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Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 10 Number 02 (2021) Journal homepage: http://www.ijcmas.com Original Research Article https://doi.org/10.20546/ijcmas.2021.1002.011 Studies on Combining Ability of Salinity Tolerant Restorer Lines in Rice M. Sri Lakshmi and Y. Suneetha* Department of Genetics and Plant Breeding, Agricultural College, Bapatla, India *Corresponding author ABSTRACT Keywords Combining ability, Grain yield, Restorers, Rice, Salinity, Yield components Article Info Accepted: 12 January 2021 Available Online: 10 February 2021 Combining ability analysis of 14 salinity tolerant restorer lines was undertaken for grain yield and yield components in rice. Non-additive gene action was noticed to be pre-ponderent for grain yield per plant and majority of the yield traits studied. A perusal of gca effects revealed MTU 1153, MCM 225, MTU 1156, MCM 48, IR 64 and MTU 1210 were noticed to be good combiners for grain yield per plant, indicating their suitability in breeding programmes for development of high yielding salinity tolerance hybrids. Among the hybrids 13 crosses had exhibited significant and desirable sca effects for grain yield per plant and are identified as potential salinity tolerant hybrids for commercial exploitation. Significant improvement in rice production and productivity was achieved through green revolution but the plateau in yield levels coupled with biotic and abiotic stresses are limiting the efforts for increasing production to meet the demands of the ever growing population especially in the developing and under developed countries. Introduction Rice is an important staple food for people in Asia, Latin America, parts of Africa and the Middle East. Rice production employs one billion people and is essential for the economic development of rural areas in India, Bangladesh and Southeast Asia. In India, rice is cultivated in an area of 43.39 million hectares with a production of 104.32 million tonnes and an average productivity of 2404 kg/ha. Andhra Pradesh is one of the leaders in rice production with an area, production and productivity of 2.16 million hectares, 7.49 million tonnes and 3466 kg/ha., respectively (Directorate of Economics and Statistics, 2015-16). Abiotic stresses alone contribute to 50 per cent of the total yield losses. Salinity (both inland and coastal salinity) is the second most important abiotic stress after drought, which affects the rice production. Nearly 20 per cent of the world’s cultivated area (800 million hectares) and nearly half of the world’s irrigated lands are affected by salinity (Maser 95 Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 et al., 2002). In Andhra Pradesh, 2.74 lakh hectares of rice area is affected by salinity (NRSC, 2010). in a single row plot of 2.0 meter length, with a spacing of 20 x 15 cm and the crop was raised following recommended package of practices. Further, data was recorded on five randomly selected plants in each replication for the characters, namely, plant height, total tillers per plant, ear bearing tillers per plant, panicle length, filled grains per panicle, ill-filled grains per panicle and spikelet fertility percentage for all the genotypes. However, for days to 50 per cent flowering and days to maturity, the data was recorded on plot basis, while observations on 100-Seed weight were obtained from a random grain sample drawn from each genotype in each replication. The