Expression of heterotic performance in F1 crosses in Bt-lines and non-Bt tester parents of upland cotton (Gossypium hirsutum L.)

163 Mangi et al. Int. J. Biosci. 2020 RESEARCH PAPER OPEN ACCESS Expression of heterotic performance in F1 crosses in Bt-lines and non-Bt tester parents of upland cotton ( Gossypium hirsutum L.) Naimatullah Mangi1,2*, Samreen Khanzada2, Achar Lashari2, Sajjad Ali Sanwal2, Zarnaz Jagirani2, Munaiza Baloch2, Xiaoyan Wang1,3, Qifeng Ma1, Fan Shuli1 1State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang 455000, China 2Department of Plant Breeding and Genetics Sindh Agriculture University Tandojam Sindh, Pakistan 3Anyang Institute of Technology, College of Biology and Food Engineering, Anyang, 455000, China Key words: Heterotic, F1, Btlines, non-Bttester, Cotton, Gossypium hirsutumL. http://dx.doi.org/10.12692/ijb/16.6.163-177 Article published on June 29, 2020 Abstract The heterotic performance of parents estimated to determine the performance of cotton in line X tester combinations and to determine heterosis for identification of potential genotypes for hybrid crop development in cotton. Two types of heterosis are estimated, the heterotic effect for the F1 hybrid upon mid parents and better parents relative heterosis and heterobeltiosis. The analysis for x line tester was performed to observe the influence of parents over hybrid with a combination of cotton. Total 7 parents including 4 lines with 3 tester and their 12 replications in Kharif season were grown at Shah Latif experimental areas Sindh Agriculture University, Tandojam in 2011. In this investigation the traits including the height of the plant, sympodial branches per plant, monopodialbranches per plant, bolls number per plant, yield of cotton seed per plant, ginning outturn percentage, sex index and staple length.Regarding heterotic estimates, crosses Bt. NIAB-777 x Sadorigave maximum heterosis for plant height, sympodial branches, seed index, lint index and Bt.CIM-595 x CIM-506 manifested maximum heterosis for G.O.T%, seed index and lint index. Other hybrids, Bt.886 x CIM-506 demonstrated high heterosis for sympodial branches, boll weight and staple length and Bt. NIAB-852 x sadori for monopodial branches, G.O.T% and Staple length. The high heterosis displaying hybrids may be exploited for hybrid vigor for various characters. * Corresponding Author: Naimatullah Mangi  manginaima[email protected] International Journal of Biosciences | IJB | ISSN: 2220-6655 (Print), 2222-5234 (Online) http://www.innspub.net Vol. 16, No. 6, p. 163-177, 2020 164 Mangi et al. Int. J. Biosci. 2020 Introduction Cotton crops are generally known as a cash crop in the World. Cotton thread made from its fiber is utilized for breathable and soft textile, that commonly used in natural fiber thread cloth in recent days (Ramamoorthy et al., 2015; Sarfraz et al., 2020). For the fulfilment of these requirement, major production gained through different cotton upland varieties as well as some required is also fulfilled through American Egyptian sea land cotton commonly grown in the Asia continent. This crop is not only utilized for fiber but also it is 2nd major source of plant protein than soybean as well as 5th maximum oil producing crop after soybean, sunflower, colza and soybean (Texier, 1993). It has been reported that about 7% of the value added in the agriculture, while 1.5% shared in GDP of Pakistan by cotton crop. In previous years 2013 cotton was grown on 