Genetic inheritance of resistance to Fusarium redolens in cowpea

Abstract

Fusarium related root rots have been associated with reduced cowpea productivity in Uganda. Sources of genetic resistance to Fusarium redolens which was found to be the most virulent have been identified but the mode of inheritance of the genes conferring the resistance is unknown. This study aims to investigate how the genes for resistance to F. redolens are inherited in cowpea. Four F. redolens root rot resistant cowpea genotypes were crossed with four intermediately resistant and 2 susceptible cowpea genotypes using North Carolina mating design II. The F 1 and the parents were evaluated and data were collected on resistance to seed rot, leaf chlorophyll amount, produced lateral roots, response to plant mortality and root rot severity. Results revealed that additive gene effects were significant for all evaluated traits and non-additive genetic effects were significant in resistance to seed rot and chlorophyll amount. General combining ability (GCA) effects showed that the Asontem genotype was a good combiner for increased lateral roots production and resistance to root rot. Degree of dominance estimates revealed that response to plant mortality, root rots and increased lateral root production traits were recessively inherited while seed rot and amount of leaf chlorophyll were dominantly inherited.

Challenges, Progress and Prospects for Sustainable Management of Soilborne Diseases of Cowpea

“…Moreover, CB 46 and CB 88 were reported to have resistance only against race 3 of FW while CB27 and CB50 gave resistance against both race 3 and race 4 of FW [41,42]. Following screenhouse/ greenhouse studies, four FW resistant cowpea genotypes namely: Asontem, Danila, IT89KD-88 and NE 70 were identified [43,44]. Other genotypes that could be used as resistance donors for FW are: TVu 134, TVu 410, TVu 901-1 and MNCO1-649F-2-1 [45,46].…”

“…Dominant monogenic inheritance makes it possible to effectively use backcrossing for transfer of resistance to susceptible backgrounds [46]. However, additive gene effects were also reported to control resistance [44]. For southern blight, resistance is conditioned by single dominant genes which are non-allelic in two resistant genotypes namely: Carolina Cream and Brown Crowder [57].…”