Studies on genetic diversity for seedling root parameters in maize

The D² statistics is useful tool to assess genetic diversity among genotypes. It also provides qualitative measures of association between geographical and genetic diversity based on generalized distances. In the present study hundred maize lines were subjected to D² analysis, which revealed the presence of substantial amount of genetic variability among them. To evaluate genetic diversity among the 100 inbred lines of maize over two years observations were recorded for six seedling root traits. ANOVA for dispersion for root traits in inbred maize lines revealed highly significant difference among all inbred lines. Inbred lines were grouped into ten clusters in year-1 analysis, twelve clusters in year-2 analysis and eight clusters in pooled over years analysis indicating the presence of genetic diversity. Maximum number of lines were accommodated in cluster-I in year-1, year-2 and in cluster-II in pooled over analysis. Maximum inter cluster distance in Y1 was recorded between cluster-X and cluster-IV. Similarly, in Y2 maximum inter cluster distance was recorded between cluster-XII and cluster-V and in pooled analysis maximum distance was recorded between cluster-VII and cluster-IV. Fresh root weight contributed maximum contribution towards divergence followed by primary root length. The pattern of distribution of lines into various clusters was random, suggesting that geographical and genetic diversity were not related. These genetically diverse inbred lines can be further used for developing superior hybrids and can also be utilized in developing synthetics and composites.