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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.

Development of rice genotypes possessing high yielding potential; with increased grain iron content is the need of the hour to tackle hidden hunger. Considering the above said fact, genetical analysis was conducted in six improved cultivars along with 15 potential crosses thereof. Analysis of variance for combining ability revealed significant differences in GCA and SCA variances for grain yield as well as for iron and zinc content, indicating the possibility of realization of development of iron fortified varieties with higher yielding potential. The preponderance of additive gene action for these two important characters i.e., iron and zinc content indicate that selection will be highly rewarding for genetic improvement pertaining to these two traits. The genotype Gouri was found to be very good combiner for both grain yield (0.93) and iron content of grain (2.04). Similarly, genotype Sebati was found as a very good combiner for both grain yield (0.13) and zinc content of grain (0.65). Some of the superior crosses identified concerning both grain yield and grain iron content were Birupa / Pradeep, Sebati / Gouri, Sebati / Pratap, Gouri / Pradeep and Pratap / Pradeep. Hence, these specific crosses can be used in further breeding programme for the improvement of both grain yield as well as grain iron content. The crosses viz., Bhanja / Pratap and Bhanja / Sebati were found to be superior crosses for both grain yield and grain zinc content.

Line × Tester analysis was carried out in a set of 20 crosses developed using five lines and four testers to ascertain the nature of gene action and combining ability of parents for yield, yield attributes and quality traits in groundnut. The estimates of GCA and SCA variance indicated the predominance of non-additive gene action for the inheritance of all the traits except SCMR at 60 DAS. The parents TCGS 1694, TCGS 1862, Kadiri-6 and TCGS 2251 were identified as good general combiners which could be further used in breeding programmes for yield improvement. The cross, Kadiri-6 × TCGS 1862 exhibited desirable sca effects for days to maturity, number of secondary branches plant-1, number of pods plant-1, number of mature pods plant-1 and kernel yield plant-1, while the cross Narayani × TCGS 2251 was found to be a good combiner with high sca effects for earliness (days to flowering and days to maturity).These two combinationshad either low × high or high × medium gca parents indicating the involvement of both additive and non-additive gene action.

Combining ability is a useful tool for choosing appropriate parents, while an understanding of the nature of gene action can help develop effective crop improvement initiatives. In order to study if genetic diversity affects hybrid vigour, 50 hybrids were generated by crossing five pistillate lines with ten testers and experimented across two replications during the 2020–21 kharif. Genetic divergence was evaluated as Mahalanobis distance among all potential pairs of lines and testers and also in relation to combining ability. Hybrids were classified into four divergent classes using statistics like distance (D2), overall gca effects among parents, overall sca effects, and midparent heterotic status across crosses. Genetic diversity studies revealed the that parents to be used in hybridization programmes should be moderately divergent, to derive crosses with high better parent heterosis. Hybrids, viz., MCP-1 × ICS-240, MCP-1 × RG-2787, MCP-1 × RG-3160, YRCP-1 × ICS-258, and DPC-22 × RG-2787, were identified as superior to standard checks for economically important traits. Superior male and female base populations can be created through random mating of lines and testers with high breeding values, such as DPC-22, MCP-1, ICP-30, RG-2787, RG-3160, RG-72, and YRC-1904, respectively.

Prolonged crop duration (150-210 days) and tall plant height (>100 cm) of castor either hinders its adaptability to newer and niche areas or fitting into the cropping sequence of conventional castor growing areas. The present study aims at evaluating male lines for their agro-morphological characters, combining ability for seed yield, yield components and resistance to Fusarium wilt. Node number to primary, first and second order of secondary (P, S1 and S2) racemes were taken as indicators of flowering and maturity duration of male lines while data on plant height up to primary spike was recorded for plant stature. Twenty-six improved monoecious lines were evaluated for their agro-morphological characters in an ARBD design along with three checks replicated five times during 2017-18 kharif season. Simultaneously all the 26 lines were screened for wilt resistance in wilt sick plot in two replications. Nineteen monoecious lines were resistant to wilt (0-20% wilt incidence) while four lines were moderately resistant to wilt (20-30%). Four lines viz., ICS-121, ICS-150, ICS-127 and ICS-139 were promising with significantly low node number to P, S1 and S2 order of racemes compared to early maturing check, DCS-9 (12.1, 5.8, 4.9). Eight male lines were significantly shorter than the very tall type checks, 48-1 and DCS-107 (>85 cm) while ICS-121 (57.5 cm) was on par with the medium statured check, DCS-9 (59.7 cm). Fifteen hybrids, generated by crossing three pistillate lines and five selected wilt resistant male lines in a line x tester design were evaluated along with eight parents and two hybrid checks during 2019-20 kharif season. SKP-84 (pistillate line) and ICS-139 (male line) were identified as good combiners for seed yield and majority of the yield components.

