SCA Effects Research Articles

Analysis of Heterosis and Combining Ability for Seed Yield and its Components in Bread Wheat (Triticum aestivum L.)

The present study was carried out during the two successive seasons 2020-21 and 2021-22 at the Crop Research Farm, R.A.K. College of Agriculture, RVSKVV, Sehore (MP). General and specific combining ability estimates were obtained by employing Griffin’s diallel cross analysis, model 1 (fixed model) method 2. Heterosis over mid parents and better parents were determined as per standard procedure. Significance of heterosis value was tested using ‘t’ test. The analysis of variance revealed highly significant values among the treatments and parents for all the characters, indicating appreciable variability. The aim of this work was to study the general (GCA) and specific (SCA) combining ability and heterosis through half diallel mating among six different wheat genotypes. Based on GCA effects, GS-2031, HI-1634 and HI-1633 considered as good general combiners Seed yield /plant (g), Based on per se performance and significant SCA effects, the following crosses viz., GS-2031 x HI-8777, HI- 8777 x HI -1633, CWYT-614 x HI-1633, CWYT-644 x HI-1634, CWYT-614 x GS-2031, CWYT-644 x HI-8777, CWYT-644 x HI-1633, HI-1634 x HI-1633 and CWYT-644 x GS-2031 combination emerged as promising combiners for Seed yield/plant. A perusal of estimates of economic heterosis for yield and yield contributing characters revealed that hybrid CWYT-614 x GS -2031, CWYT-614 x HI -1633, CWYT- 644 x HI -1634, CWYT- 644 x GS -2031, CWYT- 644x HI -1633, HI -1634 x GS -2031, HI -1634 x HI -1633, GS -2031 x HI- 8777 and HI- 8777 x HI -1633 exhibited maximum estimates of significant positive economic heterosis for Seed yield/plant (g).

Gene Action and Combining Ability Analysis for Seed Yield and Component Traits in Castor Genotypes

General and specific combining ability was studied in castor genotypes under three different environments at Mandor, Jodhpur using three lines and ten testers along with their resultant 30 hybrids and one check (GCH-8) for seed yield and yield attributing traits. Analysis of variance showed significant influence on gca (general combining ability) and sca (specific combining ability) variances for most of the characters studied. Tester MCP-1-1 was found good general combiner for seed yield at 120, 150, 180 and 210 days after sowing and for other yield determining traits. On the contrary, two testers viz., MP-12-17 and MP-27-17 were found superior for overall seed yield at final harvest done at 210 days after sowing and also for some yield governing traits. Hybrids possessing high sca effects for overall seed yield were SKP-84 × MP-36-17, MCP-1-1 × MP-12-17 and DPC-15 × MP-34-17, these hybrids were found promising for high seed yield in arid regions of Rajasthan.

Inheritance, heterosis and combining ability analysis in line × tester crosses of cotton

Abstract. The aim of this research was to study heterosis, combining ability and genetic control of most important traits in line × tester crosses. It was found that the non-additive variance (σ2D) was larger than the additive variance (σ2A) for productivity per plant and fiber length revealing the greater importance of non-additive gene action in the inheritance of both traits and the selection of desirable forms should be conducted in the later hybrid generations. Non-additive genetic variance was also more important for boll weight, whereas additive gene action was of greater importance for lint percentage and the selection for this trait can be effective in early segregated generations. Line 266 was identified as a good general combiner for productivity per plant and fiber length, line 346 for lint percentage and fiber length. The Turkish cultivar Nazili 954 can be used in crosses to improve productivity, while the Spanish cultivar FR-H-1001 can be used to increase lint percentage and fiber length. The hybrids 191 × Nazili 954 and 266 × FR-H-1001 exhibited the highest productivity per plant with high SCA effects and the highest heterosis of 30.7-31.7%. The highest lint percentage of 42.1-42.3% was achieved in hybrids from the crosses Nazili 954 × 266 and 346 × FR-H-1001 showing significant positive heterosis of 2.4 - 9.0%. Hybrids from the crosses FR-H-1001 × 266 and 346 × FR-H-1001 had the longest fiber and exhibited heterosis of 8.4% and 5.7%, respectively. The cross combination 346 × FR-H-1001 was very promising for lint percentage and fiber length showing high mean levels for both traits with high SCA effects and positive heterosis.

Genetic divergence and hybrid potential for yield and fiber quality in cotton (Gossypium hirsutum. L)

ABSTRACT Fiber trait is multigenic and each parent of the population carrying different genes aid in arriving at varied blend of association between yield and fiber quality traits. Eleven parental lines were crossed in half-diallel fashion to arrive at 55 hybrid combinations, which were evaluated under seven environments. The results manifested highly significant differences among the traits studied, indicating wide range of genetic diversity in the parental genotypes. Combining ability studies revealed parental genotypes SCS-PL-01, SCS-PL-04 as best general combiners for seed cotton yield; SCS-PL-04, SCS-PL-12, SCS-PL-51, SCS-PL-59 for fiber length; SCS-PL-51 for fiber strength and SCS-PL-02 for micronaire value. Genetic diversity of parental genotypes estimated using microsatellites was compared with SCA effects to understand the role of genetic distance (GD) in realizing the heterosis. Comparative characterization of parental genotypes indicated efficiency of capillary gel electrophoresis over metaphor agarose gel electrophoresis and could identify 55 unique bands. The study indicated predicting heterosis using GD estimates is competent when markers linked to the QTLs are used. Also, marker-assisted parental selection in combining ability studies would be a better approach in realizing potential crosses with high yield and fiber quality traits.

