Effects of soluble starch synthase IIa allelic variation on rice grain quality with different Waxy backgrounds
Hui You1, Ouling Zhang1, Liang Xu1
1Lab of Plant Molecular Genetics and Breeding, Southwest University of Science and Technology, Mianyang, China.
Background:
Soluble starch synthase IIa (ALK, SSII-3) is the major gene regulating gelatinization temperature (GT) and SSII-3 M1 is an effective marker for identifying SSIIa alleles. However, the haplotypes of SSIIa alleles amplified by SSII-3M1 and their allelic effect sunder different Waxy (Wx) background in non-glutinous rice remain unclear.
Results:
By integrating the genetic background analysis and by the identification of the genotypes of Wx and SSIIa, we found that the SSIIa alleles amplified by SSII-3 M1 were haplotype 1 (G/G/GC, indica-type) and 4 (A/G/TT, japonica-type), which had a significant effect on pasting temperature (PaT), hot paste viscosity (HPV), and the alkali spreading value (ASV). There were significant effects of SSIIa alleles on HPV, cool paste viscosity (CPV), and consistency value with different Wx backgrounds. The apparent amylose content (AAC) of samples significantly affected the accuracy of GT, which was represented by the manually determined pasting temperature (PTm).
Conclusions:
The SSIIa alleles amplified by SSII-3 M1 are indica type and japonica type. Different SSIIa haplotypes significantly affect HPV, CPV, PaT, and ASV. GT, PaT, and PTm are mainly affected by SSIIa alleles. The classification of all samples with different haplotypes of SSIIa indicates that their AAC (Wx genotypes) is essentially. The effects of SSIIa alleles are themselves affected by different Wx alleles. © 2020 Society of Chemical Industry.
