Rajat Kumar Maurya, Ashish Kumar Singh, Rohit Maurya, Aastik Jha, C.N. Ram, Shweta Verma and Niharika Singh
Abstract
The present study was conducted to evaluate genetic variability and morphological distinctiveness among forty-five tomato genotypes along with one standard check using DUS (Distinctness, Uniformity and Stability) descriptors under field conditions. The experimental material was evaluated in a Randomized Block Design, and selected parental lines were utilized in a half-diallel mating design to generate hybrid combinations for assessing breeding potential. The observation were recorded for fifty six genotypes including ten parent, forty five derived hybrid and one standard check on important qualitative morphological traits, including growth habit, stem pubescence, Flower pubescence of style, Flower Colour, Stem anthocyanin colouration of upper third portion, Leaf Attitude, Leaf structure, Inflorescence type 2nd and 3rd truss, Flower nature of stigma, Fruit Intensity of green colour (before maturity, Fruit Green shoulder before maturity, Fruit Shape in longitudinal section, Fruit Ribbing at peduncle end, Fruit Cross section, Fruit Depression at peduncle end, Fruit Shape at blossom end, Fruit colour at maturity, Fruit Colour of flesh at maturity, following DUS testing guidelines. Significant variation was observed among the genotypes and their derived hybrids, indicating the presence of substantial genetic diversity within the experimental material. Distinct morphological expressions enabled clear differentiation among genotypes, supporting their identification, characterization and varietal protection under DUS testing. The evaluated traits served as reliable morphological markers for selection in segregating populations and for identifying superior parental combinations in breeding programmes. The study highlights the importance of DUS characterization and half-diallel analysis in exploiting genetic variability for hybrid development and improvement of tomato cultivars with desirable horticultural traits, enhanced productivity and wider adaptability.