estimates of combining ability variances and effects were obtained using Line x Tester analysis detailed by Kempthorne (1957). Out of the various approaches contemplated to enhance rice productivity, hybrid rice technology has been considered to be a more practically feasible option, particularly under stress environments. The success of hybrid rice programme for salinity tolerance depends on the availability of male sterile and salinity tolerant restorer lines with good combining ability. The present investigation was undertaken in this context to study the combining ability of salinity tolerant restorer lines for yield and yield components. Materials and Methods The experimental material comprised of three cytoplasmic male sterile lines namely, APMS 6A, APMS 9A, APMS 12A and 14 salinity tolerant restorer lines as testers, namely, MTU 1010, MTU 1153, MTU 1156, MTU 1121, MTU 1210, MTU 1229, MTU 1032, IR 64, IR 7693-2B-7, MCM 223, MTU 1031, MCM 48, MCM 225 and MTU 1213 obtained from Regional Agricultural Research Station (RARS), Maruteru and their 42 hybrids derived from the 3 x 14 Line x Tester mating design. The hybrids and parents were evaluated in a Randomized Block Design with three replications at RARS, Maruteru during Rabi 2016-17 for grain yield; yield component characters, namely, days to 50 per cent flowering, days to maturity, plant height, total tillers per plant, ear bearing tillers per plant, panicle length, filled grains per panicle, ill-filled grains per panicle, spikelet fertility percentage; and 100-seed weight. The sowings were undertaken in the nursery during the second fortnight of November and the transplanting of seedlings were affected 25 days after sowing depending on the growth of seedlings. Normal, healthy and vigorous seedlings of each genotype were transplanted Results and Discussion The results on analysis of variance are presented in Table 1. Significant mean sum of squares were noticed for parents, hybrids and parents vs. hybrids components of variation for all the characters studied, with the exception of total tillers per plant and ear bearing tillers per plant for parents; and ear bearing tillers per plant, filled grains per panicle and 100- seed weight for parents vs. hybrids component of variation. The results indicated the existence of significant differences among the parents and hybrids, in addition to heterosis for the characters with significant mean sum of squares for parents vs. hybrids. Further, partitioning of the hybrids component of variation into lines, testers and line x testers also revealed significant mean squares for grain yield per plant, days to 50 per cent flowering, days to maturity, plant height, filled and ill-filled grains per panicle, spikelet fertility and 100-seed weight indicating the importance of both additive and non-additive gene actions. A perusal of the 96 Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 results on gca:sca variance ratio indicated pre-ponderant non-additive gene action for grain yield per plant (Savita et al., 2015); and majority of the yield components studied, namely, days to 50 per cent flowering (Sathya and Jebaraj, 2015), days to maturity (Upadhyay and Jaiswal, 2015), plant height (Sathya and Jebaraj, 2015), total tillers per plant (Jhansi and Satyanarayana, 2015), panicle length (Sathya and Jebaraj, 2015), filled grains per panicle (Upadhyay and Jaiswal, 2015), ill-filled grains per panicle, spikelet fertility (Senguttuvel, 2008) and 