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Combining ability of nine sunflower inbreds (four cytoplasmic male sterile lines and five restorers) was tested in line x tester mating design. The material including parents and cross combinations were evaluated for nine agro-biochemical parameters. The inbreds viz., 67A and 47R were identified as good general combiners for seed yield and oil yield, 88A, 89A, 47R and GMU 1080 were identified as good general combiners for oil content and 67A, 179R and GMU 1080 exhibited good general combining ability for early maturity. Similarly, highest significant positive specific combining ability effects for seed yield were observed for crosses 38A x 179R followed by 89A x 179R and 88A x 159R. On the basis of positive significant SCA effects for oil percent the crosses 67A x GMU 1080, 89A x 159R and 88A x 150R were found to be superior. All the traits exhibited non-additive gene action and the proportional contribution to variability was maximum by crosses except for seed yield where lines contributed more towards variability. The crosses 67A x 47R, 89A x 179R, 38A x 179R and 88A x 150R recorded maximum average heterosis for seed and oil yield and the cross combinations 67A x 47R, 88A x 150R and 67A x GMU 1080 revealed maximum heterosis against better parent also for the above traits.

Combining ability of nine sunflower inbreds (four cytoplasmic male sterile lines and five restorers) was tested in line x tester mating design. The material including parents and cross combinations were evaluated for nine agro-biochemical parameters. The inbreds viz., 67A and 47R were identified as good general combiners for seed yield and oil yield, 88A, 89A, 47R and GMU 1080 were identified as good general combiners for oil content and 67A, 179R and GMU 1080 exhibited good general combining ability for early maturity. Similarly, highest significant positive specific combining ability effects for seed yield were observed for crosses 38A x 179R followed by 89A x 179R and 88A x 159R. On the basis of positive significant SCA effects for oil percent the crosses 67A x GMU 1080, 89A x 159R and 88A x 150R were found to be superior. All the traits exhibited non-additive gene action and the proportional contribution to variability was maximum by crosses except for seed yield where lines contributed more towards variability. The crosses 67A x 47R, 89A x 179R, 38A x 179R and 88A x 150R recorded maximum average heterosis for seed and oil yield and the cross combinations 67A x 47R, 88A x 150R and 67A x GMU 1080 revealed maximum heterosis against better parent also for the above traits. [ABSTRACT FROM AUTHOR]

This study was aimed to investigate combining ability and genetic parameters in summer squash (cucurbita pepo L.). Eight inbred lines of summer squash were crossed in line x tester method in summer season 2020. The parental lines (3 tester and 5 lines) and their off springs (15 hybrids) were planted out in the summer season 2021 at vegetable field, Horticulture Department, College of Agricultural Engineering Science, Duhok University. The experiment lay out using randomized complete block design with three replications. The results indicated that the mean square for genotypes were highly significant effect for tester, line and line x tester in all studied traits. The Tester LBL2 and line PEP1670 were the best combiner for days to 50% female flowering, number of fruit plant-1 and yield kg plant-1 . The crosses (LBL2 X N33133) and (LES3 X CNS2881) exhibited significant positive effect of specific combining ability for fruit length cm, number of fruit plant-1 and yield plant-1 . The heritability in broad sense were higher than narrow sense heritability for all studied traits ranged between 93% for days to 50% female flowering to 40% for fruit weight. The average degree of dominance less than one in all traits except days to 50% female flowering and fruit length. [ABSTRACT FROM AUTHOR]

The study was carried out to learn about the nature of gene action and combining ability in rice hybrids for grain yield and its component traits. For this, eight lines were crossed with four testers in an L x T mating design. The analysis of variance revealed significant variance for all the characters studied among the parents and hybrids. GCA variances were higher than SCA variances for most of the characters, indicating the predominance of additive gene action, while SCA variances were higher than GCA variances for number of productive tillers per plant, pollen fertility, hulling, milling, head rice recovery and grain yield per plant, indicating the predominance of non-additive gene action. The testers JMS 13A (3.91) and CMS 59A (2.46), as well as the lines MTU 1153 (9.52), RNR 28355 (3.26) and RNR 26085 (3.09), were the best combiners for grain yield and important yield components due to positive GCA effects. Based on SCA effects and corresponding mean performance for grain yield and its component traits, the hybrids CMS 59Ax RNR 26015, CMS 23A x JGL 25960, CMS 64Ax RNR 26015 and JMS 13Ax MTU 1153 were identified as the best specific combiners. These hybrids could be tested in multi-environment trials for commercial use.

A study was carried out to assess the combining ability of ten CMS lines with four testers using the line x tester method. Biometrical observations were taken for days to 50% flowering, plant height, head diameter, days to maturity, volume weight, hundred seed weight, seed yield /plant, oil content and oil yield/plant. Specific combing ability variance was greater than the general combining ability variance for all the characters which indicated that non-additive gene action played a major role in inheritance. The gca of parents were not in agreement with the per se performance for various traits. Hence, the selection of parents should be based on gca alone for a breeding programme. Three lines viz., COSF 12A, COSF 13A and CMS 207A, and tester IR 6 were identified as good general combiners for seed and oil yield. Among the hybrids generated using good general combiners, COSF 13A x IR 6 had the additive type of gene action for seed and oil yield per plant. In general, most of the crosses had non-significant sca for oil yield per plant and oil content which indicated the presence of an additive type of gene action. Hence, the selection of good general combiners for oil content, seed and oil yield will help to evolve high oil yielding hybrids in sunflowers.

