稻瘟病抗病育种研究

Studies on the Breeding of Blast Resistant Rice

自1986至1990年对云南西南175、滇榆1号及滇型杂交粳稻恢复系之一的南25三个丰产而抗瘟性差的品种,用能抗云南优势小种和潜在危险性小种的16个抗病品种作抗源,与它们杂交,共配制19个杂交组合,进行生产品种改造.通过对 F_4、F_5和5个高代材料的抗性研究表明,对于抗病亲本为单基因的,其杂交后代宜采用抗病亲本的非致病小种进行混合接种,严格淘汰感病植株,在第5代转入以农艺性状为主并继续用混合接种法淘汰感病植株进行选育;对于抗病亲本为二基因或二基因以上的,F_2、F_3可采用抗病亲本的非致病小种混合接种淘汰感病植株,在 F_3根据农艺性状优劣,筛选优良单株,在 F_4用抗病亲本的非致病小种分别接种这些单株后代,把反应型相同的归属一类,以后用对应抗病反应的非致病小种混合接种这一类单株后代,定向选育,这样有可能从一个优良组合后代中选育出多个丰产抗病的优良品种.本研究表明,金刚的抗性基因已导入到西南175,大理1001、福锦、密阳23的抗性基因已导入到滇榆1号,这4个高代材料农艺性状较好,通过继续选育有可能成为优良品种.

During 1986～1990,we used three major cultivated rice varietise,Southwest 175,Dianyu No.1,South 25,and one of the restoring lines of crossed Japonica of Dian type in Yunnan which are all highly yielded,but susceptible to rice blast crossed with 16 varieties,resistant against the dominant races and the potential dangerous physiological races for improving their resistance to rice blast and 19 crosses have been done successfully.Through the resistance assessment of the F4,F5,and 5 progenies of high generations suggested that if there is monogenic in the resistant parentage,their proge- nies from the cross are better to be inoculated by combined avirulent races and the sus- ceptible plants are eliminated,and in F5 the main breeding process should be turned to the selection of agronomic characters and further elimination of susceptible plants,and continuing selection and breeding,and if there are two or more genes in the resistant par- entage,their progenise of F2 and F3 should be inoculated by combined avirulent races and the susceptible plants are eliminated,in F3 the good plants are screened according to prominent agronomic chareters,and in F4 those plants are inoculated respectively by avirulent races,then put together the plants with same reaction type into a group and to be inoculated by the combined avirulent races,then,by consecutive selection more resistant and highly-yielded varieties would be bred from the progenies of a good com- bination. The study indicate that Jingang had transmitted its resistant genes to Southwest 175, and Dali 1001,Fukunishik and Miyang 23 had respectively transmitted their resistant genes to Dianyu No.1.The 4 progenies of high generations with prominent agronomic characters will possibly become good lines by continuing selection and breeding.