Quantitative Trait Loci Analysis Of Japonica Rice Landrace Heikezijing Cofering Resistance To Rice Blast

Rice blast, caused by Magnaporthe Oryzae (Hebert) Barr, is one of the most widespread and destructive diseases of rice. To breed and grow resistant-blast cultivars is the most effective and economical way for controlling this disease in rice production. The japonica rice landraces in Taihu lake area in China is the special genetic resource in China as this region has a long history of rice-growing. And the Rice blast has also been in the region is the long-standing rice disease. This study aims at exploration of blast-resistance of japonica landrace Heikezijing in Taihu lake area and identification of resistance loci by SSR molecular markers to serve rice blast-resistance breeding in delta of Yangtze River.Sixteen rice blast isolates, belong to different populations, collected in Jiangsu provinces in China from2007-2011, were inoculated in japonica landrace Heikezijing to identify its resistance spectrum to the blast. The results showed that Heikezijing is highly resistant to sixteen isolates with the lesion score0, and were consistent with previous research. It further proved that the landrace Heikezijing is a broad-spectrum and highly resistant-blast resourceg. One population of recombinant inbred lines (RILs) consisting of162lines were obtained by SSD method from the cross of heikezijing (resistant)×Suyunuo (susceptible), and were inoculated with7isolates with obviously different virulence.1,578pairs of SSR markers were used to be amplified polymorphisms between the two parents..146SSR markers with polymorphisms between the two parents were used for constructing the linkage map, with a total distance of1,867.1cM and an average distance of about12.8cM between every two markers, covering the whole rice genome according to the information from the International Rice Microsatellite Initiative (IRMI). The different reactions of RILs corresponding to7isolates are used for QTL analysis. According to the average disease score of each line, the average lesion number of each line and the average lesion size of each line,21QTLs, distributing on chromosome1,3,4,5,6,8,9and11, are detected corresponding to7 isolates. Six new QTLs are detected on chromosome4, while six and two QTLs are detected on chromosome11and9respectively and four QTL are detected On chromosome1,5,6and8.