Morphological Variation of Sorghum Landrace Accessions On-Farm in Semi-Arid Areas of Zimbabwe

Sorghum landraces from two districts of Zimbabwe were studied to ascertain the genetic relationships among germplasm from different areas. The study analyzed 47 landraces from Nyanga North and Tsholotsho using 24 Sorghum agromorphological characters. Genetic similarities (Manhattan coefficient) were calculated and genetic relationships between accessions were analysed by principal component analysis and cluster analysis. The landraces were grouped into 6 clusters according to the geographical location of collection, suggesting environmental adaptation. Accessions with the same name had a tendency to group together, although some of the materials were found to be scattered in the dendrogram. Agromorphological traits were highly variable even for landraces with the same farmer-given name and source. Study results also alluded to the heterogeneity of farmer varieties, whose naming appears to be a function of a few traits. The study suggests that optimisation of on-farm conservation strategy for this germplasm should primarily focus on high diversity areas and perhaps recognise those traits envisaged to be of importance by farmers for varietal identification.