The purpose of this research was to examine the extent of heterosis in 21crosses of bread wheat (Triticum aestivum L.). These hybrids originated from a line x tester mating scheme in which seven lines were crossed with three testers. Combining ability analysis revealed that the parental lines HP-25 and HD-3086 performed well for grain yield, while HP-24, HP-22, and HP-06 were observed to be better for other qualities that contribute to yield. Significantly higher positive Specific Combining Ability (SCA) for grain yield per plant was observed for the crosses HP-22 x JAUW-683, HP-44 x HD-3086, and HP-45 x RSP-561 suggesting the role of non-additive gene action. The ratio of variances was observed to be less than unity indicating the presence of non-additive genetic effects in these cross combinations. In terms of heterotic impacts on grain yield, yield contributors, and morpho-physiological features, HP-06 x RSP-561 was shown to be the best combination.

The study was conducted to estimate the magnitude of heterosis and combining ability effects in groundnut for yield attributing traits. Fifty-six F1 hybrids developed through Line × Tester mating fashion were evaluated along with the parents in RCBD with two replicates during kharif-2022. Analysis of variance showed significant differences among genotypes for all the studied traits. The hybrids K 6 × ICGV 15402, VRI 10 × ICGV 15402, VRI 10 × ICGV 15426 exhibited positive heterosis for traits number of primary branches, pods/plant, kernel yield, 100 kernel weight and shelling percentage. Significant negative heterosis was observed for plant height in these crosses namely, CO 7 × ICGV 15412, VRI 7 × ICGV 15408 and VRI 8 × ICGV 15402. The study recorded significantly higher SCA variances compared to GCA variances, indicating a predominant role of non-additive gene action for all the traits studied. Line VRI 7 showed significant gca effects for all the traits except shelling % and hundred kernel weight and was identified as a best general combiner. The hybrids VRI 8 × ICGV15426 and VRI 7 × ICGV15402 revealed superior performance in terms of pod yield per plant. Notably, the cross VRI 7 × ICGV15402 exhibited outstanding performance across all traits, highlighting the prominence of a parent with strong SCA. Pod yield was significantly correlated with kernel yield/plant and sound mature kernel. Path analysis highlighted the direct and indirect effects of traits on pod yield, emphasizing the importance of kernel yield and sound mature kernel. This study underscores the utility of heterosis breeding in improving groundnut for enhanced yield and suggests specific parent combinations for future breeding.

The purpose of this research was to examine the extent of heterosis in 21crosses of bread wheat (Triticum aestivum L.). These hybrids originated from a line x tester mating scheme in which seven lines were crossed with three testers. Combining ability analysis revealed that the parental lines HP-25 and HD-3086 performed well for grain yield, while HP-24, HP-22, and HP-06 were observed to be better for other qualities that contribute to yield. Significantly higher positive Specific Combining Ability (SCA) for grain yield per plant was observed for the crosses HP-22 x JAUW-683, HP-44 x HD-3086, and HP-45 x RSP-561 suggesting the role of non-additive gene action. The ratio of variances was observed to be less than unity indicating the presence of non-additive genetic effects in these cross combinations. In terms of heterotic impacts on grain yield, yield contributors, and morpho-physiological features, HP-06 x RSP-561 was shown to be the best combination. [ABSTRACT FROM AUTHOR]

A half-diallel cross involving nine diverse brinjal genotypes, excluding reciprocals, yielded thirty-six combinations for the investigation of combining ability and gene action related to yield components. Varied genetic differences were observed among the genotypes for analyzed features, indicating that both additive and non-additive gene actions are influencing most traits. Examination of the overall combining ability effects highlighted JBR-5, JBR-3, and JBR-4 as effective general combiners for both fruit yield per plant and fruit and shoot borer infestation. Crosses demonstrating substantial specific combining ability effects in fruit yield also displayed noteworthy impacts on one or more components of yield. Promising combinations like JBR-3 X JBR-5, JBL-1 X JBR-5, and JBL-2 X JBL-3 showed potential for varietal improvement, pending multi-location yield trials to confirm their effectiveness. The most favourable cross, JBR-3 X JBR-5 (0.60), demonstrated significantly positive SCA effects for yield per plant, coupled with high and positive effects for fruit length and number of fruits per plant. Further, it also demonstrated enhanced fruit and shoot borer resistance. Most traits exhibited high narrow-sense heritability, suggesting a predominant role of additivity in phenotypic variability. Understanding the genetic mechanisms influencing economically important quantitative traits is crucial for devising successful breeding strategies. Future research should delve into advanced genomic techniques to unravel the genetic architecture of these traits and expedite the development of improved brinjal varieties with enhanced yield and resistance characteristics.

