Main content area

Genetic Effects of Wx Allele Combinations on Apparent Amylose Content in Tropical Hybrid Rice

Wang, Kai, Zhou, Qunfeng, Liu, Junyu, Qiu, Fulin, dela Paz, Madonna Angelita, Larazo, Wenceslao, Yang, Yuanzhu, Xie, Fangming
Cereal chemistry 2017 v.94 no.5 pp. 887-891
Oryza sativa, alleles, amylose, dry season, genotype, genotype-environment interaction, hybrids, parents, rice, starch synthase, wet season, South East Asia
Apparent amylose content (AAC), as one of the most important quality traits of rice grain, is primarily controlled by the Wx gene, which encodes a granule-bound starch synthase. Effects of putative alleles of Wx of tropical rice hybrids generated from parents with three different nonglutinous Wx alleles (Wxᵃ, Wxᵇ, and Wxⁱⁿ) were examined in a multienvironment trial. Genotypes of Wxᵇ/Wxⁱⁿ and Wxⁱⁿ/Wxⁱⁿ were associated with intermediate AAC (20.2–23.7%), and genotype of Wxᵃ/Wxᵃ was associated with high AAC (24.9–28.0%). Wx alleles of Wxⁱⁿ/Wxⁱⁿ could be the most favorable combinations in selecting hybrid parents with desirable intermediate amylose content (20–25%) for rice consumers of South and Southeast Asian countries. Genotype and genotype × environment interaction were the major contributing factors to the variation in parental accessions’ and hybrids’ AAC, and in terms of AAC, hybrids were more sensitive than parental varieties to environment. Genotypes of Wxᵃ/Wxᵃ, Wxᵃ/Wxⁱⁿ, and Wxⁱⁿ/Wxⁱⁿ showed higher AAC performance in the wet season than in the dry season.