100 seed weight (Bineetha and Lal, 2015), similar to the reports of earlier workers. Nonadditive gene action is desirable in the present context, as lines used in the present investigation are all cytoplasmic male sterile lines facilitating the exploitation of heterosis. However, ear bearing tillers per plant had recorded pre-ponderant additive gene action. Similar pre-ponderant additive gene action for ear bearing tillers per plant was reported earlier by Zaazaa and Anis (2014). the lines and from -0.92 (MCM 225) to 1.52 (MTU 1032) in the testers. The gca effects for panicle length ranged from -0.92 (APMS 9A) to 0.88 (APMS 12A) in the lines and from -1.97 (MTU 1121) to 1.66 (MTU 1031) in the testers. Further, the effects ranged from -18.43 (APMS 9A) to 13.67 (APMS 6A) in the lines and from -48.17 (IR 7693-2B-7) to 116.50 (MTU 1229) in the testers for filled grains per panicle, while for ill-filled grains per panicle, the effects ranged from -3.67 (APMS 9A) to 4.14 (APMS 12A) in the lines and from -24.92 (MCM 48) to 31.30 (MTU 1032) in the testers. For spikelet fertility per cent, the effects ranged from -0.76 (APMS 9A) to 0.89 (APMS 12A) in the lines and -12.88 (MTU 1032) to 10.16 (MCM 48) in the testers. The gca effects ranged from -0.11 (APMS 9A) to 0.09 (APMS 12A) in the lines and from -0.45 (MTU 1213) to 0.25 (IR 64) in the testers for 100 seed weight, while general combining ability effects for grain yield per plant ranged from -2.38 (APMS 9A) to 2.65 (APMS 12A) in the lines and from -6.18 (MTU 1031) to 6.66 (MTU 1153) in the testers. The good general combiners identified for the various traits studied are presented in Table 3. A perusal of the results on categorization of the lines and salinity tolerant testers studied based on gca effects are presented in Table 4. The results revealed APMS 12 A to be a good combiner for grain yield per plant, 100-seed weight, panicle length and filled grains per panicle and hence may be utilized in hybrid breeding programmes for development of high yielding hybrids with long panicles, greater number of filled grains and higher seed weight. Further, among the testers, MTU 1153, MTU 1156, MTU 1210, IR 64, MCM 48 and MCM 225 were observed to be good combiners for grain yield per plant and few yield component characters, indicating their importance in hybrid breeding programmes aimed at the development of high yielding salinity tolerant hybrids. The results of general combining ability effects for grain yield and yield components for lines and testers are presented in Table 2. General combining ability effects for days to 50 per cent flowering ranged from -1.43 (APMS 6A) to 0.74 (APMS 9A) in lines and from -7.50 (MTU 1121) to 8.83 (MTU 1229) in the testers, while for days to maturity, it ranged from -1.90 (APMS 6A) to 0.98 (APMS 9A) in the lines and from -7.26 (MTU 1121) to 9.07 (MTU 1229) in the testers. General combining ability effects for plant height ranged from -1.78 (APMS 6A) to 1.56 (APMS 12A) in the lines and from -10.75 (IR 64) to 21.70 (MCM 225) in the testers, while for total tillers per plant, the effects ranged from -0.50 (APMS 9A) to 0.67 (APMS 6A) in the lines and from -0.94 (MCM 225) to 1.39 (MTU 1032) in the testers. However, for ear bearing tillers per plant, the effects ranged from -0.46 (APMS 9A) to 0.80 (APMS 6A) in 97 Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 Table.1 Line × Tester analysis of variance for grain yield and yield component characters in rice