Two sets of 28 interspecific HxB hybrids generated in LxT fashion, along with their parents were evaluated for 11 yield and fibre quality parameters. GCA variances were lower than SCA variances for all the characters in both sets, as indicated by their lower ratios suggesting predominance of non-additive gene action. Based on both per se and gca effects, GJHV 374 BT, RAJAT BT, ICB 39 and CCB 141 in Set I and GJHV 374 BT, SURAJ BT, ICB 176 and SUVIN in Set II were found to be the best parents which could be utilized for the hybridization programme to obtain superior segregants with yield and fibre qualities. The hybrids viz., RAJAT BTxICB 99, RAJAT BTxICB 34,SURAJ BTxICB 39, GJHV 374 BTxICB 264, SURAJ BTxICB 264 and SURAJ BTxICB 284 showed significant sca effects. Hence, it may be concluded that the above hybrids are the best specific combiners for different yield-contributing and fibre-quality traits. The sca effect was found to be positive in17 crosses and 11 crosses for single plant yield in set I and II, respectively. Similarly, six crosses each in sets I and II were found with a positive sca effect for fibre length.

The present study involved assessment of 70 three-line hybrids obtained by crossing five CMS lines and 14 testers using line x tester mating design for combining ability and heterosis for 13 yield and grain quality traits. The Analysis of Variance identified significant difference among crosses and the ratio of GCA and SCA variances were less than unity indicating non-additive gene action for all the traits. The line COMS 24A and testers RNR 15048, WGL 32100, CBSN 504, CBSN 509, CBSN 511 and IR64 DRT were identified as best general combiners through gca effects. Among the hybrids, COMS 24A X WGL 32100, COMS 24A X CBSN 504, COMS 25A X CBSN 511, COMS 25A X CBSN 517, COMS 23A X IR64 DRT and COMS 23A X CBSN 509 demonstrated outstanding sca effects, mean and standard heterosis over CORH 3 and CORH 4. Two hybrids viz., COMS 25A X CBSN 511 and COMS 25A X RNR 15048 had medium slender grain type and hold promise for commercial exploitation in south India especially Tamil Nadu.

The current study involved the evaluation of 96 pearl millet hybrids synthesized by crossing eight lines with 12 testers using a Line x Tester mating design. The experiment was conducted during the Kharif season of 2022 with two replications and included standard checks COH10 and 86M38. Analysis of variance for combining ability revealed that, significant amount of variation was present in all hybrids for studied traits. The contribution of lines to the total variance in hybrid was greater than tester. The ratio between GCA and SCA variance was less than one for all traits and it showed that non additive gene action was predominant and highlighting the potential of heterosis breeding to exploit hybrid vigor. Among the parents, ICMB 02777 and PT 6679 were identified as good combiners, showing positive gca effects and high mean performance for grain yield, test weight, single earhead weight, and single earhead threshed weight. The other parents viz., ICMB 02444, ICMB 93222, PT 6067, and PT 6476 were also recognized as good combiners for grain yield. Out of the 96 hybrids, the cross ICMB 02777 x PT 6679 exhibited significant positive heterosis along with high standard heterosis over both checks for grain yield, test weight and single earhead threshed weight. Additionally, the crosses ICMB 02444 x PT 6679, ICMB 93222 x PT 6067 also recorded significant sca effect for grain yield per plant. These promising hybrid combinations hold great potential for heterosis breeding programs and may be suitable for commercial exploitation after thorough evaluation under multi-location trials.

The investigation was carried with 65 genotypes of Ashwagandha in three different environments to get information on combining ability for root yield at harvest, yield attributing traits and total alkaloid content. The analysis of variance indicated that experimental material contained considerable variability, furthermore the expression of both GCA as well as SCA was highly influenced by the environment. Based on the study five parental lines viz., L9, L5, L14, L15 and L8 along with tester T3 were reported as good general combiners for root yield and total alkaloid content over the environments. Among the crosses 10 hybrids and 22 hybrids were found useful specific combiner for root yield at harvest and total alkaloid content, respectively on pooled basis due to significant desirable SCA effects across the environments. Hence the above-selected genotypes may be useful for further exploitation in breeding programme of ashwagandha.

