Multi-season-based estimation of genetic diversity, correlation and path analysis in spearmint (Mentha spicata L.) half-sib populations.

Spearmint (Mentha spicata L.) is popular for its medicinal benefits and industrial uses, in this study forty-three half-sib progenies were evaluated over three seasons at CSIR-CIMAP, Research Centre Pantnagar to study genetic variability, correlation, path coefficient analysis and Mahalanobis D2 diversity by using five morphological and two biochemical traits. These forty-three half-sib populations were derived from nine commercially existing spearmint varieties through an intra-population improvement method. Results of correlation and path coefficient studies indicated the paramount importance of certain key traits in the selection process. Notably, traits such as herb yield per plot (kg), plant height (cm) and oil content (%) emerged as pivotal, exhibiting positive correlations, high heritability and moderate to high genetic advance. These attributes, therefore need primacy in the selection of superior lines. Furthermore, genotypes OPSP-106, OPSP-92, OPSP-47, OPSP-35 and OPSP-76 showed significant genetic divergence. These accessions hold promise as parent candidates for hybridization experiments aimed at finding transgressive segregants in later generations. Additionally, this study highlighted the presence of specific oil components, such as carvone and limonene, offering insights into potential avenues for targeted breeding efforts. This study provides a holistic view of the genetic makeup of Mentha spicata genotypes, enabling informed decisions in breeding programs. By prioritizing traits and maximizing genetic diversity, the results of this investigation will contribute to the development of improved spearmint varieties with enhanced morphological and biochemical characters, thus advancing the medicinal and industrial applications of spearmint. [Display omitted] • Key traits like herb yield, plant height, and oil content correlated positively. • Improvement in plant height, herb yield, oil content improves oil yield. • Genotypes OPSP-106, −92, −47, −35, −76 are diverse and used for hybridization. • Carvone and limonene-enriched lines are good for transgressive breeding • Selection among diverse half-sibs will boost spearmint oil yield. [ABSTRACT FROM AUTHOR]