Study of Heterosis in Interspecific Hybrids of Cotton (Gossypium hirsutum L. x Gossypium barbadense L.)

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1 2017; 6(4): E-ISSN: P-ISSN: JPP 2017; 6(4): Received: Accepted: SB Gohil Department of Genetics and Plant Breeding, Anand Agricultural University, Anand, Gujarat, India MB Parmar Main Rice Research Station, Nawagam, Anand Agricultural University, Anand, Gujarat, India DJ Chaudhari Department of Genetics and Plant Breeding, Anand Agricultural University, Anand, Gujarat, India Study of Heterosis in Interspecific Hybrids of Cotton (Gossypium hirsutum L. x Gossypium barbadense L.) SB Gohil, MB Parmar and DJ Chaudhari Abstract A line x tester analysis was undertaken to estimates the magnitude of heterosis in interspecific hybrids of cotton (Gossypium hirsutum L. x Gossypium barbadense L.) for yield and its components characters in 56 entries including (42 hybrids along with 13 parents and 1 standard check hybrid). Analysis of variance indicated the significant difference among the parents and hybrids for all thirteen characters studied which revealed existence of variability among the genotypes. Studies revealed that for seed cotton yield per plant out of 42 cross combinations, 10 hybrids had registered significant positive estimates of heterobeltiosis. The hybrids, GJC 101 x TCB 27 (31.64%) followed by SI x ARBB 1302 (29.35%) and GN Cot. 22 x ARBB 1302 (28.83%) had significant value with maximum estimates of heterobeltiosis. Six hybrids had registered significant positive standard heterosis over G. Cot. HB 102, of which, GN Cot. 22 x ARBB 1302 (24.61%) followed by GJC 101 x TCB 27 (22.71%) and AC 738 x ARBB 1302 (20.71%) had significant value with maximum estimates and its attributing characters like total number of bolls per plant, average boll weight, lint yield per plant, seed index and lint index. Keywords: Cotton, Line x Tester analysis, Heterobeltiosis, Standard heterosis, Seed cotton yield per plant Introduction Cotton the king of fibre reside one of the momentous and important cash crop exercising profound influence on economics and social affairs of the world. The word cotton derived from the Arabic word al qatan and popularly known as White Gold. India is going to be in surge in textile industry ahead of China which has been possible only due to cotton crop, which is the backbone of textile industry. Cotton plays vital role in Indian economy. The Gossypium species were domesticated in both the old and new world. It supplies products such as lint, oil, seed meal, hulls and linters. The genus Gossypium, a member of the Malvaceae family, consists of 50 species, four of which are generally cultivated species. Out of the four cultivated species, Gossypium hirsutum L. and Gossypium barbadense L. are tetraploids (2n=4x=52) and are commonly called as new world cottons. Whereas, Gossypium arboreum L. and Gossypium herbaceum L. are diploids (2n=2x=26) and known as old world cottons. India is the only country, where all four cultivated species of cotton viz., G. herbaceum, G. arboreum, G. hirsutum and G. barbadense are grown. These four species are referred as cotton. The area under cotton cultivation in the India is about 10.5 million hectare with annual production of 35.1 million bales with productivity 568 kg/ha [1]. India reside pioneer in commercialization of heterosis in cotton. A noticeable heterosis is reported in cotton by many workers. For better exploitation of heterosis in cotton, development of simple and economically variable hybrid seed production technique should be strengthen. Thereafter, number