ARS | Publication request: In Vitro Regeneration of Cowpea (Vigna Unguiculata L. WALP.) Plants Through Organogenesis.

Submitted to: In Vitro Biology Meeting
Publication Type: Abstract
Publication Acceptance Date: April 15, 2005
Publication Date: June 1, 2005
Citation: Manoharan, M., Dahleen, L.S., Okiror, S.O., Garner, J. 2005. In vitro regeneration of cowpea (vigna unguiculata l. walp.) plants through organogenesis. In Vitro Biology Meeting.

Technical Abstract: Cowpea, Vigna unguiculata L. Walp., used as a grain crop, animal fodder or as a vegetable, is widely grown in tropical and subtropical regions including the southern United States. The protein in cowpea seed is rich in the amino acids lysine and tryptophan, compared to cereal grains and therefore cowpea is valued as a nutritional supplement to cereals. In Arkansas and southern Mississippi delta, cowpea is grown by small acreage farmers for fresh produce and large acreage farmers for dried bean. Cowpea production has declined sharply in recent years due to insects such as cowpea weevil and pod borer. Currently, there are no cultivars that resist insect damage. Efforts to incorporate insect resistant genes through genetic transformation into cowpea did not succeed, due to lack of an efficient regeneration system. We are screening four different genotypes (Early Scarlet, Coronet, Quick Pick and 87-435-68) to establish an efficient regeneration system in cowpea. Embryonal axes were cultured on MS medium with different concentrations of various growth hormones. Among the four cultivars tested, Early Scarlet responded well to MS medium with 2.0 mg/L BAP and 1.0 mg/L zeatin. After 6-8 weeks, callus with shoots were transferred to MS medium with 1.0 mg/L IBA for shoot elongation and rooting. After four weeks, fully established plants were transferred to peat pellets first and then to the greenhouse. Further improvements of the regeneration protocol are in progress.