Haplotype Analysis and Gene Pyramiding for Pre-Harvest Sprouting Resistance in White-Grain Wheat

Area of Science:

• Agricultural Science
• Plant Breeding
• Genetics

Background:

• Pre-harvest sprouting (PHS) in wheat significantly reduces yield and quality in China's main production region.
• Developing PHS-resistant white-grained wheat varieties is essential for national food security.

Purpose of the Study:

• To evaluate PHS rates in 344 white-grained wheat varieties.
• To analyze the impact of allelic variations in six key genes on PHS resistance.
• To identify superior haplotypes and gene combinations for enhanced PHS resistance.

Main Methods:

• Field evaluation of 344 white-grained wheat varieties over two growing seasons.
• Analysis of allelic variations in six PHS-related genes (Tamyb10, TaDFR, TaMKK3-A, TaGASR34, Tasdr, TaMFT).
• Identification and assessment of superior haplotypes and their combinations for PHS resistance.

Main Results:

• Average PHS rates ranged from 64.4% to 66.1% across seasons, with high genetic variation (heritability 0.72).
• The superior haplotype GS34-7Bb showed the lowest PHS rate (41.9%).
• Two advantageous haplotype combinations demonstrated significantly reduced PHS rates (20.8% and 34.2%).

Conclusions:

• Substantial genetic variation exists for PHS resistance in white-grained wheat.
• Specific haplotypes and their combinations offer strong potential for breeding PHS-resistant varieties.
• The frequency of superior haplotypes and combinations has declined, highlighting the need for targeted breeding efforts.