Integrated characterization of gamma-induced pomegranate mutants using morphological, pathological and SSR-based analysis

Pomegranate ( Punica granatum L.) is a commercially important fruit crop valued for its nutritional and therapeutic properties. The present study evaluates promising pomegranate mutants exhibiting desirable horticultural traits following gamma irradiation, and performs their molecular characterization. The LD 50 dose was standardized using probit curve analysis based on survival percentages across seven irradiation doses (6–24 kR) for three cultivars: Kandhari Kabuli, Bhagwa, and Daru. Morphological evaluation followed UPOV descriptors, while disease tolerance screening was performed against bacterial blight ( Xanthomonas axonopodis pv. punicae ). Molecular characterization using 26 SSR markers revealed distinct genetic profiles among mutants, with polymorphic information content (PIC) values ranging from 0.08 to 0.58, effective multiplex ratio (EMR) from 0.00 to 0.17, and marker index (MI) from 0.00 to 0.06. Cluster analysis grouped mutants by genetic similarity, providing insights into genetic divergence. The cv. Daru exhibited the lowest disease severity (6.57–10.20%), indicating superior tolerance. Integration of morphological and molecular data supports identification of promising mutant lines for cultivar improvement and potential breeding resources. This study underscores the role of mutation breeding in pomegranate genetic enhancement.