Full Length Research Paper

Genetic variation and trait correlations in a bird-resistant pearl millet landrace population

R. Akromah¹*, D. Afribeh² and M. S. Abdulai²

¹Department of Crop and Soil Sciences, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

²CSIR- Savanna Agricultural Research Institute, Manga Station, P.O. Box 46, Bawku, Ghana.

*Corresponding author. E-mail: rakromah@yahoo.com.

Accepted 9 May, 2008

Genetic variation and correlations among traits within a Ghanaian bird-resistant pearl millet landrace population were investigated by evaluating S₁ plants derived from the population, at two locations and for two years in Ghana. The objectives were to study genetic variation and correlations among traits in the population, determine the feasibility of selection and to suggest appropriate selection methods and selection indices for effective improvement. There was significant genetic variation for grain yield and most yield component traits, indicating that selection within the population would be feasible. Genetic variation was, however not significant for the percent incidence of downy mildew, implying that selection for improving resistance to the disease would not be effective. Heritabilities ranged from moderate to high (0.4- 0.73) for most traits, in view of which the use of recurrent selection methods, with progeny testing, could be effective for improvement of the population. Grain yield was observed to have significant phenotypic and genotypic correlations with days to 50% blooming and with earhead length, indicating that those two traits could be relied upon as selection indices for selection to improve grain yield. However, significant positive correlations were also observed between earhead length and plant height, which is undesirable, as plants with tall height tend to have a low harvest index and are also prone to lodging. In view of this, caution would be needed during selection, in order to achieve an improved population with good grain yielding ability and not very tall plant height.

Key words: Pearl millet, Ghanaian landrace, genetic variation, trait correlations, selection indices.