Source of variation Degrees of freedom Days to 50 per cent flowering Days to maturity Plant height (cm) Total tiller per plant Ear bearing tillers per plant Panicle length (cm) Filled grains per panicle Ill- filled grains per panicle Spikelet fertility (%) 100Seed weight (g) Grain yield per plant (g) Replications 2 2.87 2.87 31.15 1.80 2.15 1.03 17.51 11.60 5.67 0.04 2.53 Parents 16 464.00** 467.71** 1783.74** 2.52 2.63 13.67** 30099.69** 1951.20** 950.76 ** 0.46** 277.75** Hybrids 41 141.06** 145.03** 434.66** 4.56** 4.11** 13.47** 13719.29** 2298.25** 220.70** 0.26** 192.10** Lines 2 38.11** 38.11** 242.66** 8.78** 9.33** 4.38 434.33** 40.11* 28.94** 1.27** 28.40** Testers 13 549.24** 553.52** 2137.19** 1.44 1.78 16.02** 33388.48** 2225.58** 316.76** 0.31** 312.61** Line × Tester 26 126.69** 122.08** 254.08** 4.24** 2.79** 14.20** 10913.52** 2136.58** 187.43** 0.22** 215.86** Parents Crosses 1 263.90** 304.26** 1198.50** 36.31** 1.88 87.26** 51.09 4165.50** 2075.65** 0.05 651.15** 118 vs. 1.69 1.67 15.27 1.49 1.54 2.74 24.67 8.86 4.77** 0.02 2.74 2 4.75 6.01 18.27 0.30 0.42 0.73 610.75 68.73 6.59 0.01 7.73 2 41.66 40.13 79.60 0.91 0.41 3.82 3629.61 709.24 60.88 0.06 71.03 0.22 0.32 1.02 0.19 0.16 0.09 0.10 0.16 0.10 Error σ GCA σ SCA 2 0.11 0.14 σ GCA/ σ2SCA *,**Significant at 5 and 1 per cent levels, respectively 98 Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 Table.2 General combining ability effects of male sterile lines and salinity tolerant restorer testers for grain yield and yield component characters in rice Parents Days to 50 per cent flowering Days to maturity Plant Height (cm) Lines -1.43** -1.90** -1.78** APMS6A 0.74** 0.98** 0.22 APMS9A 0.69** 0.93** 1.56* APMS12A 0.20 0.19 0.60 SE(gi) 0.28 0.28 0.85 SE(gi-gj) Testers 2.39** 2.63** -8.30** MTU 1010 -5.83** -5.60** -3.08* MTU 1153 -6.50** -6.26** -5.30** MTU 1156 -7.50** -7.26** -3.63** MTU 1121 -1.50** -4.60** -0.97 MTU 1210 8.83** 9.07** 5.59** MTU 1229 3.39** 3.63** -7.52** MTU 1032 -0.83 -0.60 -10.75** IR64 -1.83** -1.60** -1.97 IR7693-2B-7 -0.61 -0.37 19.14** MCM 223 3.06** 3.29** 0.03 MTU 1031 1.17** 1.40** 2.14 MCM 48 2.39** 2.63** 21.70** MCM 225 3.39** 3.63** -7.08** MTU 1213 0.43 0.43 1.30 SE(gi) 0.61 0.60 1.84 SE(gi-gj) *,**Significant at 5 and 1 per cent levels, respectively Total tillers per plant Ear bearing tillers per plant Panicle Length (cm) Filled grains per panicle Ill -filled grains per panicle Spikelet fertility (%) 100- seed Weight (g) Grain yield per plant (g) 0.67** -0.50** -0.17 1.18 0.26 0.80** -0.46* -0.34 0.19 0.27 0.04 -0.92** 0.88** 0.25 0.36 13.67** -18.43** 4.76** 0.76 1.08 -0.48 -3.67** 4.14** 0.45 0.64 -0.13 -0.76 0.89 0.33 0.47 0.02 -0.11** 0.09** 0.01 0.02 -0.27 -2.38** 2.65** 0.25 0.36 -0.06 0.17 0.28 0.17 0.39 -0.94* 1.39** 0.06 -0.61 -0.28 0.28 -0.50 -0.94* 0.61 0.40 0.57 0.08 0.30 0.41 0.41 0.52 -0.81 1.52** 0.19 -0.48 -0.14 0.41 -0.70 -0.92* -0.81 0.41 0.58 -1.30 0.13 -0.54 -1.97** 0.14 -0.23 0.47 -0.10 0.40 0.26 1.66** 0.34 1.64** -0.91 0.55 0.78 28.61** -25.39** -32.06** -16.28** 58.94** 116.50** -46.50** -38.94** -48.17** 21.61** 12.72** -20.17** 22.06** -32.94** 1.65 2.34 -0.25 2.97** -21.48** -22.48** 3.08** 9.63** 31.30** 1.52 -17.59** -7.70** 30.41** -24.92** 2.30* 13.19** 0.99 1.40 0.46 -4.62 5.76 5.73 2.17 -0.30 -12.88 -3.77 2.36 3.70 -7.41 10.16 1.15 -2.51 0.72 1.02 -0.14** 0.06 0.04 0.03 -0.13** -0.09* 0.23** 0.25** 0.18** -0.15** 0.03 0.03 0.11** -0.45** 0.04 0.06 -4.18** 6.66** 4.10** -2.72** 2.35** -4.34** -2.71** 