Genetics of Inheritance and Interrelationship of Various Agronomic Traits of F2 Population in Cotton (Gossypium hirsutum L.)

Background: Cotton (Gossypium hirsutum L.) is grown in more than sixty countries worldwide. It is an important fiber crop in the world. It plays a vital role in our national economy being the source of earning of foreign exchange, therefore, it is considered to be the backbone of the economy of Pakistan. In Pakistan, millions of families are associated with cotton and textile industry for their livelihood.

Results: In this experiment F2 population of the cross L. A. Frego Bract x CIM-600 and their parents was sown in randomized complete block design with three replications during normal growing season of the year 2014 to sort out best performing genotypes for yield related traits. Analysis of variance (ANOVA) revealed that parental and their F2 population showed significant differences for all the observed agronomic traits (plant height, number of monopodia branches, number of sympodial branches, number of bolls per plant, boll weight, ginning out turn, bract type, boll shape, beak size, seed cotton yield, staple length, fiber strength and fiber fineness). Estimation of correlation revealed that seed cotton yield was found positively correlated sympodial branches, fiber fineness and boll weight while ginning out turn, bract type, beak size, staple length and fiber strength were negatively associated with seed cotton yield. Epistasis was not found to be involved in any of the traits.

Conclusion: The correlation and genetics study of various yield related traits provides us useful information for effective selection and sustainable breeding programs. Estimation of broad sense heritability ( ) in F2 populations for different traits vary as following order; ginning out turn>plant height>seed cotton yield>sympodia branches>fiber length>fiber strength>bolls per plant>monopodia branches>boll weight>fiber fineness with heritability 0.90, 0.79, 0.78, 0.75, 0.73, 0.71 0.67, 0.64, 0.63 and 0.50 respectively. Results suggested form heritability and correlation that these traits can be improved either through appropriate selection method or hybrid breeding programme.