Open AccessGenomic regions, cellular components and gene regulatory basis underlying pod length variations in cowpea ( V. unguiculata L. Walp)
Author(s) -
Xu Pei,
Wu Xinyi,
MuñozAmatriaín María,
Wang Baogen,
Wu Xiaohua,
Hu Yaowen,
Huynh BaoLam,
Close Timothy J.,
Roberts Philip A.,
Zhou Wen,
Lu Zhongfu,
Li Guojing
Publication year - 2017
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12639
Subject(s) - biology , point of delivery , germplasm , vigna , quantitative trait locus , domestication , marker assisted selection , single nucleotide polymorphism , gene , agronomy , genetics , genotype
Summary Cowpea ( V. unguiculata L. Walp) is a climate resilient legume crop important for food security. Cultivated cowpea ( V. unguiculata L) generally comprises the bushy, short‐podded grain cowpea dominant in Africa and the climbing, long‐podded vegetable cowpea popular in Asia. How selection has contributed to the diversification of the two types of cowpea remains largely unknown. In the current study, a novel genotyping assay for over 50 000 SNP s was employed to delineate genomic regions governing pod length. Major, minor and epistatic QTL s were identified through QTL mapping. Seventy‐two SNP s associated with pod length were detected by genome‐wide association studies ( GWAS ). Population stratification analysis revealed subdivision among a cowpea germplasm collection consisting of 299 accessions, which is consistent with pod length groups. Genomic scan for selective signals suggested that domestication of vegetable cowpea was accompanied by selection of multiple traits including pod length, while the further improvement process was featured by selection of pod length primarily. Pod growth kinetics assay demonstrated that more durable cell proliferation rather than cell elongation or enlargement was the main reason for longer pods. Transcriptomic analysis suggested the involvement of sugar, gibberellin and nutritional signalling in regulation of pod length. This study establishes the basis for map‐based cloning of pod length genes in cowpea and for marker‐assisted selection of this trait in breeding programmes.