Background: Indian mustard is an important oilseed crop which occupies premier position in Indian agriculture. Developing high yielding genotypes is a major breeding objective in Indian mustard. Present study was conducted at Experimental Farm of Ranaghat, Nadia, West Bengal, during 2017 to 2019. Methods: Line x tester analysis of seven lines and five testers was carried out to identify the high heterotic crosses and their relationship in terms of GCA and SCA in Indian mustard. The parents and F1 hybrids were evaluated in RBD with three replications. Result: The analysis of variances revealed significant differences of genotypes for all characters studied, indicating sufficient genetic variability for the characters. The estimates of SCA variances were higher than GCA variance the characters indicating that dominance variance was more than the additive variance. The ratio of variance due to general and specific combining ability was less than unity for all the traits that indicated the non-additive gene action was predominant over additive gene action. Five lines, viz. PM 24, PM 25, PM 30, Pusa Agrani, JD-6 and one tester, Pusa Bold were deemed to be the good general combiner for seed yield and yield attributing traits. On the basis of high heterosis over mid parent as well as better parent and significant SCA effects for seed yield per plant and its component traits, hybrids namely, JD-6 x Pusa Bold, PM 30 x Seeta, PM 25 x Pusa Bold, PM 24 x Kranti and PM 22 x Sarama were found to be very promising for further exploitation in breeding program. [ABSTRACT FROM AUTHOR]

Information on combining ability and standard heterosis are crucial for the success of any hybrid breeding program. The present study was conducted in sweet corn involving crossing of twenty inbreds as female lines and five inbreds as testers in line × tester mating fashion during kharif, 2019. Resulted 100 F1s were evaluated in rabi, 2019-2020 for twelve yields and its attributing traits. Analysis of variance for combining ability revealed the existence of wider variability in the material studied exhibiting significant differences due to lines, testers, hybrids and various interactions. Non-additive gene action was observed pre-dominant for all the traits. Inbreds SCGP-88, SCGP-111, SCGP-36-3- 1, SCGP-91, BSL-4, SCGP-44-2, VNR-SC-24, VNR-SC-23, SCGP-66-1 and SCGP-61-1-4 were identified as good general combiners. Crosses viz., SCGP-207-1 × SCGP-44-2, SCGP-54 × VNR-SC-29, SCGP-42 × SCGP-80, SCGP-82 × SCGP-80 and SCGP-66-1 × SCGP-44-2 were identified as promising hybrid combinations based on per se performance, sca effects and standard heterosis over the commercial checks.

The study was carried out to learn about the nature of gene action and combining ability in rice hybrids for grain yield and its component traits. For this, eight lines were crossed with four testers in an L x T mating design. The analysis of variance revealed significant variance for all the characters studied among the parents and hybrids. GCA variances were higher than SCA variances for most of the characters, indicating the predominance of additive gene action, while SCA variances were higher than GCA variances for number of productive tillers per plant, pollen fertility, hulling, milling, head rice recovery and grain yield per plant, indicating the predominance of non-additive gene action. The testers JMS 13A (3.91) and CMS 59A (2.46), as well as the lines MTU 1153 (9.52), RNR 28355 (3.26) and RNR 26085 (3.09), were the best combiners for grain yield and important yield components due to positive GCA effects. Based on SCA effects and corresponding mean performance for grain yield and its component traits, the hybrids CMS 59Ax RNR 26015, CMS 23A x JGL 25960, CMS 64Ax RNR 26015 and JMS 13Ax MTU 1153 were identified as the best specific combiners. These hybrids could be tested in multi-environment trials for commercial use. [ABSTRACT FROM AUTHOR]

An investigation was undertaken with 54 hybrids obtained by crossing nine lines and six testers in L x T mating design to analyse heterosis and combining ability. Sixteen biometric traits were measured. The SCA variance was observed to be more than GCA variance for all the traits except for days to 50% flowering and days to green fodder harvest indicating the preponderance of non-additive gene action governing the traits studied. Results of gca effects and the mean performance of parents revealed that the genotypes viz., IP 17424, IP 17435, CO 8, GP 15074 and PT 5588 were identified as good combiners for green fodder yield and its component traits. Based on the standard heterosis over the standard check TNAU pearl millet hybrid CO 9, the hybrids viz., PT 5701 x GP 18219, CO 8 x PT 5588, CO 8 x GP 16026, IP 17424 x GP 15074, IP 17424 x PT 5682, IP 17424 x PT5365, IP 17424 x PT 5588 and IP 17424 x GP 18219 recorded superior heterosis for green fodder yield. Considering sca effects, mean performance and standard heterosis, the hybrids viz., IP 17424 x GP 15074, IP 17424 x PT 5682 and CO 8 x PT 5588 were identified as the superior performing hybrids for green fodder yield. Similarly, for high crude protein, the hybrid PT 5652 x PT 5588 was identified as the superior one. The above hybrids could be exploited further to improve green fodder yield with quality traits in pearl millet.