2.13** -0.45 0.45 -6.18** 1.52** 5.11** -1.74** 0.55 0.78 99 Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 Table.3 Promising salinity tolerant general combiners identified for grain yield and yield component characters in rice Character Lines Testers Days to 50% flowering APMS 6A MTU 1121,MTU 1156,MTU 1153,IR 7693-2B-7,MTU 1210 Days to maturity APMS 6A MTU 1121,MTU 1156,MTU 1153,MTU 1210, IR 7693-2B-7 Plant height APMS 6A IR 64, MTU 1010, MTU 1032,MTU 1213,MTU 1156, MTU 1153 Total tillers per plant APMS 6A MTU 1032 Ear bearing tillers per plant APMS 6A MTU 1032 Panicle length APMS 12A MTU 1031,MCM-225 Filled grains per panicle APMS 6A MTU 1229,MTU 1210,MTU 1010,MCM 225,MCM 223, MTU 1031 Ill filled grains per panicle APMS 9A MCM-48,MTU 1121,MTU 1156,IR 7693-2B-7,MCM 223 Spikelet fertility (%) - - 100 seed weight APMS 12A IR64,MTU 1032,IR7693-2B-7,MCM 225 Grain yield per plant APMS 12A MTU 1153,MCM-225,MTU 1156,MCM 48,IR 64, MTU 1210 100 Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 Table.4 Characterization of parents based on gca effects Line / Tester Days to 50 per cent flowering Days to maturity Plant Height (cm) Total tillers per plant Ear bearing tillers per plant Lines H H H H H APMS6A L L L L L APMS9A L L L L L APMS12A Testers L L H L L MTU 1010 H H H L L MTU 1153 H H H L L MTU 1156 H H H L L MTU 1121 H H L L L MTU 1210 L L L L L MTU 1229 L L H H H MTU 1032 L L H L L IR64 H H L L L IR7693-2B-7 L L L L L MCM 223 L L L L L MTU 1031 L L L L L MCM 48 L L L L L MCM 225 L L H L L MTU 1213 H – High- significant effect in desirable direction for gca), L – Low - non-significant effect or significant in undesirable direction for gca) 101 Panicle Length(cm) Filled grains per panicle Ill-filled grains per panicle Spikelet fertility (%) 100- seed Weight (g) Grain yield per plant (g) L L H H L H L H L L L L L L H L L H L L L L L L L L L L H L H L H L L L H H L L L H H L H L L L H H L L L L H H L H L L L L L L L L L L L L L L L L L L L L L L H H H L L L H L L H H L H L L H L L L H H L Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 Table.5 Specific combining ability effects of the hybrids for grain yield and yield component characters in rice Cross Days to 50 per cent flowering Days to maturity Plant Height (g) Total tillers per plant APMS6A x MTU 1010 APMS6A x MTU 1153 APMS6A x MTU 1156 APMS6A x MTU 1121 APMS6A x MTU 1210 APMS6A x MTU 1229 APMS6A x MTU 1032 APMS6A x IR64 APMS6A x IR7693-2B-7 APMS6A x MCM 223 APMS6A x MTU 1031 APMS6A x MCM 48 APMS6A x MCM 225 APMS6A x MTU 1213 APMS9A x MTU 1010 APMS9A x MTU 1153 APMS9A x MTU 1156 APMS9A x MTU 1121 APMS9A x MTU 1210 APMS9A x MTU 1229 APMS9A x MTU 1032 APMS9A x IR64 9.87** -5.24** -7.24** -4.90** 5.10** 5.76** -1.46 8.76** -1.90* -1.13 -2.13** 1.10 -0.79 -5.79** -5.63** -3.40** -2.07** -2.40** -2.07** 1.60* -1.96* 4.26** 10.35** -4.76** -6.76** -4.43** -1.10 6.24** -0.98 9.24** -1.43 -0.65 -1.65* 1.57* -0.32 -5.32** -5.87** -3.64** -2.31** -2.64** 1.02 1.36 -2.20** 4.02** 0.44 3.22 4.44 2.11 -6.55** 7.22** -5.00* 2.56 -12.56** 2.33 -16.89** 19.67** -0.89 -0.11 -2.22 -1.44 -4.89* -1.22 0.78 3.22 -3.00 -3.44 0.22 0.00 0.22 0.00 0.11 0.78 0.44 0.44 0.11 -1.22 1.56* -0.33 1.11 -3.44** 1.06 -0.17 -0.28 -0.50 -0.06 -0.06 -0.72 0.61 Ear bearing tillers per plant 0.09 -0.13 0.09 -0.25 -0.02 0.64 0.31 0.31 -0.02 -1.36 1.42 -0.13 1.09 -2.02** 1.02 -0.21 -0.32 -0.65 -0.10 -0.10 -0.76 0.57 102 Panicle Length (g) 0.85 0.08 0.75 0.85 1.08 0.11 -2.26* -1.02 -2.18* 1.28 -1.12 0.21 