Breeding methods

Pedigree selection
  • The pedigree system of breeding is the most common method used by cowpea breeders.
  • This method has been successful in developing cowpea cultivars with new combinations of characteristics and resistance to diseases.
  • Single plant selections are carried out within larger F2 / F3 populations. Individual plant progenies are planted in one or more rows, 4-6 m in length and 1.5 m apart.
Backcross method
  • The backcross breeding procedure has been found efficient for transferring single-gene resistance to specific diseases into cowpea cultivars.
  • For example, this procedure has been used to transfer Cls gene, which provides resistance to Cercospora leaf spot, into the susceptible cultivar Colossus in USA.
Heterosis breeding
  • Seven Vigna unguiculata var. sesquipedalis varieties were crossed in diallel. Of the 42 hybrids, only three exceeded the higher parent in seed protein content and pods / plant.
  • The methods of F1 hybrid production are hand emasculation and pollination, use of ‘protruded stigma’ types female and use of male sterile line.
Mutation breeding
  • Mutation breeding in cowpea has been utilized on a limited scale through irradiation (9-40 Krad) by gamma rays to isolate mutants with increased yield and earliness.
Salient breeding achievements
  • Varieties Pusa Phalguni suited for spring season, Pusa Barsati for rainy season and Pusa Dofasli for both the seasons have been evolved.
  • K 1552 (Pusa Komal) evolved is an early variety which is resistant to bacterial blight
  • Variety Grant is resistant to Fusarium wilt, Chinese Red is resistant to Phytophthora stem rot, Mississipi 57-1 and Iron are resistant to root-knot nematodes have been evolved
  • Variety Goit, Dixies-Cream and Alabunch are resistant to cowpea mosaic disease.
Future prospects
  • Many valuable genes like male sterility, high protein and methionine content, resistance to thrips, aphids, pod-borers, root-knot nematodes, anthracnose and cowpea mosaic virus are available which need further utilization.
  • Bush types of yard-long bean have been developed (Los Banos Bush Sitao No.1).
  • There is a need to evolve high essential amino acid lines in cowpea. The extent of damage due to various diseases has not been estimated except for a few diseases.

Last modified: Monday, 30 January 2012, 9:05 PM