Heterosis Studies and per se Performance of Intra Hirsutum Hybrids (G.hirsutum x G.hirsutum) for Kapas Yield and its Components in Cotton  

Yanal Alkuddsi , M.R. Gururaja Rao , S.S. Patil , Mukund Joshi , T.H. Gowda
Department of Genetics and Plant Breeding, University of Agricultural Sciences, Bangalore, Karnataka, India
Author    Correspondence author
Plant Gene and Trait, 2013, Vol. 4, No. 21   doi: 10.5376/pgt.2013.04.0021
Received: 07 Jul., 2013    Accepted: 21 Sep., 2013    Published: 11 Nov., 2013
© 2013 BioPublisher Publishing Platform
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:

Alkuddsi et al., 2013, Heterosis Studies and per se Performance of Intra Hirsutum Hybrids (G.hirsutum× G.hirsutum) for Kapas Yield and its Components in Cotton, Plant Gene and Trait, Vol.4, No.21 124-141 (doi: 10.5376/pgt.2013.04.0021)

Abstract

Fourty eight intra hirsutum hybrids from Line×Tester design along with three checks ((BUNNY Bt, RCH2 Bt, RAHH 95) (one repeated two times) was laid out in Randomized Complete Block Design (RCBD) with two replications. Each entry was sown in 3 row plots of 6 m length spaced at 90 cm with recommended dose of fertilizer and treatment of seeds with imidochloprid were sown on 10-7-2008 at the Agricultural Research Station, Bavikere, UAS, Bangalore. The analysis of variance among 48 hybrids and checks tested in 2 replications indicated that mean sum of squares for hybrids was highly significant for all the characters except number of monopodia per plant, mean boll weight and seed index indicating presence of significant differences among the hybrids evaluated in respect of these traits. The mean sum of squares for hybrids vs checks was highly significant for plant height number of sympodia per plant, number of bolls per plant, kapas yield per plant and ginning outturn revealing superiority of hybrids over checks and presence of heterosis in respect of these traits. The performance of three top hybrids viz., RAH 97×SC 18, RAH 146×RGR 37 and RAH 146×RGR 58 in respect of kapas yield per plant needs to be verified for their performance on large scale basis. Two hybrids RAH 97×SC 18 and RAH 146×RGR 37 were superior over standard commercial check RAHH 95 for kapas yield per plant, number of sympodia per plant, number of monopodia per plant, number of bolls per plant and ginning outturn and the hybrid RAH 146×RGR 58 exceeded best Bt check hybrid (RCH2 Bt) for kapas yield per plant. 

Keywords
Heterosis; per se performance; Intra hirsutum

Cotton is an important fiber yielding crop of global importance, which is grown in tropical and subtropical regions of more than 80 countriesthe world over. It provides livelihood to about sixty million people and is an important agricultural commodity providing remunerative income to million of farmers both in developed and developing countries. In India, inspite of severe competition from synthetic fibers in recent years, it is occupying the premiere position with 70% share in the textile industry.

Gossypium hirsutum L. provides 90% of world fiber and is major cash and industrial crop. Cotton is grown on almost 32.4 million hectares in more than 90 countries of temperate, sub-tropical, and tropical regions of the world. The four main producing countries are China, India, USA and Pakistan and accounted for approximately three quarters of world output. If Uzbekistan and Brazil are added, six countries would account for 83% of world cotton production. Cotton is long day and often cross-pollinated crop, and usually requires little heavy soil, moderate rainfall and mostly sunshine. Intra- hirsutumhybrids have been released for commercial cultivation in all nine major cotton growing states. These hybrids cover maximum area, among cotton hybrids, under cultivation and can be grown both under irrigated and rainfed conditions. Intra- hirsutum hybrids are more tolerant to sucking pests than inter specific hybrids between G. hirsutum and G. barbadense.
Heterosis works as a basic tool for improvement of crops in form of F1 and F2 populations, and economic heterosis (over standard cultivar). It also contributes to choose genotypes with desired genetic variance, vigor and maternal effects. Therefore, it is essential to have detailed information about desirable parental combiners in any breeding program, which can reflect a high degree heterotic response. In intra- and inter-specific heterosis, yield increase over better parent or greater than best commercial cultivar (useful heterosis) has been documented (Baloch et al., 1993b; Galanopoulou- Sendouca & Roupakias, 1999; Wei et al., 2002; Yuan et al., 2001 & 2002; Khan et al., 2007; Khan, 2011). Both positive and negative heterotic values have been detected, demonstrating potential of hybrid combinations for traits improvement in breeding programs (Hassan et al., 1999; Khan et al., 2009). F1 hybrids with high heterosis were also associated with higher inbreeding depression; therefore, moderate type of heterosis has some stability in segregating populations (Tang et al., 1993; Soomro, 2000; Soomro & Kalhoro, 2000). Therefore, heterotic studies can provide basis for exploitation of valuable hybrid combinations in future breeding program.
The main objective of this study to study the heterosis and per se performance of new cotton intra hirsutum hybrids in respect of kapas yield and its attributing characters.
Results and Discussion
Analysis of variance
The mean sum of squares for kapas yield and its attributing characters in 51 hybrids of cotton are presented in Table 1. Mean sum of squares for hybrids was highly significant for all the characters except number of monopodia per plant, mean boll weight and seed index indicating presence of significant differences among the hybrids evaluated in respect of these traits. The mean sum of squares for hybrids vs checks was highly significant for plant height number of sympodia per plant, number of bolls per plant, kapas yield per plant and ginning outturn revealing superiority of hybrids over checks and presence of heterosis in respect of these traits.


Table 1 Analysis of variance for kapas yield per plant and its attributing characters in checks and experimental hybrids of cotton (G. hirsutum L.)


Mean per se performance of hybrids
The mean per se performance of hybrids in respect of kapas yield and its attributing characters (Table 2) are briefly presented below.