Abstract
Zombi pea (Vigna vexillata (L.) A. Rich) is an underutilized crop belonging to the genus Vigna. Two domesticated forms of zombi pea are cultivated as crop plants; seed and tuber forms. The cultivated seed form is present in Africa, while the cultivated tuber form is present in a very limited part of Asia. Genetics of domestication have been investigated in most of cultivated Vigna crops by means of quantitative trait locus (QTL) mapping. In this study, we investigated genetics of domestication in zombi pea by QTL analysis using an F2 population of 139 plants derived from a cross between cultivated tuber form of V. vexillata (JP235863) and wild V. vexillata (AusTRCF66514). A linkage map with 11 linkage groups (LGs) was constructed from this F2 population using 145 SSR, 117 RAD-seq and 2 morphological markers. Many highly segregation distorted markers were found on LGs 5, 6, 7, 8, 10 and 11. Most of the distorted markers were clustered together and all the markers on LG8 were highly distorted markers. Comparing this V. vexillata linkage map with linkage maps of other four Vigna species demonstrated several genome rearrangements in V. vexillata. QTL analysis for 22 domestication-related traits was investigated by inclusive composite interval mapping in which 37 QTLs were identified for 18 traits; no QTL was detected for 4 traits. Number of QTLs detected in each trait ranged from 1 to 5 with an average of only 2.3. Five QTLs for tuber width and three QTLs for tuber weight. Interestingly, 2 QTLs each for tuber width and tuber weight detected on LG2 and LG4 were located at similar position and wild allele increased tuber width and weight. This indicated wild germplasm having small tuber have potential to increase yield of large tuber cultivated type. Large-effect QTLs (PVE > 20%) were on LG4 (pod length), LG5 (leaf size and seed thickness), and LG7 (for seed-related traits). Comparison of domestication-related QTLs of the zombi pea with those of cowpea (Vigna unguiculata), azuki bean (Vigna angularis), mungbean (Vigna radiata) and rice bean (Vigna umbellata) revealed that there was conservation of some QTLs for seed size, pod size and leaf size between zombi pea and cowpea and that QTLs associated with seed size (weight, length, width and thickness) in each species were clustered on same linkage.
Highlights
The genus Vigna is an important taxon of leguminous plants
The wild zombi pea (JP235863 from India) and the Bali cultivated zombi pea were genetically closely related [4], while the wild zombi pea used in the study of Damayanti et al [8] were from Africa and Australia and they were genetically highly differentiated from the Bali cultivated zombi pea [4]
A genetic linkage map was constructed for this population utilizing 145 simple sequence repeat (SSR), 117 RAD-seq and 2 morphological markers and to locate quantitative trait locus (QTL) for domestication syndrome traits
Summary
The genus Vigna is an important taxon of leguminous plants This genus comprises more than 100 species that distribute in all major continents including Africa, America, Asia, Australia and Europe. Among those species, as high as nine Vigna species are domesticated/cultivated. Rich) [1,2]. The former six species are of Asian origin and belong to the same subgenus Ceratotropis, while the latter three species are of African origin. Cowpea and Bambara groundnut belong to the subgenus Vigna, while zombi pea belongs to the subgenus Plectrotropis These crops are generally cultivated by resource-poor farmers as a sole crop or a component in various cropping systems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
