Genetic Diversity Analysis in Nerium oleander L. Genotypes

Abstract

Genetic diversity analysis plays a crucial role in plant breeding and horticultural improvements. This study evaluated the morphological and floral characteristics of fifteen nerium genotypes to assess genetic variability and potential for selection. Significant variations were observed in plant height, leaf morphology, flowering traits, and flower yield. Genotype T13 exhibited the tallest plants (167.38 cm), while T5 recorded the shortest (59.25 cm). Leaf blade dimensions varied considerably, with T11 exhibiting the longest leaves (24.01 cm) and T5 the shortest (12.36 cm).  Genotypic differences were prominent in floral traits, including flower diameter, corolla throat dimensions and flower yield. T5 exhibited the highest number of flowers (16.7) per plant at full flowering stage ie., two months after first flowering, whereas T3 had the highest total flower yield (65.09 g) during the experimental period. The highest phenotypic (PCV) and genotypic (GCV) coefficients of variation were recorded for flower yield and plant height, indicating substantial genetic diversity. Floral traits demonstrated high heritability (0.70-0.99) with significant genetic advances, particularly in flower yield and corolla throat diameter, suggesting strong selection potential. These findings provide valuable insights for breeding programs aimed at enhancing ornamental and commercial traits in nerium.