2879 thousand hector areas about 1.6% higher as compared to other previous years which 2835 thousand hector area. In 2013 the 14.5 million targets were mandated by the government of Pakistan which were tried to achieve about 13.0 million bales in the same year, that showed 10.3 reductions in target with reeducation in 4.2% in during next year was 13.6 million number of bales (GOP, 2013). Cotton production has been reported about 4.2% reduced during the year of 2013, it may be due to different pest attack during the early time of crop(GOP, 2013). The world cotton breeders have taken this task, but could not proceed beyond the preliminary stage due to its self-pollinated nature that showed few variation influences for the seed production of hybrid as compared to cross pollinated, while the presence of male sterility source has opened a way for commercial exploitation of hybridization in cotton crop; hence, the importance of the study of the performance of hybrids needs attention of the breeders (Ashokkumar et al., 2014). Heterosis exploitation is one of the effective tools to improve plant yields and different heterosis values have been reported for yield and fiber quality properties by the breeders in their studies. In studies, 26% and 24.5% heterosis and heterobeltiosis in fiber yield have been reported by(Rauf et al., 2005) who also obtained the highest heterosis and heterobeltiosis for lint yield. For fiber quality properties no significant heterotic effects were obtained for miconaire and strength. (Meredith Jr & Brown, 1998) found that significant heterosis for lint yield, lint percentage and fiber length suggest at least one parent should have above average fiber quality. Stagnant cotton yields have been reported in recent years and by exploiting heterosis. Cotton yields can be increased. Significant Heterosis of 1st harvested production, weight of bolls, and percentage of lint and length of 50 percentage life span observed in investigations. Material and methods The present experiment was performed at Latif Farm, Sindh Agriculture University, Tandojam, during Kharif 2013, to assess the performance of cotton in line x tester combinations and to determine heterosis for identification of potential genotypes for hybrid crop development in cotton. The experimental material has consisted of F1 crosses and their parents belonging to GossypiumhirsutumL. the seeds were sown in a Randomized Complete Block Design (RCBD) with two replications. There were seven parents, out of which 4 were lines/females and 3 were testers/pollinators and their 12 F1 hybrids. Thus total 23 genotypes were evaluated for plant height (cm), monopodial branches plant-1, sympodial branches plant-1, boll weight (g), number of bolls plant-1, cotton seed yield plant-1 (g), ginning outturn percentage (GOT %), seed index (g), lint index (g) and staple length (mm). Statistical analysis Analysis of variance was applied to the data and data Analysis Statistics’ 8.1 according to the method suggested by Gomez and Gomez (1984). Number Females 1 CIM-595 2 NIAB-852 3 NIAB-777 4 Bt-886 165 Mangi et al. Int. J. Biosci. 