黄瓜枯萎病由黄瓜专化型尖镰孢菌(Fusarium oxysporum f.sp.cucumerinum,Foc)侵染引起,是黄瓜生产中较难防治的一种土传病害,发病时多造成植株萎蔫枯死,可导致黄瓜大幅减产。本研究从美国农业研究菌种保藏中心(Agricultural Research Se...黄瓜枯萎病由黄瓜专化型尖镰孢菌(Fusarium oxysporum f.sp.cucumerinum,Foc)侵染引起,是黄瓜生产中较难防治的一种土传病害,发病时多造成植株萎蔫枯死,可导致黄瓜大幅减产。本研究从美国农业研究菌种保藏中心(Agricultural Research Service Culture Collection,NRRL)获得了一株可产生抗菌肽的木霉菌株3199,经形态学和分子生物学鉴定确定为苇状木霉(Trichoderma arundinaceum)。平板对峙试验发现菌株3199对Foc抑制效果明显。盆栽试验表明菌株3199孢子悬浮液(浓度1×10^(8)个孢子·mL^(-1))灌根对黄瓜枯萎病的防效为51.3%。进一步对该菌株的抑菌活性物质进行分析,发现其发酵液乙酸乙酯提取物(12 mg·mL^(-1))可显著抑制Foc生长。结果表明,T.arundinaceum菌株3199可代谢产生抑制Foc的活性天然产物,在黄瓜枯萎病生物防治方面有较大应用潜力。展开更多
This paper summarizes the results of our study of the pinewood nematode(Bursaphelenchus xylophi-lus).By population genetic analysis,it was determined that there was no genetic bottle caused by the founder effect and g...This paper summarizes the results of our study of the pinewood nematode(Bursaphelenchus xylophi-lus).By population genetic analysis,it was determined that there was no genetic bottle caused by the founder effect and genetic drift in the Chinese invasive population.Multiple invasions with large amounts of nematodes from different sources led to rich genetic diversity in the invasive population.Keeping high genetic diversity in the invasive process may be one of the genetic mechanisms in its successful invasion.By testing interspecies competition,it was shown that,with high fecundity and a strong competitive ability,B.xylophilus outcompeted the native species B.mucronatus in the natural ecosystem during the invasion process.Competitive displacement may be one of the ecological mechanisms of B.xylophilus's invasion.In addition,an unequal interspecific hybridization with intro-gress was in favor of the invasive species which also accelerated the replacement of B.mucronatus by B.xylophilus.The structures,functions and evolutions of a few important genes that are closely related to the ecological adaptation of pinewood nematodes were studied to explore the molecular mechanism of its ecological adaptations.Further,the resistance and resilience mechanism of the pine ecosystem invaded by pinewood nematodes was also investigated.The results of these studies uncovered a portion of the genetic and ecological mechanisms of PWN's successful invasion and laid a foundation for further study to obtain a comprehensive interpretation of the mechanisms of the nematode invasion.The results also provided a scientific basis for effectively controlling the occurrence and spread of pine wilt disease which is caused by nematodes.Various aspects requiring further investigation are considered.展开更多
文摘黄瓜枯萎病由黄瓜专化型尖镰孢菌(Fusarium oxysporum f.sp.cucumerinum,Foc)侵染引起,是黄瓜生产中较难防治的一种土传病害,发病时多造成植株萎蔫枯死,可导致黄瓜大幅减产。本研究从美国农业研究菌种保藏中心(Agricultural Research Service Culture Collection,NRRL)获得了一株可产生抗菌肽的木霉菌株3199,经形态学和分子生物学鉴定确定为苇状木霉(Trichoderma arundinaceum)。平板对峙试验发现菌株3199对Foc抑制效果明显。盆栽试验表明菌株3199孢子悬浮液(浓度1×10^(8)个孢子·mL^(-1))灌根对黄瓜枯萎病的防效为51.3%。进一步对该菌株的抑菌活性物质进行分析,发现其发酵液乙酸乙酯提取物(12 mg·mL^(-1))可显著抑制Foc生长。结果表明,T.arundinaceum菌株3199可代谢产生抑制Foc的活性天然产物,在黄瓜枯萎病生物防治方面有较大应用潜力。
基金Supported by the National Key Basic Research and Development Program of China(Grant Nos.2009CB119200 and 2002CB111400)
文摘This paper summarizes the results of our study of the pinewood nematode(Bursaphelenchus xylophi-lus).By population genetic analysis,it was determined that there was no genetic bottle caused by the founder effect and genetic drift in the Chinese invasive population.Multiple invasions with large amounts of nematodes from different sources led to rich genetic diversity in the invasive population.Keeping high genetic diversity in the invasive process may be one of the genetic mechanisms in its successful invasion.By testing interspecies competition,it was shown that,with high fecundity and a strong competitive ability,B.xylophilus outcompeted the native species B.mucronatus in the natural ecosystem during the invasion process.Competitive displacement may be one of the ecological mechanisms of B.xylophilus's invasion.In addition,an unequal interspecific hybridization with intro-gress was in favor of the invasive species which also accelerated the replacement of B.mucronatus by B.xylophilus.The structures,functions and evolutions of a few important genes that are closely related to the ecological adaptation of pinewood nematodes were studied to explore the molecular mechanism of its ecological adaptations.Further,the resistance and resilience mechanism of the pine ecosystem invaded by pinewood nematodes was also investigated.The results of these studies uncovered a portion of the genetic and ecological mechanisms of PWN's successful invasion and laid a foundation for further study to obtain a comprehensive interpretation of the mechanisms of the nematode invasion.The results also provided a scientific basis for effectively controlling the occurrence and spread of pine wilt disease which is caused by nematodes.Various aspects requiring further investigation are considered.
