中国小麦条锈菌转主寄主小檗的鉴定

用萌发的小麦条锈菌冬孢子接种采自陕西省境内的陕西小檗、少齿小檗和长穗小檗，3种小檗均产生了性孢子器和锈孢子器。用人工接种小麦条锈菌冬孢子在陕西小檗上产生的锈孢子器接种小麦铭贤169产生了典型的条锈菌夏孢子堆症状。特异性PCR和DNA序列分析表明，人工接种产生于小檗上的锈孢子、接种锈孢子于小麦上产生的夏孢子堆与小麦条锈菌DNA的ITS区序列完全一致。更为重要的是，用采自田间受锈菌侵染的小檗叶片产生的锈孢子接种小麦铭贤169，经培养在小麦铭贤169叶片上产生了典型的条锈病症状。从而证实，在自然条件下，在中国，小檗不仅可作为小麦条锈菌的转主寄主，而且小麦条锈菌可在小檗上完成其有性繁殖过程。这一发现对进一步揭示我国小麦条锈菌高度的群体遗传多样性与毒性变异机理、完善小麦条锈病的防治策略具有十分重要的理论和实际意义。

Confirmation of Berberis spp. as alternate hosts of Puccinia striiformis f. sp. tritici on wheat in China

Pycnia and aecia were produced on Berberis shensiana, B. potaninii and B. dolichobotrys in Shaanxi Province after inoculation using germinating telia of Puccinia striiformis f. sp. tritici. Wheat cultivar Mingxian 169 was inoculated with aeciospores produced from the inoculated B. shensiana, and resulted in typical uredia of P. striiformis on the wheat leaves. Analyses using polymerase chain reaction and DNA sequence confirmed the rust fungus as P. striiformis f. sp. tritici. Wheat Mingxian 169 inoculated using aeciospores from the rust-infected leaves of B. shensiana collected from fields, produced uredia typical of stripe rust. In natural conditions, therefore, it demonstrated barberries (Berberis spp.) not only serve as alternate hosts for stripe rust pathogen of wheat in China, but the pathogen of wheat stripe rust, P. striifromis f. sp. tritici, can also perform its sexual stage on Berberis spp. This finding will provide a more satisfactory interpretation for high level of genetic diversity and virulence variation, and a powerful support to improve strategies for a better control of wheat stripe rust in future studies in the country.