2020 Number Testers/Pollinators/males 1 CIM-506 2 CIM-554 2 Sadori Number Crosses/F1 hybrids 1 Bt-CIM-595 × CIM-506 2 Bt-CIM-595 × CIM-554 3 Bt-CIM-595 × Sadori 4 Bt-NIAB-852 × CIM-506 5 Bt-NIAB-852 × CIM-554 6 Bt-NIAB-852 × Sadori 7 Bt-NIAB-777 × CIM-506 8 Bt-NIAB-777 × CIM-554 9 Bt-NIAB-777 × Sadori 10 Bt-886 × CIM-506 11 Bt-886 × CIM-554 12 Bt-886 × Sadori No Parents = 07/Lines/Females = 04 1 CIM-595 2 NIAB-852 3 NIAB-777 4 Bt-886 No Testers/Pollinators/males = 03 1 CIM-506 2 CIM-554 3 Sadori NO Crosses/F1 hybrids = 12 1 Bt-CIM-595 × CIM-506 2 Bt-CIM-595 × CIM-554 3 Bt-CIM-595 × Sadori 4 Bt-NIAB-852 × CIM-506 5 Bt-NIAB-852 × CIM-554 6 Bt-NIAB-852 × Sadori 7 Bt-NIAB-777 × CIM-506 8 Bt-NIAB-777 × CIM-554 9 Bt-NIAB-777 × Sadori 10 Bt-886 × CIM-506 11 Bt-886 × CIM-554 12 Bt-886 × Sadori For collecting the data, total of 5 plants were randomly selected from each replication. The distance between plants to plant was kept at 30 cm whereas the distance between rows to row was 75 cm. all the recommended agronomic and cultural practices were carried out properly. At maturity, the data for different characters were recorded as under. Plant height cm Plant height was measured from the base of tree soil level to top of tree highest pointWhen apical growth of the main stem had ceased, the final height of the plants was measured from the first cotyledonarynode to apical bud in centimetersusing measuring rod. The averages of these measurements were then calculated. Monopodial branches plant-1 At the time of maturity, monopodial branches were counted manually from all selected plants in each replication. Then average monopodial branches of each genotype were calculated. Sympodial branches plant-1 Sympodial branches are direct fruit bearing branches. At maturity, number of sympodial branches of all selected plants was counted manually. These are vegetative branches usually present at the base of the plant. These are also called indirect fruit bearing branches. Boll weight g Boll weight per plant was recorded through dividing the yield of cotton seed per plant through number of bolls per plant, therefore the average of boll weight per plant was recorded with the following formula. Number of bolls per plant Complete open bolls were collected and counted as a total number of productive bolls per plant. Cottonseed yield per plant g The Cotton seed of each index per plant from all genotypes was collected and weighted separately to 166 Mangi et al. Int. J. Biosci. 2020 record data for cotton seed yield per plant in grams. Ginning outturn% (GOT) Cotton seed of all randomly selected plant was cleaned, and gained, while lint was weighted in grams. The outturn of ginning was recorded with the formula of Seed Index g Total of 100 seeds were randomly selected from each plant and weighted in grams. Lint index g This is the weight of lint per 100 seeds weighted in grams. The lint index was observed through following formula. Staple length (mm) The most important fiber quality of cotton is the fiber length. The representative numbers of samples of lint from each plant were measured for staple length with the help of digital fibro graph model 330, developed by spin laboratory. The mean sample staple length was obtained by taking the average of the readings of each sample. Classification of fiber length Number Fiber length (mm) Group 1 20.5 and below short fiber 2 21.0 to 25.5 medium finer 3 26.0 to 27.5 mediumlong fiber 4 28.5 to 33.5 Long fiber 5 34.0 and above Extra - long fiber Classification No Fiber length (mm) Group 1 20.5 and below short fiber 2 21.0 to 25.5 medium fiber 3 26.0 to 27.5 medium-long fiber 4 28.5 to 33.5 long fiber 5 34.0 and above extra-long fiber After recording the all parameters for study traits, the analysis of variance to showed difference between genotypes parents and F1 performed