Combining Ability Analysis Research Articles

Genetic Analysis of Green Pod Yield in Table Pea [Pisum sativum var. hortense

Background: Garden pea (Pisum sativum L. var. hortense) belongs to family leguminosae is an important legume vegetable grown throughout the world during cool season. It is self pollinated pulse crop with chromosome number 2n = 2x = 14. Based on genetic diversity its primary centre of origin is Mediterranean region. It is used as fresh vegetable and processed frozen vegetable in India and abroad. It is good source of vegetarian protein (6.8%-7.2%) which is consumed as green seed. The experiment was carried out to estimate the GCA effect of parents and SCA effect of 28 hybrids for green pod yield and its related traits using eight parents in crossing programme. Methods: In this experiment crosses was made in 2018-2019 using diallel mating design (excluding reciprocal crosses) and the data investigated in 2019-2020 at Vegetable Research Farm of C.S. Azad University of Agriculture and Technolgy, Kanpur. Result: In our investigation combining ability analysis revealed significant GCA and SCA for all characters. On the basis of gca effect of parents AP1, KS111, KS282 were good general combiners. Based on SCA effect crosses KS282 x Kashi Nandani, KS280 x Kashi Nandani, AP3 x KS282 were good specific combination for pod yield per plant. Such crosses could be further exploited to obtain transgressive segregants in future breeding programme.

Understanding Gene Action, Combining Ability, and Heterosis to Identify Superior Aromatic Rice Hybrids Using Artificial Neural Network

The aromatic rice represents a smaller but independent rice collection, the quality of which is considered to be highly acceptable. Farmers are interested in growing aromatic rice due to high premium market price. The prime objective of this study was to enhance genetic improvement of aromatic rice. Combining ability analysis (GCA and SCA) and gene action are studied in a set of 7 × 7 half-diallel crosses. Twenty-one hybrids along with their seven parents were assessed in randomized complete block design. Different quantitative characters were used to estimate the magnitude of heterosis. GCA and SCA significance for all traits revealed the importance of both additive and nonadditive genetic components. Several genes determine quantitative traits, with each gene having very little impacts and being easily influenced by environmental factors. Pusa Basmati-1 and Govindobhog were the best combiners among the seven parents. In terms of per se performance, heterosis, and SCA effects on seed yield per plant and important yield qualities, the crosses BM-24 Deharadun Pahari, Baskota × Tulaipanji, and Pusa Basmati-1 × Tulaipanji may be of interest. Because of its interconnected processing properties, ANN can play a critical role in this experiment. As a result, the current study was carried out to collect data and validate it using an artificial neural network (ANN) on the combining ability, gene action, and heterosis involved in the expression of diverse fragrant rice features. Using ANN, the validation of the result was done and it was found that the overall efficiency was approximately 99%.

Multi-environment Assessment of Combining Ability, Heterosis of Bt Introgressed Lines and Hybrids of Upland Cotton (Gossypium hirsutum L.)

A study was conducted at Dharwad, Raichur and Aurangabad in India during the rainy season of 2018 to investigate the environmental impact on combining ability and heterosis estimates in cotton. Combining ability analysis across locations showed significant effects on the performance of genotypes, GCA, SCA, genotype×environment, GCA×environment and SCA×environment interactions for most of the characters. Combining ability variance revealed the predominance of non-additive gene actions for characters under study. The parents and crosses varied with locations for combining ability and better parent heterosis estimates. Out of 22 parents, ten parents recorded high overall gca and among them, two BGII, six BGI and two non-Bt parents were under study. Similarly, 55 hybrids were exhibited high overall sca and better parent heterosis from the study and most of the crosses were derived from lines crossed with high overall gca (H) with low overall gca (L) or vice versa. This study indicated the requirement of parents with contrasting gca effects to realize a higher frequency of heterotic hybrids. The predominance of H×L type of crosses indicated the presence of non-additive gene action suggesting exploitation of good heterotic hybrids from the study. The frequency of hybrids with high overall sca and heterobeltiosis was more in BG II hemizygous hybrids compared to BG II homozygous condition with H×L type. Similar were the results with BGI hemizygous hybrids.

