Variability in Capsaicinoids content and phylogenetic analysis of AT3, an Acyltransferase gene in Chilli (Capsicum annuum L.)

Capsaicinoids are the alkaloids responsible for pungency in chilli fruits. Estimates of capsaicinoids obtained by colorimetric method and HPLC were highly correlated (R² =0.996). Data suggest that colorimetric method an effective means for estimating total capsaicinoids in extracts of fresh chilli fruits. Thirty accesions were screened using colorimetric method and considerable variability was observed for total capsaicinoids (0–1.65%). In order to see sequence polymorphism associated with pungency level, we cloned and sequenced part of AT3 gene, an acyltransferase belonging to the BAHD family of acyltransferases. Results revealed that abundant indel (insertion and deletion events) and SNP (single nucleotide polymorphisms) in the cloned AT3 partial sequence. Both AT3-1 and AT3-2 are present in many cultivars that suggest paralogous gene lineages.