来源于疣粒野生稻的白叶枯病新抗源的鉴定

疣粒野生稻对白叶枯病高抗甚至免疫。粳稻品种8411与疣粒野生稻体细胞杂交获得了2个高抗所有栽培稻白叶枯病抗性基因均不能抵御的国际广致病菌系P6的新种质SH5和SH76,遗传分析鉴定出新种质含有1个抗P6小种的显性基因。本研究以高感白叶枯病水稻品种IR24及携带不同抗性基因的16个材料为参照,对分蘖期、孕穗期的SH5和SH76分别接种11个白叶枯病小种,抗性分析表明SH5和SH76的抗谱广,与IRBB21(Xa21)抗谱一致,与IRBB5(xa5)、IRBB7(Xa7)和Asominori(Xa17)的较相近。用Xa21的分子标记pTA248和XA21检测,确定SH5和SH76不携带Xa21基因,前期研究结果证实新种质中不含xa5和Xa7;与Asominori的杂交试验表明其抗性基因与Xa17基因不等位。这些结果表明SH5和SH76中存在1个抗P6小种的新基因。

Identification of New Rice Germplasms for Resistance to Bacterial Blight from Oryza meyeriana L.

The wild rice species Oryza meyeriana Baill exibited high resistance or immunity to bacterial blight (BB). Two new germplasms, SH5 and SH76, were acquired through somatic hybridization with O. meyeriana L. as the donor parent. Using 11 BB races, the resistance spectrum of SH5, SH76 and other 16 reference lines carrying different major BB resistance genes were compared at the tillering and booting stages. The results showed that SH5 and SH76 had a broad resistance spectrum. The resistance spectrum of SH5 and SH76 was the same as IRBB21 (carrying Xa21), and similar to IRBB5 (carrying xa5), IRBB7 (carrying Xa7) and Asominori (carrying Xa17). The molecular marker pTA248 and XA21 were used to detect whether Xa21 existed in SH5 and SH76. The allelic test of Xa17 was conducted by crossing SH5 and SH76 with Asominori, respectively. The results combined with those of our previous analysis indicated that no Xa5, Xa7, Xa17 and Xa21 but a new resistance gene might exist in SH5 and SH76.