Genetic Dissection for Yield and Yield-Related Traits in Bread Wheat (Triticum aestivum L.)

Wheat is one of the most important cereal crops of global importance. Wheat crop provides one-fifth of the daily calories and dietary proteins for human consumption. Improving grain yield (GY) and yield-contributing traits is considered important for increasing wheat production and therefore for food security. The yield and traits related to yield in wheat are mostly quantitative traits controlled by several small effect/minor genes/QTLs. Hundreds of studies have been conducted in wheat for the discovery of genes/QTLs for yield and related traits using different approaches. Among different approaches, linkage-based QTL mapping and association mapping are most commonly used approaches. Traditional QTL mapping involves the use of biparental mapping populations derived from crossing two contrasting parental genotypes. The other recently emerged mapping approach “association mapping” also known as genome-wide association studies (GWAS) that involves the use of diverse germplasm is considered the method of choice nowadays to unravel and understand genetics of yield and yield-related traits. Using these different mapping approaches, several genes/QTLs have been already identified for GY and yield-related traits in wheat. The QTLs/genes identified belong to all the 21 bread wheat chromosomes. In addition, QTL × Environment, QTL × QTL, and QTL × QTL × Environment interactions have been also worked out in detail. The important stable and major QTLs identified will prove useful in wheat molecular breeding programs aimed at enhancing GY for food security.