Marker assisted selection for resistance to Striga gesnerioides in Cowpea (Vigna unguiculata L. Walp)

2017

English

Cowpea is an important warm-season grain legume primarily found in the semi-arid tropics. It is mostly cultivated by subsistence farmers in West and Central, sub-Saharan Africa, where its grains and leaves are used mainly as food. Its productivity is challenged by several biotic and abiotic factors. A major biotic constraint in cowpea production is the parasitic weed Striga gesnerioides. This study was to assess three molecular markers (SSR-1, 61RM2 and C42-4B) and their abilities to identify resistance and susceptibility of F2 cowpea progenies to S. gesnerioides. To determine the genetic diversity among parental lines and progenies based on markers associated with Striga resistance. A total of 93 F2 progenies from a cross between IT99K-573-1-1 and Hewale were screened. The results showed that the three markers had discriminating power to distinguish between resistant and susceptible genotypes. Marker SSR-1 was found in 61 F2 individuals suggesting that the resistant alleles were highly repeatable within the population. Marker C42-2B was found in 58 F2 individuals while marker 61RM2 was also found in 68 F2 individuals. Allele frequency yielded by the three markers ranged from 0.62 to 0.73 with the mean of 0.67. Genetic diversity range from 0.39 to 0.42 with the mean of 0.43. Polymorphic Information Content (PIC) ranged from 0.32 to 0.36 with the mean of 0.34. The results obtained from these findings indicated that these markers would acilitate and shorten the breeding time as the markers can be used to screen lines or accessions two weeks after planting.

Larweh, V.; Akromah, R.; Amoah, S.; Asibuo, J. Y.; Prempeh, R.; Kusi, F.