MAS Breeding Of Rice Resistance Xa23 To Bacterial Blight And Resistance Pi1, Pi2 To Rice Blast

Rice Bacterial Blight (BB) and Rice Blast (RB) are the most serious rice diseases and widely distributed in the rice cultivation areas. At present, using broad spectrum resistant sources and genes are the key means to improve the rice resistance to BB and RB. NO.386 variety includes the resistant gene Xa23 to BB. NO.105 variety includes main resistant genes Pi1 and Pi2 to RB.SSR marker RM206 is closely-linked to gene Xa23 and used to make molecular identification in (384x386), (385x386) and (387x386) BC₂, BC₃ and F₄ populationsJt's successful to select the plants which contain the segments of RM206, and provide resistant source materials to BB.The No.582 and No.84 have good agronomic characters.NO.105 variety was hybridized separately with No.582 and No.84 to produce F₁, inbred line F₂, F-3. And No.582 was used as the return parent to obtain the (582x105) BC₁ populations. Molecular track was carried out in the separated breeding populations with SSR markers RM144 and SRM24.The RM144 is linked to Pi1,the SRM24 is closely-linking to Pi2.The pyramiding-genes plants that contained the segments of RM144 and SRM24 concurrently was selected to enrich the resistant materials of rice blastRice blast local pathogens of Xia Lei and Yu Lin were gathered in southern of Guangxi. The NO.47, NO. 105 and NO.106 were inoculated by the local pathogens to identify their rice blast resistance.The results showed that NO.47 and NO.105 had a certain resistance to same parts of Guangxi local pathogens. But,their resistances were not steady.