RAPD based molecular genetic diversity in corn inbreds and its relationship with heterosis in single cross hybrids

摘要

RAPD, a PCR-based molecular marker technique was employed to study the genetic diversity in 24 corn inbreds and to investigate the relationship of genetic distance (GD) of parental inbreds with heterosis in their 20 Fj single cross hybrids for grain yield and other traits. Seventeen 10-mer primers were used giving a total of 91 reproducible products, out of which 68 were polymorphic. GD among pairs of inbreds, as estimated by Jaccards similarity coefficient, ranged from 0.19 to 0.32 with an average of 0.25. The dendrogram, constructed using UPGMA, clustered 24 inbreds into six groups. The intra-cluster similarity ranged from 75 to 90 %, whereas inter-cluster similarity was found to be 72 to 77 %. No correlation was observed between the CDs among parental inbreds and heterosis in their Fj single cross hybrids for important agronomic traits including grain yield. The results suggested that RAPDs are useful in investigating relationship among corn inbreds but they are of limited usefulness for predicting heterotic performance of single cross hybrids as such. Possible reasons of lack of any relationship between GD of inbreds with heterosis and future scope of such studies have been discussed in the article.