through the method of Gomez and Gomez, (1984). The heterosis was recorded in the term of increase percentage (+) or decrease (-) F1 hybrids against the mid of parents and better parent decrease was recorded as formula suggested by(Memon et al., 2017). The heterobeltiosis was estimated in terms of percent increase or decrease of the F1 hybrid over its better parent according to (Z. Soomro et al., 2006). Data were further subjected for (t) test that it can be determined that F1 hybrid means are statistically differed from mid parent and better parent values. While the t-test values will be recorded with the below mentioned formula of (Wynne et al., 1970). Where F1ij = Mean of ijth F1 cross MPij = Mid parents value for ijth cross BPij = Better parents values for ijth cross EMS Errors mean square. Results Analysis of variances In this experiment analysis of variance for all F1 hybrid genotypes were observed higher and significant difference (P≤0.01) about all the traits (Table 1). 167 Mangi et al. Int. J. Biosci. 2020 Table 1. The mean square of line × tester analysis for different traits of the upland cotton crop. Source of variation D.F Height of plant Monopodial branches Sympodial branches Boll weight No of bolls plant-1 Cotton seed yield GOT% Seed index Lint index Staple length Replication 2 24.596 0.011 0.170 0.009 2.362 64.986 0.689 0.053 0.055 0.155 Genotypes 18 65.35** 1.20** 10.15** 1.88** 18.34** 45.68** 10.56** 5.10** 6.89** 28.38** Lines (L) 3 58.920** 0.028** 1.989** 0.043** 8.765** 15.765** 0.454** 0.045** 0.050** 0.075** Testers (T) 2 23.00** 2.30** 1.89** 4.45** 6.78** 9.87** 0.89** 0.67** 0.13** 0.87** L × T 11 11.78** 5.89** 12.78** 7.90** 5.67** 8.78** 4.70** 3.67** 2.87** 1.30** Error 36 1.535 0.003 1.989 0.001 1.082 9.844 0.010 0.007 0.002 0.004 **= significant at 1% probability level. Mean performance The recorded data about mean performance of F1 12 hybrids with 7 parents' lines were interpreted to find out major quantitative characteristics in crop of cotton. The results have been described in Tabel 2 the F1 hybrid produced a maximum amount as compare to its parent lines for all under investigation traits. While SadoriX F1BtCIM95 showed highest height of plant 131.35 and contains 35.25 numbers of bolls per plant and produced highest cotton seed yield per plant. (115.42), and Bt-NIAB-852 x CIM-554 gave minimum monopodial branches plant-1 (1.25), was next ranker in boll weight (3.56g) and seed index (7.37) among the twelve hybrids. While Bt-NIAB-852 x Sadori gave highest seed index (7.56) and lint index (4.38), gave next maximum sympodial branches plant-1 (22.42) and GOT% (36.67), among the hybrids. The F1 hybrid Bt-NIAB-777 x CIM-506 gave lowest plant height (119.39), lowest seed cotton yield (100.87), ginned lowest (35.32) lint and lowest seed index (6.88), minimum lint index (3.76). While BtNIAB-777 x Sadori gave maximum sympodial branches plant-1(22.59), and was next ranker in number of bolls plant-1 (34.54), gave smaller bolls (3.28g); however, Bt-886 x CIM-506 gave maximum monopodial branches plant-1 (1.59) and was next ranker in seed cotton yield plant-1 (113.75), and fiber length ( 28.10), Bt-886 x Sadori gave highest GOT% (37.10), and fiber length (28.20), was next ranker in lint index (4.25), and plant height (130.79) among the hybrids. Among the parents, line NIAB-852 gave maximum performance for sympodial branches plant1 (21.2), seed index (7.80), and lint index (4.43). Among the testers, Sadori