Yield-Related QTL Clusters and the Potential Candidate Genes in Two Wheat DH Populations.

Area of Science:

• Agricultural Science
• Genetics
• Plant Breeding

Background:

• Grain protein content (GPC) and yield are critical traits in wheat breeding.
• Understanding the genetic architecture of these traits is essential for developing improved wheat varieties.
• Quantitative trait loci (QTL) analysis is a powerful tool for dissecting the genetic basis of complex traits.

Purpose of the Study:

• To identify QTL and QTL clusters associated with GPC and yield-related traits in wheat.
• To investigate correlations between yield and its related traits within identified QTL clusters.
• To propose candidate genes and specific QTL clusters for direct utilization in wheat breeding programs.

Main Methods:

• Conducted four large-scale field trials over two years using two doubled haploid wheat populations.
• Investigated GPC and 21 other yield-related traits.
• Mapped 227 QTL across 18 chromosomes, forming 35 QTL clusters, and analyzed trait correlations within these clusters.

Main Results:

• Identified 35 QTL clusters, with several showing consistently positive correlations for yield and GPC, recommended for direct breeding use (e.g., 1B.2, 2A.2, 2B, 3B, 4A.2, 4B.2, 4D, 5A.1, 5A.2, 5B.1, 5D).
• Highlighted QTL clusters with negative trait alignments that may offer specific environmental advantages for yield or GPC improvement (e.g., 1A.1, 2B.1, 1B.3, 5A.3, 5B.2, 7A.1, 7A.2, 7B.1, 7B.2).
• Discovered a GPC QTL (5B.2) associated with nitrogen use efficiency and grain protein yield, and another GPC QTL on chromosome 2A with no negative pleiotropic effects, both recommended for breeding.

Conclusions:

• The study successfully identified numerous QTL clusters associated with GPC and yield-related traits in wheat.
• Specific QTL clusters with positive correlations are prime targets for direct application in breeding for enhanced GPC and yield.
• QTL with specific environmental benefits or no negative pleiotropic effects offer strategic options for targeted wheat quality and yield improvement.