a substitute host for the mass rearing of the parasitoid Dinarmus basalts Rond (Hymenoptera: Pteromalidae), a biological agent for the control of beetles that are pests of cowpea, Vigna unguiculata (L.) Walpers (Fabales: Fabaceae). Population dynamics at the field level; and survival, fecundity and offspring production by A. macrophthalmus under laboratory conditions were measured when fed on its natural plant-host Leucaena leucocephala (Lamark) deWit (Fabales: Mimosaceae). The data resulting from the laboratory study were used to calculate the demographic parameters of A. macrophthalmus by establishing its fertility and life tables. Contrary to cultivated leguminous food plants, L. leucocephala is a perennial sub-spontaneous leguminous plant whose pods are available year round. Although A. macrophthalmus was present in nature throughout the year, its infestation rate of the pods fluctuated according to the phenology of the plant. The maximum infestation of L. leucocephala pods was observed between August and December. Four larval stages and one pupal stage of A. macrophthalmus were identified in the laboratory. The total mean development time varied on average 33.75 ± 2.87 days on the mature pods and 33.39 ± 2.02 days on seeds. The adult female lived from one to two weeks. During its life time, the female laid an average of 62.3 ± 19 and 43.1 ± 13 eggs on the mature pods and seeds respectively and produced an average of 36.7 ± 11.3 offspring on the mature pods and 21.8 ± 8.4 offspring on seeds. On seeds, the net reproduction rate was 5.88 females per female and the intrinsic rate of population increase 0.051 per day. The generation time was 34.59 days and the doubling time 13.59 days. The demographic parameters of A. macrophthalmus in this study are close to those of Callobruchus maculatus F. (Bruchidae), the natural host of D. basalts in a previous study. A. macrophthalmus could therefore be used as substitute host for the mass rearing of D. basalts and subsequently its release in farmers' storage containers. The data presented in this study provide some baseline information regarding the reproductive capacities of A. macrophthalmus that may be useful for its promotion as a substitute host for mass rearing of D. basalts. PMID:20879923

Effowe, T Q; Amevoin, K; Nuto, Y; Mondedji, D; Glitho, I A

2010-01-01

174

The effect of protein supplement source or supply pattern on the intake, digestibility, rumen kinetics, nitrogen utilisation and growth of Ethiopian Menz sheep fed teff straw  

Microsoft Academic Search

A series of trials were conducted to study the effect of either nitrogen source or supply pattern on the growth, rumen fermentation pattern and utilisation of straw by Ethiopian Menz sheep. All experimental sheep were given teff straw basal diet (CON). Irrespective of the trial, treatment sheep were offered either cottonseed cake (CSC), leucaena (LEU) and sesbania (SESM) in the

M. L. K. Bonsi; A. K. Tuah; P. O. Osuji; V. I. Nsahlai; N. N. Umunna

1996-01-01

175

Effect of supplementation of maize stover with foliage of various tropical multipurpose trees and Lablab purpureus on intake, rumen fermentation, digesta kinetics and microbial protein supply of sheep  

Microsoft Academic Search

Foliage of four multipurpose trees (Calliandra calothyrsus, Chamaecytisus palmensis, Leucaena diversifolia and Vernonia amygdalina) and a woody leguminous perennial (Lablab purpureus) were evaluated for their potential as protein supplements for sheep fed maize stover ad libitum. The chemical composition of the feed was analysed, and maize stover degradation, rumen kinetics, passage rate were measured and enumeration of microbial population in

I. K Hindrichsen; P. O Osuji; A. A Odenyo; J Madsen; T Hvelplund

2004-01-01

176

Re-marriage of crops and trees  

SciTech Connect

Agroforestry is defined and its role in the productive use and conservation of marginal or forested lands explained. Examples are given of existing agroforestry and silvo-pastural systems involving plantation crops (coffee, tea, cacao, rubber) and multipurpose species (Leucaena leucocephale, Casuarina, Almis, Parasponia, Acacia, Prosopis). The origin and activities of ICRAF are outlined.

Nair, P.K.R.

1983-01-01

177

Growth analysis of nine multipurpose woody legumes native from southern Mexico  

Microsoft Academic Search

The growth of nine multipurpose woody legumes was evaluated in nursery conditions. These species, belonging to the genera Acacia, Leucaena, Lysiloma, Prosopis and Pithecellobium, inhabit both primary and secondary tropical deciduous and thorn forests. The total length of the experiments was 165 days. At a variable frequency, the following four variables were measured: (1) relative growth rate (RGR), (2) root\\/shoot

Virginia Cervantes; Vicente Arriaga; Jorge Meave; Julia Carabias

1998-01-01

178

Temporal Resource Switching by Ants between Honeydew Produced by the Fivespotted Gama Grass Leafhopper (Dalbulus quinquenotatus) and Nectar Produced by Plants with Extrafloral Nectaries  

Microsoft Academic Search

A field study was conducted in Jalisco, Mexico, to quantify temporal resource switching by ants between honeydew produced by the fivespotted gama grass leafhopper, Dalbulus quinquenotatus, and nectar produced by plants with extrafloral nectaries (EFNs). Four plant taxa (Acacia pennatula, Leucaena esculenta, Lobelia laxiflora and Lysilona sp.) which produced nectar from EFNs were monitored for ants during the dry and

GUSTAVO MOYA-RAYGOZA; KIRK J. LARSEN

2001-01-01

179

In vitro and in situ evaluation of selected multipurpose trees, wheat bran and Lablab purpureus as potential feed supplements to tef ( Eragrostis tef) straw  

Microsoft Academic Search

In vitro and in situ evaluations of feed samples were carried out at Debre Zeit Research Station (Ethiopia) of the International Livestock Research Institute. The feed samples consisted of tef straw, wheat bran, dried Lablab purpureus, and dried foliage of the multipurpose trees (MPT), namely Sesbania sesban 1198, Sesbania sesban 15019, Acacia angustissima 15132, Leucaena pallida 14203, and mixtures of

Solomon Melaku; Kurt J Peters; Azage Tegegne

2003-01-01

180

Systematic analysis of in vitro photo-cytotoxic activity in extracts from terrestrial plants in Peninsula Malaysia for photodynamic therapy.  

PubMed

One hundred and fifty-five extracts from 93 terrestrial species of plants in Peninsula Malaysia were screened for in vitro photo-cytotoxic activity by means of a cell viability test using a human leukaemia cell-line HL60. These plants which can be classified into 43 plant families are diverse in their type of vegetation and their natural habitat in the wild, and may therefore harbour equally diverse metabolites with potential pharmaceutical properties. Of these, 29 plants, namely three from each of the Clusiaceae, Leguminosae, Rutaceae and Verbenaceae families, two from the Piperaceae family and the remaining 15 are from Acanthaceae, Apocynaceae, Bignoniaceae, Celastraceae, Chrysobalanaceae, Irvingiaceae, Lauraceae, Lythraceae, Malvaceae, Meliaceae, Moraceae, Myristicaceae, Myrsinaceae, Olacaceae and Sapindaceae. Hibiscus cannabinus (Malvaceae), Ficus deltoidea (Moraceae), Maranthes corymbosa (Chrysobalanaceae), Micromelum sp., Micromelum minutum and Citrus hystrix (Rutaceae), Cryptocarya griffithiana (Lauraceae), Litchi chinensis (Sapindaceae), Scorodocarpus bornensis (Olacaceae), Kokoona reflexa (Celastraceae), Irvingia malayana (Irvingiaceae), Knema curtisii (Myristicaceae), Dysoxylum sericeum (Meliaceae), Garcinia atroviridis, Garcinia mangostana and Calophyllum inophyllum (Clusiaceae), Ervatamia hirta (Apocynaceae), Cassia alata, Entada phaseoloides and Leucaena leucocephala (Leguminosae), Oroxylum indicum (Bignoniaceae), Peronema canescens,Vitex pubescens and Premna odorata (Verbenaceae), Piper mucronatum and Piper sp. (Piperaceae), Ardisia crenata (Myrsinaceae), Lawsonia inermis (Lythraceae), Strobilanthes sp. (Acanthaceae) were able to reduce the in vitro cell viability by more than 50% when exposed to 9.6J/cm(2) of a broad spectrum light when tested at a concentration of 20 microg/mL. Six of these active extracts were further fractionated and bio-assayed to yield four photosensitisers, all of which are based on the pheophorbide-a and -b core structures. Our results suggest that the main photosensitisers from terrestrial plants are likely based on the cyclic tetrapyrrole structure and photosensitisers with other structures, if present, are present in minor amounts or are not as active as those with the cyclic tetrapyrrole structure. PMID:19647445

Ong, Cheng Yi; Ling, Sui Kiong; Ali, Rasadah Mat; Chee, Chin Fei; Samah, Zainon Abu; Ho, Anthony Siong Hock; Teo, Soo Hwang; Lee, Hong Boon

2009-07-01

181

NolL of Rhizobium sp. Strain NGR234 Is Required for O-Acetyltransferase Activity  

PubMed Central

Following (iso)flavonoid induction, nodulation genes of the symbiotic nitrogen-fixing bacterium Rhizobium sp. strain NGR234 elaborate a large family of lipooligosaccharidic Nod factors (NodNGR factors). When secreted into the rhizosphere of compatible legumes, these signal molecules initiate root hair deformation and nodule development. The nonreducing glucosamine residue of NodNGR factors are N acylated, N methylated, and mono- or biscarbamoylated, while position C-6 of the reducing extremity is fucosylated. This fucose residue is normally 2-O methylated and either sulfated or acetylated. Here we present an analysis of all acetylated NodNGR factors, which clearly shows that the acetate group may occupy position C-3 or C-4 of the fucose moiety. Disruption of the flavonoid-inducible nolL gene, which is preceded by a nod box, results in the synthesis of NodNGR factors that lack the 3-O- or 4-O-acetate groups. Interestingly, the nodulation capacity of the mutant NGR?nolL is not impaired, whereas introduction of the nod box::nolL construct into the related strain Rhizobium fredii USDA257 extends the host range of this bacterium to Calopogonium caeruleum, Leucaena leucocephala, and Lotus halophilus. Nod factors produced by a USDA257(pnolL) transconjugant were also acetylated. The nod box::nolL construct was also introduced into ANU265 (NGR234 cured of its symbiotic plasmid), along with extra copies of the nodD1 gene. When permeabilized, these cells possessed acetyltransferase activity, although crude extracts did not.

Berck, S.; Perret, X.; Quesada-Vincens, D.; Prome, J.-C.; Broughton, W. J.; Jabbouri, S.

