黑龙江省东部大豆疫霉群体结构及其时空动态

为明确大豆疫霉群体结构及其时空变化规律,连续3年对黑龙江省东部4个具有代表性地块桦南县土龙山镇生产田Ht、桦南县曙光一队生产田Hs、黑龙江省农科院佳木斯分院大豆品种试验田Jn和农垦科学院大豆品种试验田Nk土样,采用叶碟诱捕法分离其中的大豆疫霉,利用一套含单个不同抗病基因的大豆近等基因系,通过国际通用下胚轴伤口接种法鉴定大豆疫霉生理小种。结果表明,379株大豆疫霉分别属于105种致病型,其中包括24个生理小种,1种IRT和80种新致病型,每种致病型优势度不明显。24个生理小种中,0、10、14和40号小种为中国首次报道。供试大豆疫霉群体对单个Rps基因的致病频率显示,在黑龙江省东部种植含有Rps7基因的大豆品种风险较高,而种植含有Rps1c、Rps1k和Rps3a基因的大豆品种较安全。随着时间推移,黑龙江省东部大豆疫霉单个菌株聚合对更多Rps基因毒性,单个菌株毒性增强。大豆疫霉群体毒性结构复杂,且随时间推移群体毒性也增强。空间上,生产田大豆疫霉群体较试验田群体毒性结构更复杂多样。

Spatial-temporal dynamics of Phytophthora sojae on population structure in the east of Heilongjiang Province

In order to clarify the spatial-temporal dynamics of population structure of Phytophthora sojae in Heilongjiang Province,the soil samples of four typical fields,including the production fields of Ht and Hs and the experimental fields of Jn and Nk,were isolated for Phytophthora sojae by using a modified leaf disc baiting method.The pathotypes of the P.sojae isolates were determined by using the universal hypocotyl inoculation method on a set of soybean near-isogenic line which had eight different Rps alleles.The investigation showed that 379 isolates belonged to 105 pathotypes which included 24 races,1 IRT and 80 new pathotypes.The dominance of each pathotype was not obvious.Race 0,10,14 and 40 were the first report in China.The virulence frequencies of the tested P.sojae population to each single Rsp gene showed that soybean cultivars containing Rps7 gene would have a higher risk and these containing Rps1c,Rps1k,and Rps3a genes were more secure than the other five Rps genes in the east of Heilongjiang.P.sojae in the east of Heilongjiang tended to integrate more virulence to Rps genes within individual isolate with time,which resulted in appearance of more virulent isolates.The virulence composition of P.sojae population in the east of Heilongjiang became more complicated and more virulent with time.Compared with the experimental fields,the virulence structure of P.sojae population from production fields was more complex.