The prediction of best line combiners and heterosis in Tanzanian maize breeding lines through the use of Amplified fragment length polymorphism (AFLPs)

Abstract

Amplified fragment length polymorphism DNA markers have been used to assist plant breeders in the choice of maize parents for commercial hybrid production. However, maize yield in Tanzania is significantly reduced by gray leaf spot (GLS) disease, which is now regarded as the most yield limiting disease of maize worldwide. Thus combining GLS resistance genes and high yielding traits in hybrids is an important breeding strategy. The main aim of this study was to assess the genetic diversity of Tanzanian germplasm and to predict the potential of these inbreds in producing high yielding GLS resistant hybrids. Furthermore, the potential of such data to predict the best line combiners was investigated. This research used AFLP-DNA fingerprinting data from 21 moderately and highly GLS resistant maize inbreds. Results revealed that the genetic distance (GD) of some intergroup crosses were as high as 0.5. Theoretically, these intergroup hybrids with high GD could potentially produce high yielding GLS resistant hybrids. However, such hybrids would require field-testing in order to confirm these observations. Finally the results revealed high f values consistent with other reports in maize. In summary these results also corroborate the usefulness of AFLP in genetic diversity studies of germplasm, prediction of best line combiners and high heterosis level for commercial maize hybrid production.