1999-01-01

182

Induction of pathogenic-like responses in the legume Macroptilium atropurpureum by a transposon-induced mutant of the fast-growing, broad-host-range Rhizobium strain NGR234.  

PubMed

Mutant strain ANU2861, a transposon Tn5 mutant of the fast-growing, broad-host-range Rhizobium strain ANU280 (NGR234 Smr Rfr) overproduces polysaccharide, is an ade auxotroph, and induces poorly developed nodules on Leucaena leucocephala and Lablab purpureus (H.C. Chen, M. Batley, J.W. Redmond, and B.G. Rolfe, J. Plant Physiol. 120:331-349, 1985). Strain ANU2861 cannot form nodules on Macroptilium atropurpureum Urb. (siratro) or on Desmodium intortum and D. uncinatum and the nonlegume Parasponia. The parent strain, ANU280, effectively nodulates all these legume species except Parasponia, on which it forms ineffective nodules. Ultrastructural examination of infection sites on the legume siratro showed that mutant strain ANU2861 caused root hair curling (Hac+ phenotype), some cortical cell division (Noi+), but no infection threads (Inf-). Localized cellular responses, known to occur in phytopathological interactions, were observed in electron micrographs of the epidermal tissue at or near the infection zone after inoculation with strain ANU2861 but not the wild-type parental strain. These include (i) the rapid (within 20 h) accumulation of osmiophilic droplets attached to membranes at potential sites of strain ANU2861 penetration and (after 48 h) in the epidermal cells in the immediate region of the curled root hairs, and (ii) localized cell death of the epidermal cells. In addition, strain ANU2861 can initiate a systemic response in split-root siratro plants which prevents the successful nodulation of strain ANU280. A 6.3-kilobase fragment of wild-type genomic DNA, which includes the site of Tn5 insertion in strain ANU2861, was cloned and introduced to strain ANU2861. All the phenotypic defects of the mutant strain were corrected by the introduction of this DNA fragment. This indicates that the original Tn5 insertion is responsible for the phenotype. PMID:2832384

Djordjevic, S P; Ridge, R W; Chen, H C; Redmond, J W; Batley, M; Rolfe, B G

1988-04-01

183

Induction of pathogenic-like responses in the legume Macroptilium atropurpureum by a transposon-induced mutant of the fast-growing, broad-host-range Rhizobium strain NGR234.  

PubMed Central

Mutant strain ANU2861, a transposon Tn5 mutant of the fast-growing, broad-host-range Rhizobium strain ANU280 (NGR234 Smr Rfr) overproduces polysaccharide, is an ade auxotroph, and induces poorly developed nodules on Leucaena leucocephala and Lablab purpureus (H.C. Chen, M. Batley, J.W. Redmond, and B.G. Rolfe, J. Plant Physiol. 120:331-349, 1985). Strain ANU2861 cannot form nodules on Macroptilium atropurpureum Urb. (siratro) or on Desmodium intortum and D. uncinatum and the nonlegume Parasponia. The parent strain, ANU280, effectively nodulates all these legume species except Parasponia, on which it forms ineffective nodules. Ultrastructural examination of infection sites on the legume siratro showed that mutant strain ANU2861 caused root hair curling (Hac+ phenotype), some cortical cell division (Noi+), but no infection threads (Inf-). Localized cellular responses, known to occur in phytopathological interactions, were observed in electron micrographs of the epidermal tissue at or near the infection zone after inoculation with strain ANU2861 but not the wild-type parental strain. These include (i) the rapid (within 20 h) accumulation of osmiophilic droplets attached to membranes at potential sites of strain ANU2861 penetration and (after 48 h) in the epidermal cells in the immediate region of the curled root hairs, and (ii) localized cell death of the epidermal cells. In addition, strain ANU2861 can initiate a systemic response in split-root siratro plants which prevents the successful nodulation of strain ANU280. A 6.3-kilobase fragment of wild-type genomic DNA, which includes the site of Tn5 insertion in strain ANU2861, was cloned and introduced to strain ANU2861. All the phenotypic defects of the mutant strain were corrected by the introduction of this DNA fragment. This indicates that the original Tn5 insertion is responsible for the phenotype. Images

Djordjevic, S P; Ridge, R W; Chen, H C; Redmond, J W; Batley, M; Rolfe, B G

1988-01-01

184

Allelopathic potential of Macaranga tanarius (L.) muell.-arg.  

PubMed

Macaranga tanarius is widely distributed in the abandoned lowlands of Taiwan where substantial amounts of leaves accumulate on the ground. A unique pattern of weed exclusion underneath trees is often found and thought to result from allelopathic interactions. Density-dependent phytotoxicity analysis of Lactuca sativa L. (lettuce) growing in soil mixed with the powder of M. tanarius leaves showed a significant deviation from the expected yield-density relationship. Lettuce growth was most suppressed in the low seed density experiment suggesting that the phytotoxins produced during leaf decomposition inhibit the growth of lettuce seedlings. Bidens pilosa and Leucaena leucocephala, growing in soil mixed with the leaf powder of M. tanarius were also suppressed. Aqueous leaf extracts were bioassayed against lettuce and B. pilosa, and exhibited a significant suppression in radicle growth. Compounds identified from leaves included nymphaeol-A (1), nymphaeol-B (2), nymphaeol-C (3), quercetin (4), abscisic acid (ABA) (5), blumenol A (6), blumenol B (7), roseoside II (8), tanariflavanone A (9), and tanariflavanone B (10), ABA was the major growth inhibitor. At concentrations of 20 ppm, ABA suppressed lettuce germination, while at 120 ppm it inhibited the growth of Miscanthus floridulus, Chloris barbata, and Bidens pilosa. At 600 ppm, quercetin, blumenol A, and blumenol B, caused 20-25% inhibition of radicle and shoot growth of M. floridulus. The amount of ABA in M. tanarius leaves was approximately 3-5 microg g(-1) dry weight, significantly higher than previously reported. We conclude that the pattern of weed exclusion underneath stands of M. tanarius and its invasion into its adjacent grassland vegetation results from allelopathic interactions. PMID:12857035

Tseng, Mei-Huims; Kuo, Yueh-Hsiung; Chen, Yih-Ming; Chou, Chang-Hung

2003-05-01

185

Changes in soil quality indicators under long-term sewage irrigation in a sub-tropical environment  

NASA Astrophysics Data System (ADS)

Though irrigation with sewage water has potential benefits of meeting the water requirements, the sewage irrigation may mess up to harm the soil health. To assess the potential impacts of long-term sewage irrigation on soil health and to identify sensitive soil indicators, soil samples were collected from crop fields that have been irrigated with sewage water for more than 20 years. An adjacent rain-fed Leucaena leucocephala plantation system was used as a reference to compare the impact of sewage irrigation on soil qualities. Soils were analyzed for different physical, chemical, biological and biochemical parameters. Results have shown that use of sewage for irrigation improved the clay content to 18-22.7%, organic carbon to 0.51-0.86% and fertility status of soils. Build up in total N was up to 2,713 kg ha-1, available N (397 kg ha-1), available P (128 kg ha-1), available K (524 kg ha-1) and available S (65.5 kg ha-1) in the surface (0.15 m) soil. Long-term sewage irrigation has also resulted a significant build-up of DTPA extractable Zn (314%), Cu (102%), Fe (715%), Mn (197.2), Cd (203%), Ni (1358%) and Pb (15.2%) when compared with the adjacent rain-fed reference soil. Soils irrigated with sewage exhibited a significant decrease in microbial biomass carbon (-78.2%), soil respiration (-82.3%), phosphatase activity (-59.12%) and dehydrogenase activity (-59.4%). An attempt was also made to identify the sensitive soil indicators under sewage irrigation, where microbial biomass carbon was singled out as the most sensitive indicator.

Masto, Reginald Ebhin; Chhonkar, Pramod K.; Singh, Dhyan; Patra, Ashok K.

2009-01-01

186

The alternative sigma factor RpoH2 is required for salt tolerance in Sinorhizobium sp. strain BL3.  

PubMed

The objectives of this investigation were to isolate the rpoH2 gene encoding an alternative sigma factor from Sinorhizobium sp. BL3 and to determine its role in exopolysaccharide (EPS) synthesis, salt tolerance and symbiosis with Phaseolus lathyroides. The rpoH2 gene of Rhizobium sp. strain TAL1145 is known to be required for EPS synthesis and effective nodulation of Leucaena leucocephala. Three overlapping cosmid clones containing the rpoH2 gene of BL3 were isolated by complementing an rpoH2 mutant of TAL1145 for EPS production. From one of these cosmids, rpoH2 of BL3 was identified within a 3.0-kb fragment by subcloning and sequencing. The cloned rpoH2 gene of BL3 restored both EPS production and nodulation defects of the TAL1145 rpoH2 mutants. Three rpoH2 mutants of BL3 were constructed by transposon-insertion mutagenesis. These mutants of BL3 grew normally in complete or minimal medium and were not defective in EPS synthesis, nodulation and nitrogen fixation, but they failed to grow in salt stress conditions. The mutants complemented with cloned rpoH2 from either BL3 or TAL1145 showed higher levels of salt tolerance than BL3. The expression of rpoH2 in BL3 started increasing during the exponential phase and reached the highest level in the mid-stationary phase. These results indicate that RpoH2 is required for salt tolerance in Sinorhizobium sp. BL3, and it may have additional roles during the stationary phase. PMID:16934437

Tittabutr, Panlada; Payakapong, Waraporn; Teaumroong, Neung; Boonkerd, Nantakorn; Singleton, Paul W; Borthakur, Dulal

2006-08-02

187

Isolation and Characterization of Alfalfa-Nodulating Rhizobia Present in Acidic Soils of Central Argentina and Uruguay  

PubMed Central

We describe the isolation and characterization of alfalfa-nodulating rhizobia from acid soils of different locations in Central Argentina and Uruguay. A collection of 465 isolates was assembled, and the rhizobia were characterized for acid tolerance. Growth tests revealed the existence of 15 acid-tolerant (AT) isolates which were able to grow at pH 5.0 and formed nodules in alfalfa with a low rate of nitrogen fixation. Analysis of those isolates, including partial sequencing of the genes encoding 16S rRNA and genomic PCR-fingerprinting with MBOREP1 and BOXC1 primers, demonstrated that the new isolates share a genetic background closely related to that of the previously reported Rhizobium sp. Or191 recovered from an acid soil in Oregon (B. D. Eardly, J. P. Young, and R. K. Selander, Appl. Environ. Microbiol. 58:1809–1815, 1992). Growth curves, melanin production, temperature tolerance, and megaplasmid profiles of the AT isolates were all coincident with these characteristics in strain Or191. In addition to the ability of all of these strains to nodulate alfalfa (Medicago sativa) inefficiently, the AT isolates also nodulated the common bean and Leucaena leucocephala, showing an extended host range for nodulation of legumes. In alfalfa, the time course of nodule formation by the AT isolate LPU 83 showed a continued nodulation restricted to the emerging secondary roots, which was probably related to the low rate of nitrogen fixation by the largely ineffective nodules. Results demonstrate the complexity of the rhizobial populations present in the acidic soils represented by a main group of N2-fixing rhizobia and a second group of ineffective and less-predominant isolates related to the AT strain Or191.

del Papa, Maria F.; Balague, Laura J.; Sowinski, Susana Castro; Wegener, Caren; Segundo, Eduardo; Abarca, Francisco Martinez; Toro, Nicolas; Niehaus, Karsten; Puhler, Alfred; Aguilar, O. Mario; Martinez-Drets, Gloria; Lagares, Antonio

1999-01-01

188

Galactomannan thin films as supports for the immobilization of Concanavalin A and/or dengue viruses.  