Combining Ability Analysis and Marker-Based Prediction of Heterosis in Yield Reveal Prominent Heterotic Combinations from Diallel Population of Rice

Combining ability along with heterosis was elucidated in the 21 F1 hybrid population of rice derived from a 7 × 7 diallel mating design. Furthermore, to formulate a strategy for marker-based prediction of heterosis, the molecular genetic diversity (GD) was then surveyed among the seven parental lines with RAPD markers. Analysis of combining ability revealed significant GCA and SCA variances and the ratio between the aforesaid genetic parameter was more than unity for most of the traits signifying the preponderance of additive gene action. Hybrid combination Double Rice × Pokkali was the best specific combiner for the traits pollen fertility percentage (%), panicle length (cm), filled grains/panicle (no.) and grain yield/hill (g) while Muktagacha × BRRI dhan29 and Basmati × Double Rice were the best specific combiners for grain length (mm) and 1000-grain weight (g), respectively. Regarding the magnitude of heterosis, Double Rice × Pokkali exhibited maximum heterobeltiosis for panicle length (33.33%) and the number of filled grains/panicle (144.01%). Furthermore, Pokkali × Chinigura was verified for producing the highest heterobeltiosis for tillers/hill (173.17%), as well as grain yield/hill (71.05%). The heatmap relying on molecular genetic diversity exposed the highest genetic distance between Chinigura and Pokkali followed by Muktagacha and Pokkali. Unweighted neighbor-joining trees clustered the parental lines into three groups indicating the presence of considerable genetic diversity among those seven parental genotypes. A positive and significant correlation was explored between molecular GD with specific combining ability as well as heterosis for all of the traits revealing the huge potentiality of hybrid performance prediction using RAPD markers with the present set of individuals. Thus, exploration of definite genomic regions underlying the candidate genes for respective traits relying on such RAPD-generated data following an advanced molecular marker approach would pave the path of mining out yielder heterotic combinations.

Line × Tester Analysis and Estimating Combining Abilities for Yield and Some Quality Attributes in Tomato (Solanum lycopersicum L.)

General and specific combining ability (GCA & SCA) for yield and quality traits in tomato were studied by involving fourteen parental line were crossed in line x tester mating design comprising eleven line and three tester at M.E.S department of vegetable science ANDUAT, Ayodhya to estimate combining ability in tomato for fruit yield and quality traits. Combining ability analysis revealed that both additive and non-additive gene action for most of the characteristics and heterosis breeding for the improvement of these traits have been enhanced. Based on GCA effects of parents, the line NDT-4 and the testers Kashi chayan were identified as the best general combiner for yield and its important component. The crosses NDT-2×Arka vikash superior specific combiners for fruit yield per plant.

Review on Heterosis and Combining Ability Study for Yield and Morphological Characters of Coffee (Coffea arabica L) in Ethiopia

Ethiopia is both the center of origin and diversification of Coffee arabica. Despite the existence of high genetic diversity in coffee population that provides immense opportunities for improvement program, shortage of improved varieties (pure line and hybrid varieties) is the major one. It is obvious that research work carried out so far on coffee genetics and breeding was not adequate to address these diverse agro-ecologies of the country. Heterosis and combining ability studies are some of the basic breeding tools to address such problems. Some studies had been focused on assessment of heterosis and combining ability analysis for yield and morphological characters of coffee in Ethiopia and the presence of heterosis was reported in crosses of selected indigenous C. arabica L. varieties in Ethiopia under different set of studies mainly due to presence of diverse parental lines. These results clearly suggested that the possibility to bring significant coffee improvement through heterosis and combining ability analysis. Therefore, continuous crossing program should be required to acquire many more cross combinations for intensive and extensive evaluation to develop better performing and high yielding hybrids for Ethiopian origin coffee. Keywords: Coffee Arabica, morphological traits, yield, Heterosis and combining ability DOI: 10.7176/JEES/12-7-02 Publication date: July 31 st 2022

Combining ability and heterosis for yield contributing and fibre quality traits in the hybrids of Gossypium hirsutum L.

