Fusarium redolens, a virulent fungus which causes damping off, leaf yellowing, wilting and root rots has recently been devastating cowpea fields in Uganda. This study aimed at identifying cowpea genotypes that are res...Fusarium redolens, a virulent fungus which causes damping off, leaf yellowing, wilting and root rots has recently been devastating cowpea fields in Uganda. This study aimed at identifying cowpea genotypes that are resistant to Fusarium redolens. Therefore, ninety cowpea genotypes were evaluated two times against a highly virulent Fusarium redolens (isolate from Zombo in Paidha district) in the screen house in 2016. Genotype effect was highly significant (P 0.001) for root rot severity. Based on the Index of Susceptibility (IS), three genotypes (Asontem, Dan1 LA and IT89KD-88) remained resistant (IS 3.5) over the two screening periods, 72 moderately resistant (3.5 ≤ IS 6.5) and 11 susceptible (IS ≥ 6.5). Resistance was found to be enhanced by presence of lateral roots above or at the ground level. Further results suggested a difference in genetic control of resistance to root rots and seed rots caused by Fusarium redolens. All the released varieties tested (SECOW 1 T, SECOW 2 W, SECOW 3 B, SECOW 4 W and SECOW 5 T) had moderate resistance to Fusarium redolens. Correlation analysis revealed root rot severity was strongly correlated to disease incidence (+0.64, P 0.001), to proportion of plants with lateral roots (-0.56, P 0.001), to amount of leaf chlorophyll (-0.53, P 0.001) and to proportion of plants that died prematurely due to Fusarium redolens infection (+0.45, P 0.001). No significant correlation was detected between root rot severity and proportion of plants that germinated. The established resistance could be exploited for improvement of farmer preferred cowpea varieties towards Fusarium redolens resistance in Uganda.展开更多
Widespread corn ear mold development in North Dakota and in other states was associated with cool, wet weather after physiological maturity in 2009. In response to concerns about possible grain mold and mycotoxin cont...Widespread corn ear mold development in North Dakota and in other states was associated with cool, wet weather after physiological maturity in 2009. In response to concerns about possible grain mold and mycotoxin contamination in North Dakota, a survey of corn ear diseases was conducted in 2009 prior to harvest. Corn ears were collected from 94 field locations from 24 counties and were examined macroscopically and microscopically for mold identification. Mycotoxin testing was done with a screen for 17 tricothecenes using gas chromatography/mass spectrometry techniques. Cladosporium was the most commonly identified fungus with some Fusarium contaminated samples being observed. Other fungi identified include Alternaria, Penicillium, Aureobsidium, Rhizopus, Stemphylium and an unidentified non-pigmented fungus. Five mycotoxins were identified in 25 out of the 94 samples;deoxynivalenol, T-2, HT-2, zearalenone and nivalenol. Of the mycotoxin-positive samples, 88% had less than 2 ppm of any mycotoxin. Despite the growing season’s weather being favorable for corn ear mold development late in the season, observed mycotoxin levels were surprisingly low and most grain was deemed safe for use in food and feed channels. Surveys were planned in subsequent years, but late season molds did not develop in the 2010-2015 growing seasons.展开更多
Different fungi alter apples in the post-harvest period, causing considerableeconomic losses and risks to consumer health due to the mycotoxinsthat some of these fungi produce. The control of these fungal alterationsi...Different fungi alter apples in the post-harvest period, causing considerableeconomic losses and risks to consumer health due to the mycotoxinsthat some of these fungi produce. The control of these fungal alterationsin apples is mainly dependent on the use of chemical fungicides, the effectivenessof which has been well proven. However, this use is subject torestrictions due to growing concerns about risks to human health and theenvironment and the continued development of pathogen resistance to commonlyused fungicides. A new approach to control post-harvest fungi hasbeen implemented through the application of plant extract.It is estimatedthat there are more than 250,000 higher plant species on Earth that can beevaluated for their antimicrobial bioactive chemical compounds. In recentdecades, researchers have evaluated plant extracts and essential oils againstfungi responsible for post-harvest apple rot. Interesting results have beenobtained. The purpose of this project is to summarize and discuss the resultsof in vitro and in situ experiments of different literatures concerning the effectsof compounds derived from plants on the control of fungi responsiblefor rotting apples in storage.展开更多
