Genetic Diversity in Indian Landraces of Cucumber (Cucumis sativus L.) Based on Morpho-Horticultural Traits

Until recently, the main focus of breeding programmes in cucumber (Cucumis sativus L.) was the development of varieties and hybrids for high yield. However, consumer preference of cucumber is mainly determined by the qualitative traits of the fruit namely colour, shape, size, tenderness, crispness, texture and organoleptic qualities. In this study, observations on 15 qualitative traits, three major quantitative traits, storage characters and organoleptic attributes were recorded in 53 cucumber accessions, collected from 12 Indian states. The skin colour of the tender fruits ranged from light green, green, dark green to cream and fruit shapes of elliptical elongate, oblong ellipsoid and globular were observed. Ten accessions exhibited orange coloured flesh during the ripe stage of the fruit, indicating carotenoid content in the flesh. Shelf life of 4-6 days was exhibited by IC331627, IC613481, IC613461, IC202058A, IC331619, IC613460, IC613477 and IC613478 with a weight loss of less than 10 g during storage under room temperature. Four accessions namely IC613480, IC613481, IC618084A and IC613484 exhibited organoleptic qualities better than the control variety, AAUC-2. Based on the multivariate analysis using PCA, fruit skin colour and texture were identified as the most discriminating qualitative traits explaining greater variability in cucumber. Elliptical elongate shape with green or light green colour of the fruits are the most common and preferred characters for commercial cucumber varieties. IC613481 and IC613480, both collections from West Bengal ranked superior with respect to organoleptic scoring, preferable storage qualities and promising yield attributes. Systematic characterization of the genotypes revealed that they are potential sources of genetic variability, worth harnessing through improvement programmes.