Sample records for mycoherbicides
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Marco Masi; Susan Meyer; Alessio Cimmino; Anna Andolfi; Antonio Evidente
2014-01-01
A new phytotoxic sesquiterpenoid penta-2,4- dienoic acid, named pyrenophoric acid, was isolated from solid wheat seed culture of Pyrenophora semeniperda, a fungal pathogen proposed as a mycoherbicide for biocontrol of cheatgrass (Bromus tectorum) and other annual bromes. These bromes are serious weeds in winter cereals and also on temperate semiarid rangelands....
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Marco Masi; Antonio Evidente; Susan Meyer; Joshua Nicholson; Ashley Munoz
2014-01-01
The seed pathogen Pyrenophora semeniperda has demonstrated potential as a mycoherbicidal biocontrol for eliminating persistent seed banks of annual bromes on western North American rangelands. This pathogen exhibits variation in virulence that is related to mycelial growth rate, but direct laboratory tests of virulence on seeds often have low repeatability. We...
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Annual brome control using a native fungal seed pathogen
Susan E. Meyer; Suzette Clement; Julie Beckstead
2013-01-01
Formulations having a selective, mycoherbicide activity for killing ungerminated seeds of invasive grass species are provided. An agricultural, mycoherbicide formulation is taught for killing ungerminated seeds of invasive grass species. The formulations can comprise, for example, a slow-growing strain of Pyrenophora semeniperda, a fast-growing strain of Pyrenophora...
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Granular formulation of Fusarium oxysporum for biological control of faba bean and tomato Orobanche.
Nemat Alla, Mamdouh M; Shabana, Yasser M; Serag, Mamdouh M; Hassan, Nemat M; El-Hawary, Mohamed M
2008-12-01
Orobanche spp. represent a serious threat to a wide range of crops. They are difficult targets for herbicides, and biological control could provide a possible solution. This work therefore aimed to formulate mycoherbicides of Fusarium with adequate shelf life and virulence against Orobanche but safe to faba bean and tomato. Only two isolates of Fusarium oxysporum Schlecht. (Foxy I and Foxy II) obtained from diseased Orobanche shoots were found to be pathogenic to Orobanche crenata Forsk. and Orobanche ramosa L. Conidial suspension of both isolates significantly decreased germination, attachments and tubercles of Orobanche. Microconidia and chlamydospores of both isolates were formulated as mycoherbicides encapsulated in a wheat flour-kaolin matrix (four different formulations). All formulations greatly diminished Orobanche emerged shoots, total shoot number, shoot height, attachment of emerged shoots, the germinated seeds that succeeded in emerging above the soil surface and dry weight. Meanwhile, disease incidence and disease severity of emerged shoots were enhanced. The shelf life was adequate, particularly for coarse, freshly prepared, low-temperature-stored, microconidia-rich formulations. The induced growth reduction of Orobanche-infected host plants seemed to be nullified by formulations, particularly at the highest dose. These formulations seemed to destroy Orobanche but appeared harmless to host plants. Hence, they could be efficiently used as mycoherbicides for biological control of Orobanche in faba bean and tomato.
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USDA-ARS?s Scientific Manuscript database
In greenhouse experiments, an experimental invert emulsion (MSG 8.25) was tested as an adjuvant with spores of the mycoherbicidal fungus Colletotrichum gloeosporioides f. sp. aeschynomene, a highly virulent pathogen of the leguminous weed Aeschynomene virginica (northern jointvetch), but non-pathoge...
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USDA-ARS?s Scientific Manuscript database
A fungal pathogen, Colletotrichum gloeosporioides was isolated from a greenhouse-grown seedling of coffee senna (Cassia occidentalis) and evaluated as a mycoherbicide for that weed. Host range tests revealed that coffee senna, wild senna (C. pilosa),and sicklepod (C. obtusifolia) were also affected...
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Biological control studies on Convolvulus arvensis L. with fungal pathogens
USDA-ARS?s Scientific Manuscript database
Field bindweed (Convolvulus arvensis) is a perennial, noxious weed in Europe and in many agricultural areas of the world, including Turkey. Some pathogenic fungi were identified with potential to control bindweed and some of them could be used as mycoherbicide components. In the summers of 2008, 200...
