Authentication of Carnaroli Rice by HRM Analysis Targeting Nucleotide Polymorphisms in the Alk and Waxy Genes

Carnaroli is a high quality and priced variety, being considered as one of the finest Italian rice varieties due to its sensorial and rheological properties and, thus being a potential adulteration target. The present work aimed at exploiting polymorphisms in the Alk (A/G and GC/TT in exon 8) and Waxy ((CT)n and G/T in intron 1) genes by HRM analysis to differentiate Carnaroli rice from closely related varieties. The HRM method targeting the Alk gene did not allow gathering the Carnaroli subgroup genotypes in the same cluster. The HRM approach targeting Waxy gene successfully discriminated the varieties sold as Carnaroli from all the others with high level of confidence (>98%), which corroborated sequencing data. Its applicability to commercial rice samples was successful. Therefore, the proposed new HRM method can be considered a simple, specific, high-throughput and cost-effective tool for the authentication of Carnaroli rice, contributing to valorise such premium variety.