摘要： 为了研究大豆疫霉生理小种和致病型随时间和空间而变化的规律，连续4 a从黑龙江省东部地区发病较严重的4个代表性地块采集土壤样品，采用叶碟诱捕法分离出其中的大豆疫霉，将确认为大豆疫霉的菌株利用下胚轴伤口接种法鉴定其生理小种和致病型，对于科学使用大豆品种具有重要意义。结果表明，497株大豆疫霉属于135种致病型，包含29个生理小种，1株IRT和105个新致病型，其中16，18，22，28，35号生理小种为中国首次报道，而4，33，38，39，43，48，49号生理小种未分离到。13号小种分离频率最高，为3.2%，1号小种分离频率仅为2.4%。结果显示，黑龙江东部大豆疫霉群体致病力偏弱，对8个Rps基因致病频率为27.8%~53.1%，其中对Rps1k、Rps3a、Rps1c和Rps6基因的致病频率低于35%，对Rps7基因的致病频率为53.1%，说明在黑龙江东部种植含有Rps1k、Rps3a、Rps1c和Rps6基因的大豆品种较安全，种植含Rps7基因的大豆品种较危险。随时间推移黑龙江东部大豆疫霉生理小种和致病型分化迅速，致病型变得复杂多样，对绝大多数Rps基因致病频率增加，单株毒性和群体致病力均增强；生理小种和新致病型在试验田与生产田间数量差异不大，但种类差别较大，试验田单株毒性和群体致病力更强。

关键词: 大豆疫霉, 生理小种, 毒性结构, 时空动态, 黑龙江东部

Abstract: In order to study the spatial-temporal dynamics of physiological races and virulence structure of Phytophthora sojae, the soil samples were collected from four destructive fields in Eastern Heilongjiang Province for four years, and the P.sojae isolates were isolated by modified leaf disc baiting method. The isolates were acquired after morphological and DNA molecular identification, and their physiological races and virulence structure were identified using the universal hypocotyl inoculation method. The results showed that the 497 isolates included 135 pathotyps with 29 races, 1 IRT and 105 new pathotyps, of which races 16, 18, 22, 28 and 35 were first reported in China, while races 4, 33, 38, 39, 43, 48 and 49 were not detected. Race 13 had the highest isolation frequency of 3.2%, and race 1 was only 2.4%. It suggested that the virulence of P.sojae population in Eastern Heilongjiang was weak. The virulence frequencies to eight Rps genes varied from 27.8% to 53.1%, of which the virulence frequencies to Rps1k, Rps3a, Rps1c and Rps6 genes were less than 35%, but that to Rps7 gene reached to 53.1%, indicating that the soybean cultivars containing Rps1k, Rps3a, Rps1c or Rps6 were safer in Eastern Heilongjiang and that containing Rps7 was more dangerous. The races and pathotypes of P.sojae in Eastern Heilongjiang differentiated rapidly with time, their virulence and population pathogenicity had enhanced, and the virulence frequencies to majority of Rps genes increased. The number of races and new pathotypes had no significant difference between the production field and the experimental field, but their types were quite different and the virulence of single isolate and population in experimental fields was stronger.

Key words: Phytophthora sojae, Physiological race, Virulence structure, Spatial-temporal dynamics, Eastern Heilongjiang

中图分类号: 

• S432.1