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Surveys for Pathogens of Monoecious Hydrilla in 2013
2014-10-01
formulated as a mycoherbicide. Species in the genera Fusarium and Verticillium are best known as vascular wilt pathogens of vegetables, flowers , field...attacks only bananas (Agrios 2005). The causal agents of most Verticillium wilts are V. albo- atrum and V. dahlia. Although both species have been reported
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Pyrenophoric acids B and C, two new phytotoxic sesquiterpenoids produced by Pyrenophora semeniperda
Marco Masi; Susan Meyer; Alessio Cimmino; Suzette Clement; Beth Black; Antonio Evidente
2014-01-01
Two new phytotoxic sesquiterpenoid acids, named pyrenophoric acids B and C, were isolated together with the related pyrenophoric and abscisic acids from solid Bromus tectorum (cheatgrass) seed culture of the seed pathogen Pyrenophora semeniperda. This fungus has been proposed as a mycoherbicide for biocontrol of cheatgrass (Bromus tectorum), a Eurasian annual grass...
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[Biological activity of fungi from the phyllosphere of weeds and wild herbaceous plants].
Berestitskiĭ, A O; Gasich, E L; Poluéktova, E V; Nikolaeva, E V; Sokornova, S V; Khlopunova, L B
2014-01-01
Antimicrobial, phytotoxic, and insecticidal activity of 30 fungal isolates obtained from leaves of weeds and wild herbaceous plants was assessed. Antibacterial, antifungal, phytotoxic, and insecticidal activity was found in over 50, 40, 47, and 40% of the isolates, respectively. These findings may be important for toxicological assessment of potential mycoherbicides, as well as provide a basis for investigation of the patterns of development of phyllosphere communities affected by fungal metabolites.
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Presence of adhesive vesicles in the mycoherbicide Alternaria helianthi
USDA-ARS?s Scientific Manuscript database
Alternaria helianthi conidia have been shown to cause disease on common cocklebur. Conidia were applied to slides made hydrophobic by coating with dimethyldicholorosilane (mimics leaf surface), then rinsed and treated with FITC-Con A to stain the adhesive material. Alternaria helianthi coni...
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Fungal Phytotoxins with Potential Herbicidal Activity to Control Chenopodium album.
Cimmino, Alessio; Masi, Marco; Evidente, Marco; Evidente, Antonio
2015-06-01
This review deals with the isolation and chemical and biological characterization of phytotoxins produced by Ascochyta caulina and Phoma chenopodiicola proposed as mycoherbicides for the biological control of Chenopodium album, a worldwide spread weed which causes serious problems to some agrarian crops, including sugar beet and maize. Studies on the structure activity relationships and on the modes of actions of toxins isolated are also described, as well as the optimization of analytical methods focused on selection of the best fungal toxin producers. The attempts to scale up production of these phytotoxins aimed to obtain sufficient amounts for their application in greenhouse and field trials are also reported.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Buhr, T.L.; Dickman, M.B.
1994-11-01
Colletotrichum gloeosporioides (Penz.) Sacc. F. sp. aeschynomene incites anthracnose on Aeschynomene virgininica (northern jointvetch). Northern jointvetch is a leguminous weed in rice and soybean fields. Contaminating northern jointvetch seeds greatly reduce the market value of rice. C. gloeosporioides (Penz.) Sacc. F. sp. aeschynomene has been commercially marketed as a mycoherbicide to decrease populations of northern jointvetch. Development of a transformation system would be extremely useful for investigating the molecular biology of C. gloeosporioides (Penz.) Sacc. F. sp. aeschynomen. This paper reports the nucleotide sequence of a second gene for {beta} Tub (TUB2) in C. gloeosporioides (Penz.) Sacc. F. sp. aeschynomenemore » and identifies a molecular lesion which likely confers BEN (systemic fungicide) resistance.« less
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USDA-ARS?s Scientific Manuscript database
Eastern black nightshade (Solanum ptycanthum; EBN), found throughout the eastern U.S., is difficult to control and a problematic weed, partly due to its tolerance or resistance to certain herbicides. Greenhouse and field experiments were conducted to determine the effects of an invert (water - in -...