gave maximum production regarding length of fiber 28.18 and bolls number per plant 30.5 while in 2nd position ginning outturn% cotton seed yield and sympodial branches per plant. Table 2. Mean performance of 12 hybrids and their 7 parents of different quantitative traits of upland cotton. F1 Hybrids Height of plant cm Monopodial branches per plant Sympodial branches per plant Boll Wight g No. of bolls per plant Cotton seed yield per plant (g) Got% Seed index (g) Lint index (g) Staple length (mm) Bt.CIM-595 x CIM-506 122.25 1.52 21.50 3.42 34.33 113.32 35.70 7.22 4.01 27.50 Bt.CIM-595 x CIM-554 128.13 1.43 20.78 3.60 32.54 112.91 35.66 7.31 4.05 27.45 Bt.CIM-595 x Sadori 131.35 1.31 22.34 3.39 35.25 115.42 36.27 7.30 4.15 27.75 Bt.NIAB-852 x CIM-506 119.43 1.46 21.87 3.34 32.29 103.88 35.98 7.23 4.06 27.72 Bt.NIAB-852 x CIM-554 121.52 1.25 21.26 3.56 29.72 101.38 36.17 7.37 4.18 27.66 Bt.NIAB-852 x Sadori 124.36 1.34 22.42 3.31 34.45 109.89 36.67 7.56 4.38 28.00 Bt. NIAB-777 x CIM-506 119.39 1.46 21.96 3.35 31.29 100.87 35.32 6.88 3.76 27.52 Bt. NIAB-777 x CIM-554 123.56 1.43 21.48 3.49 30.85 103.28 35.48 7.10 3.90 27.62 Bt. NIAB-777 x Sadori 127.38 1.27 22.59 3.28 34.54 109.34 35.91 7.23 4.05 27.73 Bt-886 x CIM-506 122.46 1.59 21.67 3.50 33.78 113.75 36.57 7.12 4.11 28.10 Bt-886 x CIM-554 129.52 1.42 20.55 3.55 32.45 111.21 36.35 7.27 4.15 27.92 Bt-886 x Sadori 130.79 1.47 22.36 3.42 33.16 109.15 37.10 7.18 4.25 28.20 PARENTS Female line CIM-595 121.4 1.1 20.4 3.39 28.6 92.98 35.47 7.27 4.00 27.10 NIAB-852 111.5 0.9 21.2 3.25 27.5 85.98 36.24 7.80 4.43 27.55 NIAB-777 112.4 1.0 20.5 3.20 28.2 86.37 34.84 7.05 3.77 27.41 Bt-886 118.7 1.5 19.5 3.47 28.0 93.11 37.09 7.20 4.24 28.02 Tester CIM-506 108.4 1.6 18.9 3.30 30.0 95.00 35.50 6.41 3.53 27.77 CIM-554 117.7 1.3 18.1 3.67 25.4 90.03 35.67 6.58 3.65 27.64 Sadori 120.1 1.2 20.7 3.26 30.5 94.70 36.45 6.71 3.85 28.18 168 Mangi et al. Int. J. Biosci. 2020 Plant height Among twelve-line X tester crosses, results in (Table3) showed that ten F1 hybrids exceeded in plant height over their respective mid parents as well as better parents. The relative heterosis of this character ranged from 6.03% to 9.57% and 0.70% to 8.90% was heterobeltiosis whereas only two F1 hybrids gave negative heterosis over their only better parents. The highest heterosis (9.57%) was manifested by Bt-866 x CIM-554 and BtNIAB-777 x sadori over their mid parents followed by the cross Bt-CIM-595 x sadorithat showed the 8.77% of heterosis upon the mid parents, while maximum heterosisof 8.90% over better parent. Table 3. The F1hybrids heterotic influence upon the mid parents and their heterobeltiosis better parent’s forplant height cm. F1 hybrids Parent seed Parent pollen F1 hybrids Mid parents Percentage + increase or decrease - over Mid parent Better parent Bt.CIM-595 x CIM-506 121.4 108.4 122.25 114.90 6.39 0.69 Bt.CIM-595 x CIM-554 121.4 117.7 128.13 119.55 7.17 5.54 Bt.CIM-595 x Sadori 121.4 120.1 131.35 120.75 8.77 8.19 Bt.NIAB-852 x CIM-506 111.5 108.4 119.43 109.95 8.62 7.11 Bt.NIAB-852 x CIM-554 111.5 117.7 121.52 114.60 6.03 3.24 Bt.NIAB-852 x Sadori 111.5 120.1 124.36 115.80 7.39 3.54 Bt. NIAB-777 x CIM-506 112.4 108.4 119.39 110.40 8.14 6.21 Bt. NIAB-777 x CIM-554 112.4 117.7 123.56 115.05 7.39 4.97 Bt. NIAB-777 x Sadori 112.4 120.1 127.38 116.25 9.57 6.06 Bt-886 x CIM-506 118.7 108.4 122.46 113.55 7.84 3.16 Bt-886 x CIM-554 118.7 117.7 129.52 118.20 9.57 9.11 Bt-886 x Sadori 118.7 120.1 130.79 119.40 