The Genetic Analysis And Gene Mapping Of Resistance To Rice Blast In Cultivar Dongnong415

Rice is one of the most important crops in the world, which has always been a dominantposition in the food production and consumption. Rice blast is rice disease worldwide, that inevery growth stage could occur at any time, which caused a huge loss to rice production and theeating quality of rice is decreasing. Practice shows that, planting resistant varieties of rice is one ofthe most basic and effective measures for prevention and controlling of rice blast, but in recentyears due to simple rice varieties in Heilongjiang province, the rice blast aggravates day byday.Germplasm resource contains abundant gene of genetic improvement, exploring germplasmresources efficiently was the precondition of breakthrough in disease resistance breeding.Dongnong415is well known for early maturity, resistance to multiple diseases and high yield sincebred, therefore it could be used as a good source for resistance breeding in Heilongjiang.In the study, the evaluation of Dongnong415for their resistance against158blast isolatescollected from the main rice regions of Heilongjiang Province, showed that Dongnong415canresist89.2%of158isolates, indicating that Dongnong415could has a broad-spectrumblast-resistant. F2populations derived from a cross of415×LTH were used as test material, whichwere inoculated with four rice blast isolates,Ken54-04,Ken54-20,Ina72and F-10-11, the geneticanalysis of Dongnong415showed that the resistance of Dongnong415to Ken54-04isolate,Ken54-20and Ina72were controlled by two dominant genes, to Ken53-33isolate wascontrolled by two complementary dominant genes, to F-10-11isolate was controlled by a singledominant gene.Six hundred pairs of SSR markers were used to examine the polymorphism betweenDongnong415and LTH, the results showed that there were one hundred and thirty pairs of primersdisplaying the polymorphism between Dongnong415and LTH, the polymorphism ratio was21.6%.We constructed a mapping population composing of ninty-nine F2plants which wereseriously infected by isolate F-10-11,using molecular markers and BSA-RCA strategy. The resultsshowed that RM5300was linked with the blast resistance gene of Dongnong415,and mapped thegene Pi-dn within a3.0cM in chromosome2of rice. Pi-dn loci were mapped rice referencegenome founding that there were three resistance loci in the genome segment coding genes withresistance genes domain structure, and can be used as resistance candidate genes for subsequentresearch.