Abstract
Grain weight is a key determinant for grain yield potential in wheat, which is highly governed by a type of quantitative genetic basis. The identification of major quantitative trait locus (QTL) and functional genes are urgently required for molecular improvements in wheat grain yield. In this study, major genomic regions and putative candidate genes for thousand grain weight (TGW) were revealed by integrative approaches with QTL linkage mapping, meta-analysis and transcriptome evaluation. Forty-five TGW QTLs were detected using a set of recombinant inbred lines, explaining 1.76-12.87% of the phenotypic variation. Of these, ten stable QTLs were identified across more than four environments. Meta-QTL (MQTL) analysis were performed on 394 initial TGW QTLs available from previous studies and the present study, where 274 loci were finally refined into 67 MQTLs. The average confidence interval of these MQTLs was 3.73-fold less than that of initial QTLs. A total of 134 putative candidate genes were mined within MQTL regions by combined analysis of transcriptomic and omics data. Some key putative candidate genes similar to those reported early for grain development and grain weight formation were further discussed. This finding will provide a better understanding of the genetic determinants of TGW and will be useful for marker-assisted selection of high yield in wheat breeding.
Highlights
Wheat (Triticum aestivum L.) is one of the leading cereal crops and is vital for global food and nutrition security, providing approximately 20% of total calories and proteins for more than 35% of the human population (FAO)1
The variance component analysis showed that all the variance values in the recombinant inbred lines (RILs) reached a very significant level (P < 0.01), where the phenotypic variation of thousand grain weight (TGW) was highly influenced by the environment, genotype, and genotype × environment interaction (GEI) (Supplementary Table 1)
TGW trait in the present study showed a prominent main-effect of genotype, with a high heritability (h2B = 0.77), relatively lower CV% (6.08-12.80%), and significant correlations (r = 0.62∗∗−0.92∗∗) in the performance of the RILs under eight different environments
Summary
Wheat (Triticum aestivum L.) is one of the leading cereal crops and is vital for global food and nutrition security, providing approximately 20% of total calories and proteins for more than 35% of the human population (FAO). It has been estimated that wheat yield must grow at least 2.4% per year to meet food demands in the 30 years (Ray et al, 2013). In this context, the genetic improvement in grain yield potential is urgently required to achieve future increases in wheat productivity. QTL-Meta-Analysis for Wheat Grain Weight number (Duan et al, 2020). TGW is an important trait due to its phenotypic stability with moderate to high heritabilities of 0.6-0.8, and serves as a practical selection criterion for increasing grain yield in the wheat breeding process (Wang L. et al, 2012; Avni et al, 2018; Duan et al, 2020). The corresponding grain yield increased from 2.01 to 6.58 t ha−1, where selection for higher TGW showed a significant contribution to yield improvement (Qin et al, 2015)
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
