|Ravelombola, Waltram - University Of Arkansas|
|Qin, Jun - University Of Arkansas|
|Shi, Ainong - University Of Arkansas|
|Weng, Yuejin - University Of Arkansas|
|Bhattarai, Gehendra - University Of Arkansas|
|Dong, Lingdi - University Of Arkansas|
|Morris, John - Brad|
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2017
Publication Date: 11/22/2017
Citation: Ravelombola, W., Qin, J., Shi, A., Weng, Y., Bhattarai, G., Dong, L., Morris, J.B. 2017. A Single Nucleotide Polymorphism (SNP)-based association analysis for plant growth habit in worldwide Cowpea (Vigna unguiculata (L.) Walp) germplasm. Euphytica. 213:284. https://doi.org/10.1007/s10681-017-2077-z.
Interpretive Summary: The Cowpea is a pea crop grown in Africa, the Americas, and Asia. The plant consists of 3 primary growth habits including upright, semi-spreading and spreading types. Cowpea growth habit is an important trait because of needs by growers such as reducing weeds and more leaves for livestock feed. Very little information about the genetics of cowpea growth habit is known and will be useful in cowpea breeding for this trait. The association analysis was conducted for cowpea growth habit and to study molecular markers associated with growth habit in 487 cowpea samples from the USDA, ARS, Plant Genetic Resources Conservation Unit (PGRCU) cowpea collection. DNA sequencing was used to identify differences in single nucleotides among the cowpea samples. A total of 1,031 single nucleotide markers were identified. Using molecular genetic techniques and statistical analysis, ten single nucleotide markers were found to be strongly associated with cowpea growth habit. These genetic markers can be used by breeders to develop cowpea cultivars with a specific growth habit.
Technical Abstract: Cowpea is a legume widely grown in Africa, North, Central and South America, and Asia. The Cowpea plant growth habits consist of erect, semi-prostrate, and prostrate types. Developing a cultivar while considering plant growth habit is essential within a breeding program since the need for a particular plant growth habit is region-specific, and significantly depends on the end user preference. Some cowpea growers might prefer erect types over semi-prostrate and prostrate typesones, whereas others would choose prostrate types, which provide more leaves for feed supplies to livestock. However, very little is known regarding the genetics behind plant growth habit in cowpea to assist plant breeders in developing suitable cowpea cultivars having the desired plant growth habit along with the other required features. Therefore, the objectives of this study were to conduct an association mapping for cowpea growth plant habit in cowpea, and to investigate Single Nucleotide Polymorphism (SNP) markers associated with this trait. A total of 487 cowpea genotypes were as evaluated for plant growth habit and a total of 1,031 SNPs postulated from genotyping-by-sequencing to conduct association analysis study for cowpea plant growth habit in cowpea. Our results showed that: (1) significant differences in cowpea growth plant habit were identified between countries, (2) the cowpea erect-type was prevalent, and (3) ten SNP markers, C35060651_729, C35061339_799, C35062457_1855, C35072764_1384, C35080248_2355, Scaffold2771_4351, Scaffold29522_3213, Scaffold35913_2678, Scaffold53560_188, and Scaffold58098_4297, were significantly associated with plant cowpea growth habit in cowpea. These results could be used for enhancing marker-assisted selection (MAS) in breeding programs aimed at developing cowpea cultivars having a particular plant growth habit-type.