9.53 8.90 Monopodial branch per plant The results from heterosis (Table-4) showed that the cross Bt.NIAB-852 x Sadori gave maximum (27.61%) relative heterosis whereas Bt.NIAB-777 x CIM-506 recorded highest (30.00%) heterobeltiosis while the cross Bt-886 x CIM-554 ranked minimum heterosis over both mid parent and better parent. Our findings conform with those of (Aslam, 2004; Muhammad et al., 2014) who also reported significant values for character monopodial branches. Present results, however, suggested that hybrids Bt. NIAB-852 x Sadori and Bt. NIAB-777 x CIM-506 may be utilized for hybrid crop development to improve yield. Table 4. The heterotic influence on hybrids upon the mid parents with better parent’s heterobeltiosis for monopodial branch per plant trait. F1 hybrids Parent seed Parent pollen F1 Mid parent Percentage + increase and decrease – over F1 hybrids Mid parents Better parents Bt.CIM-595X CIM-506 1.1 1.6 1.52 1.35 12.59 -5.00 Bt.CIM-595X CIM-554 1.1 1.3 1.43 1.20 19.16 10.00 Bt.CIM-595X Sadori 1.1 1.2 1.31 1.15 13.91 9.16 Bt.NIAB-852X CIM-506 0.9 1.6 1.46 1.25 16.8 -8.75 Bt.NIAB-852X CIM-554 0.9 1.3 1.25 1.10 13.63 -3.84 Bt.NIAB-852X Sadori 0.9 1.2 1.34 1.05 27.61 11.66 Bt. NIAB-777X CIM-506 1.0 1.6 1.46 1.30 12.30 -8.75 Bt. NIAB-777X CIM-554 1.0 1.3 1.43 1.15 24.34 10 Bt. NIAB-777X Sadori 1.0 1.2 1.27 1.10 15.45 5.83 Bt-886X CIM-506 1.5 1.6 1.59 1.55 2.58 -0.625 Bt-886X CIM-554 1.5 1.3 1.42 1.40 1.42 -5.33 Bt-886X Sadori 1.5 1.2 1.47 1.35 8.88 -2 169 Mangi et al. Int. J. Biosci. 2020 Sympodial branches per plant Regarding heterosis (Table-5), cross Bt-886 x CIM506 gave maximum (12.86%) relative heterosis, however, cross Bt. NIAB-777 x Sadori gave maximum heterobeltiosis. Other hybrids also show the fair amount of heterosis for sympodial branches. Other researchers like (Abro et al., 2009; Aslam, 2004; Muhammad et al., 2014), described a sufficient amount of heterosis for the sympodial branch. The findings of heterotic suggested hybrids, Bt-886 x CIM-506 and Bt. NIAB-777 x Sadori is the best crosses for exploiting hybrid vigor in cotton crop. Table 5. The heterotic influence of F1 hybrids upon mid parent and better parent’s heterobeltiosis for sympodial branches per plant trait. F1 hybrids Parent seed Parent pollen F1 hybrids Mid parent Percentage + increase or decrease – over F1 hybrids Mid parents Better parents Bt.CIM-595X CIM-506 20.4 18.9 21.5 19.65 9.42 5.39 Bt.CIM-595X CIM-554 20.4 18.1 20.78 19.25 7.948 1.86 Bt.CIM-595X Sadori 20.4 20.7 22.34 20.55 8.71 7.92 Bt.NIAB-852X CIM-506 21.2 18.9 21.87 20.05 9.07 3.16 Bt.NIAB-852X CIM-554 21.2 18.1 21.26 19.65 8.19 0.28 Bt.NIAB-852X Sadori 21.2 20.7 22.42 20.95 -7.01 5.75 Bt. NIAB-777X CIM-506 20.5 18.9 21.96 19.70 11.47 7.12 Bt. NIAB-777X CIM-554 20.5 18.1 21.48 19.30 11.29 4.78 Bt. NIAB-777X Sadori 20.5 20.7 22.59 20.60 9.66 9.13 Bt-886X CIM-506 19.5 18.9 21.67 19.20 12.86 11.12 Bt-886X CIM-554 19.5 18.1 20.55 18.80 9.30 5.38 Bt-886X Sadori 19.5 20.7 22.36 20.10 11.24 8.019 Boll weight The results for heterotic and heterobeltiotic influenced for boll weight (Table 6) showed 11 F1 hybrids showed positive heterosis, mid parent, that change 1.46 to 3.24% with 7 positive crosses showed better parents heterosis 0.00 to 1.535 between 12 hybrids. The highest (3.24%) relative heterosis was produced by Bt-886 x CIM-506. While hybrid BtNIAB-852 x Sadori which displayed maximum (1.53%) heterobeltiosis for the character of boll weight. Table 6. The heterotic influence of