Onion (Allium cepa L.) is the second most important vegetable crop in Burkina Faso and provides an important source of income for those involved in the sector. However, producers are facing significant pre-harvest and...Onion (Allium cepa L.) is the second most important vegetable crop in Burkina Faso and provides an important source of income for those involved in the sector. However, producers are facing significant pre-harvest and post-harvest losses. To date, knowledge of major diseases of the crop is limited, limiting the development of effective control strategies. The objective of this study was to test the pathogenicity of some species of Fusarium. To this end, 33 fungal isolates collected from onion plants in 17 localities and belonging to five Fusarium species were used to inoculate onion seeds and bulbs to determine the pathogenic species responsible for damping-off on seedlings and basal bulb rot in Burkina Faso. The virulence of pathogenic isolates was determined according to the percentages of seedling damping-off evaluated 28 Days After Sowing, and the extent of rot in millimetres on inoculated bulbs. The evaluation of isolates on seedlings revealed that the most pathogenic isolates belong to the species F. proliferatum (I29, I21, I37, I33, I31), F. thapsinum (I35) and F. solani (I38) which resulted in 58.33% - 70.83% of seedling damping-off. The most pathogenic isolates on bulbs belong to the species F. proliferatum (I4, I29, I32) and F. oxysporum (I52, I50, I16) which caused 21.67 to 25 mm of rot on bulbs. Isolate I29 was very virulent on both seedlings and bulbs. The isolates of F. fujikuroi species were all low pathogenic on seedlings but one of them, (I27), expressed average pathogenicity on bulbs.展开更多
Over the few last years, cucumber （Cucumis sativus L） root rot disease became common and inflicted marked losses to yield in Fayoum. Isolation trails from infected cucumber roots revealed that Thielaviopsis basicola...Over the few last years, cucumber （Cucumis sativus L） root rot disease became common and inflicted marked losses to yield in Fayoum. Isolation trails from infected cucumber roots revealed that Thielaviopsis basicola and Fusarium moniliforme were the main cucumber root rot pathogens. The isolation trials from the rhizosphere of healthy cucumber plants revealed that two fungal isolates and four bacterial isolates had antagonistic effects against cucumber root rot fungi. All the tested biocontrol agents reduced the radial growth of all the tested root rots fungi in dual cultures. However, all culture filtrates of the tested biocontrol agent significantly reduced radial growth of all the tested pathogenic fungi, except that T. harzianum. Under field conditions, soil treatment with any of T. harzianum and B. subtilis BI and BF, significantly reduced percentages of infected plants and significantly increased percentages of survived plants and fruit yield compared with the control. Application of the commercial product Harpin protein （Messenger）~ product, as a resistance inducer at 0.3, 0.5 and l g/L significantly reduced the percentage of infected plants under greenhouse and field conditions. Field experiments indicated that the average percentage of infected plants after 90 days significantly decreased. The percentage of the survived plants as well as fruit yield increased by using integrated disease management （IDM） package, including the most effective treatments： tolerant cultivar, Trichoderma harzianum granules formula as soil treatment, Purging cassia plant extract, Harpin protein, and a half dose of Vitavax/thiram comparing with the treatment recommended by the Ministry of Agricultural or applied treatments individually.展开更多
Our study consists of a careful literature review carried out with the aim of better understanding the models developed in the field of biocontrol of postharvest fungal rot in apples(PHFRA)over the past two decades.It...Our study consists of a careful literature review carried out with the aim of better understanding the models developed in the field of biocontrol of postharvest fungal rot in apples(PHFRA)over the past two decades.It aims,more specifically,to shed light on the progress made by examining the products developed,their nature,their target pathogens,their effectiveness,theirs modes of action and the stage of their development.The post-harvest biocontrol of apples has made remarkable progress during the last twenty years of research.Several products(yeasts,bacteria,filamentous fungi and actinomycetes)have been selected.Some,are already marketed,others are at different stages of development.However,several points limit the optimal use of microbial antagonists in the bio-management of post-harvest apple rots as an alternative to chemicals.It is,in fact,still necessary to develop appropriate formulations of these microbial biocontrol agents,to better study their mechanisms of action,to test them under commercial conditions and against a broad spectrum of pathogens and hosts.However,although sometimes considered less effective than chemical treatments,biocontrol products based on microorganisms have major advantages for an application in an integrated post-harvest apple protection strategy.展开更多