PubMed

The immobilization of the glucose/mannose-binding lectin from Concanavalia ensiformis seeds (ConA) onto a monolayer made of a galactomannan extracted from Leucaena leucocephala seeds (GML), which was adsorbed onto - amino-terminated surfaces, was investigated by means of ellipsometry and atomic force microscopy. The mean thickness of GML monolayer, which polysaccharide consists of linear 1?4-linked ?-D-mannopyranosil units partially substituted at C-6 by ?-D-galactopyranosyl units, amounted to (1.5±0.2) nm. ConA molecules adsorbed onto GML surfaces forming (2.0±0.5) nm thick layers. However, in the presence of mannose the adsorption failed, indicating that ConA binding sites were blocked by mannose and were no longer available for mannose units present in the GML backbone. The GML film was also used as support for the adsorption of three serotypes of dengue virus particles (DENV-1, DENV-2 and DENV-3), where DENV-2 formed the thickest film (4±2) nm. The adsorbed layer of DENV-2 onto ConA-covered GML surfaces presented mean thickness values similar to that determined for DENV-2 onto bare GML surfaces. The addition of free mannose units prevented DENV-2 adsorption onto ConA-covered GML films by ~50%, suggesting competition between virus and mannose for ConA binding sites. This finding suggests that if ConA is also adsorbed to GML surface and its binding site is blocked by free mannose, virus particles are able to recognized GML mannose unities substituted by galactose. Interactions between polysaccharides thin films, proteins, and viruses are of great relevance since they can provide basis for the development of biotechnological devices. These results indicate that GML is a potential polysaccharide for biomaterials development, as those could involve interactions between ConA in immune system and viruses. PMID:22020153

Valenga, Francine; Petri, Denise F S; Lucyszyn, Neoli; Jó, Tatiane A; Sierakowski, Maria Rita

2011-10-15

189

Gut microbiology - broad genetic diversity, yet specific metabolic niches.  

PubMed

Analysis of 16S ribosomal RNA (rRNA)-encoding gene sequences from gut microbial ecosystems reveals bewildering genetic diversity. Some metabolic functions, such as glucose utilisation, are fairly widespread throughout the genetic spectrum. Others, however, are not. Despite so many phylotypes being present, single species or perhaps only two or three species often carry out key functions. Among ruminal bacteria, only three species can break down highly structured cellulose, despite the prevalence and importance of cellulose in ruminant diets, and one of those species, Fibrobacter succinogenes, is distantly related to the most abundant ruminal species. Fatty acid biohydrogenation in the rumen, particularly the final step of biohydrogenation of C18 fatty acids, stearate formation, is achieved only by a small sub-group of bacteria related to Butyrivibrio fibrisolvens. Individuals who lack Oxalobacter formigenes fail to metabolise oxalate and suffer kidney stones composed of calcium oxalate. Perhaps the most celebrated example of the difference a single species can make is the 'mimosine story' in ruminants. Mimosine is a toxic amino acid found in the leguminous plant, Leucaena leucocephala. Mimosine can cause thyroid problems by being converted to the goitrogen, 3-hydroxy-4(1H)-pyridone, in the rumen. Observations that mimosine-containing plants were toxic to ruminants in some countries but not others led to the discovery of Synergistes jonesii, which metabolises 3-hydroxy-4(1H)-pyridone and protects animals from toxicity. Thus, despite the complexities indicated by molecular microbial ecology and genomics, it should never be forgotten that gut communities contain important metabolic niches inhabited by species with highly specific metabolic capability. PMID:22443591

John Wallace, R

2008-05-01

190

Comparison of the formation of nicotinic acid conjugates in leaves of different plant species.  

PubMed

There are three metabolic fates of nicotinic acid in plants: (1) nicotinic acid mononucleotide formation for NAD synthesis by the so-called salvage pathway of pyridine nucleotide biosynthesis; (2) nicotinic acid N-glucoside formation; and (3) trigonelline (N-methylnicotinic acid) formation. In the present study, the metabolism of [carbonyl-(14)C]nicotinamide was investigated in leaves of 23 wild plant species. All species readily converted nicotinamide to nicotinic acid, and only a fraction of nicotinic acid was utilised for NAD and NADP synthesis. The remaining nicotinic acid is converted to the nicotinic acid conjugates. Only one plant species, Cycas revoluta, produced both nicotinic acid N-glucoside and trigonelline; the other 22 species produced one or other of the conjugates. The nicotinic acid N-glucoside-forming plants are Cyathea lepifera, Arenga trewmula var. englri, Barringtonia racemosa, Ilex paraguariensis, Angelica japonica, Scaevola taccada and Farfugium japonicum. In contrast, trigonelline is formed in C. lepifera, Ginkgo biloba, Pinus luchuensis, Casuarina equisetifolia, Alocasia odora, Pandanus odoratissimus, Hylocereus undatus, Kalanchoe pinnata, Kalanchoe tubiflora, Populus alba, Garcinia subelliptica, Oxalis corymbosa, Leucaena leucocephala, Vigna marina, Hibiscus tiliaceus and Melicope triphylla. The diversity of nicotinic acid conjugate formation in plants is discussed using these results and our previous investigation involving a few model plants, various crops and ferns. Nicotinic acid N-glucoside formation was restricted mostly to ferns and selected orders of angiosperms, whereas other plants produce trigonelline. In most cases the formation of both nicotinic acid conjugates is incompatible, but some exceptions have been found. PMID:22983143

Ashihara, Hiroshi; Yin, Yuling; Katahira, Riko; Watanabe, Shin; Mimura, Tetsuro; Sasamoto, Hamako

2012-08-29

191

Thermal efficiency and particulate pollution estimation of four biomass fuels grown on wasteland  

SciTech Connect

The thermal performance and concentration of suspended particulate matter were studied for 1-hour combustion of four biomass fuels, namely Acacia nilotica, Leucaena leucocepholea, Jatropha curcus, and Morus alba grown in wasteland. Among the four biomass fuels, the highest thermal efficiency was achieved with Acacia nilotica. The suspended particulate matter concentration for 1-hour combustion of four biomass fuels ranged between 850 and 2,360 {micro}g/m{sup 3}.

Kandpal, J.B.; Madan, M. [Indian Inst. of Tech., New Delhi (India). Centre for Rural Development and Technology

1996-10-01

192

Nutritional Evaluation of non Forage High Fibrous Tropical Feeds for Ruminant Using in vitro Gas Production Technique  

Microsoft Academic Search

Six non forage high fibrous tropical feedstuffs were used to evaluate their nutritive value using an in vitro gas production technique. The rumen mixed microbe inoculums were taken from 2 fistulated Brahman-Thai native crossbred steers. The treatments were 1) palm meal (mech-extd), 2) palm meal (solv-extd), 3) leucaena meal (leaf and stem), 4) coconut meal (mech-extd), 5) mung bean meal

2005-01-01

193

Mimosine Mitigates Oxidative Stress in Selenium Deficient Seedlings of Vigna radiata Part I: Restoration of Mitochondrial Function  

Microsoft Academic Search

Mimosine, a non-protein plant amino acid found in Mimosa pudica and certain species of Leucaena, was beneficial for the growth of seedlings of Vigna radiata germinated under selenium-deficient stressed condition (?Se stressed) despite the recognized toxicity of the allelochemical.\\u000a Exposure of mimosine at 0.1 mM (Mim-0.1) promoted the growth of the seedlings and significantly enhanced mitochondrial functional\\u000a efficiency. Growth-related parameters including

K. Lalitha; S. Rajendra Kulothungan

2007-01-01

194

Biological nitrogen fixation to maximize productivity of intercropped legumes and non?legumes: Ten years of field experimentations in semi?arid deserts of egypt  

Microsoft Academic Search

A number of field trials was executed in semi?arid deserts of Ismailia, Egypt, to experiment growth and productivity of sole or mixed canopies of legumes (soybean, leucaena, sesbania, berseem and grasspea) and non?legumes (corn, Rhodes grass, elephant grass, ryegrass and barley) when inoculated with N2?fixing bacteria (diazotrophs) in presence or absence of N fertilizers. An average estimate of > 20

N. A. Hegazi; M. Fayez

2001-01-01

195

Rhizobium multihospitium sp. nov., isolated from multiple legume species native of Xinjiang, China.  

