Wxlv, the Ancestral Allele of Rice Waxy Gene

In rice endosperms, the Waxy (Wx) gene is important for amylose synthesis, and various Wx alleles control the amylose content and affect the taste of cooked rice. Herein, we report the cloning of the ancestral allele Wxlv of the Wx locus, which affects the mouthfeel of rice grains by modulating the size of amylose molecules. Using evolutionary analysis, we demonstrated that Wxlv originated directly from wild rice, and the three major Wx alleles in cultivated rice (Wxb, Wxa, and Wxin) differentiated after the substitution of one base pair at the functional sites. These data indicate that the Wxlv allele played an important role in artificial selection and domestication. The findings also shed light on the evolution of various Wx alleles, which have greatly contributed to improving the eating and cooking quality of rice.

Agronomic characteristics of hard red spring wheat (Triticum aestivum L.) near-isogenic lines differing at the Waxy (Wx) locus

Hucl, P. and Ramachandran, A. 2015. Agronomic characteristics of hard red spring wheat (Triticum aestivum L.) near-isogenic lines differing at the Waxy (Wx) locus. Can. J. Plant Sci. 95: 201–204. Null mutations of the Waxy gene in all three genomes of hexaploid wheat (Triticum aestivum L.) produce a waxy starch phenotype. The agronomic performance of 32 waxy, partially waxy and wild-type near-isogenic spring wheat lines and four check cultivars was assessed at two locations over three cropping seasons. Differences in grain yield, kernel weight and test weight among allelic groups were generally small. The results of our study suggest that no significantly negative effects are likely to occur in the commercial cultivation of partially waxy wheat lines derived from a CWRS cultivar.