The present study was investigated in thirty five hybrids of Gossypium hirsutum L. for combining ability and heterosis for ten yield and fibre contributing traits. These hybrids were obtained by the crosses made between seven lines and five testers. None of the crosses was  superior for all the traits studied for the mean performance. The hybrid TCH 1199 × GTHV 323 showed the highest mid and better parent heterosis for the lint index and the hybrid TCH 1828 × RHC 1409 exhibited the highest significant mid and better parent heterosis for ginning outturn. The characters viz., boll weight and single cotton yield per plant were identified to have the highest significant mid and better parent values in the hybrid BSH 18 × RHC 1409. For yield contributing traits viz., the number of sympodial branches per plant and the number of bolls per plant out numbered in the hybrid CO 14 × KC 3 with the maximum standard heterosis among the thirty five hybrids. Combining ability analysis exhibits the dominance of non- additive gene action in all yield and fibre quality contributing traits. Among the lines CO 14 and TCH 1828 were estimated as the best combiners for yield and quality traits, respectively. Among the testers, KC 2 and KC 3 were found to be the best among all the five testers. The hybrid BSH 18× RHC 1409 exhibited the highest sca for the boll weight and seed cotton yield per plant and the hybrid BSH 18 × GISV 323 exhibited the highest sca for the quality traits viz., ginning out turn and upper half mean length; TCH 1828 × KC 3 and CO 14 × KC 2 best performed hybrids for sca values for the quality traits viz., elongation length and micronaire values. Keywords: Cotton, F1 hybrids, heterosis, combining ability.

Selection for high yield and quality in half-diallel bread wheat F2 populations (Triticum aestivum L.) through heterosis and combining ability analysis

The study was carried out to evaluate the combining ability and heterosis of seven parents and their 21 half-diallel F2 populations for yield and quality traits during the 2013-14 season in the randomized complete block design with three replications. Significant differences were observed among the genotypes, GCA (general combining ability) and SCA (specific combining ability) effects for all traits, except spike length. The best combiner parents were identified as Esperia and Pehlivan for grain yield, and Flamura85, Aldane and Selimiye for quality traits because of significant GCA and per se performance. The ranges of best parent heterosis were -12.71 to 8.23% for plant height, -15.46 to 8.36% for spike length, -16.62 to 24.80% for number of grains per spike, -23.61 to 36.50% for grain weight per spike, -17.13 to 8.84% for harvest index and -44.26 to 15.83 for grain yield, -17.61 to 8.38% for thousand grain weight, -18.55 to 8.44% for wet gluten content, -33.80 to 24.78% for gluten index, -20.24 to 15.23% for Zeleny sedimentation value, -15.58 to 10.00% for quality index and -8.96 to 6.87 for grain protein content. The three (Slm/Phl, F85/Slm and F85/Esp) and seven (F85/Phl, Sb/Fs, Fs/Slm, Esp/Slm, Fs/Phl, Esp/Sb and Sb/Slm) of F2 populations are offered a good opportunity in base material for selection of potential because of significant SCA effects and best parent heterosis for grain yield and quality traits respectively.

Selection of Suitable Pearl Millet Hybrids for Arid and Semi-Arid Conditions through Combining Ability Analysis

Present investigation was carried out to study combining ability effects for grain yield and its component traits in 77 hybrids of pearl millet. From the results of GCA effects, it was revealed that a number of parents namely, ICMA 98222, ICMA 93333, ICMA 30199, ICMA 30201 (female parents), and BIB 481-500, BIB 561-570 and BIB 571-581 (male parents) were found to be good general combiner for grain yield and most of its component characters. On the basis of GCA effects, lines ICMA 98222, ICMA 88004, ICMA 93333, ICMA 30199, ICMA 30201 and testes BIB 571-580, BIB 561- 570, BIB 511- 520, BIB 481- 500, BIB 531- 540 were good general combiner for more than nine yield contributing characters. The SCA effects of the crosses namely, ICMA 97111 x BIB 561- 570, ICMA 98222 x BIB 481- 500, ICMA 88004 x BIB 501- 510 and ICMA 93333 x BIB 551-560 were significant and were identified as superior for seed yield and related traits over the environments. Therefore, these parents and hybrids were recommended for utilization in development of promising populations as well as hybrid development.

