Abstracts Earth and Environmental Sciences

Genetic diversity and nutritional content of sorghum [Sorghum bicolor (L.) Moench] accessions from Southern Africa

by Tiny Mpho Motlhaodi

Sorghum [Sorghum bicolor (L.) Moench] is an important cereal crop in semi-arid regions of the world especially in Africa, South Asia and China. It is an important food and fodder crop in the semi-arid tropics (SAT) of Africa, where it is used for making different kinds of food. In Southern Africa, it serves as a principal source of energy, protein, vitamins and mineral nutrients for the people in the region. The aim of this study was to characterise sorghum landrace accessions from Southern Africa in order to generate information that could help design appropriate breeding and conservation strategies in the region. Both agro-morphological and DNA markers were used to study the genetic diversity of accessions from five countries in the region. Nutritional diversity in terms of protein and mineral contents was also characterised. A significant level of genetic variation was observed among 30 sorghum accessions from different agro-ecological regions in Botswana (70% among accessions and 30% within accessions), when genetic diversity was assessed using microsatellite (SSR) markers. The analysis of genetic diversity in 22 sorghum accessions from five countries (Botswana, Namibia, Swaziland, Zambia and Zimbabwe) of Southern Africa, revealed a significant variation in both agro-morphological traits and SSR markers. There were significant differences for protein and mineral content among 23 sorghum accessions from Southern Africa in terms of nutritional composition (protein and minerals). The patterns of genetic diversity and relationships observed in this research provide insights for genetic resource conservation and utilization of sorghum germplasm in Southern African. The protein and mineral content variation found among the sorghum accessions could also be exploited in sorghum improvement programs in the region.