PubMed

Thirty-one rhizobial strains isolated from nodules of legumes native of Xinjiang, China, were characterized. These strains were classified as belonging to the genus Rhizobium based on amplified 16S rDNA restriction analysis (ARDRA). The strains were distinguished from recognized Rhizobium species using analysis of 16S-23S rDNA intergenic spacers (IGS-RFLP), SDS-PAGE analysis of whole proteins and BOX-PCR; the test strains always formed a distinct cluster with patterns that were quite different from those of the reference rhizobial strains used. According to the phylogenetic analysis based on the 16S rRNA gene, the test strains belonged to the genus Rhizobium, with Rhizobium tropici, Rhizobium rhizogenes and Rhizobium lusitanum as the closest related species, with 99.6, 99.2 and 99.4 % sequence similarities, respectively, between the type strains of the three Rhizobium species and strain CCBAU 83401(T). Phylogenetic analyses of the representative strains using IGS and atpD, recA and glnII genes all confirmed the phylogenetic arrangements obtained using the 16S rRNA gene. The DNA-DNA relatedness values between strain CCBAU 83401(T) and strains CCBAU 83364, CCBAU 83345 and CCBAU 83523 ranged from 80.8 to 100 %, showing that they belong to the same species. The DNA-DNA relatedness between strain CCBAU 83401(T) and R. tropici IIB CIAT 899(T), R. tropici IIA CFN 299, R. rhizogenes LMG 150(T) and R. lusitanum P1-7(T) were 26.9, 27.7, 38.2 and 22.6 %, respectively, clearly indicating that strain CCBAU 83401(T) represents a novel species. Phenotypic characterization of four representative strains, CCBAU 83401(T), CCBAU 83364, CCBAU 83345 and CCBAU 83523, showed several distinctive features that differentiated them from closely related species. The 31 strains had identical nodD and nifH genes, which were very similar to those of the bean-nodulating R. lusitanum, Devosia neptuniae and R. tropici IIB. Based upon these results, the strains from this study are considered to represent a novel species, for which the name Rhizobium multihospitium sp. nov. is proposed. The DNA G+C content ranged from 65.3 to 66.0 mol% (T(m)). The type strain is CCBAU 83401(T) (=LMG 23946(T)=HAMBI 2975(T)), which nodulates Robinia pseudoacacia, but not Leucaena leucocephala, Phaseolus vulgaris, Pisum sativum or Medicago sativa. PMID:18599718

Han, Tian Xu; Wang, En Tao; Wu, Li Juan; Chen, Wen Feng; Gu, Jin Gang; Gu, Chun Tao; Tian, Chang Fu; Chen, Wen Xin

2008-07-01

196

Exo-Oligosaccharides of Rhizobium sp. Strain NGR234 Are Required for Symbiosis with Various Legumes  

PubMed Central

Rhizobia are nitrogen-fixing bacteria that establish endosymbiotic associations with legumes. Nodule formation depends on various bacterial carbohydrates, including lipopolysaccharides, K-antigens, and exopolysaccharides (EPS). An acidic EPS from Rhizobium sp. strain NGR234 consists of glucosyl (Glc), galactosyl (Gal), glucuronosyl (GlcA), and 4,6-pyruvylated galactosyl (PvGal) residues with ?-1,3, ?-1,4, ?-1,6, ?-1,3, and ?-1,4 glycoside linkages. Here we examined the role of NGR234 genes in the synthesis of EPS. Deletions within the exoF, exoL, exoP, exoQ, and exoY genes suppressed accumulation of EPS in bacterial supernatants, a finding that was confirmed by chemical analyses. The data suggest that the repeating subunits of EPS are assembled by an ExoQ/ExoP/ExoF-dependent mechanism, which is related to the Wzy polymerization system of group 1 capsular polysaccharides in Escherichia coli. Mutation of exoK (NGR?exoK), which encodes a putative glycanase, resulted in the absence of low-molecular-weight forms of EPS. Analysis of the extracellular carbohydrates revealed that NGR?exoK is unable to accumulate exo-oligosaccharides (EOSs), which are O-acetylated nonasaccharide subunits of EPS having the formula Gal(Glc)5(GlcA)2PvGal. When used as inoculants, both the exo-deficient mutants and NGR?exoK were unable to form nitrogen-fixing nodules on some hosts (e.g., Albizia lebbeck and Leucaena leucocephala), but they were able to form nitrogen-fixing nodules on other hosts (e.g., Vigna unguiculata). EOSs of the parent strain were biologically active at very low levels (yield in culture supernatants, ?50 ?g per liter). Thus, NGR234 produces symbiotically active EOSs by enzymatic degradation of EPS, using the extracellular endo-?-1,4-glycanase encoded by exoK (glycoside hydrolase family 16). We propose that the derived EOSs (and not EPS) are bacterial components that play a crucial role in nodule formation in various legumes.

Staehelin, Christian; Forsberg, Lennart S.; D'Haeze, Wim; Gao, Mu-Yun; Carlson, Russell W.; Xie, Zhi-Ping; Pellock, Brett J.; Jones, Kathryn M.; Walker, Graham C.; Streit, Wolfgang R.; Broughton, William J.

2006-01-01

197

Rhizobium lusitanum sp. nov. a bacterium that nodulates Phaseolus vulgaris.  

PubMed

The species Phaseolus vulgaris is a promiscuous legume nodulated by several species of the family Rhizobiaceae. During a study of rhizobia nodulating this legume in Portugal, we isolated several strains that nodulate P. vulgaris effectively and also Macroptilium atropurpureum and Leucaena leucocephala, but they form ineffective nodules in Medicago sativa. According to phylogenetic analysis of the 16S rRNA gene sequence, the strains from this study belong to the genus Rhizobium, with Rhizobium rhizogenes and Rhizobium tropici as the closest related species, with 99.9 and 99.2% similarity, respectively, between the type strains of these species and strain P1-7T. The nodD and nifH genes carried by strain P1-7T are phylogenetically related to those of other species nodulating Phaseolus. This strain does not carry virulence genes present in the type strain of R. rhizogenes, ATCC 11325T. Analysis of the recA and atpD genes confirms this phylogenetic arrangement, showing low similarity with respect to those of R. rhizogenes ATCC 11325T (91.9 and 94.1% similarity, respectively) and R. tropici IIB CIAT 899T (90.6% and 91.8% similarity, respectively). The intergenic spacer (ITS) of the strains from this study is phylogenetically divergent from those of R. rhizogenes ATCC 11235T and R. tropici CIAT 899T, with 85.9 and 82.8% similarity, respectively, with respect to strain P1-7T. The tRNA profile and two-primer random amplified polymorphic DNA pattern of strain P1-7T are also different from those of R. rhizogenes ATCC 11235T and R. tropici CIAT 899T. The strains isolated in this study can be also differentiated from R. rhizogenes and R. tropici by several phenotypic characteristics. The results of DNA-DNA hybridization showed means of 28 and 25% similarity between strain P1-7T and R. rhizogenes ATCC 11235T and R. tropici CIAT 899T, respectively. All these data showed that the strains isolated in this study belong to a novel species of the genus Rhizobium, for which we propose the name Rhizobium lusitanum sp. nov.; the type strain is P1-7T (=LMG 22705T=CECT 7016T). PMID:17082403

Valverde, Angel; Igual, José M; Peix, Alvaro; Cervantes, Emilio; Velázquez, Encarna

2006-11-01

198

Effect of tropical browse leaves supplementation on rumen enzymes of sheep and goats fed Dichanthium annulatum grass-based diets.  

PubMed

In a switch-over experiment, eight male animals, four each of sheep and goats of local breeds with mean body weight of 26. 8 +/- 2.0 and 30.0 +/- 2.1 kg, were fed Dichanthium annulatum (DA) grass and four browse species viz. Helictris isora, Securengia virosa, Leucaena leucocephala (LL) and Hardwickia binnata (HB) in four feeding trials to assess their supplementary effect on activity of rumen enzymes. The sheep and goats were offered DA grass with individual browse in 75:25 and 50:50 proportions, respectively, for more than 3 months during each feeding trial, and rumen liquor samples were collected twice at 0 and 4 h post feeding after 60 and 90 days of feeding. Glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and glutamate dehydrogenase (GDH) enzymes were determined in the bacteria and protozoa fractions of rumen liquor, while cellulase enzyme activity was measured in mixed rumen liquor. LL and HB had the highest and lowest contents of CP, while fibre contents were lower in early than later browse leaves. Supplementation of browse leaves significantly (P < 0.05) affect the specific activity of GDH enzyme in bacteria fraction of rumen liquor of animal species, while GDH activity was similar in protozoa fraction of rumen liquor of sheep and goats on all DA grass-browse-supplemented diets except DA-HB (42.8 units/mg protein), where activity was significantly (P < 0.05) low. Specific activities of GOT and GPT enzymes in both bacteria and protozoa fractions of rumen liquor differ significantly (P < 0.05) due to supplementation of browse leaves to DA grass. Browse leaves significantly (P < 0.05) affect the cellulase enzyme activity in animal rumen liquor, being highest on DA-LL (193.4) and lowest on DA-HB diet (144.8 microg sugar/mg protein). Goat exhibited higher activities of GOT and GPT than sheep in both bacteria and protozoa fraction of rumen liquor, while cellulase activity was similar between the animal species on the grass-browse leaves diets. Results indicate that browse leaves supplementation affect the enzyme activities of sheep and goats rumen, while the goats rumen liquor had higher activities of GOT, GPT and GDH enzyme than sheep. PMID:20352330

Singh, Sultan; Kundu, S S

2010-03-31

199

Hydropyrolysis of biomass to produce liquid hydrocarbon fuels. Report on Energy Tree Farm Workshop No. 2, Hilo, Hawaii, June 1982  

SciTech Connect

Results of the workshop show that a eucalyptus tree plantation, including a small nursery to produce the seedlings not available from the Waimea State Tree Nursery, could be established on 12,000 acres of Puna Sugar Company land. At approximately six years of age, the trees could be harvested, chipped, and burned in the renovated Puna Sugar Company's bagasse boiler to generate electricity. The cost of a bone dry ton of chips would be $37 if a real money rate of 3% is assumed, and $50 at a real money rate of 8%. Electricity could be produced at 7.7 cents per kWh assuming a 3% real money rate, and at 9.8 cents per kWh at an 8% rate. This workshop included an evaluation of soils at the selected Keeau site. Tree crop requirements were matched with soil and other environmental characteristics such as rainfall, altitude, and temperature. Leucaena Leucocephala, L. diversifolia, Eucalyptus saligna, E. grandis, and E. robusta were among the primary species considered, and based upon known environmental requirements and previous experience, E. grandis was selected. A conservative yield estimate for E. grandis at the specified site is 10 bone dry tons (20 green tons)/acre/year of total biomass. The 12,000 acre area would be planted continuously over period of six years at an annual production rate of 2000 acres per year. Spacing would be 6x6, or 1210 trees per acre, which, including a 10% seedling discard rate, would bring the total number of seedlings required to 2.7 million/year. Harvesting operations would begin in the 7th year, and three coppice crops would be harvested before replanting became necessary again. For the production of 120,000 bone dry tons (240,000 green tons) per year, four separate harvesting systems would be needed. Each would consist of 1 mobile whole tree chipper, 2 tracked feller-bunchers, 3 rubber-tired and tracked grapple skidders, 2 truck trailers, 3 chip vans, and 1 D-4 dozer. 10 figures, 31 tables.

Troy, M. (ed.)

1982-11-01

200

Mesorhizobium gobiense sp. nov. and Mesorhizobium tarimense sp. nov., isolated from wild legumes growing in desert soils of Xinjiang, China.  