Information on combining ability and standard heterosis are crucial for the success of any hybrid breeding program. The present study was conducted in sweet corn involving crossing of twenty inbreds as female lines and five inbreds as testers in line × tester mating fashion during kharif, 2019. Resulted 100 F1 s were evaluated in rabi, 2019-2020 for twelve yields and its attributing traits. Analysis of variance for combining ability revealed the existence of wider variability in the material studied exhibiting significant differences due to lines, testers, hybrids and various interactions. Non-additive gene action was observed pre-dominant for all the traits. Inbreds SCGP-88, SCGP-111, SCGP-36-3- 1, SCGP-91, BSL-4, SCGP-44-2, VNR-SC-24, VNR-SC-23, SCGP-66-1 and SCGP-61-1-4 were identified as good general combiners. Crosses viz., SCGP-207-1 × SCGP-44-2, SCGP-54 × VNR-SC-29, SCGP-42 × SCGP-80, SCGP-82 × SCGP-80 and SCGP-66-1 × SCGP-44-2 were identified as promising hybrid combinations based on per se performance, sca effects and standard heterosis over the commercial checks. [ABSTRACT FROM AUTHOR]

Heat tolerance is a physiologically and genetically complex trait regulated by multiple genes. To investigate the genetic basis of heat tolerance, eight parents (five lines and three testers) and their fifteen F1 hybrids were evaluated under normal and high-temperature stress conditions for two consecutive years. Data were recorded for plant height, number of bolls, boll weight, seed cotton yield, ginning out turn (GOT%), H2O2, catalase, peroxidase, super-oxidase dismutase, total soluble proteins, carotenoids, chlorophyll a & b contents, short fiber index, fiber strength, UHML, micronaire value, reflectance, and uniformity index. Line × tester analysis suggested that the contribution of lines was higher than testers. Non-additive gene action was observed for all studied traits. The variances of SCA were greater than GCA variances for all studied traits revealed that these traits were governed by a few largely dominant genes. Fb-Shaheen, Eagle-2 and JSQ White Gold were found good general combiner whereas the cross Fb-Shaheen × JSQ White Gold was a good specific combiner and revealed significant better parent heterosis for most of the traits during two years under normal and high temperature stress conditions. The information obtained could be utilized in a breeding program for the development of new synthetic varieties of heat tolerance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Twelve parental genotypes and twenty F1 hybrids developed in a Line x Tester fashion were used in the present study to estimate gene action, combining ability and standard heterosis for eleven quantitative and five quality traits in cotton. All the traits studied exhibited greater SCA variance than GCA except days to fifty per cent flowering suggesting that these traits are controlled by dominant gene action. Among the parents used, SVPR 2 and TSH 325 were detected with higher general combining ability for seed cotton yield and should be given importance while developing hybrids or recombinants. The hybrids namely SVPR 2 x TSH 325, SVPR 2 x Suraj and GJHV 370 x PBH 116 were identified as the best hybrids for seed cotton yield and SVPR 2 x TCH 1828 for fibre properties and recommended for heterosis breeding. Besides, the hybrid between GJHV 370 x CPD 1702 was suggested for recombination breeding for earliness and ginning percentage as it fulfilled the criteria of non-significant sca effects for hybrid and significant gca effects for respective parents.

The present investigation was made to study the combining ability and gene action in sunflower. Five standard CMS lines and nine restorers were included as parental material. Forty five hybrids were developed andevaluated in RBD at Oilseeds Research Station, Latur during Rabi season 2018-2019 for 9 characters viz., days to 50 percent flowering, days to maturity, plant height, head diameter, seed yield per plant, seed filling percentage, 100 seed weight, volume weight and oil content.CMS 10A was good general combiner for days to 50% flowering, days to maturity, head diameter, 100 seed weight, seed yield per plant, volume weight and seed filling percentage. Similarly CMS 519A and CMS 62A were found to be good general combiners for seed yield and component traits. Among the testers, TSG-04 was good general combiner for days to 50% flowering, days to maturity, plant height and 100 seed weight. Similarly, TSG-281 and SCG-04 exhibited good general combining ability for oil content and component traits. Out of 45 hybrids, five hybrids viz. CMS 62A X SCG-04, CMS 234-1017A X TSG-327, CMS 234-1017A X TSG-111, CMS SUN-35-519A X TSG-289 and CMS 519A X TSG-289 exhibited the significant desirable sca effect for seed yield and component traits. The variance component due to specific combining ability was greater in magnitude than that of general combining ability for all the characters except seed yield per plant, volume weight and seed filling which indicated that the non-additive gene action played important role for the inheritance of these traits whereas seed yield per plant, volume weight and seed filling were governed by additive gene action.