Genetic studies for isolation of superior parents and hybrids for a further breeding programme in safflower (Carthamus tinctorious L)

Combining ability analysis discriminates the parents and crosses, provides information about the breeding method to be adopted for genetic improvement of a specific character. Thirty hybrids obtained by mating two females with fifteen males in L × T fashion were evaluated in RBD along with parents to estimate the combining ability of parents and crosses for seed yield and yield contributing traits. The parents and hybrids significantly differed amongst themselves for different characters, viz., days to maturity, 100 seeds weight, capsules per plant, branches per plant, seed yield, seed volume weight and oil content. Among the males, GMU-590, GMU-2273, GMU-2830 and GMU-589 and the females, AKS CMS-3B had good gca effects for seed yield and some other yield contributing traits. However, GMU-7573 and GMU-2830 were found best general combiners for the trait oil content. All these selected parents may be utilised in a different breeding programme for genetic enhancement of the trait involved. The hybrids AKS CMS-2A × GMU-1731 and AKS CMS-3A × GMU-7448 were identified as good combinations for seed volume weight and capsules per plant. Whereas the hybrids AKS CMS-3A × GMU-2273 and AKS CMS-2A × GMU-6891 were effective for seed filling percentage and seed yield per plant. Three promising hybrids viz., AKS CMS-3A × GMU-7448, AKS CMS-3A × GMU-2273 and AKS CMS-2A × GMU-6891 were designated as promising hybrids as they had good per se performance and significant sca effects for seed yield per plant and most of its contributing characters which can be utilized for heterosis breeding and release of new hybrids at commercial level after thorough multilocation testing. Further, the hybrids AKS CMS-3A × GMU-7448, AKS CMS-3A × GMU-590 and AKS CMS-3A × AKS-589 involving one or both good general combining parents with non-significant sca effects for many studied characters which may be utilized to isolate desirable segregants in progressive generations for identification and release of new varieties by hybridizing the ‘B’ lines of concerned CMS line with similar males again. Keywords: Safflower, line × tester, general combining ability, specific combining ability, seed yield

Combining Ability of Drought-Tolerant Bread Wheat Genotypes for Agronomic and Physiological Traits

A combining-ability analysis is key to select desirable parents and progenies with enhanced response to selection under water-limited environments. The objective of this study was to determine combining ability for agronomic and physiological traits among distantly related drought-tolerant bread wheat (Triticum aestivum L.) genotypes under well-watered (WW) and terminal-drought (TD) conditions to determine their genetic merit for breeding. Ten heat- and drought-tolerant wheat genotypes were crossed in a half-diallel mating design to generate 45 F1s, which were evaluated under WW and TD moisture regimes in rainout shelter (RS) and greenhouse (GH) environments. The following agronomic traits were assessed: days to 50% maturity (DTM), plant height (PH), spike length (SL), number of productive tillers (TN), spikelets number per spike (SPS), number of grains per spike (GPS), grain yield (GY) and thousand-kernel weight (TKW); and physiological traits (stomatal conductance (SC) and chlorophyll content index (CCI)). Variances attributable to general combining ability (GCA) and specific combining ability (SCA) were significant (p < 0.05) for GY, DTM, PH, SL, SPS, GPS, TKW and CCI. The parental genotypes LM72, LM81 and LM95 with positive and significant GCA effects on GY were selected to make crosses to develop high-yielding wheat genotypes for water-limited environments. Crosses LM71 × LM02, LM71 × LM81, LM82 × LM02, LM82 × LM81, LM22 × LM100, LM22 × LM81 and LM95 × LM22 were selected with positive and significant SCA effects for GY. The selected parents and crosses are valuable genetic resources for breeding and genetic advancement.

