Effects of Soluble Starch Synthase IIa Allelic Variation on Rice Grain Quality under Different Waxy Background.

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 identifyingSSIIaalleles. 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 ofWxandSSIIa, we found that theSSIIaalleles 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 ofSSIIaalleles on HPV, cool paste viscosity (CPV), and consistency value with differentWxbackgrounds. The apparent amylose content (AAC) of samples significantly affected the accuracy of GT, which was represented by the manually determined pasting temperature (PTm). CONCLUSIONS TheSSIIaalleles amplified by SSII-3 M1 areindicatype andjaponicatype. DifferentSSIIahaplotypes significantly affect HPV, CPV, PaT, and ASV. GT, PaT, and PTm are mainly affected bySSIIaalleles. The classification of all samples with different haplotypes of SSIIa indicates that their AAC (Wx genotypes) is essentially. The effects ofSSIIaalleles are themselves affected by differentWxalleles. (c) 2020 Society of Chemical Industry