Line x tester analysis was carried out involving six lines and 4 testers for seed cotton yield, yield contributing traits and fibre quality traits for estimation of combining ability effects of parents for sixteen characters. The analysis of combining ability revealed that the variance for SCA were larger than GCA except uniformity ratio which corresponds with non- additive gene action which can be improved by heterosis breeding. Based on the high per se performance and high gca effect, the parents C 10-8 and RAHC 1917 were considered as best general combiner for boll weight and single plant yield per plant. Regarding boll weight, TCH 1822 and C 10-8 were good general combiners with significantly high per se performance. These parents were found to be recorded as good general combiners for different characters. Hence, these can be used in recombination breeding to obtain more favorable gene recombinations for seed cotton yield. The cross TCH 1819 x RS 2821 showed a positive and significant sca effect for the number of bolls, boll weight and seed cotton yield. The cross Anjali x CPD 1501 showed a positive and significant sca effect for boll weight, lint index, seed index and seed cotton yield. The cross TCH 1926 x RS 2821 exhibited a positive significant sca for the number of bolls, 2.5 % span length and fibre strength. The non – additive gene action has played an important role in expression of seed cotton yield and its component traits which justify the heterosis breeding and its exploitation commercially.

The proficiency and efficacy of the parental selection programmes in most of the crops including popcorn can be significantly improved by estimating the combining ability and its effects. The present study was planned with an aim to assess the combining ability variances and effects in 28 cross combinations developed by crossing eight inbred lines of popcorn in half diallel fashion design (without reciprocals). The thirty eight genotypes including twenty eight hybrids along with their eight parents and two checks were evaluated in randomized complete block design to estimate the GCA and SCA of parents as well as crosses. Results for combining ability shown that mean sum of squares due to hybrids and parents vs. hybrids were significant, which in turn exhibits significant genotypic differences for all the characters under study except grain protein content. It was also apparent that both general combining ability and specific combining ability variances were significant for all the characters except grain protein content which indicated importance of both additive and non additive gene action in the inheritance of these traits. The inbred lines viz., HKI PC 1473-5, HKI PCBT 3, HKI PC 4B were found as good combiners and desirable for both grain yield and quality traits with high popping expansion. The cross combination HKI PC 1473-5 x HKI PCBT 3, HKI PC 4 x HKI PC 7 and HKI PC 4B x HKI PCBT 3 showed good SCA effects for grain yield, yield related traits and quality traits and thus indicated non additive gene effects is more pronounced and selection may prove reliable in maize hybridization programme for improvement of yield and other characters.

Six lines and four testers were involved in the combining ability and gene action study in line x tester mating design to discern desirable general and specific combiner for breeding programme. The combining ability variance indicated that sca variance was higher than gca variance indicating the preponderance of non-additive gene action for the characters studied viz., days to 50 percent flowering, panicle length, plant height, the number of grains per panicle, the number of tillers per plant, the number of productive tillers per plant, flag leaf length, flag leaf breadth, spikelet fertility, test weight and single plant yield. Among the parents, Improved White Ponni, RG192, RG163 and RG105 were discovered as the best general combiners for single plant yield. The cross combinations viz., ADT37 X RG163, ADT43 X RG105, ADT45 X RG163, ADT(R)48 X RG105, CO51 X Kavuni and Improved White Ponni X RG192 were the ideal specific combiners for single plant yield. Therefore, the aforementioned cross combinations may be employed in the upcoming breeding programmes in order to develop a higher heterosis for yield.

Seven cucumber (Cucumissativus L.) genotypes (3 lines and 4 testers) were crossed in a line × tester mating design. The resultant 12 hybrids and their parents were evaluated using Randomised Block Design with two replications during Kharif 2018. Sufficient genetic variability was observed for all the characters under study. In this study, the parents L2 (Koradacherry local), T2 (Orathanadu local) and T3 (Aipatti local) exhibited high positive GCA (General Combining Ability) effects for yield related traits and high negative GCA effects for earliness characters. The parent T2 identified in this study may be used in multiple crossing programme to isolate high yielding varieties. Among the hybrid combinations, L2xT3, L1xT2 and L3xT4 expressed the maximum positive significant SCA (Specific Combining Ability) effects for yield and yield associated characters. In the above cross combinations one parent was a good combiner and the other was an average/poor combiner; hence the hybrids can be exploited for transgressive selection.

A Line X Tester mating set of eight newly developed Quality Protein Maize inbred lines were utilized to evaluate combining ability and heterosis for yield and its components characters, at Field Experimentation Centre, Department of Genetics and Plant Breeding, SHUATS, Allahabad, during kharif-2017. Analysis of variance revealed that significant differences among the parents and experimental hybrids for all the characters except anthesis silking interval. Combining ability analysis revealed that estimate of specific combining ability (sca) variances were higher than general combining ability (gca) variances for maximum traits under study, indicating predominance of non-additive gene action of these traits. The parents LM-13 and DMR-N21 were identified as best combiners for yield and its related traits. The best experimental hybrid, on the basis of per se performance, sca effect and standard heterosis for grain yield per plant and its component was LM-13 X IC-32809 was followed by DMR-N21 X IC-32809 and LM-13 X IC-31899. Parents BBB-B2-NBBB, TSK-194and DMR-N21 recorded positive significant GCA for protein content indicating these parents are good combiner for protein content. Further, the study of analysis of variance for combining ability revealed the preponderance of non-additive gene action for all of the traits favouring the exploitation of heterosis breeding.

