Evaluation of Genetic Diversity and Heterosis in Cotton (Gossypium hirsutum L.) genotypes: A Comprehensive Study on Yield, Fibre Quality, and Breeding Potential

The study aimed to evaluate the genetic diversity, heterosis, and variability in cotton genotypes under the climatic conditions of Guntur, Andhra Pradesh, India. A total of 11 test cross hybrids and 3 check varieties (US-7067, CRISTAL 369, and RASHI SWIFT) were evaluated for growth, yield, and fibre quality traits using Randomized Block Design (RBD). Cluster analysis grouped the genotypes into three distinct clusters, highlighting significant genetic diversity among them. Heterosis analysis revealed that H-1357 exhibited the highest positive heterosis for traits such as plant height (30.00%), number of bolls (71.77%), yield per plot (20.20%), and lint weight (25.23%), making it a superior genotype for commercial breeding. Variability analysis indicated that number of bolls (NB) and monopodial branches (MP) had high GCV (20.66% and 21.81%) and PCV (22.90% and 36.38%), suggesting a strong potential for genetic improvement. Path analysis identified yield per plant (YPL), lint weight (LW), and boll weight (BW) as the most influential traits for yield improvement, with high direct effects on yield per plot (YPO). The results suggest that H-1357 and H-1349 are the most promising hybrids for further breeding and commercial cultivation. These findings provide valuable insights for cotton improvement programs, focusing on yield enhancement, fibre quality, and genetic stability.