Effect of Allelic Variations in Wx and SSIIa on Rice Cooking and Eating Quality

Area of Science:

• Agricultural Science
• Genetics
• Food Science

Background:

• Rice cooking and eating quality (CEQ) is crucial for consumer acceptance.
• The Wx and SSIIa genes are primary regulators of rice CEQ.
• Understanding allelic combinations of Wx and SSIIa is key to improving rice quality.

Purpose of the Study:

• To investigate the effects of allelic variations in Wx and SSIIa genes, individually and in combination, on rice CEQ.
• To analyze the impact of these genetic variations on physicochemical properties of rice.

Main Methods:

• Sequencing of Wx and SSIIa genes in 164 rice accessions.
• Analysis of nucleotide variations and their effects on apparent amylose content (AAC), gelatinization temperature (GT), pasting viscosities, and gel texture.
• Comparison of genotypes across different environmental conditions (Hangzhou and Sanya).

Main Results:

• Six Wx alleles identified, with Wx^lv showing highest AAC and wx showing lowest.
• Three SSIIa alleles identified (G/GC, G/TT, A/GC); G/GC exhibited significantly higher GT.
• Significant interactions between Wx and SSIIa alleles influenced GT, viscosity, and gel texture.
• Environmental factors (location) showed a minor effect on GT.

Conclusions:

• Wx gene variations primarily affect AAC, viscosity, and gel texture.
• SSIIa gene variations primarily affect GT.
• Interactions between Wx and SSIIa alleles significantly modulate rice physicochemical properties and CEQ.
• Findings provide a basis for marker-assisted selection to breed rice with desired eating and cooking quality.