安徽稻区稻瘟病菌生理小种的鉴定

稻瘟病菌的致病性分化严重,生理小种多、变化快,是水稻抗病品种容易丧失抗性而沦为感病品种的主要原因之一。笔者用中国统一鉴别品种对2002年安徽稻区308个稻瘟病菌的单孢菌株进行了生理小种的活体和离体鉴定,结果表明:两种鉴定方法的鉴定结果基本一致,稻瘟病菌ZA、ZB、ZC、ZD、ZE、ZF、ZG和ZH等8个群在安徽省均有分布,但其优势群为ZB群,ZB13和ZB15为优势小种;优势小种在不同水稻品种上出现的频率存在一定差异。在供试的四种保鲜剂中,以6-BA保鲜效果最好,对离体稻叶接种稻瘟病菌后病情的发展也无明显的抑制作用,适合于稻瘟病菌的离体接种。

Identification of the physiological races of rice blast fungus in Anhui province

The pathogenicity of rice blast fungus has an obvious differentiation, and there are many physiological races, which vary frequently. That is one of the most primary reasons that results in the comedown of the resistance of rice variety, which become sensitive to rice blast disease, sequentially. Three hundreds and eight monoconidial isolates were obtained from rice blast specimens collected from Anhui province in 2002. The physiological races of the isolates were identified with seven Chinese differential rice cultivars in vivo and in vitro; the results showed that the conclusion of identification in vivo and in vitro is substantial agreement. There are eight group physiological races in Anhui province, that is ZA?ZB?ZC?ZD?ZE?ZF?ZG and ZH, respectively. The dominating group was ZB, and the dominating physiological races were ZB13 and ZB15. The physiological races of Pyricularia grisea occurred differently on various rice cultivars. The effects of keeping rice-leaves fresh of Benzimidazole, 6-BA, IAA and NAA were tested and the results were that the effect of 6-BA was the best which could keep the leaves fresh for 13 days, and it did not inhibit the disease potential, so 6-BA is adapted for inoculating the rice blast fungus in vitro.