Estimation of combining ability and heterosis for yield and its component traits for identification of promising red rice (Oryza sativa L.) hybrids developed from new WA-based CMS lines and red kernel breeding lines

Combining ability analysis and heterosis enables plant breeders in anticipating improvement in productivity through hybridization and selection. In this study, line × tester mating design was used to develop 42 red rice hybrids by utilizing newly developed six WA-based CMS lines and seven testers selected from red kernel breeding lines at Zonal Agricultural Research Station, V.C. Farm, Mandya during kharif, 2018. The phenotypic performance of hybrids along with parents and checks were evaluated for grain yield and yield contributing traits. Analysis of variance revealed that variance due to the line × tester was significant for almost all the characters studied. Combining ability analysis revealed the predominance of non-additive gene action for most of the characters studied. On the basis of gca effects, CMS 2 among the lines and MO-21 among testers were identified as good general combiners for most of the traits studied. High sca effects were observed in the crosses, viz., CMS-1 × ME-19, CMS-2 × IET-14757 and CMS-4 × MSN-98 and they were also found to be the best combinations for grain yield and its component traits. The crosses CMS 5 × MSN-10-3, CMS 2 × ME-19 and CMS 5 × IET-14757 exhibited high mean grain yield and high standard heterosis over the standard commercial check KRH-4. These hybrids further need to be evaluated in multi-location trails for commercial exploitation of heterosis in red rice hybrid breeding program. Keywords: Hybrid rice, CMS, Combining ability, Heterosis, GCA, SCA &nbsp

Gene action and combining ability analysis for kernel yield and its attributing traits in maize [Zea mays (L.)

Combining ability estimates were studied for kernel yield, its components and morphological traits in nine maize parents and 36 F1 hybrids generated from cross in half diallel mating design. Analysis of variance for combining ability revealed that mean sum of squares due to general combining ability were found significant for all the traits except cob length and cob girth, whereas, the specific combining ability effects were found highly significant for all the characters except cob length, cob girth and anthesis - silking interval. Based on estimates of general combining ability, two parents viz., WNC 40228 (6.17) and WNC 31702 (5.47) were found as good general combiners because they registered significant and positive gca effects. The estimates of sca effects revealed that 13 hybrids were exhibited significant positive sca effects. The top most three hybrids for kernel yield per plant on the basis of specific combining ability effects were Z 485-50 x Z 485-11 (22.77), WNC 40228 x BLD - 105 (20.13) and WNC 40228 x Z 485-11 (17.47). The low ratio (<1.0) of GCA to SCA variance for fourteen traits indicated that non-additive type of gene action was predominant in the expression of yield and component traits. Keywords: Maize, geneal combining ability, specific combining ability, hybrid, kernel yield

Heterosis and combining ability analysis for yield and its component traits in Indian mustard (Brassica juncea)

Ten diverse lines of Indian mustard [Brassica juncea (L.) Czern. & Coss.] were crossed in diallel mating design excluding reciprocals during winter (rabi) season 2014–15 to study heterosis and combining ability. The mean squares due to genotypes including parents, crosses and parents vs. crosses were significant for all the traits. The analysis of variance revealed significant mean sum of squares of general combining ability (GCA) and specific combining ability (SCA) for most of the characters at all three environments, except mean sum of squares due to GCA for length of siliqua in E3 environment and mean sum of squares due to SCA for plant height in E1 and for number of secondary branches per plant in E3 environment. In pooled analysis, mean squares due to GCA, SCA, GCA × E and SCA × E were significant for all the eight characters except SCA × E for plant height and GCA × E for protein content. The estimates of GCA effects revealed that parents, viz. Pusa Vijay, PM-30 and Bio-902 were good general combiners for yield contributing traits and the best specific cross combinations for yield and its attributing traits were PM-27 × RGN-229, PM-27 × RGN-73, Pusa Vijay × Laxmi, Pusa Vijay × DRMR-IJ-31 and Pusa Vijay × RGN-73 on the basis of pooled analysis. The crosses Bio-902 × RGN-48, PM-30 × Bio-902 and Bio-902 × RGN-73 exhibited highest and positive significant heterotic effects for seed yield per plant and its important component traits. These F1s may be exploited for obtaining transgressive segregants for development of hybrid varieties in Indian mustard.

Combining Ability Analysis of Relevant Characters of Maize Inbred Lines Suitable for Machine Harvest.