An investigation was carried out to understand the gene action for seed oil, seed protein, seed gossypol, seed cotton yield and fiber density through intra-hirsutum crosses. Combining ability and gene action were studied in eighteen hybrids involving six elite varieties as lines (females) and three fuzzless G. hirsutum accessions as testers (males) in Line x Tester analysis. This study revealed the preponderance of non-additive gene action on all the traits studied including seed cotton yield. The elite general combiners identified were CO14 for seed oil and seed protein and CO17 and AKH98-81 for fiber per seed and fiber density. The best specific combiner was SVPR4 x AKH98-81 for seed oil, fiber density and seed cotton yield. A correlation study revealed a strong positive association of seed oil content, lint index, micronaire value, fiber per seed and seed fiber density traits with seed cotton yield. This study indicated the possibility of developing high-yielding hybrids with high seed oil, seed protein content and better fiber quality traits through heterosis breeding. [ABSTRACT FROM AUTHOR]

The objective of the present study is to estimate the combining ability effects among parents and their crosses in pearl millet, to identify promising cross combinations for grain yield and its component traits. In combining ability analysis, the extent of sca variance was higher than gca variance for all of the characters demonstrating the predominance of non-additive gene action except for panicle length and 1000-grain weight. The estimates of general combining ability suggested that parents, RIB 17 S/109, RIB 16300, RIB 37-40 S/17, RIB 13-16 S/17, ICMA 96666 and ICMA 94111 were good general combiners for yield and its contributing characters. The best hybrid, ICMA 94111 x RIB 16296 involved low x low performing parents which exhibited high positive and significant SCA effect for grain yield and most of the yield contributing and quality traits like protein, iron and zinc. These good combiner lines may be exploited to develop iron and zinc rich hybrids along with grain yield to alleviate malnutrition in people of the country.

Six diverse parents were crossed in a half diallel fashion to study the heterosis and combining ability in sesame. Parents, 15 F1s with one check was planted in RBD design at College Farm, NAU, Campus Bharuch during kharif-2021. The mean sum of squares due to genotypes and hybrids were significant for all the traits while, due to parents were significant for most of the traits. The mean sum of squares due to parents vs. hybrids were found to be significant for some traits. The gca and sca ratio was less than unity indicated that non-additive components play a greater role in the inheritance of most of the traits. Parents, Ingorala 5 and DC 4 had high per se and also good general combiner for seed yield and its traits, while hybrids AT 476 x Ingorala 5 and AT 332 x Ingorala 5 had the highest standard heterosis and sca effects for seed yield and some of its traits.

An investigation was carried out to understand the gene action for seed oil, seed protein, seed gossypol, seed cotton yield and fiber density through intra-hirsutum crosses. Combining ability and gene action were studied in eighteen hybrids involving six elite varieties as lines (females) and three fuzzless G. hirsutum accessions as testers (males) in Line x Tester analysis. This study revealed the preponderance of non-additive gene action on all the traits studied including seed cotton yield. The elite general combiners identified were CO14 for seed oil and seed protein and CO17 and AKH98-81 for fiber per seed and fiber density. The best specific combiner was SVPR4 x AKH98-81 for seed oil, fiber density and seed cotton yield. A correlation study revealed a strong positive association of seed oil content, lint index, micronaire value, fiber per seed and seed fiber density traits with seed cotton yield. This study indicated the possibility of developing high-yielding hybrids with high seed oil, seed protein content and better fiber quality traits through heterosis breeding.

The estimates of combining ability and nature of gene action were worked out by Line x Tester analysis (Kempthorne, 1957). The experimental material included 45 entries containing six pistillate lines (DPC 9, DPC 21, D PC 24, YRCP 1, YRCP 2 and JP 65), five monoecious lines (TMV 5, SKI 215, 48-1, M3/28-3-1, and JM 6), thirty cross combinations, and four standard checks (YRCH 1, YRCH 2, ICH 66, and YTP 1). Four hybrids (DPC 9 x M3/28-3-1, DPC 9 x TMV 5, JP 65 x M3/28-3-1 and JP 65 x 48-1) exhibited high and significant positive economic heterosis for seed yield. The combining ability analysis demonstrated that the mean sum of squares due to genotypes and crosses were significant for all yield and its contributing traits. The magnitude of genetic variances for 11 quantitative traits revealed the predominance of dominant gene action for all the traits except oil content and hundred seed weight. For most traits, testers contributed more to total variance than the lines and L x T interaction. DPC 9, DPC 24, TMV 5, and JP 65 were identified to be the best general combiners for seed yield and its yield components. The hybrids DPC 9 x M3/28-3-1, DPC 9 x TMV 5, JP 65 x M3/28-3-1, and JP 65 x 48-1 were the most effective specific combiners for seed yield and also exhibited significant and high standard heterosis in the desired direction for seed yield and majority of the yield contributing traits. Hence, these parents and cross combinations could be effectively utilized for development of high yielding castor hybrids.