PubMed

Twenty-four Mesorhizobium strains were isolated from desert soils in the Xinjiang region of China and were characterized by a polyphasic approach. These strains grouped into three clusters in IGS-RFLP, SDS-PAGE analysis of whole-cell proteins and BOX-PCR analysis, corresponding to genomic species V, VI and VII as found in a previous study. The results were supported by sequencing analyses of rrs, IGS, atpD and recA genes. Genospecies VII was most related to Mesorhizobium septentrionale, while genospecies V and VI were both most closely related to Mesorhizobium tianshanense, but were distinct from each other and from M. tianshanense. The DNA-DNA hybridization value between the representative strain CCBAU 83284 (genospecies VII) and the type strain of M. septentrionale was 90.1 %. Genospecies VII was thus defined as M. septentrionale. The DNA-DNA relatedness value for representative strains of genospecies V or VI with the related reference strains of recognized species were always lower than 60 %. Low values of DNA-DNA hybridization (32.79 %) between representative strains of genospecies V (CCBAU 83330(T)) and of VI (CCBAU 83306(T)) were also observed. Based upon these results, two novel species are proposed: Mesorhizobium gobiense sp. nov. represented by genospecies V (type strain, CCBAU 83330(T)=LMG 23949(T)=HAMBI 2974(T)) and Mesorhizobium tarimense sp. nov. represented by genospecies VI (type strain, CCBAU 83306(T)=LMG 24338(T)=HAMBI 2973(T)). Strain CCBAU 83278 grouped as the most peripheral member with genospecies VI in SDS-PAGE of whole-cell proteins and BOX-PCR analysis and in the phylogenetic tree of 16S-23S rRNA intergenic spacer (IGS) sequences. The results of analyses of rrs, atpD and recA gene sequences, as well as those of DNA-DNA hybridization studies, strongly supported the suggestion that this strain belonged to a species quite different from genospecies V and VI and from any other recognized species of the genus Mesorhizobium. As only one strain has been isolated to date, strain CCBAU 83278 was not proposed as a novel species in this study. Mesorhizobium gobiense sp. nov. and Mesorhizobium tarimense sp. nov. could be differentiated from each other as well as from recognized species of the genus Mesorhizobium on the basis of phenotypic characteristics. The symbiotic loci (nodC and nifH) of the two novel species formed two phylogenetic branches related to Mesorhizobium loti and M. tianshanense. The type strains of the two novel species were able to nodulate Glycyrrhiza uralensis, Lotus corniculatus, Oxytropis glabra and Robinia pseudoacacia but not Astragalus membranaceus, Leucaena leucocephala, Phaseolus vulgaris, Pisum sativum or Medicago sativa. PMID:18984702

Han, Tian Xu; Han, Li Li; Wu, Li Juan; Chen, Wen Feng; Sui, Xin Hua; Gu, Jin Gang; Wang, En Tao; Chen, Wen Xin

2008-11-01

201

Influence of the Size of Indigenous Rhizobial Populations on Establishment and Symbiotic Performance of Introduced Rhizobia on Field-Grown Legumes †  

PubMed Central

Indigenous rhizobia in soil present a competition barrier to the establishment of inoculant strains, possibly leading to inoculation failure. In this study, we used the natural diversity of rhizobial species and numbers in our fields to define, in quantitative terms, the relationship between indigenous rhizobial populations and inoculation response. Eight standardized inoculation trials were conducted at five well-characterized field sites on the island of Maui, Hawaii. Soil rhizobial populations ranged from 0 to over 3.5 × 104 g of soil-1 for the different legumes used. At each site, no less than four but as many as seven legume species were planted from among the following: soybean (Glycine max), lima bean (Phaseolus lunatus), cowpea (Vigna unguiculata), bush bean (Phaseolus vulgaris), peanut (Arachis hypogaea), Leucaena leucocephala, tinga pea (Lathyrus tingeatus), alfalfa (Medicago sativa), and clover (Trifolium repens). Each legume was (i) inoculated with an equal mixture of three effective strains of homologous rhizobia, (ii) fertilized at high rates with urea, or (iii) left uninoculated. For soybeans, a nonnodulating isoline was used in all trials as the rhizobia-negative control. Inoculation increased economic yield for 22 of the 29 (76%) legume species-site combinations. While the yield increase was greater than 100 kg ha-1 in all cases, in only 11 (38%) of the species-site combinations was the increase statistically significant (P ? 0.05). On average, inoculation increased yield by 62%. Soybean (G. max) responded to inoculation most frequently, while cowpea (V. unguiculata) failed to respond in all trials. Inoculation responses in the other legumes were site dependent. The response to inoculation and the competitive success of inoculant rhizobia were inversely related to numbers of indigenous rhizobia. As few as 50 rhizobia g of soil-1 eliminated inoculation response. When fewer than 10 indigenous rhizobia g of soil-1 were present, economic yield was significantly increased 85% of the time. Yield was significantly increased in only 6% of the observations when numbers of indigenous rhizobia were greater than 10 cells g of soil-1. A significant response to N application, significant increases in nodule parameters, and greater than 50% nodule occupancy by inoculant rhizobia did not necessarily coincide with significant inoculation responses. No less than a doubling of nodule mass and 66% nodule occupancy by inoculant rhizobia were required to significantly increase the yield of inoculated crops over that of uninoculated crops. However, lack of an inoculation response was common even when inoculum strains occupied the majority of nodules. In these trials, the symbiotic yield of crops was, on average, only 88% of the maximum yield potential, as defined by the fertilizer N treatment. The difference between the yield of N-fertilized crops and that of N2-fixing crops indicates a potential for improving inoculation technology, the N2 fixation capacity of rhizobial strains, and the efficiency of symbiosis. In this study, we show that the probability of enhancing yield with existing inoculation technology decreases dramatically with increasing numbers of indigenous rhizobia.

Thies, Janice E.; Singleton, Paul W.; Bohlool, B. Ben

1991-01-01

202

Microsatellite markers for two stifftail ducks: the white-headed duck, Oxyura leucocephala, and the ruddy duck, O. jamaicensis  

Microsoft Academic Search

Hybridization with a close relative, the North American ruddy duck (Oxyura jamaicensis), is a major problem for the conservation of the endangered white-headed duck (Oxyura leu- cocephala). We report the development of 11 microsatellite markers that can facilitate the identification of hybrids as well as the study of the population structure of both species across their distributions. These markers were

VIOLETA MUÑOZ-FUENTES; NICLAS GYLLENSTRAND; JUAN J. NEGRO; ANDY J. GREEN; CARLES VILÀ

203

Comparing the genetics of wild and captive populations of White-headed Ducks Oxyura leucocephala : consequences for recovery programmes  

Microsoft Academic Search

The White-headed Duck is a globally threatened species historically recorded from Spain in the west to China in the east. It has suffered major population declines, local extinctions and range fragmentation. Several projects have attempted to reintroduce captive-bred birds into parts of the former range in Europe, but with little success. Two captive stocks currently exist, one originating from Pakistan

VIOLETA MUÑOZ-FUENTES; ANDY J. GREEN; MICHAEL D. SORENSON

2008-01-01

204

Hawaii integrated biofuels research program, phase 1  

NASA Astrophysics Data System (ADS)

Hawaii provides a unique environment for production of biomass resources that can be converted into renewable energy products. The purpose of this work is to evaluate the potential of several biomass resources, including sugarcane, eucalyptus, and leucaena, particularly for utilization in thermochemical conversion processes to produce liquid or gaseous transportation fuels. This research program supports ongoing efforts of the Biofuels and Municipal Solid Waste Technology (BMWT) Program of the Department of Energy (DOE) and has goals that are consistent with BMWT. The Hawaii Natural Energy Institute (HNEI) work completed here consists of research activities that support two of the five renewable fuel cycles being pursued by DOE researchers. The results are directly applicable in the American territories throughout the Pacific Basin and the Caribbean, and also to many parts of the United States and worldwide. The Hawaii Integrated Biofuels Research Program is organized into the following six research tasks, which are presented as appendices in report form: Biomass Resource Assessment and System Modeling (Task 1); Bioenergy Tree Research (Task 2); Breeding, Culture, and Selection of Tropical Grasses for Increased Energy Potential (Task 3); Study of Eucalyptus Plantations for Energy Production in Hawaii (Task 4); Fundamental Solvolysis Research (Task 5); and Effects of Feedstock Composition on Pyrolysis Products (Task 6).

Takahashi, Patrick K.

1989-10-01

205

Feed inventory and smallholder farmers' perceived causes of feed shortage for dairy cattle in Gisagara District, Rwanda.  

PubMed

A survey was conducted to indentify dairy cattle feed resources and smallholder farmers' perceived causes of feed shortage in the central and southern plateaus of Gisagara District, Rwanda. Data were obtained by interviewing 120 smallholder milk producers using structured questionnaires and through direct observations made during transect walks. In all the surveyed areas, rangelands (mean rank = 1.12), crop residues (1.21), improved grasses (2.34), browse (3.23) and herbaceous (4.84) legumes were ranked as the main feed resources. Pennisetum purpureum (95% of the respondents), Leucaena diversifolia (60%) and Calliandra calothyrsus (40%) were the most cultivated fodders in all the plateaus. The dominant crop residue was Zea mays stover (65% of the farmers) in the surveyed areas. In both plateaus, land scarcity was ranked (mean rank = 1.45) as the most important cause of feed shortage followed by inadequacy of forage planting material (2.72) and lack of knowledge on forage production and utilisation (3.02). To ensure sustainable viability of smallholder dairying in densely populated highlands, screening and evaluation of high-yielding and easily propagated pastures, incorporation of forages into cropping systems, value addition of low quality roughages and training farmers on forage production and utilisation should be prioritized. PMID:22278082

Kamanzi, Moses; Mapiye, Cletos

2012-01-26

206

Novel Rhizobium lineages isolated from root nodules of the common bean (Phaseolus vulgaris L.) in Andean and Mesoamerican areas.  

