The Study On Heterotic Grouping Of Several Maize Inbred Lines

Maize heterotic grouping and the relationship between differentiation and heterosis were studied using SSR technique and SCA for yield. The materials consisted of 12 maize inbred lines inclouding Zong3 and Zong31. Besides, the parental contribution of Zong3 and Zong31 were evaluated on the basis of genetic distance of SSRs and SCA of yield data. Following results were obtained:1.12 inbred lines has been divided into six groups that consistent with the pedigree information using SCA of yield as distance in a diallel set of crosses between them, SCA among groups was greater than that within groups.2.12 inbred lines were assayed for SSR technique, 107 primers generated a total of 419 alleles. The number of alleles per locus ranged from 2 to eleven, with an average of 3.916.Mean polymorphic information content (PIC) was 0.601 .The result showed maize inbred lines had different genetic basis and genetic diversity could be detected by mean of SSRs at molecular level.3.Similarity coefficient and genetic distance based on SSR data were computed by Nei-li s method. A cluster analysis revealed that 12 inbred lines were divided into six groups, which agreed well with pedigree information. Genetic distances among groups were greater than those within groups after cluster. The result showed that SSRs could be used to heterosis grouping.4.Genetic distance was significantly correlated with yield performance, heterosis and SCA for yield, but determination coefficient was low. Thus, SSRs was not able to predict yield performance and heterosis.5.Genetic distance and SCA for yield showed that inbred lines Zong3 and Zong31 were furthest to Tail83 and B73, next to Ji63, Lv28, Daqiu36 and Huangzaosi, and were closest to Zi330 and Va35. Compared to Zong31, Zong3 has less genetic divergence to Va35 and more to Zi330. Zong31 was on the contrary.