F1 hybrids upon mid parents and better parent’s (heterobeltiosis) for the character boll weight (g). F1 hybrids Seed parent Pollen parent F1 hybrid Mid parent Percentage increase + or decrease – over F1 hybrids Mid parent Better parent Bt.CIM-595X CIM-506 3.39 3.30 3.42 3.35 2.089 0.88 Bt.CIM-595X CIM-554 3.39 3.67 3.60 3.53 1.98 1.907 Bt.CIM-595X Sadori 3.39 3.26 3.39 3.33 1.80 0.00 Bt. NIAB-852X CIM-506 3.25 3.30 3.34 3.28 1.09 1.21 Bt.NIAB-852X CIM-554 3.25 3.67 3.56 3.46 2.89 -2.997 Bt. NIAB-852X Sadori 3.25 3.26 3.31 3.26 1.53 1.53 Bt. NIAB-777X CIM-506 3.2 3.30 3.35 3.25 3.016 1.52 Bt. NIAB-777X CIM-554 3.20 3.67 3.49 3.44 1.45 -4.90 Bt. NIAB-777X Sadori 3.20 3.26 3.28 3.23 1.547 0.61 Bt-886X CIM-506 3.47 3.30 3.50 3.39 3.24 0.86 Bt-886X CIM-554 3.47 3.67 3.55 3.57 0.56 -3.269 Bt-886X Sadori 3.47 3.26 3.42 3.37 1.48 -1.44 170 Mangi et al. Int. J. Biosci. 2020 Number of bolls plant-1 Among the twelve-line x tester crosses, results (Tabel 7) showed 11 F1 hybrids positive heterosis as well as heterobeltiosis of numbers of bolls per plant trait over their respective mid parents as well as better parents. Whereas, only one F1 hybrids gave negative heterosis over its better parent. Relative heterosis ranging from 12.31 to 21.54% and heterobeltiosis varied from 1.15 to 15.57%. Bt-866 x CIM-554 showed highest heterosis (21.54%) over its mid parent and the highest heterobeltiosis 15.57% was manifested by CIM-595 x Sadori. Table 7. The heterotic influence of F1 upon mid parent as well as better parent heterobeltiosis of number of bolls per plant trait. F1 hybrids Parent seed Parent pollen F1 hybrid Mid parents Percentage increase + or decrease – F1 hybrids Mid parent Better parent Bt.CIM-595X CIM-506 28.6 30.0 34.33 29.30 17.17 14.43 Bt.CIM-595X CIM-554 28.6 25.4 32.54 27.00 20.52 13.78 Bt.CIM-595X Sadori 28.6 30.5 35.25 29.55 19.29 15.57 Bt. NIAB-852X CIM-506 27.5 30.0 32.29 28.75 12.31 7.63 Bt.NIAB-852X CIM-554 27.5 25.4 29.72 26.45 12.36 0.07 Bt. NIAB-852X Sadori 27.5 30.5 34.45 29.00 18.79 12.95 Bt. NIAB-777X CIM-506 28.2 30.0 31.29 29.10 7.53 4.3 Bt. NIAB-777X CIM-554 28.2 25.4 30.85 26.80 15.11 9.39 Bt. NIAB-777X Sadori 28.2 30.5 34.54 29.35 17.68 13.24 Bt-886X CIM-506 28.0 30.0 33.78 29.00 16.48 12.6 Bt-886X CIM-554 28.0 25.4 32.45 26.70 21.54 15.89 Bt-886X Sadori 28.0 30.5 33.16 29.25 13.37 8.72 Cotton seed yield plant-1 Between 12 F1 hybrids, total hybrids were found positive results for heterosis and heterobeltiosis of cotton seed yield trait (Tabel 8). The heterosis values are between 11.23 to 23.39% and heterobeltiosis varied from 12.61% to 21.88% in which Bt-CIM-595 x CIM-554 showed highest heterosis (23.39%) over its mid parent and the highest heterosis (21.88%) over its better parents was manifested by CIM-595 x Sadori. Table 8. Heterotic effect of F1 over mid-parents (relative heterosis) and better parents (heterobeltiosis) for the character cotton seed yield plant-1. F1 hybrids Parent seed Parent pollen F1 hybrids Mid parent Percentage increase + decrease – upon F1 hybrids Mid parent Better parent Bt.CIM-595X CIM-506 92.98 95.00 113.32 93.99 20.56 19.28 Bt.CIM-595X CIM-554 92.98 90.03 112.91 91.51 23.38 21.43 Bt.CIM-595X Sadori 92.98 94.70 115.42 93.84 22.9 21.88 Bt.NIAB-852X CIM-506 85.98 95.00 103.88 90.49 14.79 9.34 Bt.NIAB-852X CIM-554 85.98 90.03 101.38 88.01 15.19 12.60 Bt.NIAB-852X Sadori 85.98 94.70 109.89 90.34 21.64 16.04 Bt. NIAB-777X CIM-506 86.37 95.00 100.87 90.69 11.225 6.17 Bt. NIAB-777X CIM-554 86.37 90.03 103.28 88.20 17.09 14.7 Bt. NIAB-777X Sadori 86.37 94.70 109.34 90.54 20.76 15.45 Bt-886X CIM-506 93.11 95.00 113.75 94.06 20.93 19.73 Bt-886X CIM-554 93.11 90.03 111.21 91.57 21.45 19.43 Bt-886X Sadori 93.11 94.70 109.15 93.91 16.23 15.26 171 Mangi et al. Int. J. Biosci. 