of intraspecific hybrids (G. hirsutum L. x G. hirsutum L.) and interspecific hybrids (G. hirsutum L. x G. barbadense L.) having high yield potentiality, big boll size, early in maturity coupled with extra-long staples (ELS) and desirable fibre traits have been released for commercial cultivation. Improvement in yield has been achieved through distant hybridization, particularly through interspecific hybridization. Correspondence SB Gohil Department of Genetics and Plant Breeding, Anand Agricultural University, Anand, Gujarat, India Materials and methods The experimental materials comprised of two species of Cotton Gossypium hirsutum L. used as females and Gossypium barbadense L. as pollen parents. Seven females (ACH 15-01, AC 738, SI 13-31, GJHV 507, GJC 101, GN Cot. 22 and G. Cot. 12) and six males (DB 1301, ARBB 1302, GSB 43, CCB 40, TCB 27 and Suvin) were crossed using line x tester mating design to prepare forty two hybrids at Regional Research Station, Anand Agricultural University, Anand during kharif Thus, the experimental material consisted of 56 entries, comprising of seven females and six males and resultant forty two hybrids evaluated ~ 804 ~

2 along with a G. Cot. HB 102 (H x B) hybrid as standard check. Single row of 4.5 meter length was assigned to each genotype with 10 plants having 45 cm intra row spacing and 120 cm inter row spacing. All the recommended agronomic and plant protection practices were uniformly applied throughout the crop growth period to raise a good crop. Five plants were randomly selected from each replication for each genotype and the average value per plot was computed for recording observations on plant height, number of monopodia per plant, number of sympodia per plant, total number of bolls per plant, average boll weight, seed cotton yield per plant, seed index and staple length; whereas, ginning percentage, lint yield per plant and lint index were calculated on formula basis. While, days to 50 per cent flowering was recorded on plot basis and oil content was estimated by NMR (Nuclear Magnetic Resonance) machine. Analysis of variance technique suggested by [6] was followed to test the differences between the genotypes for all the characters under study. Heterosis was estimated in terms of two parameters, i.e. heterobeltiosis [3] and standard heterosis [5]. Results and discussion The analysis of variance revealed that the mean squares due to genotypes were significant for all the characters under study (Table 1). The mean squares due to genotypes were further partitioned into parents, hybrids, parents vs. hybrids and check vs. hybrids. The parents differed significantly for all the characters except plant height and lint index, hybrids highly significant for all characters. This revealed the existence of considerable genetic variability among the parents and hybrids for all the characters under study. The mean squares due to parents vs. hybrids were significant for all the characters except average boll weight, which indicated that the performance of parents was different from that of hybrids, thereby supporting the possibility of heterotic effects for all the traits. The mean squares due to check vs. hybrids were significant for majority of the traits viz., day to 50 per cent flowering, plant height, number of monopodia per plant, average boll weight, ginning percentage, oil content and staple length, suggesting presence of heterosis for these traits. The estimates of heterobeltiosis (HB) varied from -7.61% (GN Cot. 22 x Suvin) to 13.41% (ACH x GSB 43) for days to 50 per cent flowering, % (SI x CCB 40) to 29.88% (GJC 101 x DB 