Genetic Divergence and Multivariate Analysis of Isabgol Genotypes for Yield-Related Traits in Arid Environments

Isabgol is a commercially significant medicinal crop cultivated for its valuable seed husk, but its productivity in arid environments remains constrained by limited genetic diversity. To cope up with this limitation, 25 genotypes were examined with the objective of assessing genetic variability and identifying high-performing genotypes for yield enhancement in the present study under arid conditions, including two checks (GI-4 and VI-3). A broad spectrum of genetic variability was observed among the isabgol genotypes for yield and related traits. Genotype CZI-24-1 recorded higher seed yield (23.72 g), whereas CZI-24-20 demonstrated superior performance for key yield-contributing traits, including the number of seeds per spike (134.17), number of spikes per plant (127.78), and spike length (8.19 cm). Multivariate analyses using Principal Component Analysis (PCA) and cluster analysis identified genotypes CZI-24-6 and CZI-24-16 as potential candidates for yield enhancement, whereas CZI-24-20, CZI-24-23, and CZI-24-21 demonstrated superior performance for key yield-contributing traits. The genotype CZI-24-16 displayed a unique expression of white-color spikes, representing the first documented occurrence of this trait in isabgol. PCA and correlation analyses indicated that spike morphology traits such as spike length, spikes per plant, and seeds per spike, were the major determinants of yield variability; whereas seed yield per plant contributed independently with limited association to other yield traits. These findings revealed the significant genetic diversity, offering a foundation for selecting elite genotypes of isabgol. However, multilocation and multiyear testing is needed to confirm their stability and adaptability.