1.24 0.12 1.80 -0.63 -1.96* -1.20 2.36* -1.94* -0.97 -0.40 Filled grains per panicle 16.22** -37.44** 3.56 48.11** 15.56** -53.00** -54.33** 8.11** -14.33** 32.89** -35.22** -33.00** 30.44** 72.44** 8.65* 16.32** -31.35** 18.87** 37.65** -99.57** -6.24* 16.54** Ill-filled grains per panicle Spikelet fertility (%) 100- seed Weight (g) -0.41 16.03** 23.81** 1.48 12.92** 6.03** -36.30** 32.48** -1.41 17.03** -21.08** -3.41 -2.97 -44.19** -9.56** 25.22** -7.00** 4.67** 26.44** -2.11 -26.78** -25.00** 1.81 -7.30 -8.22 2.32 -2.87 -0.84 5.38 -8.94 0.81 -3.68 7.36 -1.40 1.44 14.13 4.56 -6.02 3.14 0.77 -5.12 -4.28 5.34 11.78 -0.42** -0.22** -0.11 0.02 0.09 -0.07 0.09 -0.31** 0.18* 0.28** 0.10 0.18* -0.13 0.33** 0.24** 0.31** 0.19* 0.10 0.20** 0.25** 0.00 -0.20** Grain yield per plant (g) -6.93** -7.10** -8.55** 1.25 -0.90 -9.00** -1.40 13.44** 9.01** 5.12** -4.91** 3.04** 1.46 5.45** 14.51** -5.66** -6.77** 1.38 0.97 8.01** 6.38** -4.46** Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 Table.5 Contd... Cross Days to 50 per cent flowering Days to maturity Plant Height (cm) -2.40** -2.64** 14.78** APMS9A x IR7693-2B-7 2.37** 2.13** -0.67 APMS9A x MCM 223 -0.96 -1.20 -2.56 APMS9A x MTU 1031 5.26** 5.02** -3.67 APMS9A x MCM 48 4.04** 3.80** 5.11* APMS9A x MCM 225 3.37** 3.13** -0.78 APMS9A x MTU 1213 -4.25** -4.48** 1.78 APMS12A x MTU 1010 8.64** 8.40** -1.78 APMS12A x MTU 1153 9.31** 9.07** 0.44 APMS12A x MTU 1156 7.31** 7.07** -0.89 APMS12A x MTU 1121 -3.02** 0.07 5.77* APMS12A x MTU 1210 -7.36** -7.60** -10.44** APMS12A x MTU 1229 3.42** 3.18** 8.00** APMS12A x MTU 1032 -13.02** -13.26** 0.89 APMS12A x IR64 4.31** 4.07** -2.22 APMS12A x IR7693-2B-7 -1.25 -1.48* -1.67 APMS12A x MCM 223 3.09** 2.85** 19.44** APMS12A x MTU 1031 -6.36** -6.60** -16.00** APMS12A x MCM 48 -3.25** -3.48** -4.22 APMS12A x MCM 225 2.42** 2.18** 0.89 APMS12A x MTU 1213 0.75 0.74 2.25 SE(sij) 1.06 1.05 3.19 SE(sij-skl) *,**Significant at 5 and 1 per cent levels, respectively Total tillers per plant 0.28 -0.06 -0.61 -0.83 -0.06 1.39 -1.28 0.17 0.06 0.50 -0.06 -0.72 0.28 -1.06 -0.39 1.28 -0.94 1.17 -1.06 2.06** 0.70 0.99 Ear bearing tillers per plant 0.24 -0.10 -0.65 -0.54 -0.32 1.90** -1.10 0.34 0.23 0.90 0.12 -0.55 0.45 -0.88 -0.21 1.45 -0.77 0.67 -0.77 0.12 0.71 1.01 103 Panicle Length (cm) 2.44* -3.43** 0.52 2.10 -1.30 2.61** -2.66** 0.54 1.21 0.34 -3.43** 1.82 3.23** 1.42 -0.25 2.14* 0.59 -2.30* 0.06 -2.73** 0.95 1.35 Filled grains per panicle 24.76** -63.02** 11.21** 99.43** -19.13** -14.13** -24.87** 21.13** 27.79** -66.98** -53.21** 152.57** 60.57** -24.65** -10.43** 30.13** 24.02** -66.43** -11.32** -58.32** 2.86 4.05 Ill-filled grains per panicle Spikelet fertility (%) 100- seed Weight (g) -3.22 -21.44** 13.78** 7.11** -2.78 20.67** 9.97** -41.25** -16.81** -6.14** -39.37** -3.92* 63.08** -7.48** 4.63** 4.41* 7.30** -3.70* 5.75** 23.52** 1.71 2.43 4.63 6.65 -4.21 -1.10 -1.37 -14.77 -6.37 13.32 5.08 -3.10 7.99 5.12 -10.72 -2.84 -5.44 -2.96 -3.15 2.50 -0.07 0.64 1.26 1.78 0.01 -0.45** -0.16* -0.26** 0.06 -0.31** 0.17* -0.09 -0.08 -0.12 -0.29** -0.18* -0.09 0.51** -0.19* 0.17* 0.06 0.08 0.07 -0.02 0.07 0.10 Grain yield per plant (g) -5.55** -8.32** -3.49** 2.50* 0.34 0.17 -7.58** 12.76** 15.31** -2.64** -0.07 0.99 -4.98** -8.98** -3.46** 3.20** 8.40** -5.54** -1.80 -5.62** 0.95 1.35 Int.J.Curr.Microbiol.App.Sci (2021) 10(02): 95-105 Results of specific combining ability effects of the 42 hybrids derived from the line x tester mating of the three male sterile