北半球针叶林最严重的森林病害是由广义的多年异担子菌(Heterobasidion annosum sensu lato)引起的干基白色腐朽病,但近年的研究表明多年异担子菌并不是单一的物种,目前在欧洲已分出3个独立的种,即原始多年异担子菌(Heterobasidion anno...北半球针叶林最严重的森林病害是由广义的多年异担子菌(Heterobasidion annosum sensu lato)引起的干基白色腐朽病,但近年的研究表明多年异担子菌并不是单一的物种,目前在欧洲已分出3个独立的种,即原始多年异担子菌(Heterobasidion annosum sensu stricto)、小孔异担子菌(Heterobasidion parviporum)和冷杉异担子菌(Heterobasidi-on abietinum),它们生物学习性、形态结构,生态学,寄主范围和发生区域均有差异。应用大伏革菌Phlebiopsisgigantea对该类病害进行生物防治是较好的方法。将中国东北和西南(云南)的异担子菌单孢菌株与欧洲的三种异担子菌进行交配,结果表明中国东北和西南地区的异担子菌与原始多年异担子菌无性亲和反应,而与小孔异担子菌有性融合反应,因此中国东北和西南地区的异担子菌是小孔异担子菌,目前中国并不存在原始多年异担子菌。由于原始多年异担子菌和冷杉异担子菌均为严重的森林病原菌,应将其作为对外检疫对象。展开更多
文摘Fusarium redolens, a virulent fungus which causes damping off, leaf yellowing, wilting and root rots has recently been devastating cowpea fields in Uganda. This study aimed at identifying cowpea genotypes that are resistant to Fusarium redolens. Therefore, ninety cowpea genotypes were evaluated two times against a highly virulent Fusarium redolens (isolate from Zombo in Paidha district) in the screen house in 2016. Genotype effect was highly significant (P 0.001) for root rot severity. Based on the Index of Susceptibility (IS), three genotypes (Asontem, Dan1 LA and IT89KD-88) remained resistant (IS 3.5) over the two screening periods, 72 moderately resistant (3.5 ≤ IS 6.5) and 11 susceptible (IS ≥ 6.5). Resistance was found to be enhanced by presence of lateral roots above or at the ground level. Further results suggested a difference in genetic control of resistance to root rots and seed rots caused by Fusarium redolens. All the released varieties tested (SECOW 1 T, SECOW 2 W, SECOW 3 B, SECOW 4 W and SECOW 5 T) had moderate resistance to Fusarium redolens. Correlation analysis revealed root rot severity was strongly correlated to disease incidence (+0.64, P 0.001), to proportion of plants with lateral roots (-0.56, P 0.001), to amount of leaf chlorophyll (-0.53, P 0.001) and to proportion of plants that died prematurely due to Fusarium redolens infection (+0.45, P 0.001). No significant correlation was detected between root rot severity and proportion of plants that germinated. The established resistance could be exploited for improvement of farmer preferred cowpea varieties towards Fusarium redolens resistance in Uganda.
文摘Widespread corn ear mold development in North Dakota and in other states was associated with cool, wet weather after physiological maturity in 2009. In response to concerns about possible grain mold and mycotoxin contamination in North Dakota, a survey of corn ear diseases was conducted in 2009 prior to harvest. Corn ears were collected from 94 field locations from 24 counties and were examined macroscopically and microscopically for mold identification. Mycotoxin testing was done with a screen for 17 tricothecenes using gas chromatography/mass spectrometry techniques. Cladosporium was the most commonly identified fungus with some Fusarium contaminated samples being observed. Other fungi identified include Alternaria, Penicillium, Aureobsidium, Rhizopus, Stemphylium and an unidentified non-pigmented fungus. Five mycotoxins were identified in 25 out of the 94 samples;deoxynivalenol, T-2, HT-2, zearalenone and nivalenol. Of the mycotoxin-positive samples, 88% had less than 2 ppm of any mycotoxin. Despite the growing season’s weather being favorable for corn ear mold development late in the season, observed mycotoxin levels were surprisingly low and most grain was deemed safe for use in food and feed channels. Surveys were planned in subsequent years, but late season molds did not develop in the 2010-2015 growing seasons.
文摘Different fungi alter apples in the post-harvest period, causing considerableeconomic losses and risks to consumer health due to the mycotoxinsthat some of these fungi produce. The control of these fungal alterationsin apples is mainly dependent on the use of chemical fungicides, the effectivenessof which has been well proven. However, this use is subject torestrictions due to growing concerns about risks to human health and theenvironment and the continued development of pathogen resistance to commonlyused fungicides. A new approach to control post-harvest fungi hasbeen implemented through the application of plant extract.It is estimatedthat there are more than 250,000 higher plant species on Earth that can beevaluated for their antimicrobial bioactive chemical compounds. In recentdecades, researchers have evaluated plant extracts and essential oils againstfungi responsible for post-harvest apple rot. Interesting results have beenobtained. The purpose of this project is to summarize and discuss the resultsof in vitro and in situ experiments of different literatures concerning the effectsof compounds derived from plants on the control of fungi responsiblefor rotting apples in storage.
基金the Congregation of the Sisters of the Immaculate Conception of Ouagadougou(S.I.C.O)and the Institute of Environment and Agricultural Research(INERA)for their financial support for this work.