PubMed

The taxonomic affiliations of nineteen root-nodule bacteria isolated from the common bean (Phaseolus vulgaris L.) in Mexico, Ecuador and Brazil were investigated by analyses of 16S rRNA and of four protein-coding housekeeping genes. One strain from Mexico could be assigned to Rhizobium etli and two from Brazil to Rhizobium leucaenae, whereas another from Mexico corresponded to a recently described bean-nodulating species-level lineage related to R. etli and Rhizobium phaseoli. Ten strains isolated in Ecuador and Mexico corresponded to three novel Rhizobium lineages that fall into the R. phaseoli/R. etli/Rhizobium leguminosarum clade. One of those lineages, with representatives isolated mostly from Ecuador, seems to be dominant in beans from that Andean region. Only one of the Mexican strains clustered within the Rhizobium tropici clade, but as an independent lineage. Interestingly, four strains were affiliated with species within the Rhizobium radiobacter clade. The existence of yet non-described native Rhizobium lineages in both the Andean and Mesoamerican areas is discussed in relation to common-bean diversity and environmental conditions. PMID:23764913

Ribeiro, Renan Augusto; Ormeño-Orrillo, Ernesto; Dall'agnol, Rebeca Fuzinatto; Graham, Peter H; Martinez-Romero, Esperanza; Hungria, Mariangela

2013-06-11

207

Using heronry birds to monitor urbanization impacts: a case study of painted stork Mycteria leucocephala nesting in the Delhi Zoo, India.  

PubMed

Although urbanization is a frequently cited cause of biodiversity loss (Czech and Krausman 1997) our understanding about urban ecology is severely limited (Marzluff et al. 2001). Birds are popular bio-indicators of environmental change because they are ecologically versatile, their populations as well as select fitness parameters can be conveniently monitored, often with the voluntary involvement of local nature enthusiasts across large geographical scales, and their presence/absence in a particular area is consequential (Bibby et al. 1992; Urfi 2004). In India, while several studies have focused on changes in bird populations and distributions in natural habitats (Urfi et al. 2005), very few have actually attempted to study either the impacts of urbanization on birds or how different species have adjusted to environmental change. However, many Indian cities offer foraging and nesting habitat for birds, especially colonial waterbirds such as stork, ibis, spoonbill, heron, egret, cormorant, and spoonbill. Some notable examples in this regard are Piele Gardens in Bhavnagar city (Parasharya and Naik 1990), Karanji Tank in Mysore (Jamgaonkar et al. 1994) and the National Zoological Park (hence forth Delhi Zoo) in India's capital city New Delhi (Urfi 1997). In this article, I focus on the opportunities for meaningful ecological research offered by the wild waterbirds nesting in the Delhi Zoo premises and discuss the significance for initiating novel, long term conservation monitoring programs, involving volunteers and bird watchers, to create data bases that will be useful for understanding urbanization and climate change impacts on biodiversity. PMID:20653281

Urfi, Abdul Jamil

2010-03-01

208

Perspectives on ruminant nutrition and metabolism I. Metabolism in the rumen.  

PubMed

Advances in knowledge of ruminant nutrition and metabolism during the second half of the twentieth century have been reviewed. Part I is concerned with metabolism in the rumen: Part II discusses utilization of nutrients absorbed from the rumen and lower tract to support growth and reproduction. The time frame was prompted by the crucial advances in ruminant physiology which arose from the work of Sir Jospeh Barcroft and his colleagues at Cambridge in the 1940s and 50s, and by the brilliant studies of Robert Hungate on rumen microbiology at much the same time. In reviewing the growth of knowledge of the role of bacteria, protozoa, fungi and bacteriophages in the rumen, outstanding developments have included the identification and characterization of fungi and the recognition that the utilization of polysaccharides in the rumen is accomplished by the sequential activities of consortia of rumen microorganisms. The role of protozoa is discussed in relation to the long standing debate on whether or not the removal of protozoa (defaunation) improves the efficiency of ruminant production. In relation to nitrogen (N) metabolism, the predation of bacteria by protozoa increases protein turnover in the rumen and reduces the efficiency of microbial protein production. This may account for the beneficial effects of defaunation where dietary N intakes are low and possibly rate limiting for growth and production. Current approaches to the measurement of rates of production of short chain fatty acids (SCFA) in the rumen based on the mathematical modelling of isotope dilution data are outlined. The absorption of SCFA from the rumen and hindgut is primarily a passive permeation process. The role of microorganisms in N metabolism in the rumen has been discussed in relation to ammonia and urea interrelationships and to current inadequacies in the measurement of both protein degradation in the rumen and microbial protein synthesis. The growth of knowledge of digestion and absorption of dietary lipids has been reviewed with emphasis on the antimicrobial activity of lipids and the biohydrogenation of unsaturated fatty acids. The protection of unsaturated dietary fats from ruminal biohydrogenation is an approach to the manipulation of the fatty acid composition of meat and dairy products. Discussion of the production of toxins in the rumen and the role of microorganisms in detoxification has focused on the metabolism of oxalate, nitrate, mycotoxins, saponins and the amino acid mimosine. Mimosine occurs in the tropical shrub leucaena, which is toxic to cattle in Australia but not in Hawaii. Tolerance to leucaena stems from the presence of a bacterium found in the rumen of Hawaiian cattle, which when transferred to Australian cattle survives and confers protection from mimosine. The genetic modification of rumen microorganisms to improve their capacity to ultilize nutrients or to detoxify antinutritive factors is an attractive strategy which has been pursued with outstanding success in the case of fluoroacetate. A common rumen bacterium has been genetically modified to express the enzyme fluoroacetate dehalogenase. The modified organism has been shown to survive in the rumen at metabolically significant levels and to confer substantial protection from fluoroacetate poisoning. PMID:19094246

Annison, E F; Bryden, W L

1998-12-01

209

Selenium volatilization in vegetated agricultural drainage sediment from the San Luis Drain, Central California.  

PubMed

The presence of large amounts of Se-laden agricultural drainage sediment in the San Luis Drain, Central California, poses a serious toxic threat to wildlife in the surrounding environment. Effective management of the drainage sediment becomes a practical challenge because the sediment is polluted with high levels of Se, B, and salts. This two-year field study was conducted to identify the best plant species that are salt and B tolerant and that have a superior ability of volatilizing Se from drainage sediment. The drainage sediment was mixed with clean soil, and vegetated with salado alfalfa (Medicago sativa 'salado'), salado grass (Sporobulus airoides 'salado'), saltgrass-turf (Distichlis spp. 'NYPA Turf'), saltgrass-forage (Distichlis spicata (L.) Greene), cordgrass (Spartina patens 'Flageo'), Leucaenia (Leucaena leucocephola), elephant grass (Pennistum purpureum), or wild type-Brassica (Brassica spp.). Results show that elephant grass produced the greatest amount of biomass and accumulated highest concentrations of B. Highest concentrations of Se, S, and Cl were observed in wild-type Brassica. Biogenic volatilization of Se by plants and soil microbes was greater in summer. Among the treatments, the mean daily rates of Se volatilization (microg Se m(-2)d(-1)) were wild-type Brassica (39) > saltgrass-turf (31) > cordgrass (27) > saltgrass forage (24) > elephant grass (22) > salado grass (21) > leucaenia (19) > salado alfalfa (14) > irrigated bare soil (11) > non-irrigated bare soil (6). Overall, rates of Se volatilization in drainage sediment were relatively low due to high levels of sulfate. To manage Se in drainage sediment by phytoremediation, the biological volatilization process needs to be enhanced substantially under field conditions. PMID:16018890

Bañuelos, G S; Lin, Z-Q; Arroyo, I; Terry, N

2005-04-09

210

Genomic basis of broad host range and environmental adaptability of Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 which are used in inoculants for common bean (Phaseolus vulgaris L.)  

PubMed Central

Background Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 are ?-Proteobacteria that establish nitrogen-fixing symbioses with a range of legume hosts. These strains are broadly used in commercial inoculants for application to common bean (Phaseolus vulgaris) in South America and Africa. Both strains display intrinsic resistance to several abiotic stressful conditions such as low soil pH and high temperatures, which are common in tropical environments, and to several antimicrobials, including pesticides. The genetic determinants of these interesting characteristics remain largely unknown. Results Genome sequencing revealed that CIAT 899 and PRF 81 share a highly-conserved symbiotic plasmid (pSym) that is present also in Rhizobium leucaenae CFN 299, a rhizobium displaying a similar host range. This pSym seems to have arisen by a co-integration event between two replicons. Remarkably, three distinct nodA genes were found in the pSym, a characteristic that may contribute to the broad host range of these rhizobia. Genes for biosynthesis and modulation of plant-hormone levels were also identified in the pSym. Analysis of genes involved in stress response showed that CIAT 899 and PRF 81 are well equipped to cope with low pH, high temperatures and also with oxidative and osmotic stresses. Interestingly, the genomes of CIAT 899 and PRF 81 had large numbers of genes encoding drug-efflux systems, which may explain their high resistance to antimicrobials. Genome analysis also revealed a wide array of traits that may allow these strains to be successful rhizosphere colonizers, including surface polysaccharides, uptake transporters and catabolic enzymes for nutrients, diverse iron-acquisition systems, cell wall-degrading enzymes, type I and IV pili, and novel T1SS and T5SS secreted adhesins. Conclusions Availability of the complete genome sequences of CIAT 899 and PRF 81 may be exploited in further efforts to understand the interaction of tropical rhizobia with common bean and other legume hosts.

2012-01-01

211

Mimosine mitigates oxidative stress in selenium deficient seedlings of Vigna radiata--Part I: Restoration of mitochondrial function.  

PubMed

Mimosine, a non-protein plant amino acid found in Mimosa pudica and certain species of Leucaena, was beneficial for the growth of seedlings of Vigna radiata germinated under selenium-deficient stressed condition (-Se stressed) despite the recognized toxicity of the allelochemical. Exposure of mimosine at 0.1 mM (Mim-0.1) promoted the growth of the seedlings and significantly enhanced mitochondrial functional efficiency. Growth-related parameters including root and shoot lengths and dry weight were increased by 44-58% in the Mim-0.1 group compared to that of the -Se-stressed group. Oxygen uptake by mitochondria of Mim-0.1 group, studied with different substrates, revealed enhanced State 3 respiratory rates with regulated State 4 rates, resulting in high respiratory control ratio (RCR) of 3.4 to 3.9 indicative of a high degree of oxidative coupling. Specific activities of mitochondrial electron transport enzymes, nicotinamide adenine dinucleotide (reduced form) (NADH)-cytochrome (cyt) c oxidoreductase, succinate dehydrogenase, and cyt c oxidase in the Mim-0.1 group were enhanced by 53% to threefold over those of the Se-stressed group. Marked decreases in the extent of mitochondrial lipid peroxidation ensued upon mimosine exposure, indicative of its antioxidant function. Mitochondrial 45Ca2+ uptake was notably augmented twofold in the Mim-0.1 group, compared to the Se-stressed group. Detailed kinetic analyses of Ca2+ uptake revealed positive cooperative interactions in both -Se-stressed group and Mim-0.1 groups with Hill coefficient (nH) values of 1.7 and 2, respectively. The present study establishes the beneficial effects of mimosine exposure at 0.1 mM on the growth and mitochondrial function of the seedlings grown under selenium-deficient stressed condition and a significant physiological role can be ascribed to mimosine. PMID:17848734

Lalitha, K; Kulothungan, S Rajendra

2007-07-01

212

Density and microhabitat use of Bengal slow loris in primary forest and non-native plantation forest.  

