澳洲野生稻抗虫性的转育研究

EVALUATION OF THE NEWLY BRED RICE VARIETIES RESISTANCE TO BACTERIAL BLIGHT

采用改良的有性杂交与组织培养胚胎挽救法，进行栽培稻与澳洲野生稻的种间杂交，获得４个组合７个变异株。用具丰产性和适应性广泛的栽培稻与变异株进行杂交，选育出１２个某些经济性状明显超亲的或综合经济性状较好的种间杂交株系，可作为改良栽培稻的种质资源。以红莲型不育系作为桥梁母本进行自然授粉杂交的成功率较高。利用水稻分蘖扩繁潜力大的特点，可用大量的遗传背景不同的栽培稻作父本，与为数不多的ＡＥ杂Ｆ１代进行再杂交，可获得较多的子代材料供筛选。筛选结果说明，以广Ａ×ＳＢ１变异株与丰矮占再杂交１～２次选出的优良株系较多、效果最好。

One hundred and twenty five newly bred rice varieties were inoculated with 5 pathotypes, Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ, of Xanthomonas oryzae pv. oryzae , to evaluate their resistance. Results indicated that the varietal resistance may be classified into seven types, namely SSSSS, RSSSS, RRSSS, RRRSS, RRRRS, RRRSR, and RRRRR, which shows the difference of resistance against these 5 pathotypes. Breeding and utlizing of resistance varieties must base on local pathotypes distribution. Some varieties possessing resistance to the Guangdong predominant pathotype Ⅳ were recommened to plant in Guangdong. The occuring rate of varieties resistance to pathotype Ⅳ differed in different rice types: conventional rice was higher than hybrid rice, indica type was higher than japonica type. Most varieties of the japonica rice were resistant to pathotype Ⅴ, but only a few of the indica rice were. Strong correlation was shown between the two types of japonica togther with indica and the two pathotypes of Ⅳ as well as Ⅴ.