Phenotypic evaluation and seed dormancy studies in selected Stylosanthes seabrana genotypes

Abstract

A study of seven Stylosanthes seabrana genotypes was conducted during the 2022-23 kharif and rabi season at ICAR-Indian Grassland and Fodder Research Institute, Dharwad. Additionally, the effect of dormancy-breaking treatments on seed quality was assessed at the Seed Testing Lab of NSP/BSP Unit, University of Agricultural Sciences, Dharwad. Prominent variability was observed in plant height, growth habit, green fodder yield/plant, dry matter yield/per plant and 1000 seed weight. Notably, S. seabrana-11595 (G4) excelled in morphology, germination rate (33.28%), minimal hard seed percentage (62.72%), and seedling attributes, while S. seabrana-2534 (G2) had the highest hard seed percentage (77.53) and least favorable seedling characteristics. For dormancy breaking, several treatments, including FeNPs and concentrated H2SO4, were applied to freshly harvested seeds to improve germination and other seed parameters. S. seabrana -11595 (G4) showed the highest germination rate (67.1%) and lowest hard seed percentage (27.59%), benefiting significantly from FeNPs treatment (80 ppm for 12 hours), which effectively reduced hard seed percentages and enhanced seedling length and vigor index. Biochemical analyses indicated that FeNPs treatment increased total dehydrogenase and α-amylase activities in S. seabrana-11595 (G4) and S. seabrana -104710 (G3). The findings highlight the substantial genotypic variability, with G4 demonstrating superior potential across various traits and benefiting from effective dormancy-breaking treatments.