PubMed

The extent of planted forests has greatly increased in the tropics, but their conservation value while assumed to be low, is largely unknown. We compared the density and microhabitat selection of a nocturnal arboreal primate, the Bengal slow loris (Nycticebus bengalensis), in mostly undisturbed, evergreen tropical forest to those in 15-18 year old Acacia/Leucaena plantations with significant secondary regrowth, and <15 year old plantations with little regrowth. Based on estimates derived from distance sampling, loris densities in older plantations were nearly identical to primary forest (4.26 vs. 4.00 lorises per square kilometer), although encounter rates were three times higher in the older plantations probably owing to the lower detection probability in the more complex vegetation of the primary forest. The mean density estimate for the younger plantation was one-third of the above habitats (1.27 lorises per square kilometer), although not statistically different. Lorises tended to use larger diameter and taller trees, with a greater crown depth than randomly sampled trees, and tended to avoid habitats with sparsely crowned trees. The older plantations had trees with lower basal area and shorter stems than the primary forest; however, the older plantations contained higher densities of Bauhinia lianas, a commonly eaten food source and did not contain the red giant flying squirrel (Petaurista petaurista), a potential competitor. Although it is unknown whether the Bengal slow loris would persist without the presence of primary forest in the landscape, we suggest that older plantations have conservation value for at least selected species and as such, could be better managed to increase this value. PMID:20938966

Pliosungnoen, Manoon; Gale, George; Savini, Tommaso

2010-12-01

213

Effect of Various Organic Matter stimulates Bacteria and Arbuscular Mycorrhizal Fungi Plantations on Eroded Slopes in Nepal  

NASA Astrophysics Data System (ADS)

Erosion resulting from landslides is a serious problem in mountainous countries such as Nepal. To restore such sites it is essential to establish plant cover that protects the soil and reduces erosion. Trees and shrubs on the lower hillsides in Nepal form symbiosis with arbuscular mycorrhizal (AM) fungi and these fungi are important for the uptake of mineral nutrients from the soil. In addition, the mycelia formed by these fungi have an important function in stabilizing the soil. The success of plantations of these eroded slopes is therefore highly dependent on the extent of mycorrhizal colonization of the plants. Mycorrhizal fungi growing in symbiosis with plants are essential in this respect because they improve both plant and nutrient uptake and soil structure. We investigated the influence of organic matter and P amendment on recently produced biomass of bacteria and arbuscular mycorrhizal (AM) fungi in eroded slopes in Nepal. Eroded soil mixed with different types of organic matter was placed in mesh bags which were buried around the trees of Bauhinia purpurea and Leucaena diversifolia .This experiment were done in two seasons ( (the wet and the dry season). Signature fatty acids were used to determine bacterial and AM fungal biomass after the six month intervals. The amount and composition of AM fungal spores were analyzed in the mesh bags from the wet and dry seasons. More microbial biomass was produced during wet season than during dry season. Further more, organic matter addition enhanced the production of AM fungal and bacterial biomass during both seasons. The positive influence of organic matter addition on AM fungi could be an important contribution to plant survival, growth and nutrient composition in the soil in plantations on eroded slopes. Different AM spore communities and bacterial profiles were obtained with different organic amendments and this suggests a possible way of selecting for specific microbial communities in the management of eroded sites.

Shrestha Vaidya, G.; Shrestha, K.; Wallander, H.

2009-04-01

214

Hybridization between white-headed ducks and introduced ruddy ducks in Spain  

Microsoft Academic Search

The ruddy duck, Oxyura jamaicensis , was introduced to Great Britain in the mid-20th century and has recently spread to other Western European countries. In Spain, ruddy ducks hybridize with the globally endangered white-headed duck, Oxyura leucocephala . We assessed the effects of hybridization on the Spanish white-headed ducks, which constitute 25% of the global population of this species, using

V. MUÑOZ-FUENTES; C. VILÀ; A. J. G REEN; J. J. N EGRO; M. D. SORENSON

2007-01-01

215

LEAD POISONING IN THE GLOBALLY THREATENED MARBLED TEAL AND WHITE-HEADED DUCK IN SPAIN  

Microsoft Academic Search

Marbled teal ( Marmaronetta angustirostris ) and white-headed duck (Oxyura leucocephala) are the two European ducks threatened with global extinction. We investigated lead (Pb) poisoning in stifftails ( Oxyura spp., n 5 83) and marbled teal (n 5 80) shot or found dead or moribund in Spanish wetlands via gizzard examination and liver, bone, and blood Pb analysis. Ingested Pb

Rafael Mateo; Andy J. Green; Clinton W. Jeske; Vicente Urios; Cati Gerique

2001-01-01

216

A model for the management of the invasive ruddy duck to reduce interbreeding pressure on the white-headed duck  

Microsoft Academic Search

Non-native species are considered the second most important threat to global biodiversity after habitat loss and are a leading cause of animal extinctions. The North American ruddy duck Oxyura jamaicensis established a feral population in the UK over 40 years ago, and is now endangering the globally threatened white-headed duck Oxyura leucocephala through hybridisation. We utilised a simple Monte Carlo

Graham C. Smith; Iain Henderson

2007-01-01

217

The ruddy duck Oxyura jamaicensis in Europe: natural colonization or human introduction?  

Microsoft Academic Search

Native to North America, ruddy ducks Oxyura jamaicensis now occur in 21 countries in the western Palaearctic (including Iceland) and their expanding population threatens the native white-headed duck, Oxyura leucocephala , through hybridization and possibly competition for food and nest sites. We used mitochondrial DNA sequences and nuclear microsatellites to test whether the European ruddy duck population is descended solely

VIOLETA MUÑOZ-FUENTES; ANDY J. G REEN; MICHAEL D. S ORENSON; JUAN J. N EGRO; CARLES VILÀ

2006-01-01

218

Unravelling lignin formation and structure in living plants  

SciTech Connect

It is steadily being recognized that plant lignin structure can no longer be adequately represented by synthetic preparations, obtained by treatment of the monolignols with peroxidase H{sub 2}O{sub 2} in vitro. Indeed, differences in lignin composition and structure between species, tissues, and even subcellular locations indicate that a highly orchestrated and carefully controlled process occurs in plants. Because of their intractable nature, only crude representations of lignin structure have been obtained; these were proposed following examination of lignin-derived products. In this study, we have identified the specific bonding pattern of each phenylpropanoid side-chain carbon in lignin in situ for a softwood (ital P. taeda), a hardwood (ital L. leucocephala), and a grass (ital T. aestivum). These involve the positions where the majority of inter-unit linkages are found. This was achieved by administration of suitable specifically enriched C-13 lignin precursors to the plant tissue, and subsequent examination by solid-state C-13 NMR. In each case, different bonding environments were observed, and all differed substantially from artificial lignin preparations.

Lewis, N.G. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (USA))

1989-01-01

219

Lead poisoning in the globally threatened marbled teal and white-headed duck in Spain.  

PubMed

Marbled teal (Marmaronetta angustirostris) and white-headed duck (Oxyura leucocephala) are the two European ducks threatened with global extinction. We investigated lead (Pb) poisoning in stifftails (Oxyura spp., n = 83) and marbled teal (n = 80) shot or found dead or moribund in Spanish wetlands via gizzard examination and liver, bone, and blood Pb analysis. Ingested Pb shot was present in 32% of shot stifftails and 70 and 43% of dead or moribund stifftails and marbled teal, respectively. Lead-shot ingestion was more frequent in Valencia (eastern Spain), where Pb-shot densities were higher and grit scarcer. Selection of larger grit similar in size to Pb shot may explain the higher rate of Pb-shot ingestion observed in stifftails. Ingested shot was found more frequently in juvenile stifftails than in adults. Lead bone concentrations were higher in ducklings < 9 d old than in fully grown teal and were also higher in adult than in juvenile teal. Our results show the need for a ban of Pb shot for waterfowl hunting in Spain and the cleanup of spent shot at major wetlands. PMID:11764172

Mateo, R; Green, A J; Jeske, C W; Urios, V; Gerique, C

2001-12-01

220

Dynamic remediation test of polluted river water by Eco-tank system.  

PubMed

Dynamic remediation of river water polluted by domestic sewage using an aquatic plants bed-based Eco-tank system was investigated. Over a period of 18 days, the test demonstrated that average effluent concentrations of chemical oxygen demand (COD), ammonium nitrogen (NH4(+)-N) and total phosphorus (TP) were as low as 17.28, 0.23 and 0.03 mg/L, respectively, under the hydraulic retention time (HRT) of 8.7 d. The average removal efficiencies in terms of COD, NH4(+)-N and TP could reach 71.95, 97.96 and 97.84%, respectively. The loss of both NH4(+)-N and TP was mainly ascribed to the uptake by plants. Hydrocotyle leucocephala was effective in promoting the dissolved oxygen (DO) level, while Pistia stratiotes with numerous fibrous roots was significantly effective for the removal of organic compounds. The net photosynthetic rate, stomatal conductance, transpiration rate and biomass accumulation rate of Myriophyllum aquaticum were the highest among all tested plants. Thus, the Eco-tank system could be considered as an alternative approach for the in situ remediation of polluted river water, especially nutrient-laden river water. PMID:23530371

Xiao, Jibo; Wang, Huiming; Chu, Shuyi; Wong, Ming-Hung

221

Unravelling lignin formation and structure. Final report, April 1, 1988--March 31, 1991  

SciTech Connect

During this study, we established that the Fagaceae exclusively accumulate Z-monolignois/glucosides, and not the E-isomers. Evidence for the presence of a novel E{yields}Z isomerse has been obtained. Our pioneering work in lignin biosynthesis and structure in situ has also progressed smoothly. We established the bonding environments of a woody angiosperm, Leucanea leucocephala, as well as wheat (T. aestivum) and tobacco (N. tabacum). A cell culture system from Pinus taeda was developed which seems ideal for investigating the early stages of lignification. These cultures excrete peroxidase isozymes, considered to be specifically involved in lignin deposition. We also studied the effect of the putative lignin-degrading enzyme, lignin peroxidase, on monolignols and dehydropolymerisates therefrom. In all cases, polymerization was observed, and not degradation; these polymers are identical to that obtained with horseradish peroxidases/H{sub 2}O{sub 2}. It seems inconceivable that these enzymes can be considered as being primarily responsible for lignin biodegradation.