Copyright of Menoufia Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heat tolerance is a physiologically and genetically complex trait regulated by multiple genes. To investigate the genetic basis of heat tolerance, eight parents (five lines and three testers) and their fifteen F1 hybrids were evaluated under normal and high-temperature stress conditions for two consecutive years. Data were recorded for plant height, number of bolls, boll weight, seed cotton yield, ginning out turn (GOT%), H2O2, catalase, peroxidase, super-oxidase dismutase, total soluble proteins, carotenoids, chlorophyll a & b contents, short fiber index, fiber strength, UHML, micronaire value, reflectance, and uniformity index. Line × tester analysis suggested that the contribution of lines was higher than testers. Non-additive gene action was observed for all studied traits. The variances of SCA were greater than GCA variances for all studied traits revealed that these traits were governed by a few largely dominant genes. Fb-Shaheen, Eagle-2 and JSQ White Gold were found good general combiner whereas the cross Fb-Shaheen × JSQ White Gold was a good specific combiner and revealed significant better parent heterosis for most of the traits during two years under normal and high temperature stress conditions. The information obtained could be utilized in a breeding program for the development of new synthetic varieties of heat tolerance.

Combining ability analysis for yield and its component traits was carried out in rice through line x tester analysis of 20 hybrids developed by crossing 5 females with 4 male lines along with parents and checks at Agricultural Rice Research Station, Nellore, ANGRAU, AP during kharif 2014. The estimates of gca effects indicated that, among females, BPT 5204 and among males IR 64, were good general combiners for grain yield per plant. High sca effects were observed in the crosses, WGL 48684 x IR 36 and RNR 2465 x IR 36 and they were found to be best combinations for grain yield per plant.

Twenty elite yellow maize inbred lines were crossed as female parents with three different testers as male parents, i.e. Gem. Pop. (Broad genetic base), Single cross 101(Narrow genetic base) and Inbred line 100 (Narrow genetic base) at the Experiment Research Station of Moshtohor, Benha University, Egypt during 2014 growing summer season. The resulting 60 crosses with three commercial check hybrids i.e. SC 155, SC Pioneer 3080 and TWC 352 were evaluated in a yield trial in two sowing dates during 2015 growing summer season. The results showed that, sowing dates, crosses, lines, testers and line x testers mean squares were significant for all traits. The seven parental inbred lines (L-4, L-5, L-10, L-12, L-13, L-14 and L-19) possessed high GCA effects for grain yield and six lines (L-1, L-7, L-10, L-13, L-16 and L-18) possessed high GCA effects for earliness. These lines can be utilized as promising inbred lines in a hybridization program to develop high yielding and early maturity maize hybrids. The seven crosses (T-1 x L-7, T-1 x L-13, T-1 x L-17, T-2 x L-4, T-2 x L-5, T-2 x L-10 and T-2 x L-12) which had out-yielded significantly the best check SC. 3080 could be utilized for future breeding work as well as for direct release after confirming the stability of their performances observed in the current study. Hence, the information from this study may possibly be useful for researchers who would like to develop high yielding hybrids of maize. [ABSTRACT FROM AUTHOR]

The proficiency and efficacy of the parental selection programmes in most of the crops including popcorn can be significantly improved by estimating the combining ability and its effects. The present study was planned with an aim to assess the combining ability variances and effects in 28 cross combinations developed by crossing eight inbred lines of popcorn in half diallel fashion design (without reciprocals). The thirty eight genotypes including twenty eight hybrids along with their eight parents and two checks were evaluated in randomized complete block design to estimate the GCA and SCA of parents as well as crosses. Results for combining ability shown that mean sum of squares due to hybrids and parents vs. hybrids were significant, which in turn exhibits significant genotypic differences for all the characters under study except grain protein content. It was also apparent that both general combining ability and specific combining ability variances were significant for all the characters except grain protein content which indicated importance of both additive and non additive gene action in the inheritance of these traits. The inbred lines viz., HKI PC 1473-5, HKI PCBT 3, HKI PC 4B were found as good combiners and desirable for both grain yield and quality traits with high popping expansion. The cross combination HKI PC 1473-5 x HKI PCBT 3, HKI PC 4 x HKI PC 7 and HKI PC 4B x HKI PCBT 3 showed good SCA effects for grain yield, yield related traits and quality traits and thus indicated non additive gene effects is more pronounced and selection may prove reliable in maize hybridization programme for improvement of yield and other characters. [ABSTRACT FROM AUTHOR]

