Genetic divergence and selection parameters for quantita tive attributes studies on forage sorghum

Forty genotypes of forage sorghum (Sorghum bicolor L. Moench) collected from different geographic sources were analyzed by D² analysis. All genotypes were grouped in to seven different clusters. Genetic diversity was independent of geographic region. Application of this technique for the assessment of genetic diversity in plant breeding and comparison of this method with large number of character has revealed the superiority and consistency of D² analysis, canonical and factor analysis which are complementary to each other. However, usefulness of D² measure of genetic diversity will be depended on the degree of its stability over different environment. It has been found that geographical distribution and genetic diversity as estimated by the D² statistics could be directly related in the number of crop plant with different breeding system. D² statistics exhibited genetic diversity among the forty genotypes of forage sorghum. The genotypes were grouped into 7 clusters namely cluster I (11 genotypes), cluster II (10 genotypes), cluster III (6 genotypes), cluster IV (5 genotypes), cluster V (4 genotypes), cluster VI (3 genotypes) and cluster VII (1 genotype). This indicates that it was concluded in general, there was parallelism between genetic and geographic diversity. The maximum intra cluster distance exhibited for cluster III (503.37) and lowest for cluster VII (135.39). The maximum inter cluster distance was revealed between cluster III and VII (5188.68) whereas, minimum between clusters I and II (387.22). The hybridization between the genotypes Pusa Chari 6, HC 171 and HC 260 with HC 360 which indicates that the high intra cluster distance may be used for making crosses with each other to get the better recombinants and superior hybrids for the green fodder yield improvement in sorghum. The leaf breadth followed by leaves per plant, plant height, green fodder yield, leaf area and leaf stem ratio contributed most towards genetic divergence.