【作者】 阮辉辉；

【导师】 安德荣；

【作者基本信息】 西北农林科技大学 ， 植物病理学， 2008， 硕士

【摘要】 水稻白叶枯病是由革兰氏阴性菌黄单胞杆菌(Xanthomonas oryzae pv.oryzae, Xoo)水稻变种引起的一种维管束病害,是全球水稻生产中最重要的细菌性病害之一。水稻受害后,叶片干枯,瘪谷增多,米质松脆,千粒重降低,给水稻生产造成了严重的损失。目前,对于白叶枯病的防治除了传统的农业防治以外,主要采用化学防治及培育种植抗病品种,但化学防治成本高且污染环境,因而掌握较好的抗性基因来源,对水稻品种进行遗传改良,培育和种植抗病品种,就成了控制该病害的最好途径。发掘和利用新的水稻抗白叶枯病基因,培育抗白叶枯病新品种是控制该病的最经济有效的手段。近20年来,分子生物学技术的飞速发展及其在植物病理学中的广泛应用,为水稻抗病基因的研究奠定了坚实的基础,新基因的发现、鉴定、定位和克隆不断完善。。目前已有大量的抗病基因被发现,定位并克隆出来,并被广泛的应用于水稻生产上,但由于该病原菌变异频繁,新的病原小种不断出现,导致许多水稻的抗性丧失,这就要求我们不断的开发新的抗病基因,用于培养新的抗病品种。野生稻资源中含有抗逆,高产,抗病等优良性状,从野生稻资源中发掘新的抗病基因是目前水稻抗白叶枯病基因鉴定中的一个热点。疣粒野生稻具有对白叶枯病免疫、高抗细菌性条斑病、高抗褐稻虱、旱生和耐荫等重要的生理生态特征,在栽培稻遗传改良中极具潜力。我们利用体细胞杂交技术,获得大量的疣粒野生稻与栽培稻“大粒香”杂交再生植株,将这些再生植株与栽培稻“大粒香”回交,构建了F2群体,用广致菌P6对亲本和F2群体进行抗病检测鉴定,抗感株之比接近1:3,采用SSR分子技术,随机选用了覆盖水稻12染色体上的412对引物对亲本和F2代进行多态性分析,获得8对位于第12染色体上的SSR标记与F2代田间接种检测较符合,用最终筛选出水稻抗白叶枯病新基因xa32(t),并将其最终定位在水稻的第12染色体上,与RM8216和RM20A的连锁距离分别为6.9cM和1.7cM。更多还原

【Abstract】 The Bacterial Blight of rice (BBR) which caused by (Xanthomonas oryzae pv. oryzae, Xoo) is one of the most important bacterial disease on the world, it take heavy loss to the world rice product.When the pathogen invade into the rice, the disserve is very severity, and the chemical control is not so useful as we wish. So it always bring on seriouse output loss. It will be an economical and effective way to find and use new resistance genes to bacterial blight to breed new rice cultivars to control the epidemic of the bacterial blight. Up to present, there have been a lot of resistance gene found and cloned, and many of them were applied to the production of rice. But for the pathogenic bacteria variance frequently, the disciplinarian on the disease occurrence is complex, and there are much differences between planting areas, the agrochemical control is not so good but take with environment pollution, time consuming, hard sledding and so on. Therefore, using high efficiency and broad-spectrum resistant gene for genetic modify maybe the best way to control this disease.The wild rice is good at stress resistance, high-yelding, diease resistance. Therefore, it is attractive to find new resistance gene for Bacterial blight from the wild rice cultivars. In this experiment, we used SSR technology to identify and map the new gene from somatic hybridization generation of the O.meyeriana crossed with O.sativa cv Dalixiang. Finally, we find a new resistance gene xa32(t) and map it on the long arm of 12 chromosome, named xa32(t) temporarily. The genetic distance from RM8216 and RM20A on the same side is 6.9cM and 1.7cM.更多还原