Genetic basis of variation for within-boll yield components in cotton

Abstract

Cotton productivity on a per-hectare basis is low in Pakistan. As boll is the basis for seed cotton yield, within-boll yield components can potentially serve as the most basic determinants of cotton productivity on a per unit land area basis. Before attempting the improvement of any trait, it is necessary to know the genetic mechanism lying behind its inheritance. The current study aimed to estimate the genetic basis of within-boll yield components in cotton. The research trials were conducted at the research area of the Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan. Epistasis was found to be involved in all traits such as average boll weight, seed number boll -1 , seed mass boll -1 , lint mass boll -1 , lint mass seed -1 , seed index, seed volume 100-seeds -1 , seed density, and surface area seed -1 . Additive variance was greater in magnitude than dominance variance for traits such as lint mass boll -1 and lint mass seed -1 in cross I and for seed number boll -1 , seed mass boll -1 , and lint mass seed -1 in cross II. The magnitude of both variances was nearly equal for seed density in cross I and seed number boll -1 in cross II. While dominance variance was found to be greater in magnitude than additive variance for all the remaining traits in both crosses, the degree of dominance √(H/D) in cross I was partial for lint mass boll -1 and lint mass seed -1 . We found complete dominance for seed density and overdominance for the remaining traits. While in cross II the degree of dominance was partial for seed mass boll -1 and lint mass seed -1 , complete dominance was found for seed number boll -1 and overdominance for the remaining traits.

The Most Basic Selection Criteria for Improving Yield and Quality of Upland Cotton

“…These results are in accordance with Basal and Turgut (2005); Basal (2009); Imran et al (2012) and Tang and Xiao (2013). Subhan et al (2003); Pushpam and Raveendran (2005); Ali et al (2011);Ali et al (2015) indicated the preponderance of non-additive genetic effects for seed cotton yield attributes and fibre quality traits. Yuan et al (2001) and Ashraf and Ahmad (2000) advocated additive gene action owing to higher GCA variances.…”

“…Lint mass per boll and number of seeds per boll displayed 36.4 to 48.4% increase over parents and exhibited dominance genetic effects. Ali et al (2015) indicated preponderant effect of dominance variance in the expression of within-yield traits. They also reported involvement of inter-genic interactions in the phenotypic outcome of the traits.…”

“…According to Worley et al (1974) the number of bolls on unit land area was the major contributor to seed cotton yield followed by lint mass per seed and number of seeds per boll. Among within-boll yield contributors, number of seeds of medium size and amount of lint produced on unit seed surface area were the main determinants of seed cotton yield (Ali et al, 2015). Culp and Harrell (1975) reported that increase in number of seeds per boll resulted in greater surface area per seed for greater lint production.…”

Estimation of Combining Ability and Heterotic Potential for Within-Boll Yield Traits Under Leaf Curling Disease Infestation in Cotton

“…A production of about 13 million bales was obtained from 2.88-million hectares during the year 2012-13 (Anonymous, 2012-13) which was 4.2 % less than produced in 2011-12. Cotton productivity on unit land area basis, in Pakistan, is low as compared to many leading cotton producing countries of the world (Ali et al, 2015). Not only is the yield, fiber quality is also low in most of the locally developed upland cotton cultivars when compared with rest of the world cotton producers.…”

“…Seeds per boll, boll number per unit area and lint mass per seed are the important factors in enhancing cotton yield (Worley et al, 1974). Lint production can be increased by increasing the number of productive seeds, producing more lint fibers, hence increasing the surface area for increased lint production (Ali et al, 2015). Predominance of non-additive genes for bolls per plant, boll weight and seed cotton yield was reported by Waldia et al (1980) and Ahuja and Dhayal (2007), while Kumaresan et al (1999) documented the predominance of both additive and dominance gene action for seed cotton yield and boll number.…”