Assessment of the organoleptic properties, species delimits and varietal identities of pennyworts in Sri Lanka

Abstract

Asiatic pennyworts (AP) (Centella asiatica) are among the most popular leafy vegetable species in Sri Lanka. Five AP cultivars, namely, Lowland AP (LAP), Giant AP1 (GAP1), Giant AP2 (GAP2), Salad AP (SAP), and Medicinal AP (MAP) are grown in the country. Two other leafy vegetable species, water pennyworts (WP) (Hydrocotyle verticillata) and Korean pennyworts (KP) (Adenophora triphylla), are also designated under ‘pennyworts’ in Sri Lanka. The consumer-preference on the pennywort bunches available in the market and the salad properties are yet to be studied. Also, no attempts have been reported for the identification of species delimits and phylogenetic relationships among the different cultivars of C. asiatica. In the present study, consumer preference on the appearance of leaf bunches and salads of pennyworts were assessed. The intra-and interspecific variation of pennyworts grown in Sri Lanka were also studied. The genomic DNA extracted from the immature leaves was PCR amplified for the DNA barcoding markers matK-trnT, atpB-rbcL, and rbcL. The PCR products were sequenced and used to assess the intra-and interspecific variation. The consumers mostly preferred to purchase the leaf bunches of GAP2 because of its large leaf size and appealing look. However, the highest preference for salads was reported for the dishes prepared using LAP, MAP, and WP. The clade structure of the phylogenetic tree drawn for AP cultivars shows an intraspecific variation. Our study also highlights the importance of producing an improved AP cultivar with larger leaf size, improved flavor properties, and sinuate leaf margin.