1301) for plant height, % (GN Cot. 22 x Suvin) to 15.38% (G. Cot. 12 x ARBB 1302) for number of monopodia per plant, % (SI x GSB 43) to 35.42% (GN Cot. 22 x ARBB 1302) for number of sympodia per plant, % (AC 738 x Suvin) to 42.46% (ACH x ARBB 1302) for total number of bolls per plant, % (ACH x CCB 40) to 11.80% (SI x ARBB 1302) for average boll weight, % (ACH x CCB 40) to % (GJC 101 x TCB 27) for seed cotton yield per plant, % (ACH x CCB 40) to 27.04% (SI x ARBB 1302) for lint yield per plant, % (GJC 101 x Suvin) to 1.98% (G. Cot. 12 x TCB 27) for ginning percentage, % (SI x CCB 40) to 35.04% (GJC 101 x TCB 27) for seed index, % (GJHV 507 x ARBB 1302) to 33.42% (GJC 101 x TCB 27) for lint index, % (G. Cot. 12 x CCB 40) to 4.22% (GJC 101 x CCB 40) for oil content and % (G. Cot. 12 x GSB 43) to 5.45% (AC 738 x Suvin) for staple length (Table 2,3,4,5 and 6). Several hybrids exhibited significant heterobeltiosis in desirable direction for different component characters i.e. days to 50 per cent flowering (2), plant height (23), number of monopodia per plant (1), number of sympodia per plant (21), total number of bolls per plant (15), average boll weight (1), seed cotton yield per plant (10), lint yield per plant (6), seed index (12) and lint index (9). While, none of the hybrids registered significantly positive heterobeltiosis for ginning percentage, oil content and staple length. The heterotic [2, 7, response over better parent in cotton was also reported by 8, 9, 10, 11]. Improvement in seed cotton yield is one of the important objectives, so the superiority of hybrids over best cultivated hybrid is essential for increasing its commercial value. The estimates of standard heterosis (SH) ranged from % (GN Cot. 22 x DB 1301) to 2.94% (GJC 101 x GSB 43) for days to 50 per cent flowering, % (G. Cot. 12 x TCB 27) to % (GN Cot. 22 x DB 1301) for plant height, % (ACH x CCB 40) to 15.38% (G. Cot. 12 x ARBB 1302) for number of monopodia per plant, % (SI x GSB 43) to 12.93% (GJC 101 x CCB 40) for number of sympodia per plant, % (ACH x TCB 27) to 26.59% (ACH x ARBB 1302) for total number of bolls per plant, % (ACH x CCB 40) to 10.67% (GN Cot. 22 x ARBB 1302) for average boll weight, % (ACH x CCB 40) and 24.61% (GN Cot. 22 x ARBB 1302) for seed cotton yield per plant, % (GJHV 507 x ARBB 1302) and 28.05% (GN Cot. 22 x ARBB 1302) for lint yield per plant,-15.06% (GJC 101 x Suvin) to 2.73% (GN Cot. 22 x ARBB 1302) for ginning percentage, -20.0% (G. Cot. 12 x Suvin) to 21.53% (GJC 101 x TCB 27) for seed index, % (GJHV 507 x ARBB 1302) to 21.92% (GN Cot. 22 x ARBB 1302) for lint index, % (G. Cot. 12 x CCB 40) to 11.24% (GJC 101 x CCB 40) for oil content and % (G. Cot. 12 x GSB 43) to 10.61% (AC 738 x Suvin) for staple length (Table 2,3,4,5 and 6). The promising hybrids based on standard heterosis for staple length were AC 738 x Suvin (10.61%), GJC 101 x Suvin (10.00%) and SI x Suvin (9.59%). Out of 42 hybrids, several hybrids exhibited significant standard heterosis in desirable direction for different component characters i.e. days to 50 per cent flowering (25), plant height (22), number of monopodia per plant (1), number of sympodia per plant (7), total number of bolls per plant (5), average boll weight (2), seed cotton yield per plant (6), lint yield per plant (5), seed index (8), lint index (2), oil content (1) and staple length (3). While, none of the hybrids registered significantly positive standard heterosis for ginning percentage. As observed in the present investigation, several workers [2, 4, 7, 8, 9, 10, 11] had also reported the considerable degree of standard heterosis for