Abstract
Cowpea is an important grain legume and hay crop of many tropical and subtropical regions, especially in the dry savanna region of West Africa. The cowpea gene pool may be narrow because of a genetic bottleneck during domestication. Genetic variation within specific breeding programs may be further restricted due to breeding methods, ‘founder effects’ and limited exchange of germplasm between breeding programs. Genetic relationships among 60 advanced breeding lines from six breeding programs in West Africa and USA, and 27 landrace accessions from Africa, Asia, and South America were examined using amplified fragment length polymorphism (AFLP) markers with six near infrared fluorescence labeled EcoRI + 3/1bases/MseI + 3/1bases primer sets. A total of 382 bands were scored among the accessions with 207 polymorphic bands (54.2%). Despite a diverse origin, the 87 cowpea accessions shared a minimum 86% genetic similarity. Principal coordinates analysis showed clustering of breeding lines by program origin, indicating lack of genetic diversity compared to potential diversity. Accessions from Asia and the Americas overlapped and were distinct from West African breeding lines, indicating that germplasm from Asia and the Americas have common origins outside West Africa. US and Asian breeding programs could increase genetic variability in their programs substantially by incorporating germplasm from West Africa, while national programs in West Africa should consider introgression of Asian germplasm and germplasm from other parts of Africa into their programs to ensure long-term gains from selection.
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Acknowledgements
The authors thank Drs. N. Cisse, J. Ouedraogo, I. Drabo, B.B. Singh, O. Boukar for supplying cowpea breeding lines used in the present study. This research was supported in part by a grant from Bean/Cowpea Collaborative Research Support Program, USAID Grant no. DAN-G-SS-86-00008-00. The opinions and recommendations are those of the authors and not necessarily those of USAID.
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Fang, J., Chao, CC.T., Roberts, P.A. et al. Genetic diversity of cowpea [Vigna unguiculata (L.) Walp.] in four West African and USA breeding programs as determined by AFLP analysis. Genet Resour Crop Evol 54, 1197–1209 (2007). https://doi.org/10.1007/s10722-006-9101-9
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DOI: https://doi.org/10.1007/s10722-006-9101-9
Keywords
- AFLP
- Cowpea
- [Vigna unguiculata (L.) Walp.]
- Introgression
- Germplasm
- Genetic diversity