In this study, 9 maize inbred lines and 36 combinations were used as materials to analyze the combining ability of plant height, ear height, kernel depth, grain water content, tassel branches, stem diameter, and 100 kernels weight so as to screen excellent inbred lines and maize combinations with suitable mechanical harvest characters, which would provide a theoretical basis for breeding new maize varieties suitable for mechanical harvest. The results showed that JK2023, JK2368, and JK2018 were inbred lines whose comprehensive characters met the machine harvest standard and performed well. Besides, the combinations that meet the machine harvest standard and perform well were JK2023 × JK2197, JK2023 × JK2368, JK2023 × JK2005, JK2197 × JK2005, JK2197 × JK2368, and JK2368 × JK2005.

Evaluation of combining abilities and heterosis effect for a better selection of hybrid barley

Heterosis effect and the combining ability are two main indices of hybrids performance. Predicting hybrid performance and heterosis effect is an important approach in the breeding of hybrid barley. In order to i) combine the local and introduced genetic material; ii) study the combining abilities of parents and hybrids; and iii) analyze the relationships between the heterosis effect, the combining ability and the performance of hybrids, the present research has been initiated. In this study, five cultivars of barley (Hordeum vulgare L.) were crossed according to a full diallel plan comprising P² combinations. The twenty hybrids F2 were assessed by the general combining ability analysis (GCA); by the specific combining ability (SCA) as well as by the calculation of the heterosis effect of six agronomic characters, namely, the weight of the spike (WE), the number of grains per spike (NGE), the weight of a thousand grains (WTG), plant earliness at flowering (PRF), plant harvest index (IR) and plant productivity (P P). The results indicate that GCA for all parameters was significant except for the WE trait while SCA was significant for three of the six traits studied: WTG, IR and PRO. The GCA/SCA ratio revealed that non-additive effects were the main effect on traits assessed in the hybrids F2. Heterosis was significantly correlated with SCA for all traits tested, indicating that non-additive effects were the main effect of heterosis. Hybrids from two parents with a high GCA have consistently shown better SCA and better hybrid performance. Indeed, the selection of parents should be mainly based on their GCA.

Effect of environment on combining ability, heterosis for seed cotton yield in Bt introgressed lines of upland cotton

AbstractSuccessful hybrid development work in cotton involves unearthing information of combining ability, heterosis and per se performance of the genetic material. This study involved multi‐environment estimation of combining ability and heterosis along with the stability of per se performance using Bt cotton genetic materials for seed cotton (Gossypium hirsutum L.) yield. Combining ability analysis across environments showed significant effects on the performance of genotypes, general combining ability (gca), specific combining ability (sca), genotype × environment, GCA × environment, and SCA × environment interactions. Combining ability variance revealed the predominance of nonadditive gene actions for seed cotton yield. The mean performance combining ability estimates were varied with the locations for parents as well as for hybrids. In a low yielding environment, the transgenic BGI parents, as well as hybrids, showed superior seed cotton yield levels compared with BGII or non‐Bt versions. There was a significant increase in heterosis noticed in BGII hybrids compared with BGI hybrids in a low yielding environment. The stability parameters showed significant genotype × environment variation and indicated that the stability of the genotype was mainly affected by the genetic background of the material. A positive association was noticed between per se performance and gca effects, heterobeltiosis and sca, and heterobeltiosis and mean of hybrids as the environment`s yield potential increased. The majority of the Bt hybrids showed positive heterosis over a better parent. Among the two versions of Bt transgenic cotton, BGI excelled in per se performance and gca and sca effects for seed cotton yield either in the homozygous form or hemizygous hybrids.

