MOLECULAR AND MORPHOLOGICAL CHARACTERIZATION OF MAIZE GENOTYPES FOR OPAQUE 2 GENE AND YIELD CONTRIBUTING TRAITS
Maize (Zea maiz) is an important cereal crop grown on 48o N to 58o N with annual rain fall 250 mm to 5000 mm per year and having chromosome number 2n =2x=20. Like all cereal crops maize is also deficient in two essential amino acids tryptophan and lysine in maize grain, but some maize mutant identified in USA have higher tryptophan and lysine contents due to presence of opaque 2 gene. In the present study 50 maize inbred lines and 30 QPM hybrids were characterized for morphological and yield contributing traits. 50 inbred lines were screened for the presence of opaque 2 gene. Molecular characterization showed that all 50 genotypes were non QPM as two primes phi 57 and phi 112 confirmed by amplifying 169 bp in QPM and 161 in inbred lines whereas phi 112 amplified null fragments in QPM and 150 bp in all inbred lines. Analysis of variance, principal component and cluster analysis showed presence of wider diversity in maize inbred lines and QPM hybrids. There were highly significant differences present in inbred lines for all the parameters studied where as QPM hybrids were found to be non-significant for ear aspect, plant aspect, days to 50% silking, days to 50% tasseling and anthesis to silking interval. Correlation among different traits were also determined and it was found that plant height and ear height had highly significant positive correlation (0.483** and 0.423** respectively) with yield per plant, ear diameter and number of grains per row had significant positive correlation (0.303* and 0.556* respectively) with yield per plant in inbred lines whereas in QPM hybrids field weight was positively correlated (0.38*) with grain texture and negatively correlated (-0.778**) with plant aspect and ear aspect.
Zea mays, Opaque-2 gene, PCA analysis, Correlation, Cluster analysis