seed cotton yield per plant and its component traits. Conclusion Among 42 hybrids tested, six hybrids depicted significant and positive heterosis over check hybrid (G. Cot. HB 102) for seed cotton yield per plant. The promising hybrids based on standard heterosis for seed cotton yield per plant were GN Cot. 22 x ARBB 1302 (24.61%), GJC 101 x TCB 27 (22.71%) and AC 738 x ARBB 1302 (20.71%). These hybrids also depicted significant and positive heterosis over their respective better parent. The high heterotic response in these hybrids was resulted due to positive heterosis for yield contributing characters like average boll weight, total number of bolls per plant, lint yield per plant, seed index and lint index. The heterotic effect for seed cotton yield per plant can be considered as outcome of direct effect of these attributes and indirect effects of other yield contributing attributes like number of monopodia per plant, number of sympodia per plant and plant height. Therefore, heterotic effects for seed ~ 805 ~

3 cotton yield per plant could be a result of combinational heterosis. Table 1: Analysis of variance (mean squares) for yield and its components in cotton Source d. f. DF PH NMP NSP TNBP ABW SCYP Replication Genotypes ** ** 0.44** 51.59** ** 0.38** ** Parents ** ** 25.30** ** 0.56** ** Females ** ** Males ** ** * Females vs Males ** * 13.44** ** ** 5.78** ** Hybrids ** ** 0.21** 42.43** ** 0.34** ** Parents vs Hybrids ** ** 0.47** ** ** ** Check vs Hybrids ** * 0.43** ** Error Table 1: Analysis of variance (mean squares) for yield and its components in cotton Source d. f. LYP GP SI LI OC SL Replication Genotypes ** 8.59** 4.58** 0.99** 4.72** 27.03** Parents ** 18.39** 2.74** ** 53.28** Females ** 4.52* Males ** 2.72** 0.66* 2.07** 1.14 Females vs Males ** ** 17.03** ** ** Hybrids ** 5.65** 3.94** 1.04** 3.15** 19.43** Parents vs Hybrids ** 14.69** 57.19** 7.35** ** 30.98** Check vs Hybrids * * 16.42** Error *, ** Significant at P = 0.05 and P = 0.01 levels of probability, respectively, DF= Days to 50 per cent flowering, PH= Plant height (cm), NMP= Number of monopodia per plant, NSP= Number of sympodia per plant, TNBP= Total number of bolls per plant, ABW= Average boll weight (g), SCYP= Seed cotton yield per plant (g), LYP= Lint yield per plant (g), GP= Ginning percentage, SI= Seed index (g), LI= Lint index, OC= Oil content (%), SL= Staple length mm Table 2: Estimates of heterobeltiosis and standard heterosis for days to 50 per cent flowering, plant height and number of monopodia per plant Days to 50 per cent flowering Plant height Number of monopodia per plant Sr. No. Hybrids BP SC BP SC BP SC 1 ACH x DB ** 27.96** 22.46** ACH x ARBB ** -7.35** 26.53** 21.09** ACH x GSB ** ** 18.95** * ** 4 ACH x CCB ** ** 14.84* ** ** 5 ACH x TCB ** -5.39** 22.86** 17.58* ** ** 6 ACH x Suvin 7.82** -5.39** 22.65** 17.38* ** ** 7 GJHV 507 x DB ** * 8 GJHV 507 x ARBB ** * ** 9 GJHV 507 x GSB ** GJHV 507 x CCB ** * 16.21* ** ** 11 GJHV 507 x TCB ** ** ** 12 GJHV 507 x Suvin 9.14** ** ** 13 GJC 101 x DB ** -4.41** 29.88** 22.27** ** ** 14 GJC 101 x ARBB ** ** 15.63* GJC 101 x GSB ** * ** * 16 GJC 101 x CCB * -5.39** 23.37** 14.45* GJC 101 x TCB ** 22.95** 14.06* ** * 18 GJC 101 x Suvin ** 24.47** 15.23* ** AC 738 x DB ** 14.98* 19.92** ** ** 20 AC 738 x ARBB ** * * AC 738 x GSB ** ** * 22 AC 738 x CCB ** * AC 738 x TCB ** * * AC 738 x Suvin ** ** * 25 SI x DB ** -7.35** ** 26 SI x ARBB ** 17.76* 15.23* SI x GSB ** ** ** 28 SI x CCB ** -3.43* * ** 29 SI x TCB ** 20.56** 17.97* * ** 30 SI x Suvin ** ** 31 GN Cot. 22 x DB ** 26.41** 22.66** ** ** 32 GN Cot. 22 x ARBB ** ** 24.40** 20.70** ** ~ 806 ~