lines with the 14 salinity tolerant restorers and testers for yield and yield components revealed significant and desirable sca effects for several hybrids studied in the present investigation (Table 5). However, none of the hybrids studied had exhibited consistently high sca effects for all the characters studied and the best cross combination was also observed to vary from character to character. The results are in conformity with the reports of Prasad et al., (2018). For panicle length, the sca effects ranged from -3.43 (APMS 9A x MCM 223, APMS 12A x MTU 1210) to 3.23 (APMS 12A x MTU 1032). Further, significant and positive sca effects were observed for five hybrids. Specific combining ability effects for filled grains per panicle ranged from -99.57 (APMS 9A x MTU 1229) to 152.51 (APMS 12A x MTU 1229). Further, 21 hybrids had recorded significant and positive sca effects for the character. However, for ill-filled grains per panicle, the sca effects ranged from -44.19 (APMS 6A x MTU 1213) to 63.08 (APMS 12A x MTU 1032). Further, significant and negative sca effects, desirable for the trait were observed for 15 hybrids. Specific combining ability effects for spikelet fertility per cent ranged from -14.77 (APMS 9A x MTU 1213) to 13.32 (APMS 12A x MTU 1153). None of the hybrids studied had exhibited significant and positive effects for the trait Specific combining ability effects for days to 50 per cent flowering ranged from -13.02 (APMS 12A x IR 64) to 9.87 (APMS 6A x MTU 1010). Further, significant and negative sca effects, desirable for days to 50 per cent flowering were observed for 19 hybrids. The sca effects for days to maturity ranged for 13.26 (APMS 12A x IR64) to 10.35 (APMS 6A x MTU 1010). 17 hybrids had recorded significant and negative sca effects for the trait and hence were identified as good specific combiners for the trait. Specific combining ability effects for 100 seed weight ranged from -0.45 (APMS 9A x MCM 223) to 0.51 (APMS 12A x IR 64). Further, significant and positive sca effects were observed for 11 hybrids. The sca effects for grain yield per plant ranged from -9.00 (APMS 6A x MTU 1229) to 15.31 (APMS 12A x MTU 1156). Further, 13 hybrids (APMS 6A x IR64, APMS 6A x IR 7693-2B7, APMS 6A x MCM 223, APMS 6A x MCM 48, APMS 6A x MTU 1213, APMS 9A x MTU 1010, APMS 9A x MTU 1229, APMS 9A x MTU 1032, APMS 9A x MCM 48, APMS 12A x MTU 1153, APMS 12A x MTU 1156, APMS 12A x MCM 223 and APMS 12A x MTU 1031) had recorded significant and positive for the sca effects for grain yield per plant. A characterization of the parents of these hybrids with respect to their gca effects revealed the hybrids to involve either both parents with high or low gca or one parent with high and the other with low gca effects, indicating the role of additive x additive, Specific combining ability effects for plant height ranged from -16.89 (APMS 6A x MTU 1031) to19.67 (APMS 6A x MCM 48). Significant and positive effects for the trait were observed in seven hybrids. For total tillers per plant, the effects ranged from -3.44 (APMS 6A x MTU 1213) to 2.06 (APMS 12A x MTU 1213). Significant and positive effects for the trait were observed in the hybrids, namely, APMS 6A x MTU 1031 and APMS 12A x MTU 1213. Further, specific combining ability effects for ear bearing tillers per plant ranged from -2.02 (APMS 6A x MTU 1213) to 1.90 (APMS 9A x MTU 1213). Significant and positive sca effects were observed for only one hybrid, namely, APMS 9A x MTU 1213. 104