QTL mapping and candidate gene analysis for yield and grain weight/size in Tartary buckwheat

Abstract

Background Grain weight/size influences not only grain yield (GY) but also nutritional and appearance quality and consumer preference in Tartary buckwheat. The identification of quantitative trait loci (QTLs)/genes for grain weight/size is an important objective of Tartary buckwheat genetic research and breeding programs. Results Herein, we mapped the QTLs for GY, 1000-grain weight (TGW), grain length (GL), grain width (GW) and grain length–width ratio (L/W) in four environments using 221 recombinant inbred lines (XJ-RILs) derived from a cross of 'Xiaomiqiao × Jinqiaomai 2'. In total, 32 QTLs, including 7 for GY, 5 for TGW, 6 for GL, 11 for GW and 3 for L/W, were detected and distributed in 24 genomic regions. Two QTL clusters, qClu-1-3 and qClu-1-5, located on chromosome Ft1, were revealed to harbour 7 stable major QTLs for GY (qGY1.2), TGW (qTGW1.2), GL (qGL1.1 and qGL1.4), GW (qGW1.7 and qGW1.10) and L/W (qL/W1.2) repeatedly detected in three and above environments. A total of 59 homologues of 27 known plant grain weight/size genes were found within the physical intervals of qClu-1-3 and qClu-1-5. Six homologues, FtBRI1, FtAGB1, FtTGW6, FtMADS1, FtMKK4 and FtANT, were identified with both non-synonymous SNP/InDel variations and significantly differential expression levels between the two parents, which may play important roles in Tatary buckwheat grain weight/size control and were chosen as core candidate genes for further investigation. Conclusions Two stable major QTL clusters related to grain weight/size and six potential key candidate genes were identified by homology comparison, SNP/InDel variations and qRT‒qPCR analysis between the two parents. Our research provides valuable information for improving grain weight/size and yield in Tartary buckwheat breeding.

Mapping QTL for Yield and Its Component Traits Using Wheat (Triticum aestivum L.) RIL Mapping Population from TAM 113 × Gallagher

“…Sixteen QTLs were identified in two or more individual environments, and eight genomic regions affected two or more traits (Table 1 and Table S5). Several QTLs detected for PH in this study were physically close to previously reported QTL [30,[56][57][58]. Two PH QTLs, one was 3.8 Mbp away from a PH QTL located on 4B at 611.1 Mbp, and another one was 10 Mbp away from QTL on 4B at 474.9 Mbp identified by Semagn et al [57].…”

“…The similarity of findings between Dhakal et al [29] and our study can be explained by closely related parents shared by both studies with similar genetic backgrounds. Moreover, two YLD QTLs with relatively small effects on chromosome 6D and 7B at 10.33 Mbp and 4.2 Mbp were reported by previous studies [30,[56][57][58][59].…”

“…There were positive and significant correlations between kernel traits and YLD, suggesting kernel traits could be used in the selection of high YLD genotypes. A high correlation among kernel-related traits showed a common genetic structure controlling phenotypic expression for these traits [56].…”

Ethyl Methanesulfonate Mutant Library Construction in Tartary Buckwheat with Agronomic Trait and Flavonoid Screening for Germplasm Innovation

“…The standard components of TB yield include GWP, TGW, and field planting density, etc. [27][28][29]. In our study, we also found potential highyield lines with a larger grain sizes or high GWPs.…”