Genetic Dissection of Fibre Quality Traits in Upland Cotton (Gossypium hirsutum L.)

Nine upland cotton varieties were crossed in a complete diallel mating system to assess the genetics of 2.5% span length (SL), bundle strength(BS), micronaire value (MIC), Uniformity ratio (UR) and Elongation percent (EP) utilizing Jinks numerical approach. Analysis of variance had showed highly significant differences due to genotypes for all the fibre traits. Additive component (D) was significant in all the traits and was lower in magnitude than dominant components (H₁ and H₂) of variation for 2.5% SL, BS, MIC and UR which was firmly supported by the value of (H₁/D) ^½. Asymmetrical distribution of dominant and recessive genes in parents for 2.5% SL, BS, MIC and UR was confirmed, and soundly sustained by the value of H₂/4H₁. The h² value was significant for all the traits except UR. High narrow sense heritability (h²_n.s) was exhibited by MIC, while 2.5%SL, BS and EP possessed moderate heritability. The genes controlling EP were additive in nature and could be improved via selection while heterosis breeding might be fruitful for progress in 2.5% SL, BS, MIC and UR.