水稻空间诱变育种抗稻瘟病研究

The rice blast resistance of space-induced line

粤香占和青华占2个水稻品种的种子经过高空气球搭载后,选育出株型好、分蘖力强,产量提高的空间诱变高代(6代以上)品系。为了解空间诱变品系对稻瘟病的抗性变异情况,采用36个广东省稻瘟病菌不同致病型的代表菌株分别对粤香占和青华占及其空间诱变品系进行抗谱测定。研究结果表明:①空间诱变能使水稻品种产生稻瘟病抗性变异,有的诱变品系比原种抗病,有的则比原种感病。②空间诱变产生的抗病性变异比较复杂,不同品种的抗病性变异不一样。③空间诱变引起的稻瘟病抗性变异有可能是由多个抗病基因引起的。④空间诱变可以获得抗稻瘟病的特异种质。粤香占是感病品种,本研究测定的抗谱为25%,从其空间诱变品系中,获得高抗稻瘟病的2个品系 YX-8和 YX-9,抗谱达到94.4%。空间诱变抗病品系的穗颈瘟鉴定试验正在进行中。

High generation space-induced rice lines （6th and up） derived from the seeds of Yue-xiangzhan and Qing-hua-zhan, which were carried by high spaced balloon. The agronomic character including plant type, filleting ability and yield of new lines were better than the original ones. The blast resistance of these space-induced lines and their original varieties had been screened based on the test of resistance spectrum to fungi in greenhouse by using 36 representative isolates with different pathogenicity and genetic lineages of Magnaporthe grisea from Guangdong. Space inducement could cause the blast resistance variation. Some induced lines had stronger blast resistance than the original varieties, and the others were more susceptible. The resistance variation was complicated, different seeds had different variation. The variation of resistance by space inducement might be from mutation of different resistance genes. Special germplasm with broad resistance spectrum to blast could be obtained by space inducement. Yue-xiangzhan is a variety susceptible to rice blast, whose resistance frequency is just only 25% ,while two spaceinduced lines, YX-8 and YX-9, from Yue-xiang-zhan showed high resistance to blast and their resistance frequency were 94.4%. The neck blast resistance test of these high generation space-induced lines will be tested in future.