文摘Onion (Allium cepa L.) is the second most important vegetable crop in Burkina Faso and provides an important source of income for those involved in the sector. However, producers are facing significant pre-harvest and post-harvest losses. To date, knowledge of major diseases of the crop is limited, limiting the development of effective control strategies. The objective of this study was to test the pathogenicity of some species of Fusarium. To this end, 33 fungal isolates collected from onion plants in 17 localities and belonging to five Fusarium species were used to inoculate onion seeds and bulbs to determine the pathogenic species responsible for damping-off on seedlings and basal bulb rot in Burkina Faso. The virulence of pathogenic isolates was determined according to the percentages of seedling damping-off evaluated 28 Days After Sowing, and the extent of rot in millimetres on inoculated bulbs. The evaluation of isolates on seedlings revealed that the most pathogenic isolates belong to the species F. proliferatum (I29, I21, I37, I33, I31), F. thapsinum (I35) and F. solani (I38) which resulted in 58.33% - 70.83% of seedling damping-off. The most pathogenic isolates on bulbs belong to the species F. proliferatum (I4, I29, I32) and F. oxysporum (I52, I50, I16) which caused 21.67 to 25 mm of rot on bulbs. Isolate I29 was very virulent on both seedlings and bulbs. The isolates of F. fujikuroi species were all low pathogenic on seedlings but one of them, (I27), expressed average pathogenicity on bulbs.
文摘Over the few last years, cucumber （Cucumis sativus L） root rot disease became common and inflicted marked losses to yield in Fayoum. Isolation trails from infected cucumber roots revealed that Thielaviopsis basicola and Fusarium moniliforme were the main cucumber root rot pathogens. The isolation trials from the rhizosphere of healthy cucumber plants revealed that two fungal isolates and four bacterial isolates had antagonistic effects against cucumber root rot fungi. All the tested biocontrol agents reduced the radial growth of all the tested root rots fungi in dual cultures. However, all culture filtrates of the tested biocontrol agent significantly reduced radial growth of all the tested pathogenic fungi, except that T. harzianum. Under field conditions, soil treatment with any of T. harzianum and B. subtilis BI and BF, significantly reduced percentages of infected plants and significantly increased percentages of survived plants and fruit yield compared with the control. Application of the commercial product Harpin protein （Messenger）~ product, as a resistance inducer at 0.3, 0.5 and l g/L significantly reduced the percentage of infected plants under greenhouse and field conditions. Field experiments indicated that the average percentage of infected plants after 90 days significantly decreased. The percentage of the survived plants as well as fruit yield increased by using integrated disease management （IDM） package, including the most effective treatments： tolerant cultivar, Trichoderma harzianum granules formula as soil treatment, Purging cassia plant extract, Harpin protein, and a half dose of Vitavax/thiram comparing with the treatment recommended by the Ministry of Agricultural or applied treatments individually.
文摘Our study consists of a careful literature review carried out with the aim of better understanding the models developed in the field of biocontrol of postharvest fungal rot in apples(PHFRA)over the past two decades.It aims,more specifically,to shed light on the progress made by examining the products developed,their nature,their target pathogens,their effectiveness,theirs modes of action and the stage of their development.The post-harvest biocontrol of apples has made remarkable progress during the last twenty years of research.Several products(yeasts,bacteria,filamentous fungi and actinomycetes)have been selected.Some,are already marketed,others are at different stages of development.However,several points limit the optimal use of microbial antagonists in the bio-management of post-harvest apple rots as an alternative to chemicals.It is,in fact,still necessary to develop appropriate formulations of these microbial biocontrol agents,to better study their mechanisms of action,to test them under commercial conditions and against a broad spectrum of pathogens and hosts.However,although sometimes considered less effective than chemical treatments,biocontrol products based on microorganisms have major advantages for an application in an integrated post-harvest apple protection strategy.
文摘北半球针叶林最严重的森林病害是由广义的多年异担子菌(Heterobasidion annosum sensu lato)引起的干基白色腐朽病,但近年的研究表明多年异担子菌并不是单一的物种,目前在欧洲已分出3个独立的种,即原始多年异担子菌(Heterobasidion annosum sensu stricto)、小孔异担子菌(Heterobasidion parviporum)和冷杉异担子菌(Heterobasidi-on abietinum),它们生物学习性、形态结构,生态学,寄主范围和发生区域均有差异。应用大伏革菌Phlebiopsisgigantea对该类病害进行生物防治是较好的方法。将中国东北和西南(云南)的异担子菌单孢菌株与欧洲的三种异担子菌进行交配,结果表明中国东北和西南地区的异担子菌与原始多年异担子菌无性亲和反应,而与小孔异担子菌有性融合反应,因此中国东北和西南地区的异担子菌是小孔异担子菌,目前中国并不存在原始多年异担子菌。由于原始多年异担子菌和冷杉异担子菌均为严重的森林病原菌,应将其作为对外检疫对象。
