Phenotypic Diversity of Selected Dual Purpose Forage and Grain Sorghum Genotypes

Aims: To study the phenotypic diversity of 25 forage and 45 grain sorghum genotypes for dual purpose as food and feed and to identify traits that might contribute to genetic improvement.

Study Design: A 7 × 10 alpha lattice design was used with two replications at two sites.

Place and Duration of Study: The study was conducted at Makerere University Agricultural Research Institute Kabanyolo (MUARIK) and National Semi Arid Resources Research Institute (NaSARRI) in Uganda between September to December, 2013 (Season 1) and April to July 2014 (season 2).

Methodology: Morphological and agronomic data were taken for each genotype from each environment in the two seasons and subjected to combined analysis of variance separately for the grain and forage sorghums. Multivariate analysis was done based on principle component and cluster analyses in which grain and forage sorghum genotypes were combined.

Results: Analysis of variance revealed significant differences (P < 0.001) among the genotypes for biomass, grain yield, plant height and days to flowering indicating the possibilities of improving these characters through phenotypic selection. Cluster analysis grouped the genotypes into 3 clusters with cluster 1 retaining majority of the forage genotypes characterised with high biomass, Cluster 2 containing a mixture of the forage and grain sorghums characterised with high grain yield while cluster 3 contained only the grain sorghums. The first four principle components explained 89% of the total variations observed in the genotypes.

Conclusion: Based on the performance of genotypes in this study, simultaneous selection of genotypes exhibiting moderate to high levels of grain and fodder traits resulted in twelve genotypes being selected as parents for the development of dual purpose sorghum cultivars.