Accumulation pattern of catechins and flavonol glycosides in different varieties and cultivars of tea plant in China

•ECG and flavonol di-glycosides accumulate in cultivars of assamica variety.•EGCG and flavonol tri-glycosides accumulate in cultivars of sinensis variety.•Flavonoids can be used as indicators for distinguishing various tea plant resources.•Accumulation pattern of flavonoids mainly depends on tea plant genetic background.