Characteristics of Starch synthesis,Yield and Quality Provide Insights into Rice-Tartary Buckwheat Utilization and Improvement

[Objectives] Rice-Tartary buckwheat is a special type of Tartary buckwheat with easy hulling thin shell.This study was conducted to characterize the carbohydrate metabolism,quality and yield and provide a basis for food processing and breeding of rice-Tartary buckwheat.[Methods]The local rice-Tartary buckwheat‘cv.Xiaomiqiao’(XMQ) was used to explore the characteristics of photosynthesis,starch synthesis enzyme activities,traits of yield and quality,as compared to Tartary buckwheat‘cv.Jinqiao 2’(JQ2).[Results]XMQ showed significantly lower values of net photosynthetic rate,ADPGase activity and starch synthase activity at one or more periods during grain filling than JQ2.The effective branch number and grain number per plant of XMQ were similar to that of JQ2 regardless of different years,but the 1 000-grain weight was significantly lighter that resulted in the significantly lower yield.XMQ accumulated similar contents of starch(amylose,amylopectin) and protein(glutelin,albumin,prolamin,globulin) to those of JQ2,but exhibited significantly lower flavonoid content.The values of peak viscosity and hot paste viscosity in XMQ were similar to those of JQ2,but the values of cool paste viscosity,breakdown and setback were significantly lower.In conclusion,XMQ showed low yield due to the insufficient of photosynthesis and starch synthesis.XMQ exhibited high nutritional quality as well as normal Tartary buckwheat and stored 18.88 mg/g of flavonoid,that might be consumed as daily diet.[Conclusions]The present results will provide a basis for utilization and improvement of rice-Tartary buckwheat.

GC-MS Analysis of Metabolites in Filling Grains of Rice-Tartary Buckwheat (Fagopyrum tataricum) in Comparison to Conventional Tartary Buckwheat

Rice-Tartary buckwheat(RTB)is a special germplasm of Tartary buckwheat.In this study,the appraisal of taste quality between RTB and conventional Tartary buckwheat(CTB)was presented,and the metabolites in kernels at three typical grain filling stage(GFS)were investigated.Unlike CTB,RTB showed thin shell seeds without longitudinal furrows at maturity,which was easily artificially dehulled.Sense organ test indicated that RTB exhibited better taste quality because of the higher values of appearance,viscosity,taste and summary were appraised.In total,92 metabolites were identified in kernels using GM-MS metabolomics platform.The levels of most metabolites changed greatly during grain filling and a large numbers of metabolite-metabolite correlations were found by Pearson correlation coefficient analysis.ANOVA analysis identified 61 differentially expressed metabolites between RTB and CTB,while Venn diagram analysis screened 35 common differential metabolites.Compared with CTB,RTB showed similar levels of lysine and methionine,indicated that RTB own excellent nutritional value.Additionally,RTB exhibited significantly up-regulated levels of most sweeteners(sugars and polyols),which might contribute to better taste.This work provides the first comprehensive metabolomics analysis of kernels between RTB and CTB,which may potentially provide theoretical basis for further research.