Association between allelic variation at theWaxylocus and starch physicochemical properties using single-segment substitution lines in rice (Oryza sativaL.)

Abstract

The Waxy locus is the major locus controlling AM synthesis in rice endosperm. . Through Waxy genotype association analysis, functions of the four Waxy nucleotide polymorphisms on rice starch properties were determined. Analysis of correlation among the cooking and pasting parameters indicated that most of the traits were significantly correlated. The present results have important implications for rice breeders to select favorite Waxy alleles in rice grain quality improvement.

Comparison of amylopectin structure and activities of key starch synthesis enzymes in the grains of rice single-segment substitution lines with different Wx alleles

“…Correlation analysis was conducted to characterize the relationships between activities of key starch synthesis enzymes, amylopectin chain length distribution, AAC, GC, GT, and pasting viscosity parameters. The data of starch cooking and pasting parameters used for correlation calculations was cited from Teng et al (2013).…”

“…So far, at least five common Wx alleles including wx, Wx t , Wx g1 , Wx g2 and Wx g3 have been identified (Teng et al 2012). Recently, further comparison studies have revealed that each of the five Wx alleles has its unique function on rice cooking and pasting properties (Teng et al 2013). However, apart from AAC, exact physiological and starch structural mechanisms of how the Wx allelic variation affects starch properties has not been clearly reported.…”

“…1). * and ** mean the correlation is significant at P \ 0.05 and P \ 0.01, respectively a The data of the starch physicochemical properties used for calculations was cited from Teng et al (2013). AAC apparent amylose content, GC gel consistency, GT gelatinization temperature, PV peak viscosity, HPV hotpaste viscosity, CPV coolpaste viscosity, BD breakdown, SB_P setback from peak viscosity, SB_HP setback from hotpaste viscosity, P time peak time, P temp , pasting temperature b Enzyme activity indicates the mean enzyme activity over the grain filling period.…”

“…After harvest, the mature seeds were airdried, and stored at room temperature for 3 months. Starch samples from the ten tested rice used for amylopectin structure analysis were the samples previously prepared by Teng et al (2013), who reported the cooking and pasting properties of these starch samples. In the cropping season of 2011, at the day of flowering, 40-50 panicles from the middle of each plot were tagged for uniformity and the tagged panicles were sampled at 6, 11, 16, 21, and 26 days after flowering (DAF).…”

“…Moreover, we have recently demonstrated that this Wx allelic variation also plays an important role in regulating rice cooking and pasting properties in addition to the AAC (Teng et al 2013). Using single-segment substitution lines (SSSLs) as materials, specific genetic effects of the five different Wx alleles on GC, GT, and pasting viscosity traits against a common genetic background were obtained (Teng et al 2013).…”