2020 GOT% The results for heterosis and heterobeltiosis for GOT%(Table 9) revealed that eleven crosses showed positive mid parent heterosis varied from 0.25 to 0.89% and only one cross revealed negative better parent heterosis and only three hybrids showed positive better parent heterosis ranging from 0.02 to 0.56%, whereas all the rest hybrids showed negative the heterosis better parents. The maximum 0.89% of heterosis showed Bt-886 x Sadori while hybrid BtCIM-595 x CIM-506 which displayed maximum (0.56%) heterobeltiosis for the character of GOT% respectively. Seed index The results for hybrids mid parent and better parent heterosis and heterobeltiosis trait for seed index (Table 10) showed mid parent heterosis varied from 1.68 to 5.55% and only five hybrids showed positive better parent heterosis ranging from 0.41 to 2.55%, whereas all the rest hybrids showed negative for heterosis of better parent. While maximum 5.555 related heterosis showed BtCIM-595 x CIM-506 while hybrid Bt-NIAB-777 x Sadori which displayed maximum (2.55%) heterobeltiosis for the character of seed index. Table 9. The heterotic influence of F1 hybrid upon mid parent and better parent’s heterosis as well as heterobeltiosis for GOT% trait. F1 hybrid Seed index Parent pollen F1 hybrids Mid parent Percentage increase + decrease – upon Mid parent Better parent Bt.CIM-595X CIM-506 35.47 35.50 35.70 35.49 0.59 0.56 Bt.CIM-595X CIM-554 35.47 35.67 35.66 35.57 0.25 -0.02 Bt.CIM-595X Sadori 35.47 36.45 36.27 35.96 0.86 -0.49 Bt. NIAB-852X CIM-506 36.24 35.50 35.98 35.87 0.30 0.71 Bt.NIAB-852X CIM-554 36.24 35.67 36.17 35.96 0.58 -0.19 Bt. NIAB-852X Sadori 36.24 36.45 36.67 36.35 0.87 0.60 Bt. NIAB-777X CIM-506 34.84 35.50 35.32 35.17 0.42 -0.53 Bt. NIAB-777X CIM-554 34.84 35.67 35.48 35.26 0.62 -2.66 Bt. NIAB-777X Sadori 34.84 36.45 35.91 35.65 0.72 -1.48 Bt-886X CIM-506 37.09 35.50 36.57 36.30 0.74 -1.40 Bt-886X CIM-554 37.09 35.67 36.35 36.38 -0.08 -1.99 Bt-886X Sadori 37.09 36.45 37.10 36.77 0.89 0.02 Lint index The information about heterotic effect for the character lint index (Table 11) which exhibited that all the F1 hybrids gave positive relative the hybrid heterosis and showed positively and heterobeltiosis were negative. The relativity of mid parent heterosis, varied from 2.01 to 6.50% whereas positive heterobeltiosis ranged from 0.00% to 5.19%. The highest (6.50%) relative heterosis was calculated from cross Bt-CIM-595 x CIM-506. While hybrid Bt-NIAB777 x Sadori which exhibited highest (5.19%) heterobeltiosis. Staple length The results for heterosis and heterobeltiosis for the character staple length are shown in (Table 12), that showed heterosis of mid parent changed from -0.25 to 0.725 and single hybrid showed positive better parent whereas all the rest hybrids showed negative better parent heterosis respectively among the twelve hybrids. The highest (0.72%) relative heterosis was depicted by Bt-886 x CIM-506 while hybrid Bt-886 x Sadori which displayed maximum (0.07%) heterobeltiosis respectively. Discussion Plant height Height trait in cotton crop reduced with the number of branches increased. Thus, there is not too much close but positive association between plant height