Mapping Blast Resistance Genes And Application In Breeding

Rice is one of the most important crops in the world, and is the staple food of half of the world's human population. Rice blast, caused by the fungus Magnaporthe griseais, is one of the most destructive diseases in all rice growing areas worldwide. The BC3F1 and BC3F2 population of Zhenshan97B/CR185 were explored to detect blast resistance QTL under natural condition in 2008 and 2009, AB-QTL analysis were mapped blast resistance QTL during the whole duration for the blast resistance. Results are as following:1. Blast resistance of BC3F1 population at tillering stage and heading stage in 2008 was remarkable positive correlation with blast resistance of BC3F2 population at heading stage and maturation stage in 2009 (p<0.01). In some sense, the blast resistance could be easy to repeat observed at different years and living stages of rice under natural infection test.2. Using Zhenshan97B/CR185 BC3F1 and BC3F2 population,11 QTL were identified in 2 years. Of them, a main-effect QTL q-BR6 was identified at three living stages over 2 years, which explained the phenotype variation of 25.3%,20.2%,28.5% and 34.0%, respectively.3. Our mapping results elucidated the durable blast resistance mechanism of CR185. The durable blast resistance was due to the cooperation of main-effect QTL and minor-effect QTL.4. Pyramiding main-effect QTL q-BR6 for blast resistance in Zhenshan97B by marker assisted selection, and we got homozygous BC3F2 individuals.