Genetic Diversity of the Main Chinese Three-line Hybrid Rice(Oryza sativa ssp. indica) Parents Based on Functional Genetic Markers Related to Disease Resistance
Abstract：To explore broad-spectrum and durable rice resistance in breeding, as well as effective prevention and treatment of rice diseases, 43 SSR primers of functional genes related to blast and bacterial leaf blight(BLB) resistance were used to detect genetic diversity among 76 Chinese three-line hybrid rice(Oryza sativa ssp. indica) parents. The result indicated that 36 primers showed polymorphism and 87 alleles loci were detected; While the number of effective alleles (Ne) were 61.96, account for 71.22%, and Nei's genetic diversity index (He) ranged from 0.358 to 0.974, on an average of 0.629. The genetic similarity(Gs) of 76 varieties ranged from 0.341 to 0.925, on an average of 0.550. UPGMA cluster analysis showed that the 76 accessions could be classified into two distinct classes, maintainer lines and restoring lines, at similarities coefficient 0.624. The coefficient of genetic differentiation(Fst) was 0.158, showed high variation level, and the Nei's genetic distance(D) was 0.201. The study suggested that the functional gene markers had high DNA polymorphisms detection efficiency, and could be used as useful tool for measuring genetic diversity accurately and reliably; overall, the backbone parents studied in research showed nearer genetic relationship and higher homology sort of genetic basis. However, there still showed higher genetic differentiation between maintainer lines and restoring lines, which suggesting that, with more and more functional locus going to be expiscated, there can be more value in use to rice resistance by heterosis breeding.
