Morphometric analysis of mango varieties in Sri Lanka

Abstract

Mango is an important dry zone fruit crop in Sri Lanka. Mangoes grown in northern Sri Lanka show rich varietal diversity and have greater consumer demand compared with those from other regions of the country. In this study, eighteen mango varieties including 54 accessions from Jaffna were examined to evaluate morphological variations and determine fruit quality. A total of 46 morphological traits from IPBGR descriptors for mango were measured in 54 mango accessions between years 2009 and 2012. Qualitative and quantitative morphological traits including leaf, inflorescence and fruit characteristics were evaluated in the field as well as in the laboratory. High variation among the mango varieties was observed with respect to qualitative data such as colour of immature leaves, leaf shape, inflorescence axis flower colour, type of flower, fruit shape skin colour and texture. Collected quantitative data was subjected to principal component analysis (PCA) and hierarchical cluster analysis (HCA). PCA showed that first 4 principal component had 75.6% of the total variation. PC1 explained 34.2% variations and these components were fruit length, breadth, thickness and weight. Besides these parameters, seed and leaf length also showed high variation. PC2 showed 21.8% variations with the parameters of leaf length, leaf breadth and inflorescence length. Thus based on these variations and similarities in morphological traits, mango varieties were grouped into three by HCA. These PCA and HCA results suggest that broad morphologic diversity was found in mango varieties examined in this study. Over all fruit quality was measured by a trained taste panel. Fruit quality was rated excellent in 8 varieties with pink or red mixed attractive fruit skin or waxy yellow colour skin. Among the 18 mango varieties thus identified from the 54 accessions, 4 varieties were found to be exotic and 14 varieties were endemic to Sri Lanka.