Rice Neck Blast Resistance Of The New Material Created And Its Initial Positioning Of The Resistance QTL

Rice as the main food crops in China has a pivotal role in China’s food security. Rice crops are also important crop mode, there has been many research results found in rice. Caused by the rice blast fungus (Magnaporthe grisea) rice blast is one of the three major diseases in rice, and neck blast bad effect on the output of rice is more serious. Cultivating rice blast resistant varieties is the most economical and environmentally friendly method of controlling rice blast. So far, more than 100 blast resistance genes have be reported, which already 24 resistance genes have been cloned.Shuhui 498 are breeding with big spike, lodging-resistance, ideal plant type strong restorer line of hybrid rice, which have been with the group more than a dozen new hybrid rice varieties in the production of large scale. As the change of physiological race of blast, shuhui 498 showed downtrend resistance to rice blast.R1088 and HB542, after years of multi-point blast appraisal, it have been proved that it has obvious neck blast resistantance. In this study, by multi-generation backcross method and field resistance selection, both resistant material are used to improve Shuhui 498’s resistance, and we expect to get neck blast resistance related QTLs.The main results were as follows:1-. The four selected laboratories provide excellent traits of rice materials, strong restorer shuhui 498 as a comparison, these materials will be screened polymorphic primers. Neck blast resistance identification and screening blast resistance material. The results showed among rice 277 pairs SSR primers uniformly distributed on 12 chromosomes,97 is polymorphic. PCR products are tested by electrophoresis in 3% agarose gel, test results show that 35% markers has polymorphism,180 markers has no polymorphism, the percentage is 65% of the total. Blast resistance identification showed that the neck blast resistance of Qinggumei 3, shuiyuan290, R1088 and HB542 is superior to restore shuhui 498.2^ In order to make out the resistance gene distribution of the four resistance materials and shuhui 498.10 pairs of primers were designed to identify eight blast resistance.The experimental results show that the shuhui498 contains resistance genes homologous fragments of Pid3, Pizt, Pi5 and Pi9; shuiyuan290 contains resistance genes homologous fragments of Pid3, Pib, Pizt and Pi9; R1088 contains resistance genes homologous fragments of Pid3, Pi5 and Pita. Qinggumei3 contains resistance genes homologous fragments of Pid3, Piz, Pi9, Pigm and Pita; HB542 contains resistance genes homologous fragments of Pid3, Pib, Pi9 and Pita. These data provide a reference for improving disease resistance of Shuhui498 and positioning of new resistance genes.3^ The R1088 and HB542 as the donor parent, Shuhui498 hybrids as the recipient parent, after four successive backcrossing, then selfing,screened to NIL by field neck blast resistance identification. Using Rice SNP9K gene chip sequencing technology, the substitution fragments of shuihu498NILR1088 and shuhui498NILHB542 are confirmed. Combining dCAPS markers select of disease-resistant fragment. Eventually disease-resistant fragment are located in chromosome 10 of R1088,between primers R8HindⅢ and RM25122, which the total length is about 2.1 Mb, and chromosome 12 of HB542 between primers H10EcoRI and H12HindⅢ which the total length is about 2.6 Mb.