Combining Ability Studies for Seed Yield and its Quantitative Traits in F2 Crosses of Mungbean [Vigna radiata (Wilczek)

Background: Combining ability is a measure that enables breeders to select better parents and outstanding hybrids. General combining ability and specific combining ability is used to determine best performing parents and vigorous hybrids respectively and provides an opportunity to understand the nature of gene action involved in inheritance of each character. Methods: A combining ability analysis was carried out with six mungbean varieties and their 15 F2 crosses derived from half diallel fashion. Data was recorded for 10 characters and were subjected to statistical analysis using method-II and model-1 of Griffing’s approach. Result: There was importance of both additive and non-additive gene action in inheritance of all the characters as apprehended from significant values in mean sum of square due to GCA and SCA. Studies on components of variance due to GCA and SCA indicated there was preponderance of additive gene action for days to 50% flowering, days to maturity and pod length whereas non-additive gene action was expressed for other characters. Four parents viz., Kamdev, Pant Mung-8, MGG-385 and OBGG-52 were considered as best general combiners on the basis of significant GCA effects for a number of yield and its related traits. Based on SCA effects and per se performance, the crosses IPM-02-14/OBGG-58, OBGG-52/OBGG-58 and MGG-385/OBGG-52 displayed significant SCA in desirable direction along with high mean for many of the yield attributing characters. Highest significant SCA for seed yield was observed by the cross Kamdev/IPM-02-14. These selected parents and crosses can be used for further breeding programmes for crop improvement in mungbean.

Combining ability analysis in bread wheat (Triticum aestivum L.) under different environmental conditions

A Pooled analysis was carried out to evaluate the general and specific combining ability effects in 9 diverse genotypes of bread wheat of diverse origin of cultivation, their 36 F1’s and 2 checks during Rabi 2020-21 at RCA, Udaipur in three different environments for grain yield and its component traits. Analysis of variance revealed the differences between parents and crosses for GCA and SCA, respectively due to GCA and SCA effects were significant for all the characters except days to 50 % flowering in E3 (GCA) on pooled basis. Similarly, mean squares due to GCA x E and SCA x E were significant for all characters revealed influence of environment on GCA and SCA, respectively. The variance due to GCA was higher than their respective SCA for all characters except spike length, awn length and harvest index indicated that additive type of gene action played role in the expression of all the traits. Among parents, DBW 173, HD 2967, GJW 463 and RAJ 4120 were exhibited significant GCA effects for grain yield and its component traits. Maximum significant positive GCA effects were exhibited by parent DBW 173 (1.80) over the environments. Among crosses, thirteen crosses recorded showed significant SCA effects for grain yield and its related traits. Cross, HD 2967 x DBW 173 was exhibited maximum positive significant SCA effects for grain yield and harvest index in the environments as well as on pooled basis. Cross, HD 2967 x DBW 173 depicted maximum SCA effects (4.00) followed by RAJ 3777 x RAJ 4120 (2.92) for grain yield over environments. Attempting cross combinations involving different parents with high GCA for desirable yield and other traits could be useful.

Combining ability analysis in bread wheat (Triticum aestivum L.) under different environmental conditions

A Pooled analysis was carried out to evaluate the general and specific combining ability effects in 9 diverse genotypes of bread wheat of diverse origin of cultivation, their 36 F1’s and 2 checks during Rabi 2020-21 at RCA, Udaipur in three different environments for grain yield and its component traits. Analysis of variance revealed the differences between parents and crosses for GCA and SCA, respectively due to GCA and SCA effects were significant for all the characters except days to 50 % flowering in E3 (GCA) on pooled basis. Similarly, mean squares due to GCA x E and SCA x E were significant for all characters revealed influence of environment on GCA and SCA, respectively. The variance due to GCA was higher than their respective SCA for all characters except spike length, awn length and harvest index indicated that additive type of gene action played role in the expression of all the traits. Among parents, DBW 173, HD 2967, GJW 463 and RAJ 4120 were exhibited significant GCA effects for grain yield and its component traits. Maximum significant positive GCA effects were exhibited by parent DBW 173 (1.80) over the environments. Among crosses, thirteen crosses recorded showed significant SCA effects for grain yield and its related traits. Cross, HD 2967 x DBW 173 was exhibited maximum positive significant SCA effects for grain yield and harvest index in the environments as well as on pooled basis. Cross, HD 2967 x DBW 173 depicted maximum SCA effects (4.00) followed by RAJ 3777 x RAJ 4120 (2.92) for grain yield over environments. Attempting cross combinations involving different parents with high GCA for desirable yield and other traits could be useful.