稻瘟病菌对稻瘟灵抗性遗传研究

Inheritance of Magnaporthe grisea resistance to isoprothiolane.

在离体条件下就稻瘟病菌对稻瘟灵抗性的诱导、抗性水平和遗传进行了研究。结果表明，供试３个小种（ＺＡ４９、ＺＦ１和ＺＤ１）４个菌株分别经稻瘟灵５０μｇ／ｍｌ、１００μｇ／ｍｌ和稻瘟灵１００μｇ／ｍｌ＋亚硝基胍０５μｇ／ｍｌ的３种处理诱变，均得到了抗稻瘟灵突变株，在含稻瘟灵的培养基中加入诱变剂亚硝基胍可显著提高稻瘟病菌对稻瘟灵抗性的突变率。上述３个不同处理获得的突变株的抗性水平相似，为野生型亲本的２８～８８倍。突变株对稻瘟灵的抗性在单分生孢子无性系后代可以稳定遗传。

Four wild-type isolates of 3 races in Magnaporthe grisea from Jiangsu Province were induced resistance to isoprothiolane (IPT r) in vitro. IPT r mutants were obtained from all of the 4 tested isolates by inocubated the isolates on PSA medium amended with 100 μg/ml isoprothiolane and with 100 μg/ml isoprothiolane+0 5 μg/ml nitrosoguanidine after 8-60 days. IPT r mutants were also obtained from isolate PO 33 when exposed to PSA medium amended with isoprothiolane with concentration of 50 μg/ml. Mutagen nitrosoguanidine could significantly increase the frequency of mutation of resistance to isoprothiolane in M. grisea. The resistance level of IPT r mutants to isoprothiolane was 2 8-8 8 times higher than that of the isoprothiolane-sensitive wild-type parental isolates. The resistance of IPT r mutants to isoptothiolane was stably inherited in two successive conidium progenies, and resistance levels to isoprothiolane between monoconidial isolates from the same IPT r mutant were not obvious difference.