4 33 GN Cot. 22 x GSB ** 22.38** 18.75** GN Cot. 22 x CCB ** * GN Cot. 22 x TCB ** 25.20** 21.48** ** ** 36 GN Cot. 22 x Suvin -7.61** ** 19.16** 15.63* ** ** 37 G. Cot. 12 x DB ** * G. Cot. 12 x ARBB ** ** 15.38** 39 G. Cot. 12 x GSB ** ** ** 40 G. Cot. 12 x CCB ** * G. Cot. 12 x TCB G. Cot. 12 x Suvin 3.52* * * Min Max S. E No. of significant crosses Positive Negative Table 3: Estimates of heterobeltiosis and standard heterosis for number of sympodia per plant, total number of bolls per plant and average boll weight Number of sympodia per plant Total number of bolls per plant Average boll weight Sr. No. Hybrids BP SC BP SC BP SC 1 ACH x DB ** 11.85* 37.21** 21.93* ** ** 2 ACH x ARBB ** 9.91* 42.46** 26.59** ** ** 3 ACH x GSB * ** ** 4 ACH x CCB ** ** ** 5 ACH x TCB * * ** ACH x Suvin 12.37* ** ** 7 GJHV 507 x DB ** ** ** 8 GJHV 507 x ARBB * ** ** 9 GJHV 507 x GSB ** GJHV 507 x CCB * 28.52** ** ** 11 GJHV 507 x TCB ** ** -8.16* 12 GJHV 507 x Suvin * ** ** 13 GJC 101 x DB * ** ** ** 14 GJC 101 x ARBB ** ** ** 15 GJC 101 x GSB * ** -9.83** 16 GJC 101 x CCB ** 12.93** 29.16** GJC 101 x TCB ** 11.85* 36.92** 18.80* GJC 101 x Suvin 25.00** ** * 19 AC 738 x DB ** ** 20 AC 738 x ARBB ** 12.07* 27.02** 20.72* AC 738 x GSB ** AC 738 x CCB * AC 738 x TCB ** 11.64* 26.46** 20.19* AC 738 x Suvin ** * SI x DB * SI x ARBB ** ** SI x GSB ** ** 20.16* ** ** 28 SI x CCB ** ** SI x TCB ** 24.99* ** ** 30 SI x Suvin ** GN Cot. 22 x DB ** GN Cot. 22 x ARBB ** 12.07* 26.12** ** 33 GN Cot. 22 x GSB * ** ** 34 GN Cot. 22 x CCB * ** ** 35 GN Cot. 22 x TCB ** ** GN Cot. 22 x Suvin 16.67** ** ** G. Cot. 12 x DB * ** ** 38 G. Cot. 12 x ARBB ** ** 39 G. Cot. 12 x GSB * ** 40 G. Cot. 12 x CCB ** ** 22.35* ** ** 41 G. Cot. 12 x TCB ** * ** 42 G. Cot. 12 x Suvin ** 21.31* ** ** Min Max S. E No. of significant crosses ~ 807 ~

5 Positive Negative Table 4: Estimates of heterobeltiosis and standard heterosis for seed cotton yield per plant and lint yield per plant Seed cotton yield per plant Lint yield per plant Sr. No. Hybrids BP SC BP SC 1 ACH x DB ACH x ARBB * ACH x GSB * ** ** ** 4 ACH x CCB ** ** ** ** 5 ACH x TCB ** ** ** ** 6 ACH x Suvin * ** ** ** 7 GJHV 507 x DB * ** * ** 8 GJHV 507 x ARBB ** ** ** ** 9 GJHV 507 x GSB GJHV 507 x CCB * ** 11 GJHV 507 x TCB * 12 GJHV 507 x Suvin * ** 13 GJC 101 x DB GJC 101 x ARBB ** ** ** ** 15 GJC 101 x GSB * ** ** ** 16 GJC 101 x CCB ** 18.78* 22.89** 17.95* 17 GJC 101 x TCB ** 22.71** 21.63* 16.74* 18 GJC 101 x Suvin 28.64** 19.91** AC 738 x DB AC 738 x ARBB ** 20.71** 16.37* 17.50* 21 AC 738 x GSB AC 738 x CCB AC 738 x TCB ** 19.88** 16.38* 17.51* 24 AC 738 x Suvin * * * 25 SI x DB * SI x ARBB ** ** SI x GSB * ** 28 SI x CCB ** * 29 SI x TCB * * 30 SI x Suvin ** 31 GN Cot. 22 x DB * GN Cot. 22 x ARBB ** 24.61** 25.88** 28.05** 33 GN Cot. 22 x GSB * ** ** ** 34 GN Cot. 22 x CCB * * * 35 GN Cot. 22 x TCB GN Cot. 22 x Suvin G. Cot. 12 x DB ** ** 38 G. Cot. 12 x ARBB * * 39 G. Cot. 12 x GSB G. Cot. 12 x CCB * ** 41 G. Cot. 12 x TCB G. Cot. 12 x Suvin Min Max S. E No. of significant crosses Positive Negative Table 5: Estimates of heterobeltiosis and standard heterosis for ginning percentage and seed index Ginning percentage Seed index Sr. No. Hybrids BP SC BP SC 1 ACH x DB ** ** ACH x ARBB ** ACH x GSB ** ACH x CCB ** ACH x TCB ** ~ 808 ~