Line x tester analysis was carried out involving six lines and 4 testers for seed cotton yield, yield contributing traits and fibre quality traits for estimation of combining ability effects of parents for sixteen characters. The analysis of combining ability revealed that the variance for SCA were larger than GCA except uniformity ratio which corresponds with nonadditive gene action which can be improved by heterosis breeding. Based on the high per se performance and high gca effect, the parents C 10-8 and RAHC 1917 were considered as best general combiner for boll weight and single plant yield per plant. Regarding boll weight, TCH 1822 and C 10-8 were good general combiners with significantly high per se performance. These parents were found to be recorded as good general combiners for different characters. Hence, these can be used in recombination breeding to obtain more favorable gene recombinations for seed cotton yield. The cross TCH 1819 x RS 2821 showed a positive and significant sca effect for the number of bolls, boll weight and seed cotton yield. The cross Anjali x CPD 1501 showed a positive and significant sca effect for boll weight, lint index, seed index and seed cotton yield. The cross TCH 1926 x RS 2821 exhibited a positive significant sca for the number of bolls, 2.5 % span length and fibre strength. The non -- additive gene action has played an important role in expression of seed cotton yield and its component traits which justify the heterosis breeding and its exploitation commercially. [ABSTRACT FROM AUTHOR]

Six lines and four testers were involved in the combining ability and gene action study in line x tester mating design to discern desirable general and specific combiner for breeding programme. The combining ability variance indicated that sca variance was higher than gca variance indicating the preponderance of non-additive gene action for the characters studied viz., days to 50 percent flowering, panicle length, plant height, the number of grains per panicle, the number of tillers per plant, the number of productive tillers per plant, flag leaf length, flag leaf breadth, spikelet fertility, test weight and single plant yield. Among the parents, Improved White Ponni, RG192, RG163 and RG105 were discovered as the best general combiners for single plant yield. The cross combinations viz., ADT37 X RG163, ADT43 X RG105, ADT45 X RG163, ADT(R)48 X RG105, CO51 X Kavuni and Improved White Ponni X RG192 were the ideal specific combiners for single plant yield. Therefore, the aforementioned cross combinations may be employed in the upcoming breeding programmes in order to develop a higher heterosis for yield. [ABSTRACT FROM AUTHOR]

Twelve newly developed white maize inbred lines were crossed with two testers i.e. SC 128 and SC 131 at Ismailia Agricultural Research Station during 2017 season. In 2018 summer season, the 24 top crosses and two white commercial check hybrids; TWC 321 and TWC 324 were evaluated under two locations (Loc); Ismailia and Mallawy Agricultural Research Stations. The studied traits were number of days to 50% silking (DS), plant height (PH), ear height (EH), ear length (EL), ear diameter (ED), number of rows/ear (RE), number of kernels/row (KR) and grain yield (GY). Mean square due to locations were significant for DS, EL, KR and GY traits. The crosses were significant for all studied traits, except PH trait. Mean square due to lines were highly significant for all traits except PH, EH, and KR. Mean square due to testers were highly significant for EH and GY. Also, mean square attributed to lines x testers interaction were highly significant for all traits except for DS, PH, and RE. The interactions of locations (Loc) with crosses and Loc x lines were highly significant for the studied traits except for PH. The superior inbred line Ism 6007 had desirable general combining ability (GCA) effects for grain yield and yield components. Also, the inbred line Ism 7100 showed better GCA effects for PH, EH, ED, RE and GY traits and inbred line Ism 7094 for earliness and grain yield. The tester SC 128 showed the highest GCA effect for grain yield. The best crosses for specific combining ability (SCA) effects were Ism 6040 x SC 128, Ism 7094 x SC 128, Ism 7169 x SC 128, Ism 7186 x SC 131 and Ism 7259 x SC 131 for grain yield and cross Ism 6007 x SC 131 for earliness, grain yield, and yield components. The non-additive gene effects were more important in controlling all studied traits. Moreover, non-additive gene effects were more interacted by environmental conditions than additive gene effects for all studied traits. The highest mean values and significant of crosses for grain yield (GY) were obtained from the Ism 6040 x SC 128 (37.5 ard/fad.), Ism 6007 x SC 131 (37.0 ard/fad.), Ism 7169 x SC 128 (36.7 ard/fad.), and Ism 7094 x SC 128 (35.5 ard/fad.). These three ways crosses out yielding significant than the commercial hybrids TWC 321 (33.7 ard/fad.) and TWC 324 (32.5 ard/fed). These promising hybrids should be tested in advanced trails. [ABSTRACT FROM AUTHOR]

The present investigation aims at estimating per se performance, combining ability and standard heterosis for 16 biometrical traits using 40intra-hirsutumhybrids synthesized from eight ovule and five pollen parents in Line x Tester fashion. The analysis of variance was significant for all biometrical traits except fibre fineness. Apart from internode length and ginning outturn, all traits were predominantly governed by dominance gene action. Among the parents CPD 1701, RHCHD 1314, RHCHD 1406, MCU 9, CO 16 and CO 14 ranked as good general combiners. Based on mean, sca effects and standard heterosis, PBH 116 x CO 16, RHCHD 1314 x CO 14, CPD 1701 x CO 16 and CPD 1702 x MCU 7 was perceived as amenable for heterosis breeding. [ABSTRACT FROM AUTHOR]

