The proposed method can be used to screen samples for AC rapidly, with a single rice caryopsis, without any costly equipment and can be especially suitable for screening of mutants and segregants with altered AC in large breeding populations.

In human diet, the products of starch digestion are a major energy source. Starch is stored as water insoluble granules composed of amylose and amylopectin. The susceptibility of starch granule to digestive enzymes is affected by starch granule size, shape, and composition. In this study, starch characteristics and in vitro enzymatic hydrolysis in three rice (Oryza sativa L.) mutants (RSML 184, RSML 278 and RSML 352) with similar amylose concentration (24.3-25.8%) was compared to parent ADT 43 (21.4%). The three mutants had reduced thousand grain weight and starch concentration but higher protein and dietary fiber concentrations. The mutant RSML 352 had small starch granules and reduced short glucan chains [Degree of polymerization (DP) 6-12] compared to the other two mutants (RSML 184 and RSML 278). The mutant RSML 352 had the highest hydrolytic index (HI) and least concentration of resistant starch (RS) compared to the other two mutants and parent rice ADT 43. The two rice mutants (RSML 184 and RSML 278) had reduced HI and increased RS concentration than the parent ADT 43. The results showed that starch granule size and amylopectin structure influence starch enzymatic digestibility and RS concentration.

BackgroundGlycemic response, a trait that is tedious to be assayed in cereal staples, has been identified as a factor correlated with alarmingly increasing prevalence of Type II diabetes. Reverse genetics based discovery of allelic variants associated with this nutritional trait gains significance as they can provide scope for genetic improvement of this factor which is otherwise difficult to target through routine screening methods.ResultsThrough EcoTILLING by sequencing in 512 rice accessions, we report the discovery of six deleterious variants in the genes with potential to increase Resistant Starch (RS) and reduce Hydrolysis Index (HI) of starch. By deconvolution of the variant harbouring EcoTILLING DNA pools, we discovered accessions with a minimum of one to a maximum of three deleterious allelic variants in the candidate genes.ConclusionsThrough biochemical assays, we confirmed the potential role of the discovered alleles alone or in combinations in increasing RS the key factor for reduction in glycemic response.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0968-0) contains supplementary material, which is available to authorized users.

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High performance liquid chromatography (HPLC) was performed to determine the raffinose family oligosaccharides (RFOs) and sucrose content in 32 pigeonpea cultivars. The results showed that the RFOs in the pigeonpea seed extracts comprised of raffinose, stachyose and verbascose. The contents of raffinose, stachyose and verbascose were within the range of 1.15 to 2.55%, 2.25 to 4.05% and 2.05 to 4.05% with mean values of 1.63%, 2.97% and 2.80%, respectively. There was large level of variation of individual RFOs. Furthermore, to study the effect of post-harvest processing on the RFO contents, sprouting and cooking experiments were conducted with the seeds of the variety VBN 3 which possessed high RFO levels. Sprouting significantly reduced the RFO levels within 24 hours while cooking even up to 30 min in boiling water did not result in a considerable reduction. Among the local processing techniques, sprouting had significant effect on reducing RFOs content in pigeonpea.