Delineating naturally introgressed genotypes of Indian eggplant collections using morphological key traits for plant genetic resources management

Abstract Eggplant ( Solanum melongena L.) is a widely cultivated vegetable in India with enormous variability. Recent molecular techniques revealed three closely related but distinct Solanum species ( S. melongena , S. incanum and S. insanum ), with the Indian subcontinent being a domesticated centre. Spontaneous hybridization between S. insanum and S. melongena has led to the formation of naturally introgressed lines and limited studies are available to differentiate these genotypes using morphological key traits. Current study aimed to delineate naturally introgressed genotypes of Indian eggplant collections using morphological key traits for plant genetic resources (PGR) management and assess available genetic diversity. The study characterized a collection of 157 eggplant germplasm at ICAR-NBPGR, Regional Station, Kerala, and identified 30 naturally introgressed, 10 wild progenitors and 117 cultivated eggplants. The key morphological traits are prickliness (stem, petiole, calyx and pedicle), leaf base shape, fruit shape and size. Other fruit traits such as length, breadth and mesocarp texture could also provide some clues for delineating introgressed genotypes from S. insanum and S. melongena . Basic statistical analysis of six quantitative traits of 157 eggplant genotypes revealed the presence of considerable amount of variation (CV%) in which fruit length/breadth ratio showed higher variation (73.87) followed by fruit length (54.73) and average fruit weight (53.5). The frequency distribution of 14 qualitative traits revealed the presence of all character states among them. Key traits identified under study could provide clues to identify individual plants at field level to plant taxonomist/explorers and also to aid gene bank curators for PGR management.