稻瘟病抗性机制和遗传规律研究初报

 由一九八三年起,利用水稻广谱感病品种和抗性较差的生产品种与抗病品种杂交,进行抗性基因分析.结果有丽江新团黑谷×黑节谷等十二个组合F₂代的抗感分离比为3:1,抗性由一对显性基因控制;丽江黑谷×南56等两个组合的分离比为15:1,抗性是由两对同义基因控制;丽江新团黑谷×小白谷等7个组合的分离比为9:7,抗性是由两对显性互补基因控制.利用日本七个鉴别菌系测定了云南36个品种,其中24个属Pi——Z^t型,5个属于Pi——K、Pi——a型,3个属于Pi——ta型,另外属于Pi——K^S、Pi——i、Pi——K、Pi——a的各一个.利用日本13个单基因鉴别品种测定了云南稻瘟病菌株46个,结果摸清了各菌株所具有的致病基因和非致病基因,为筛选我们的一套鉴别菌系打下了基础.

STUDIES ON THE MECHANISM AND HEREDITY OF RESISTANCE OF RICE TO BLAST DISEASE

Since 1983 the resistance genes of rice varieties have been analysed by hyh ridizing the wide-range Susceptible and moderate susceptible Varieties With sore resistant varieties.The results indicated that the segregation ratio of resistance and susceptibility of F₂ generation from Ljianxintuonheigu and other Ⅱ crosses was 3:1,The resistance was controlled by one dominant gene; The segregation ratio of Lijianxintuonheigu x Nan 56 and another combination was 15:1,Showing that the resistance was controlled by two polymeric genes; the segregation ratio of Lijianxintuonheigu x Xiaobeigu and other 6 crosses was 9:7,the resitance was contyolled by two dominant complementary genes.36 Yunnan Varieties were tested by using 7 Japanese differential fungus strains of Pyricularia oryzae.The results confirmed that 24 varieties have a common Pi-z genotype;5 varieties have Pi-K,Pi-a genotype;3 Varieties have a common Pi-t genotype;and each of 4 varieties has Pi-K^S.Pi-K, Pi-a and Pi-i respectively.In addition,13 Japanse monogenic differential Varieties were also used for assaies of 46 Yunnan strains of P oryzae and the results verified that eacn strain possesses its virulent and aviruient genes Which will be usefull for furthr screening of a set of our own differential fungus Strains.