Breeding Of Rice Vaccine 131BL1 And Rice Vacancy 131BL6

Rice is one of the most important crops in the world and the main staple of our country. Rice blast which is caused by fungi is one of the three main rice diseases. Compared to the other two rice diseases, the rice blast causes more rice product loss. Culturing a new rice variety with the virtue of persisting resistances to rice blast is the most economic and effective method to prevent the disease of rice blast. The traditional blast-resistant rice culturing method is not only tending to cause the loss of targeting gene but also hard to facilitate the introduction of the blast resistant gene from the indica rice variety to the japonica rice variety for the undesirable gene redundancy. The molecular marker-assisted selection(MAS) could help to select the targeting rice plants fast and accurately, reduce the linkage-redundancy and facilitate the recovery of genetic background to the maternal genetic background. So MAS could be used to culturing the blast-resistant rice variety.The rice variety Kongyul31 is the major rice variety planted in Heilongjiang Province, as it is with the characteristics of short growing period, good quality, high product, tolerance to cold and plastic adaptation to different kinds of environments. As the wide variety of rice blast physiological races and the fast changes of the advantaged races, the Kongyul31 becomes fragile and is suffering from this disease. This research aims to improve the blast-resistant ability of Kongyu131 and culture two new rice varieties Kongyu13BL1 (Kongyu131(Pi2)) and Kongyu131BL6 (Kongyul31(Pi9)) by introducing two broad-spectrum blast-resistant genes Pi2 and Pi9 into Kongyu131 respectively with MAS method. The main results of this research are as follow.1.One SSR marker PI2-4 which is close linked to the targeting gene Pi2 was selected according to its polymorphism between the donor parent BL6 and the receptor parent Kongyu131 and could be used to identify the foreground of Kongyu131BL1. One SSR marker PI31 which is close linked to the targeting gene Pi9 was selected according to its polymorphism between the donor parent K22 and the receptor parent Kongyu131 and could be used to identify the foreground of Kongyu131BL6.2.Two SSR markers RM19778 and RM19960 were selected. The physical distance of RM19778 to the targeting gene Pi2 or Pi9 is 1.1Mb and the physical distance of RM 19960 to the targeting gene Pi2 or Pi9 is 2.6Mb. The two markers could be used to identify the cross changes of the two sides of Pi2 or Pi9, which would be effectively reduce the linkage-redundancy in the culturing of Kongyu 131BL1 and Kongyu131BL6.3.29 SSR markers and 27 SSR markers were selected to identify the background of Kongyu 131 BL 1 and Kongyu 131BL6 respectively.4.By the foreground selection and background selection of BC4F1 generation of Kongyu13BL1 and blast-resistant test in the field, the rice plants which were Pi2 positive and highly resistant to rice blast were got. And by the foreground selection, the Pi2 homozygous rice plants were obtained. The foreground selection, background selection and cross changes selection were applied to the BC5F1 generation rice plants, and the rice plants which contained Pi2 gene and were with the 100% recovered genetic background were got. These rice plants could be used to culture Kongyu13BL1.5.According to the selection of foreground of BC3F1 generation of Kongyu131BL6, the rice plants which were Pi9 positive were got. And the BC4F1 generation plants were got by crossbreed. By the foreground selection and background selection of BC4F1 generation rice plants and blast-resistant test in the field, the rice plants which were Pi9 positive and highly resistant to rice blast were got. And by the foreground selection, the Pi9 homozygous rice plants were obtained. The BC5F1 generation plants were got by crossbreed. The foreground selection, background selection and cross changes selection were applied to the BC5F1 generation rice plants, and the rice plants which contained Pi9 gene and were with the 96.3% recovered genetic background were got. These rice plants could be used to culture Kongyu131BL6.