Study On The Genetic Diversity And Association Mapping Of RVA Pasting Characteristics Of Waxy Corn Germplasms In Area Of Along The Yangtze River Of Jiangsu Province

Waxy corn originated in China is a subspecies of Zea mays. Waxy corn is the precious maize germplasm. Waxy corn possesses characteristics of sweet taste, wax and fragrance. So the waxy corn has broad application in foodstuffs and industry. The starch RVA pasting characteristics and genetic diversity of waxy corn are of importance in waxy corn breeding. 129 waxy corn inbred lines and 30 waxy corn hybrids from area along Yangtze River in Jiangsu were used to investigate the genetic potential of starch RVA traits. 56 out of 129 waxy corn inbred lines and 30 waxy corn hybrids were further used to study the genetic diversity by using 100 SSR markers covering the whole maize genome. Association analysis of marker polymorphism and seven RVA characters was also conducted. The results were showed as follows.(1) Seven starch viscosity characters were found having significant difference among varieties (inbred lines). Very significant positive correlations were observed among peak viscosity (PV), trough viscosity (TV) and final viscosity (FV). Very significant positive correlations were found among breakdown (BD) and PV, TV and FV whereas very significant negative correlations were found between peak time (PT) and pasting temperature (PTP). Setback (SB) was very significant positive correlated with TV, FV, PT and PTP. BD and SB had significant negative correlation. PT and PTP had significant positive correlation.(2) Eighty-eight of 100 SSR primers were amplified polymorphism bands among waxy corn inbred lines. The percent of polymorphism SSR primers was 88%. Eighty-eight SSR markers searched 350 alleles. The average allele number of each SSR marker was 3.98. Eighty-seven of 100 SSR primers were amplified polymorphism bands among waxy corn hybrids. The percent of polymorphism SSR primers was 87%. Eighty-seven SSR primers searched three hundreds and fifteen alleles. The average allele number of each polymorphism SSR primers was 3.62.(3) Very high genetic similarity was found among waxy corn germplasms. In 30 waxy corn hybrids, the smallest genetic similarity was found between Suyunuo14 and Huyunuo3 and between Suyunuo14 and Liaoningxiangjing, the genetic similarity coefficient is 0.546. Jinchenghuanuo and GN4, Jinchenghuanuo and GN4 were found having the biggest genetic similarity with coefficient of 0.911. In 56 waxy corn inbred lines, the smallest genetic similarity was found between Qing795 and Ganghong354354 whereas the biggest genetic similarity was found between LBW2 and LBW3, and between LBW2 and LBW5.(4) Twteny-six significant associations between SSR markers and RVA characters were identified by association analysis. Among them, there are six associated with PV, eigth with TV, six with FV, six with BD, six with SB, ten with PT and four with PTP, respectively.