一种大豆对拟茎点茎枯病抗性鉴定技术体系的构建

Establishment of a technical system for the identification of soybean resistance to Phomopsis stem blight

由Phomopsis longicolla(或Diaporthe longicolla)等拟茎点霉(间座壳)属真菌引起的拟茎点茎枯病是我国黄淮海等地大豆生产中的一种重要茎部病害。利用抗病品种是防控该病最为经济有效的措施。为构建一种大豆对拟茎点茎枯病的室内抗性鉴定技术体系,用于抗病资源的快速筛选,本研究比较了下胚轴创伤接种法、切茎接种法、黄化苗接种法、种子接种法和菌丝块贴茎法等5种接种方法,发现下胚轴创伤接种法具有操作简单、试验周期短、易于判定结果、结果稳定性好的优点。选取5个具有毒力强弱和地域代表性的P.longicolla菌株为鉴别菌株系,建立了抗性结果评价标准,形成了抗性鉴定技术体系。对2020年从黄淮海等地收集的62份大豆主栽品种进行抗性鉴定,发现对强毒力菌株DT3-3-1和弱毒力菌株ZZ1-1高抗的品种分别占31%和68%,有13个品种同时高抗5个菌株(占21%),表明我国大豆主栽品种中存在对拟茎点茎枯病的抗性种质资源。本研究为挖掘大豆对拟茎点茎枯病的抗性资源提供了新的候选方法。

The occurrence of Phomopsis stem blight,caused by Phomopsis longicolla(syn.Diaporthe longicolla)and other Diaporthe/Phomopsis genus fungi,is one of the most serious soybean stem diseases in Huang-Huai-Hai and other soybean-production areas of China.Using resistance varieties is the most economical and effective method to control the disease.To establish a technical system for the indoor and rapid identification of soybean resistance to Phomopsis stem blight,and apply it to identify the disease-resistant germplasm resources of soybean,we compared five inoculation methods,including hypocotyl inoculation with wounding,cut-seedling inoculation,etiolated hypocotyl inoculation,mycelium inoculation on seed,and mycelium inoculation on stem.We found that the hypocotyl inoculation with wounding method has the advantages of simple operation,short test period,easy to determine the results,and good stability.In addition,five representative P.longicolla strains with different virulence levels and from different areas were selected and the evaluation criteria of resistance identification results were established,making up a complete set of resistance identification technical system.The system was used to identify 62 popular soybean varieties collected in 2020 from Huang-Huai-Hai and other regions.Among these soybean varieties,31%and 68%of the varieties showed high resistance to the strong virulence strain DT3-3-1 and the weak virulence strain ZZ1-1,respectively;and 13(21%)varieties were highly resistant to all five P.longicolla strains.The results revealed that there are soybean germplasm resources resistant to Phomopsis stem blight in China.The technical system established in this study provides a new candidate method for mining the soybean germplasm resources which are resistant to Phomopsis stem blight.