Seven cucumber (Cucumissativus L.) genotypes (3 lines and 4 testers) were crossed in a line X tester mating design. The resultant 12 hybrids and their parents were evaluated using Randomised Block Design with two replications during Kharif 2018. Sufficient genetic variability was observed for all the characters under study. In this study, the parents L2 (Koradacherry local), T2 (Orathanadu local) and T3 (Aipatti local) exhibited high positive GCA (General Combining Ability) effects for yield related traits and high negative GCA effects for earliness characters. The parent T2 identified in this study may be used in multiple crossing programme to isolate high yielding varieties. Among the hybrid combinations, L2xT3, L1xT2 and L3xT4 expressed the maximum positive significant SCA (Specific Combining Ability) effects for yield and yield associated characters. In the above cross combinations one parent was a good combiner and the other was an average/poor combiner; hence the hybrids can be exploited for transgressive selection. [ABSTRACT FROM AUTHOR]

The selection of parents and superior genotypes is a primary task for plant breeders. In line x tester mating design, seven lines and three testers were crossed to create twenty-one hybrids. The hybrids and parents were evaluated together in the field for various yield and yield related traits at maturity under water stress conditions. The variance assessment implies prominent contrasts between the lines, and testers, crosses for various traits. The differences for GCA and SCA were observed significant for the traits. The line WM13RA and OH33-1 showed the highest general combining ability for most of the traits. The cross combination WM13RA C x Agati85 provided the highest positive better parents heterosis. Specific combining ability was also high, ML17 x Agati85 and ML3 x Agati85 produced higher grain yield in term of said production of early maturing hybrids. Concerning molecular component, ten SSR primers were used to check the hybrid purity. One primer showed the polymorphism with parents and hybrids, results showed that seventeen hybrids were confirmed based on the presence of the polymorphic bands. Genetic purity was 80.95%. [ABSTRACT FROM AUTHOR]

Combining ability for grain yield and its component traits were assessed utilizing line x tester method by involving three lines and six testers. For all the nine traits under study, the ratio of GCA (general combining ability) to specific combining ability (SCA) was less than unity as the relative estimates of variance due to GCA were lower than SCA, thereby reflecting the predominance of non-additive gene action. On the basis of per se performance and GCA estimates of the parents, Mash 114, RUG-46 and KU-99-21 were found to be the good general combiners for grain yield per plant. Based on SCA estimates, six hybrid combinations were found to be promising. They were: KUG 503 × KU 99-21, Mash 114 × VBN-6 and Mash 479 × RUG-46 with high × low / low × high general combiners, KUG 503 × KU 9921, Mash 479 × KU 99-21 with low × medium and KUG 503 × TU 94-2 with low x low general combiners. As the presence of high proportion of non-additive gene action was found to be pronounced, the breeding procedures such as pedigree method, bi-parental mating(s) or selection in later generations are suggested for expecting transgressive segregants on employing the promising parents and cross combinations. [ABSTRACT FROM AUTHOR]

Combining ability analysis for grain yield and its contributing traits in maize was performed with 15 inbred line and 3 tester parents and the resulting 45 hybrids using line x tester cross analysis in three environments during kharif and rabi 2014. The results of combining ability analysis over the environments revealed significant mean squares due to general and specific combining ability indicating that both additive and non-additive gene actions were important in the inheritance of characters studied. The parents L2 (EIQ -132), L4(EIQ-134), L5(EIQ-135), L6(EIQ-136), L8(EIQ-138), and L14(EIQ-144) and L15 (EIQ- 145) were good general combiners for grain yield and majority of traits over the environments. Hence, these parents can be used in crossing and further exploited for improvement of traits in the population. Six inbred lines viz., L1(EIQ-131), L2(EIQ - 132), L3(EIQ-133), L6(EIQ-136), L8(EIQ-138) and L14(EIQ-144) were identified good general combiner for maturity related traits. Whereas the crosses L7 x T2 (EIQ-137 x EIQ-102), L13 x T3 (EIQ-143 x EIQ-103), L10 x T1 (EIQ-140 x EIQ-101), L1 x T1(EIQ-131 x EIQ-101) and L11 x T3 (EIQ-141 x EIQ-103) were identified as potential ones for yield and yield components based on high sca effects along with high per se performance. These hybrids may be exploited for commercial cultivation by testing them over locations and years for their yield stability.

Present experiment was conducted with five male sterile lines (female parents) and nine testers (male parents) of pearl millet in line x tester fashion. Both GCA and SCA variances were highly significant for all characters. The predictability ratio of GCA and SCA revealed preponderance of non-additive genetic variance for all the characters. The parents like J-2340, J-2555 and J-2552 were identified as good general combiners for grain yield per plant and some other components. Majority of their crosses had also displayed significant and desirable sca effects, coupled with high per se performance for grain yield per plant. The hybrids viz., JMSA1 20141 x 81-SB-14, ICMA4 10444 x J-2555 and JMSA5 20142 x 150-SB-14 were recorded the significant sca effect in desirable direction for grain yield and some other important characters. Thus, these hybrids can be commercially exploited through heterosis breeding programme after testing in multi-locational trial to work out its stability and diseases screening trials to find out its resistance capacity against major pearl millet diseases in order to achieve hybrids with high grain yield in pearl millet.

