蚕豆和豌豆锈病病原菌的分子鉴定

为明确我国热带和亚热带地区蚕豆Vicia faba和豌豆Pisum sativum锈病的病原菌种类,通过致病性测定和ITS序列系统发育分析对来自我国云南省玉溪市的4份豌豆锈菌分离物及云南、广西、重庆和四川省(区、市)的5份蚕豆锈菌分离物进行系统鉴定。结果显示,分离自豌豆的锈菌WX1分离物对蚕豆和豌豆均具有高致病性,在侵染叶片上产生大量锈子器;分离自蚕豆的锈菌CX3分离物仅对蚕豆具有高致病性,能在叶片上产生大量夏孢子,而对豌豆的致病性相对较低,仅产生少量的夏孢子堆;分离物WX1和CX3对小扁豆和鹰嘴豆不具有致病性。基于ITS序列系统发育分析表明,所有不同寄主来源的蚕豆单胞锈菌分离物均聚类于一个系统发育组,但分离自蚕豆和豌豆的分离物分别聚类在不同的亚组。表明分离自云南省玉溪市豌豆上的蚕豆单胞锈菌Uromyces viciae-fabae应为豌豆专化型,定名为U. viciae-fabae ex P. sativaum,而来源于云南、广西、重庆和四川省(区、市)的蚕豆锈病病原菌为蚕豆专化型U. viciae-fabae ex V. faba。

Molecular identification of pathogens causing rust disease on faba bean and pea

In order to clarify the pathogen causing rust diseases on pea and faba bean in tropical and subtropical regions of China, four pea isolates from Yuxi City, Yunnan Province, and five faba bean isolates from southwestern provinces (Yunnan, Guangxi, Chongqing and Sichuan) were systematically identified through pathogenicity tests and phylogenetic analysis of ITS sequences. The results showed that the pea isolate WX1 was highly pathogenic to both faba bean and pea and produced abundant aecia on inoculated leaves. The faba bean isolate CX3 was highly pathogenic to faba bean and produced abundant uredia on inoculated faba bean leaves, while it only produced a few small uredia on inoculated pea leaves. Neither of the two isolates was pathogenic to lentil or chickpea. Phylogenetic relationship analysis based on ITS sequences showed that the isolates collected and all isolates of U. viciae-fabae from different hosts were clustered into a single phylogenetic group. Moreover, the isolates from faba bean and pea were clustered into respective subgroups according to their hosts. This indicated that the isolates from pea in Yuxi City, Yunnan Province and those from faba bean in the four southwestern provinces were host-specific although all of them belong to the same species, U. viciae-fabae. The isolates from pea were named as U. viciae-fabae ex P. sativum, and the isolates from faba bean were confirmed as U. viciae-fabae ex V. faba.