SELECTION OF PROVEN PARENTS TO ESTABLISH A BREEDING CROSS THROUGH MOLECULAR APPROACH

摘要

Genetic diversity of the thirty eight sugarcane (Saccharum spp.) genotypes was evaluated at the DNA level using fifty micro satellite (SSR) markers for the identification diverse parent genotypes. A complex banding pattern was observed with the number of amplified fragments ranging from 5 to 17 fragments. The allelic polymorphism information content (PIC) values were ranged from 0.10 to 0.79 for with an average of 0.36. The value of genetic similarity co-efficient was ranged from 0.33 to 0.84, indicated the vast genetic diversity in sugarcane genotypes. Genetic similarity co-efficient indicated high genetic similarity (GS) existed among the Saccharurn officinarum clones (84% GS), Saccharum spontaneum clones (78%), and relatively lower level of genetic diversity in the S. barberi clones (77% GS). Low level of genetic diversity was observed between the foreign commercial hybrids (81% GS), commercial hybrids (79%), and inter specific hybrids (77% GS) which indicates towards the common origin of these groups of hybrids. Genotypes with the most distinct DNA profiles (viz; CoS95255, CoS8436, UP22, CoS510, IJ76-564 and B34-104, Q49, CP44-43, PoJ2878) were identified as most diversified in our studies, which carry unique and potentially agronomically useful traits. These, diverse parent genotypes could be employed as favourable heterotic combinations in a sugarcane improvement program to broaden the genetic bases and progeny performance for complex traits such as sugar yield and multiple disease and insect pest resistance.