恶疫霉有性杂交后代的生物学研究  

BIOLOGY OF SEXUAL RECOMBINANTS OF Phytophthora cactorum

作　　者：游春平[1] 王源超[1] 郑小波[1] 

机构地区：[1]南京农业大学植保系农业部病虫监测与治理重点开放实验室,南京210095

出　　处：《植物病理学报》2001年第1期78-83,共6页Acta Phytopathologica Sinica

基　　金：国家自然科学基金! (39770 2 9);教育部跨世纪优秀人才培养计划基金

摘　　要：将 2个带有不同抗药性标记的恶疫霉菌株配对 ,培养 36 d后诱导其卵孢子萌发 ,从 376 0个单卵孢株中 ,获得 50株带有双亲标记的杂交个体。对其中 32株杂交个体的生长速率、有性和无性繁殖能力、卵孢子和游动孢子萌发率、致病力及对高温的耐受力等生物学性状进行测定。结果显示 ,测试的 32株杂交个体在 L BA培养基上均能较好地生长 ,有 2 4株的杂交个体的生长速率介于 2亲本之间 ;在 L BA和 SL培养基上 ,大多数杂交个体均能产生较大数量的卵孢子 ,有 37%的杂交个体在 SL培养基上产卵孢子能力显著大于双亲 ,仅有 1个杂交个体不产生卵孢子 ;在人工培养条件下 ,大多数供试杂交个体可以产生较大数量的孢子囊 ,其中 15株杂交个体产孢子囊能力处于双亲之间 ;被测的杂交个体产生的卵孢子或游动孢子均可以萌发形成有效的单孢株 ,有 2 2株的杂交个体的卵孢子萌发率大于 50 % ;被测的杂交个体接种在苹果上都有较强的致病力 ,有 16株杂交个体的致病力显著大于双亲。表明在群体水平上恶疫霉有性杂交后代具有较强的生活能力 ,提示同宗配合恶疫霉不同菌株间的有性重组 。Fifty sexual hybrids were obtained from 3760 single oospore isolates from pairing of two Phytophthora cactorum isolates (AP14M r 1 52 with resistance to metalaxyl and sensitivity to chloroneb, PK9Cn r 2 24 with resistance to chloroneb and sensitivity to metalaxyl) which were incubated on SL media for 36 days. Biological characteristics of randomly selected 32 hybrids were tested in growth rate, sexual and asexual reproduction capacity, oospore and zoospore germination rate,pathogenicity, and tolerance towards high temperature. Results were as follow, the 32 hybrids tested grew well on lima bean agar (LBA), 24 of which were the intermediate between their parents in growth rate; most of hybrids tested produced a great number of oospores on LBA or SL,37% of hybrids produced much more oospores than their parents on SL; most of hybrids produced a great number of zoosporangia in vitro , 15 hybrids were the intermediate between their parents in production of zoosporangia; oospores or zoospores of hybrids tested may germinate and create effective single oospore or zoospore isolates; the germination rate of oospores from 22 hybrids were more than 50%; the tested hybrids inoculated on apple fruits were of virulent, 16 of which were of significantly stronger pathogenicity as compared with their parents. These results show that sexual hybrids from homothallic P. cactorum were of strong fitness at population level in vitro , indicating that sexual recombination of different isolates might play a important role in enhancing the diversity of P. cactorum.

关 键 词：同宗配合 恶疫毒 有性杂交后代 生物学性状 植物病原菌 遗传多样性 

分 类 号：S432.44[农业科学—植物病理学] Q949.323.3[农业科学—农业昆虫与害虫防治]