The present investigation was carried for developing sweet corn (shrunken 2) hybrids coupled with high yield and extended shelf life. The selected inbreds with sh2 gene viz., six lines and five testers were crossed in Line × Tester mating design and the hybrids were evaluated for important yield contributing traits. Relative proportion of GCA variance to SCA variance was less than unity, specifying the preponderance of non-additive gene action for all the traits studied. The lines SC 11-07, SC 11-2 and testers, MRCSC 11, WNDMRSCY 19R763 were identified as ideal parents for synthesizing high yielding hybrids with high mean and gca effects for green cob yield in addition to some of the yield contributing traits. The line SC 11-07 was identified as a potential parent with high total sugar content. Among the hybrids, SC 11-07 × MRCSC 11 followed by SC 11-07 × WNDMRSCY 19R763 and SC 11-2 × WNDMRSCY 19R763 were found to be the best performers with significant per se performance and sca effects and standard heterosis for green cob yield and contributing traits. Remarkably, SC 11-07 × MRCSC 11 also recorded superiority for quality traits. Hence, these hybrids could be subjected to further multi-location evaluation to assess the yield stability across varying environments and exploited for commercial cultivation. [ABSTRACT FROM AUTHOR]

In the present study, 31 male lines and three females, were crossed in Line × Tester mating design and 93 hybrids were produced to assign these lines to three testers viz., 104A, 401A and M31-2A. Analysis of variance exhibited significant gca and sca effects for grain yield, indicating that significant breeding progress could be achieved using both inbreeding and hybridization. Heterotic grouping based on combining ability for grain yield would be useful in planning crosses in breeding programmes. In the current study, combining ability based heterotic grouping methods such as HSGCA and SCA-PY classified sorghum lines into four groups. Further, six different potential parental combinations were determined based on the HSGCA method. These combining abilities based heterotic grouping study is an additional tool that breeders could use to identify the best parents for superior hybrids development. Among the three testers, M31-2A followed by 104A was found to be the best testers.

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 conducted on maize incorporating a total of 28 single crosses, eight parental lines and two standard checks to determine the combining ability and gene action. Among the eleven traits that were studied, the analysis of variance revealed that the mean squares due to genotypes, parents and hybrids were highly significant for all traits, except for 100 grain weight in case of parents, indicating the presence of an adequate amount of genetic variability. On further analysis of variance for combining ability, the mean squares due to GCA and SCA were observed to be highly significant for almost all traits indicating the role of both additive and non additive components of genetic variance in the expression of all the studied traits. The high gca effect for grain yield per plant was associated with high or average gca for yield component traits for most parents, while the poor combiners for grain yield per plant were also poor combiners for other yield component traits. High sca effects were seen in a few cross combinations which were good specific combiners for grain yield per plant and yield component traits. Based on the gca effects some inbred lines were identified as good general combiners for various traits. This indicated that these parents could be utilized for developing synthetic variety. The inbred lines with desirable gca effects for grain yield and other agro-morphological traits could be inter-crossed to develop an improved base population and subsequent recurrent selection efforts would facilitate the derivation of elite lines excelling in desirable character. All of the cross combinations exhibiting desirable significant sca effect were having one parent as a good or average combiner for each of the eleven agro morphological traits studied. It was clear that these hybrids were the combinations of either the parents as good general combiners or one of the parents as a good general combiner for yield and yield related traits. Hence, they can be used as a potential single cross hybrid combination and tested further. The crosses that show high sca effects indicate a preponderance of non-additive genes and can be used for heterosis breeding.

Traditional rice varieties having high flavonoids and anthocyanin traits were hybridized to high-yielding quality cultivars to assess their combining ability. Significant variation was observed among parents and hybrids for the traits studied. The predominance of non-additive gene action was observed for single plant yield, total flavonoid content, amylose content, whereas, trait anthocyanin registered additive gene action in the study. The genotypes ADT 37 and ADT (R) 45 were found to be good general combiners for flavonoids and anthocyanin content. The hybrid ADT (R) 45 x IG6 exhibited significant sca for flavonoids, anthocyanin and amylose per cent. The hybrid ADT (R) 45 x Mikkuruvai exhibited significant per se and sca for single plant yield and flavonoid content.