Lewis, N.G. [Washington State Univ., Pullman, WA (United States). Inst. of Biological Chemistry

1991-12-31

222

Unravelling lignin formation and structure  

SciTech Connect

During this study, we established that the Fagaceae exclusively accumulate Z-monolignois/glucosides, and not the E-isomers. Evidence for the presence of a novel E{yields}Z isomerse has been obtained. Our pioneering work in lignin biosynthesis and structure in situ has also progressed smoothly. We established the bonding environments of a woody angiosperm, Leucanea leucocephala, as well as wheat (T. aestivum) and tobacco (N. tabacum). A cell culture system from Pinus taeda was developed which seems ideal for investigating the early stages of lignification. These cultures excrete peroxidase isozymes, considered to be specifically involved in lignin deposition. We also studied the effect of the putative lignin-degrading enzyme, lignin peroxidase, on monolignols and dehydropolymerisates therefrom. In all cases, polymerization was observed, and not degradation; these polymers are identical to that obtained with horseradish peroxidases/H{sub 2}O{sub 2}. It seems inconceivable that these enzymes can be considered as being primarily responsible for lignin biodegradation.

Lewis, N.G. (Washington State Univ., Pullman, WA (United States). Inst. of Biological Chemistry)

1991-01-01

223

Normal yeast flora of the upper digestive tract of some wild columbids  

USGS Publications Warehouse

Seven species of pigeons and doves were cultured for yeasts in the upper digestive tract. The following list gives the isolation rate for each columbid species and the yeasts cultured from them: feral pigeon Columba Livia (Gmelin) 95% -Candida albicans (Robin) Berkhout, C. tropicalis (Castellani) Berkhout, C. krusei (Cast.) Berkhout, C. guilliermondii (Cast.) Langeron et Guerra, Torulopsis glabrata (Anderson) Lodder et De Vries, Saccharomyces telluris Van der Walt, and Geotrichum sp.; white-crowned pigeon (C. leucocephala Linnaeus) 56% -- S. telluris; mourning dove (Zenaidura rnacroura Linnaeus) 24% -- C. albicans, C. tropicalis, C. guilliermondii, and Geotrichurn sp.; passerine ground dove (Collumbigallina passerina Linnaeus) 20% -- C. parapsilosis (Ashford) Langeron et Talice, Kloeckera apiculata (Reess Emend. Klocker) Janke; zenaida dove (Zenaida aurita Temminck) 16% -- C. albicans, C. guilliermondii, and T. glabrata; one moustasche dove (Geotrygon mystacea Gosse) -- C. guillierrnondii; ringed turtle dove (Streptopelia rizoria Linnaeus) 14% -- C. albicans and Geotrichurn sp. No signs of disease could be seen in the 139 birds that were examined, and it was concluded that these yeasts comprise a part of the columbid's normal microbial flora.

Kocan, R.M.; Hasenclever, H.F.

1972-01-01

224

Hybridization between white-headed ducks and introduced ruddy ducks in Spain.  

PubMed

The ruddy duck, Oxyura jamaicensis, was introduced to Great Britain in the mid-20th century and has recently spread to other Western European countries. In Spain, ruddy ducks hybridize with the globally endangered white-headed duck, Oxyura leucocephala. We assessed the effects of hybridization on the Spanish white-headed ducks, which constitute 25% of the global population of this species, using a panel of eight nuclear intron markers, 10 microsatellite loci, and mtDNA control region sequences. These data allowed parental individuals, F(1) hybrids, and the progeny of backcrossing to be reliably distinguished. We show that hybrids between the two species are fertile and produce viable offspring in backcrosses with both parental species. To date, however, we found no extensive introgression of ruddy duck genes into the Spanish white-headed duck population, probably due to the early implementation of an effective ruddy duck and hybrid control programme. We also show that genetic diversity in the expanding European ruddy duck population, which was founded by just seven individuals, exceeds that of the native Spanish white-headed duck population, which recently recovered from a severe bottleneck. Unless effective control of ruddy ducks is continued, genetic introgression will compromise the unique behavioural and ecological adaptations of white-headed ducks and consequently their survival as a genetically and evolutionary distinct species. PMID:17257118

Muñoz-Fuentes, V; Vilà, C; Green, A J; Negro, J J; Sorenson, M D

2007-02-01

225

The ruddy duck Oxyura jamaicensis in Europe: natural colonization or human introduction?  

PubMed

Native to North America, ruddy ducks Oxyura jamaicensis now occur in 21 countries in the western Palaearctic (including Iceland) and their expanding population threatens the native white-headed duck, Oxyura leucocephala, through hybridization and possibly competition for food and nest sites. We used mitochondrial DNA sequences and nuclear microsatellites to test whether the European ruddy duck population is descended solely from the captive population in the UK, which traces to seven individuals imported from the USA in 1948, or, alternatively, has been augmented by natural dispersal of birds from North America. Limited genetic diversity in the European population is consistent with a founder population as small as seven birds. In addition, shifts in allele frequencies at several loci, presumably due to genetic drift in the founding population, result in significant differentiation between the European and North American populations. Despite the recent separation of these populations, almost all individuals could be unambiguously assigned based on their composite genotypes, to one of two distinct populations, one comprising all of the European ruddy ducks we sampled (including those from Iceland and captive birds in the UK) and the other comprising all North American samples. Our results confirm that the European ruddy duck population is likely to derive solely from the captive population in the UK and we find no evidence of recent arrivals from North America or of admixture between ruddy ducks from Europe and North America. PMID:16629802

Muñoz-Fuentes, Violeta; Green, Andy J; Sorenson, Michael D; Negro, Juan J; Vilà, Carles

2006-05-01

226

The nodulation of alfalfa by the acid-tolerant Rhizobium sp. strain LPU83 does not require sulfated forms of lipochitooligosaccharide nodulation signals.  

PubMed

The induction of root nodules by the majority of rhizobia has a strict requirement for the secretion of symbiosis-specific lipochitooligosaccharides (nodulation factors [NFs]). The nature of the chemical substitution on the NFs depends on the particular rhizobium and contributes to the host specificity imparted by the NFs. We present here a description of the genetic organization of the nod gene cluster and the characterization of the chemical structure of the NFs associated with the broad-host-range Rhizobium sp. strain LPU83, a bacterium capable of nodulating at least alfalfa, bean, and Leucena leucocephala. The nod gene cluster was located on the plasmid pLPU83b. The organization of the cluster showed synteny with those of the alfalfa-nodulating rhizobia, Sinorhizobium meliloti and Sinorhizobium medicae. Interestingly, the strongest sequence similarity observed was between the partial nod sequences of Rhizobium mongolense USDA 1844 and the corresponding LPU83 nod genes sequences. The phylogenetic analysis of the intergenic region nodEG positions strain LPU83 and the type strain R. mongolense 1844 in the same branch, which indicates that Rhizobium sp. strain LPU83 might represent an early alfalfa-nodulating genotype. The NF chemical structures obtained for the wild-type strain consist of a trimeric, tetrameric, and pentameric chitin backbone that shares some substitutions with both alfalfa- and bean-nodulating rhizobia. Remarkably, while in strain LPU83 most of the NFs were sulfated in their reducing terminal residue, none of the NFs isolated from the nodH mutant LPU83-H were sulfated. The evidence obtained supports the notion that the sulfate decoration of NFs in LPU83 is not necessary for alfalfa nodulation. PMID:20971905

Torres Tejerizo, Gonzalo; Del Papa, María Florencia; Soria-Diaz, M Eugenia; Draghi, Walter; Lozano, Mauricio; Giusti, María de los Ángeles; Manyani, Hamid; Megías, Manuel; Gil Serrano, Antonio; Pühler, Alfred; Niehaus, Karsten; Lagares, Antonio; Pistorio, Mariano

2010-10-22

227

Data set incongruence and correlated character evolution: An example of functional convergence in the hind-limbs of stifftail diving ducks  

USGS Publications Warehouse

The unwitting inclusion of convergent characters in phylogenetic estimates poses a serious problem for efforts to recover phylogeny. Convergence is not inscrutable, however, particularly when one group of characters tracks phylogeny and another set tracks adaptive history. In such cases, convergent characters may be correlated with one or a few functional anatomical units and readily identifiable by using comparative methods. Stifftail ducks (Oxyurinae) offer one such opportunity to study correlated character evolution and function in the context of phylogenetic reconstruction. Morphological analyses place stifftail ducks as part of a large clade of diving ducks that includes the sea ducks (Mergini), Hymenolaimus, Merganetta, and Tachyeres, and possibly the pochards (Aythyini). Molecular analyses, on the other hand, place stifftails far from other diving ducks and suggest, moreover, that stifftails are polyphyletic. Mitochondrial cytochrome b gene sequences of eight stifftail species traditionally supposed to form a clade were compared with each other and with sequences from 50 other anseriform and galliform species. Stifftail ducks are not the sister group of sea ducks but lie outside the typical ducks (Anatinae). Of the four traditional stifftail genera, monophyly of Oxyura and its sister group relationship with Nomonyx are strongly supported. Heteronetta probably is the sister group of that clade, but support is weak. Biziura is not a true stifftail. Within Oxyura, Old World species (O. australis, O. leucocephala, O. mnccoa) appear to form a clade, with New World species (O. jamaicensis, O. vittata) branching basally. Incongruence between molecules and morphology is interpreted to be the result of adaptive specialization and functional convergence in the hind limbs of Biziura and true stifftails. When morphological characters are divided into classes, only hind-limb characters are significantly in conflict with the molecular tree. Likewise, null models of synonymous and nonsynonymous substitution based on patterns of codon-degeneracy and chemical dissimilarity indicate that the nucleotide and amino acid changes postulated by the molecular tree are more plausible than those postulated by the morphological tree. These findings teach general lessons about the utility of highly adaptive characters (in particular those related to foraging ecology) and underscore the problems that convergence can pose for attempts to recover phylogeny. They also demonstrate how the concept of natural data partitions and simple models of evolution (e.g., parsimony, likelihood, neutrality) can be used to test the accuracy of independent phylogenetic estimates and provide arguments in favor of one tree topology over another.

Mccracken, K. G.; Harshman, J.; Mcclellan, D. A.; Afton, A. D.

1999-01-01