Hybrid vigour analysis for dry root yield traits across multiple environments in Ashwagandha (Withania somnifera (L.) Dunal)
Abstract
Ashwagandha (Withania somnifera (L.) Dunal) is an important medicinal plant valued for its therapeutic properties and bioactive compounds, notably alkaloids and withanolides. Despite its economic significance, systematic crop improvement through heterosis breeding remains limited. The present study was undertaken to evaluate hybrid vigour for dry root yield and related traits across multiple environments. A line × tester mating design involving 16 lines, 3 testers and their 48 F1 hybrids were evaluated along with three standard checks across 3 locations during the rabi season of 2022–23 in Southern Rajasthan. Observations were recorded for days to 50 % flowering, plant height, root length, root diameter, fresh root yield, dry root yield and alkaloid content. Pooled analysis of variance revealed significant differences among genotypes, environments and genotype × environment interactions for all traits, indicating substantial genetic variability and environmental influence. Significant heterosis was observed for most traits. For earliness, crosses L15 × T3, L11 × T3 and L9 × T2 exhibited desirable negative heterosis. The L14 × T1 and L16 × T3 exhibited superior performance for plant height and L16 × T2 and L6 × T2 emerged as promising hybrids for root length and root diameter respectively. High heterosis for fresh root yield was recorded in L7 × T1 and L13 × T1, whereas L16 × T3, L15 × T3 and L14 × T1 demonstrated outstanding performance for dry root yield, with L16 × T3 also exhibiting significant economic heterosis. For alkaloid content, crosses L15 × T3, L16 × T3 and L2 × T3 exhibited consistent superiority across environments. The study identified promising hybrid combinations combining high dry root yield and enhanced alkaloid content highlighting the potential of heterosis breeding for developing superior Ashwagandha cultivars suited for commercial cultivation and pharmaceutical demand.