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Cimmino, Alessio; Andolfi, Anna; Zonno, Maria Chiara; Boari, Angela; Troise, Ciro; Motta, Andrea; Vurro, Maurizio; Ash, Gavin; Evidente, Antonio
2013-10-09
Phomentrioloxin is a phytotoxic geranylcyclohexenetriol produced in liquid culture by Phomopsis sp. (teleomorph: Diaporthe gulyae), a potential mycoherbicide proposed for the control of the annual weed Carthamus lanatus. In this study, seven derivatives obtained by chemical modifications of the toxin were assayed for phytotoxic, antimicrobial, and zootoxic activities, and the structure-activity relationships were examined. Each compound was tested on nonhost weedy and agrarian plants, fungi, Gram+ and Gram- bacteria, and on brine shrimp larvae. The results provide insights into an investigation of the structural requirements for activity. The hydroxy groups at C-2 and C-4 appeared to be important features for the phytotoxicity, as well as an unchanged cyclohexentriol ring. A role seemed also to be played by the unsaturations of the geranyl side chain. These findings could be useful for understanding the mechanisms of action of new natural products, for identifying the active sites, and possibly in devising new herbicides of natural origin.
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Wang, Jianshu; Wang, Xuemin; Yuan, Bohua; Qiang, Sheng
2013-01-01
Gene expression profiles of Digitaria sanguinalis infected by Curvularia eragrostidis strain QZ-2000 at two concentrations of conidia and two dew durations were analyzed by cDNA amplified fragment length polymorphisms (cDNA-AFLP). Inoculum strength was more determinant of gene expression than dew duration. A total of 256 primer combinations were used for selective amplification and 1214 transcript-derived fragments (TDFs) were selected for their differential expression. Of these, 518 up-regulated differentially expressed TDFs were identified. Forty-six differential cDNA fragments were chosen to be cloned and 35 of them were successfully cloned and sequenced, of which 25 were homologous to genes of known function according to the GenBank database. Only 6 genes were up-regulated in Curvularia eragrostidis-inoculated D. sanguinalis, with functions involved in signal transduction, energy metabolism, cell growth and development, stress responses, abscisic acid biosynthesis and response. It appears that a few pathways may be important parts of the pathogenic strategy of C. eragrostidis strain QZ-2000 on D. sanguinalis. Our study provides the fundamentals to further study the pathogenic mechanism, screen for optimal C. eragrostidis strains as potential mycoherbicide and apply this product to control D. sanguinalis.
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Herbicidal potential of ophiobolins produced by Drechslera gigantea.
Evidente, Antonio; Andolfi, Anna; Cimmino, Alessio; Vurro, Maurizio; Fracchiolla, Mariano; Charudattan, Raghavan
2006-03-08
Drechslera gigantea, a potential mycoherbicide of grass weeds, was isolated in Florida from naturally infected large crabgrass (Digitaria sanguinalis); it produces phytotoxic metabolites in liquid culture. The main metabolite was identified by spectroscopic methods and optical properties as ophiobolin A (1), a well-known phytotoxic sesterterpene produced by several phytopathogenic fungi of important crops and already extensively studied for its interesting biological activities. The other three minor metabolites proved to be related to ophiobolin A and were identified using the same techniques as 6-epi-ophiobolin A and 3-anhydro-6-epi-ophiobolin A (2 and 3) and ophiobolin I (4). Assayed on punctured detached leaves of several grass and dicotyledon weeds, ophiobolin A proved to be on average more phytotoxic as compared to the other related compounds. Some structural features appear to be important for the phytoxicity, such as the hydroxy group at C-3, the stereochemistry at C-6, and the aldehyde group at C-7. Furthermore, grass weeds usually proved to be more sensitive to the phytotoxins than dicotyledons, on which ophiobolin A caused the appearance of large necrosis even at the lowest concentration assayed. This is the first report about the production of ophiobolins from D. gigantea and of the proposed use as potential natural herbicides against grass weeds.
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Marco Masia; Susan Meyer; Suzette Clement; Anna Andolfi; Alessio Cimmino; Antonio Evidente
2014-01-01
A novel spirocyclic γ-lactam, named spirostaphylotrichin W (1), was isolated together with the well known and closely related spirostaphylotrichins A, C, D, R and V, as well as triticone E, from the liquid cultures of Pyrenophora semeniperda (anamorph: Drechslera), a seed pathogen proposed for cheatgrass (Bromus tectorum) biocontrol. Spirostaphylotrichin W was...