Using Mas Technology To Cultivate Cold Blast Resistance Rice Varieties Kongyu 131 (pi1/pi2)

Blast is one of main diseases of rice, it can cause huge losses in agricultural economy in the Blast-Pop-Year. Cultivating blast-resistance varieties is a economical and effective method to prevent the hazard of blast. Heilongjiang rice are lack of breeding genetic resources. Long-term and large-scale cultivation of rice with blast- resistance gene, that will casue the variation of structure of Pyricularia grisea in some areas, and generate some new advantage race. New cultivated varieties which growes 2-3 years can not be used because of blast infection, so there is an urgent need to import new blast-resistance gene into the genome of cold regions rice.Pi1 and Pi2 are wide-spectrum, major and dominant blast resistant genes, they can resist the most of Chinese Pyricularia grisea. In this study, in order to develop new line Kongyu131(Pi1/Pi2) with blast resistance in the cold regions, at the same time, to remove unfavorable characteristics of temperature and light sensitivity, Pi1 and Pi2 genes which exist in the early indica rice BL6 were intrduced into the genome of Kongyu131 by using backcross breeding and MAS technology. The main results were showed below.1. 24 SSR markers distributed uniformly in 12 chromosome of rice were selected, which have polymorphism in donor parent BL6 and acceptor parent Kongyu131. They can be used to select background in developing Kongyu131(Pi1/Pi2).2. BC₂F₁ and BC₂F₂ plants were obtained by the backcross between BC₁F₁ plants with Pi1 and Pi2 genes and Kongyu131. BC₂F₂ plants were analyzed based on foreground selection and background selection. The plants which have Pi1 and Pi2 genes were acquired, their other genetic characters were similar to Kongyu131. 3. BC₃F₁ population were obtained by the backcross between BC₂F₂ population and Kongyu131. Foreground selection and background selection of BC₃F₁ population were done. BC₃F₁ population with Pi1 and Pi2 genes were obtained, whose background has basically recovered to the genome of Kongyu131.4. BC₃F₁ population were analyzed through field indentification of blast resistance, the results have shown high resistance or resistance to rice blast.