General and specific combining ability variances and effects for ten characters related to yield and its contributing traits in safflower were studied using Line x Tester matting design in thirty CMS based hybrids involving 15 lines and two testers along with two checks (AKS 207 & PKV Pink). Combining ability analysis indicated the predominance of non-additive gene action for all the traits under study except seed volume weight for which both additive and non-additive gene actions were found equally important. The parents viz., GMU 2952, GMU 5609 and GMU 3420 among the males and AKS CMS 2A among the females were found good general combiners for seed yield and most of the yield contributing traits whereas for oil content GMU 3420, GMU 3715 and AKS CMS 2A were found good general combiners. For seed yield per plant the cross AKS CMS 3A x GMU 3638 was found significantly superior in addition to number of seeds per capsule. Whereas, AKS CMS 2A x GMU 2900 for seed volume weight, AKS CMS 2A x GMU 3923 for 100 seed weight, AKS CMS 2A x AKS 207 for number of seeds per capsule, AKS CMS 2A x GMU 322 for number of capsule per plant, AKS CMS 3A x GMU 3420 for number of primary branches per plant were identified as good cross combinations. Desired and fertile segregates may be isolated from segregating material of these crosses in the advanced generations if crosses are effected again by using ‘B’ lines of CMS based females along with same male parents in concerned crosses as these crosses involved CMS line as female parent. Further, early generation segregates may be intermated with each other to break undesirable linkages and obtain desirable segregates for seed yield and its contributing traits due to predominance of SCA variance for almost all the traits.

Nineteen new white maize inbred lines were top crossed with two testers i.e.; Sd. 7 and Sd. 63 at Gemmeiza Research Station in 2017 growing season. The resulted 38 crosses in addition to three commercial check hybrids i.e. SC10, SC128 and SC 2031 were evaluated at Gemmeiza and Sids Agriculture Research Station Farms during 2018 growing season. Data were recorded for the following traits: days to 50% silking, plant height, ear height and grain yield. Analysis of variance of crosses and their components, lines, testers and lines x testers showed highly significant differences for all traits, except lines x testers for days to 50% silking. σ²GCA was larger than σ²SCA for all traits. These results indicated the dominance of additive gene action in the inheritance of these traits. The inbred lines L4, L7,L10 and L19 (for earliness) and the inbred lines L1, L5,L10, L11and L12 (for grain yield) had high general combining ability. The crosses L10 x T1 (42.91 ard. /fed.), L11 x T1 (38.40 ard./fed.) and L14 x T1(35.65 ard /fed) had high mean values and highly significant SCA effects for grain yield. [ABSTRACT FROM AUTHOR]

Sorghum is one of the essential fodder crops in Egypt and its demand is increasing day by day due to increasing the number of cattle farm. While, water deficit is one of the main reasons for crop reduction worldwide including Egypt. Therefore to meet the shortage of fodder, it is very essential to develop high yielding hybrid or sorghum cultivars which are suitable to grow under water stress condition. The present investigation was conducted at Sakha Agriculture Research station farm, Egypt during two growing seasons. In 2016 twelve lines and four testers of sorghum species were crossed according to line x tester design to produce 48 crosses. The 48 crosses, their parents and two checks ('hybrid 102' and 'hybrid SX17') were evaluated during 2017 summer season at the two locations Sakha and Sids Agricultural Research Stations. Three adjacent experiments were carried out according to three irrigation interval periods viz., 14, 21, 28 days intervals at each location using randomized complete block design with three replicates. The results of the present study indicated that the mean squares for total fresh and dry forage yield plant-1 were varied significantly under the three irrigation intervals at the two locations and combined over both locations and the three irrigation intervals). In addition, mean square values for interaction of irrigation intervals, locations, and irrigation x locations were found to be highly significant. The tester parent ('Giza1') had the highest mean performance for fresh and dry forage yield plant-1 at Sakha location, while, the highest values were provided by line parent L12 ('ICS693'). Moreover, the cross 45 (L12 x T1) was superior and had the highest mean performance for fresh and dry forage yield plant-1 under normal and water deficit conditions at two locations. When data combined, L12 ('ICS693') and tester 'T4'('New parent') were the best combiner for total fresh and dry forage yield plant-1 under normal and water deficit conditions. The highest positive SCA effect was observed in the cross 45 (L12 x T1) for fresh and dry yield plant-1. followed by The cross 44 (L11 x T4). Marked variation among all crosses under study was detected under normal and water deficit which indicated considerable scope of improvement in forages. The best general and specific combiners could be used as prime materials for selection in breeding program to improve fodder yield components under water deficit conditions. [ABSTRACT FROM AUTHOR]

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