| Rice blast disease , caused by Magnaporthe grisea (hebert) barr, is one of the three major disease in rice. Utilization of genetic resistance is the most effective and environment friendly strategy for the disease control. However, breeding for stable resistance to blast has been extremely difficult. Although some cultivars with durable resistance has been recognized , the resistance of most cultivars is still short-lived. The molecular marker technology is a certain approach to overcome the difficulty, because the presence of markers tightly linked to resistance genes will allow selection and maintenance of the desirable resistance genotypes inbreeding process.SN606 is the super-rice cultivars cultivated by Shenyang Agricultural University Rice Research Institute. Recently it has been growing extensively in north of China, and the cultivars expresses a high resistance to the north rice blast races. In order to effectively using its broad spectrum resistance, two rice varieties, blast resistant SN606 and blast susceptible LTH, have been crossed. The race ZA1 of Magnaporthe grisea (hebert) barr have been used to inoculate the two parents, F1, F2 population in the conservatory. The results show that the segregation ratio of resistance and susceptible to ZA1 was 399:128 in F2 population. The X2 test shows that the genetic mechanism of resistance of ZA1 blast race is controlled by single dominant blast-resistance gene.The polymorphism between parents was examined by 84 pairs of primers of SSR. The results show that among the 84 pairs of primers, there are 35 pairs of primers displaying the polymorphism between two parents, the polymorphism rate is 44.9%. The PCR was carried out with DNA of F2 population under the 35 pairs of primers. The results reveal that two primer RM250 and RM208 is linked with the blast resistance gene of ZA1 of SN606, and preliminary mapped in chromosome 2 of rice. The possible linkage value was 4.6 and 6.1cM with marker RM250 and RM208.
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