Fine mapping of qAHPS07 and functional studies of AhRUVBL2 controlling pod size in peanut (Arachis hypogaea L.)

Abstract

SummaryCultivated peanut (Arachis hypogaea L.) is an important oil and cash crop. Pod size is one of the major traits determining yield and commodity characteristic of peanut. Fine mapping of quantitative trait locus (QTL) and identification of candidate genes associated with pod size are essential for genetic improvement and molecular breeding of peanut varieties. In this study, a major QTL related to pod size, qAHPS07, was fine mapped to a 36.46 kb interval on chromosome A07 using F2, recombinant inbred line (RIL) and secondary F2 populations. qAHPS07 explained 38.6%, 23.35%, 37.48%, 25.94% of the phenotypic variation for single pod weight (SPW), pod length (PL), pod width (PW) and pod shell thickness (PST), respectively. Whole genome resequencing and gene expression analysis revealed that a RuvB‐like 2 protein coding gene AhRUVBL2 was the most likely candidate for qAHPS07. Overexpression of AhRUVBL2 in Arabidopsis led to larger seeds and plants than the wild type. AhRUVBL2‐silenced peanut seedlings represented small leaves and shorter main stems. Three haplotypes were identified according to three SNPs in the promoter of AhRUVBL2 among 119 peanut accessions. Among them, SPW, PW and PST of accessions carrying Hap_ATT represent 17.6%, 11.2% and 26.3% higher than those carrying Hap_GAC，respectively. In addition, a functional marker of AhRUVBL2 was developed. Taken together, our study identified a key functional gene of peanut pod size, which provides new insights into peanut pod size regulation mechanism and offers practicable markers for the genetic improvement of pod size‐related traits in peanut breeding.

Identification of two major QTLs for pod shell thickness in peanut (Arachis hypogaea L.) using BSA-seq analysis

“…QTLs for traits that are positively or negatively correlated tended to co-localize in the same or adjacent genomic regions Earlier research indicated PST is strongly positively correlated with PA, PL, and PW [10]. In the current study, the correlation analysis of 350 individuals revealed the highly positive correlations among PST, PA, PL, and PW, but these traits were only weakly positively correlated with PP.…”

“…Liu QTLs on chromosomes 4, 7, and 13 (PVE of 7.36-11.61%) [9]. In a recent study, one stable major QTL for PST (qAHPS07) was nely mapped to a 36.46-kb physical interval on chromosome 7 [10]. However, PST measurements are generally imprecise and the complex genetic mechanisms underlying this trait remain relatively uncharacterized.…”

“…During the last decade, advances in next-generation sequencing technologies and decreases in sequencing costs have enabled researchers to gradually develop and improve BSA sequencing (BSAseq) methods and technical systems for analyses of multiple crops, including maize [12], soybean [13], rice [14], and wheat [15]. They have also been used in studies on various peanut traits, including testa color) [16], branch number [17], sucrose content [18], and pod size [10].…”

Identification of two major QTLs for pod shell thickness in peanut (Arachis hypogaea L.) using BSA-seq analysis

“…Yang et al examined the 267 lines of a RIL population derived from Yueyou92 and Xinhuixiaoli and detected three QTLs on chromosomes 4, 7, and 13 (PVE of 7.36–11.61%) [ 9 ]. In a recent study, one stable major QTL for PST ( qAHPS07 ) was finely mapped to a 36.46-kb physical interval on chromosome 7 [ 10 ]. However, PST measurements are generally imprecise and the complex genetic mechanisms underlying this trait remain relatively uncharacterized.…”

“…During the last decade, advances in next-generation sequencing technologies and decreases in sequencing costs have enabled researchers to gradually develop and improve BSA sequencing (BSA-seq) methods and technical systems for analyses of multiple crops, including maize [ 12 ], soybean [ 13 ], rice [ 14 ], and wheat [ 15 ]. They have also been used in studies on various peanut traits, including testa color [ 16 ], branch number [ 17 ], sucrose content [ 18 ], and pod size [ 10 ].…”