Molecular diversity and transgressive segregation in F₂ population based on SSR markers and phenotypic evaluation in quality protein maize (Zea mays L.)

The present study was conducted during the Zaid (February-June, 2023) at the P.G. Research Farm, MSSSoA, Paralakhemudi, Gajapati, Odisha aimed to identify superior segregants in the (CML149 × CML330) F₂ population and assess their potential for genetic improvement using molecular markers. Among the segregants, F₂-3 and F₂-26 exhibited the highest grain yield per plant (720 g and 719.5 g, respectively) and showed transgressive segregation for yield-contributing traits such as ear length, ear girth, kernel rows per cob and kernels per row. Additionally, variations in protein content, oil content, chlorophyll content and membrane stability index were observed, highlighting their potential for nutritional enhancement and heat stress tolerance. Molecular diversity analysis was conducted in quality protein maize (QPM) using two parent genotypes (CML149 and CML330) and F2 72 population of individuals. Initially, 91 simple sequence repeats (SSRs) markers were screened in the parent genotype and 10 polymorphic markers were selected for further analysis in the F2 population. These 10 markers revealed significant polymorphic ranging from 0.141 (p-umc1798) to 0.812 (p-phi053) with an average polymorphic information content (PIC) of 0.373. Cluster analysis grouped the F2 individuals into 10 clusters. The genetic variability observed in the F2 population of QPM provides valuable insights for exploiting heterosis and developing genetically diverse breeding lines aimed at improving QPM traits.