6 6 ACH x Suvin ** ** GJHV 507 x DB ** GJHV 507 x ARBB ** -8.46** ** * 9 GJHV 507 x GSB ** -9.04** GJHV 507 x CCB ** ** GJHV 507 x TCB ** -8.12* 18.52* GJHV 507 x Suvin ** ** 18.52* GJC 101 x DB GJC 101 x ARBB ** GJC 101 x GSB ** GJC 101 x CCB * 17 GJC 101 x TCB * ** 21.53** 18 GJC 101 x Suvin ** ** 30.44** 17.40* 19 AC 738 x DB ** * 0 20 AC 738 x ARBB * * 21 AC 738 x GSB * 22 AC 738 x CCB ** 23 AC 738 x TCB ** 16.67* 24 AC 738 x Suvin -9.66** * 25 SI x DB ** SI x ARBB SI x GSB * SI x CCB ** * 29 SI x TCB SI x Suvin ** -8.12* GN Cot. 22 x DB ** GN Cot. 22 x ARBB * 33 GN Cot. 22 x GSB ** ** GN Cot. 22 x CCB * GN Cot. 22 x TCB ** -7.24* GN Cot. 22 x Suvin ** ** 25.78** G. Cot. 12 x DB * G. Cot. 12 x ARBB G. Cot. 12 x GSB ** * 40 G. Cot. 12 x CCB ** ** G. Cot. 12 x TCB * 42 G. Cot. 12 x Suvin ** Min Max S. E No. of significant crosses Positive Negative Table 6: Estimates of heterobeltiosis and standard heterosis for lint index, oil content and staple length Lint index Oil content Staple length Sr. No. Hybrids BP SC BP SC BP SC 1 ACH x DB ** ** ACH x ARBB ** ACH x GSB ** ** ** -8.16* 4 ACH x CCB ** ** ACH x TCB ** ** -7.55* 6 ACH x Suvin ** ** ** ** 7 GJHV 507 x DB ** -16.2** GJHV 507 x ARBB ** ** ** ** ** 9 GJHV 507 x GSB ** ** -8.01* GJHV 507 x CCB * ** ** ** GJHV 507 x TCB ** ** -8.16* 12 GJHV 507 x Suvin ** GJC 101 x DB ** ** GJC 101 x ARBB ** ** ** 15 GJC 101 x GSB ** -8.47* -9.18** GJC 101 x CCB * ** ** ** 17 GJC 101 x TCB ** ** ** GJC 101 x Suvin ** ** 19 AC 738 x DB ** * -7.14* 20 AC 738 x ARBB ** ** -8.98** ~ 809 ~

7 21 AC 738 x GSB ** ** ** ** 22 AC 738 x CCB ** 16.58* ** * AC 738 x TCB ** ** ** -8.78** 24 AC 738 x Suvin ** ** ** 25 SI x DB * * SI x ARBB SI x GSB ** ** ** 28 SI x CCB * ** ** 29 SI x TCB ** SI x Suvin ** ** 31 GN Cot. 22 x DB ** ** ** GN Cot. 22 x ARBB ** 21.92** ** -7.69* -8.39* -7.55* 33 GN Cot. 22 x GSB ** ** -8.60* ** ** 34 GN Cot. 22 x CCB * ** ** 35 GN Cot. 22 x TCB ** ** ** -8.57** 36 GN Cot. 22 x Suvin ** ** ** 37 G. Cot. 12 x DB * ** ** ** ** 38 G. Cot. 12 x ARBB ** ** 39 G. Cot. 12 x GSB * ** -9.18* ** ** 40 G. Cot. 12 x CCB ** ** ** ** 41 G. Cot. 12 x TCB * -9.80* -9.45* ** ** 42 G. Cot. 12 x Suvin ** ** ** ** ** Min Max S. E No. of significant crosses Positive Negative References 1. Anonymous. AICRIP (Cotton), Annual Report, Central Institute for Cotton Research, Nagpur, Dave PB, Patel BN, Patel PC. Heterosis studies in intraspecific hybrids of upland cotton. Trends in Biosci. 2014; 7(24): Fonseca S, Patterson FC. Hybrid vigour in a seven parent diallel cross in common winter wheat. Crop Sci. 1968; 8: Kannan N, Saravanan K. Heterosis for seed cotton yield, yield contributing characters and fibre quality parameters in tetraploid cotton (Gossypium hirsutum L.) and (Gossypium barbadense L.). Int. J. Dev. Res., 2015; 5(5): Meredith WR, Bridge RR. Heterosis and gene action in cotton (G. hirsutum L.). Crop Sci. 1972; 12: Panse VG, Sukhatme PV. Statistical Methods for Agricultural Workers. ICAR Publication (2 nd Ed.), New Delhi, Patel JR. Heterosis and combining ability analysis in interspecific hybrids of cotton (Gossypium hirsutum L. x Gossypium barbadense L.) M.Sc. (Agri.) thesis submitted (Unpublished) to the Anand Agricultural University, Anand, Sawarkar M, Solanke A, Mhasal GS, Deshmukh SB. Combining ability and heterosis for seed cotton yield, its components and quality traits in G. hirsutum L. Indian J. Agric. Res., 2015; 49(2): Solanki HV, Mehta DR, Rathod VB, Valu MG. Heterosis for seed cotton yield and its contributing characters in cotton (Gossypium hirsutum L.). Elec. J. Pl. Breed. 2014; 5(1): Suryakumar M, Shunmugavalli N, Arumugachamy S. Exploitation of heterosis among interspecific hybrids of cotton (Gossypium spp.). Trends in Biosci. 2014; 7(16): Tuteja OP, Kumar S, Singh M, Luthra P. Heterosis for seed cotton yield and fibre quality characters in cotton (Gossypium hirsutum L.). J. Cotton Res. Dev. 2006; 20(1): ~ 810 ~