Analysis of genotype-by-environment effects on starch content in 281 Tartary buckwheat varieties and evaluation of the physicochemical properties of two elite varieties

Tartary buckwheat (TB) starch is a low-glycaemic-index food source. Analysis of genotype-by-environment effects on starch content is needed to improve high-quality TB production. However, an accurate and highthroughput evaluation method for starch content is a bottleneck for the analysis of genotype-by-environment effects on starch content. In the current study, a rapid and non-destructive method for detecting starch was developed based on near-infrared reflectance (NIR) spectroscopy. Overall, 281 varieties were planted in three environments for 2 years and measured. The coefficient of correlation between the laboratory-determined and NIR model-predicted starch content values was 0.9577. The average starch content of TB varieties had higher variants among the three environments. The genotype-by-environment interaction analysis showed the significant impact of environmental factors on TB starch content. Of them, two varieties (Ft155 and Ft184) with stable and relatively high starch contents (733.43 and 689.16 mg/g) were identified. The amylose content, structure character, thermal properties and pasting character revealed that these physicochemical properties of TB starch were distinct from those of potato and rice. Moreover, Ft155 was more difficult to gelatinise, and Ft184 has desired high-starch-quality cooking properties. These assessments provide robust nutritional quality evaluation approaches and food processing materials.