A yield-associated gene TaCWI, in wheat: its function, selection and evolution in global breeding revealed by...

Area of Science:

• Plant genetics
• Molecular biology
• Agricultural science

Background:

• Plant invertases hydrolyze sucrose, crucial for development.
• Cell wall invertase (CWI) plays a vital role in plant growth.
• Wheat anther-specific invertase genes are key targets for yield improvement.

Purpose of the Study:

• To haplotype wheat anther-specific invertase genes.
• To investigate allelic selection during wheat evolution and breeding.
• To identify genetic markers associated with yield traits like thousand kernel weight (TKW).

Main Methods:

• Haplotype analysis of TaCWI genes (TaCWI-4A, TaCWI-5B, TaCWI-5D).
• SNP and Indel detection in gene promoter and coding regions.
• Development of CAPS markers (caps4A, caps5D).
• Marker/trait association analysis in 348 Chinese wheat cultivars.
• Evolutionary analysis of TaCWI genes in wheat relatives.

Main Results:

• Polymorphisms were found in TaCWI-4A and TaCWI-5D, but not TaCWI-5B.
• Hap-5D-C at TaCWI-5D was significantly associated with higher TKW.
• Hap-5D-C was the most frequent and positively selected haplotype in modern cultivars globally.
• TaCWI-4A haplotypes showed balancing selection effects on TKW and grain number per spike (GN), with different preferences based on water availability.
• Genetic diversity of TaCWI genes declined significantly from diploid to polyploid wheat.

Conclusions:

• Strong allelic selection of wheat anther-specific invertase genes occurred during polyploidization, domestication, and breeding due to yield trait associations.
• Specific TaCWI haplotypes, particularly Hap-5D-C, have been strongly selected for and are linked to improved yield components.
• Understanding these evolutionary pressures provides insights into wheat breeding strategies for enhanced productivity.