Line x Tester Analysis of Combing Ability for Seed Yield and Its Contributing Traits in Soybean [Glycine max (L.) Merrill

Hybridization in Line x Tester mating design was conducted with seven lines and three diverse testers in soybean to understand the nature of gene action, combining ability of the parents (gca) and to assess the potential for the exploitation of heterosis (sca) in hybrids. Data on eleven quantitative characters viz., days to 50% flowering, plant height (cm), number of branches per plant, number of pods per plant, number of seeds per pod, pod length (cm), 100-seed weight (g), seed yield per plant (g), biological yield per plant (g) and harvest index (%) were collected on 21 hybrids and their 10 parents. The ratio of GCA variance to SCA variance is less than unity indicated that non additive genetic effects were predominant for control of most of the seed yield and its attributing characters. Among the lines, AUKS 238, RKS 18, RVS 2011-10 were found high gca effects which are use as general combiner parents for enhancing yield potential by assembling the favourable genes and crosses with sca effects such as AUKS 224 x JS 20-98 and RVS 2011-10 x NRC 150 were found to be superior for seed yield and yield components. These crosses may be utilized for heterosis breeding as well as for isolating the superior recombinants in advance generation for seed yield.

Identification of Best General and Specific Combiners for Soybean Improvement

The present study on general combining ability effects and specific combining ability effects involves 15 parents viz., lines RKS 18, RKS 113, AUKS 199, AUKS 200, AUKS 212, RVSM 2011-35, JS 20-98, AUKS 202, AUKS 208, AUKS 218, JS 21-72, NRC 165 and tester JS 20-34, NRC 138, SL 958 with their 36 F1 hybrid through Line x Tester mating system. The present investigation was undertaken using Randomized Block Design with three replications. The combining ability effects were estimated for thirteen characters viz., days to 50% flowering, days to maturity, plant height, number of branches per plant, number of pods per plant, pod length, number of seeds per pod, 100-Seed weight, seed yield per plant, biological yield per plant, harvest index, protein content and oil content. The result showed that gca effects of parents and sca effects of hybrids were significant differed. Among the parents, AUKS 212 was found to be good general combiner based on the per se performance and gca effects for seed yield and other contributing traits and four hybrids AUKS 113 x SL 958, RVSM 2011-35 x NRC 138, AUKS 199 x JS 20-34 and NRC 165 x JS 20-34 were superior high sca effects for seed yield and yield contributing traits. These crosses can be utilized in future breeding programmes and exploitation of better segregants through pedigree method or single seed descent method in advance generations for improvement of yield and yield attributes coupled with quality traits sound soybean genotypes.

Estimation of Heterosis and Combining Ability in Barley (Hordeum vulgare L.) under Normal and Limited Moisture Condition of Rajasthan

Barley is arguably the widely adapted cereal crop with drought, cold and salt tolerance. Its grain is used as feed, food and for malting purpose while the straw provides an important source of roughage for animal, particularly in the dry areas. The estimates of heterosis and inbreeding depression jointly provide information about the type of gene action involved in the expression of several quantitative characteristics. Combining ability analysis is required for this method to identify the desirable parents for a hybridization program. The cross DWRUB 64 × RD 2508 in E1 and DWRB 137 × RD 2052 in E2 exhibited desirable heterosis for grain yield per plant and its attributing traits. On the basis of per se performance and GCA effects, the parents RD 2508, RD 2052 and PL 419 in both the generations and environments identified as good general combiners for grain yield per plant and some other associated characters. On the basis of per se performance and SCA effects, the crosses BH 946 × PL 419 and RD 103 × RD 2508 in F1 of E1, RD 2592 × PL 419 and DWRUB 64 × RD 2508 in F1 of E2, RD 2592 × PL 419 and DWRB 137 × RD 2052 in F2 of E2 were identified as good specific cross combinations for grain yield per plant and some associated traits.

Optimization the selection of lint percentage and fiber length in cotton based on the combining effects of parental forms

Forty F1 crosses obtained from 5 × 8 line by tester mating design methodology were studied. The varieties Chirpan-539, Sirius, Darmi (Bulgarian selection), Nazili 954 (Turkish) and FR-H-1002 (Spanish) were used as female parents, selection lines 449, 489, 639, 535, 550, 572, 578 and 678 were used as male parents. The aim of the study was to identify the best F1 crosses for improving lint percentage and fiber length in new cotton varieties, by applying a new approach to select parents with the highest possible general combining ability (GCA) for both traits. Crosses and their parents were sown in one row, randomized in three replications. The highest values of the GCA effects of the two parental forms for each trait were taken as “ideal” and the Euclidean distances between them and the GCA effects of the two parents for each F1 cross were calculated. Combining ability analysis of variance showed that females and males differed in general and specific combining abilities. The cultivars Chirpan-539 and Nazili-954 from the females, and lines 550 (Tiara variety) and 578, from the males, appeared to be very good general combiners for lint percentage. The cultivar FR-H-1002 and Darmi variety, from the females, and lines 449, 572, and 578, from the males, appeared to be very good general combiners for fiber length. Some crosses showed high positive SCA effects and heterosis for both traits. Cross combinations FR-H-1002 × 578, Darmi × 578 and Nazili 954 × 578 had the highest possible GCA for both studied traits and are most valuable for selection programs. A total of seven crosses with short Euclidean distances to the “ideal” population in which desirable segregates are expected to occur were selected.

Combining Ability and Heterosis Analysis in Maize: Insights from Line × Tester Hybridization

Fifty hybrids were obtained by crossing twenty five lines with two testers and were evaluated to study heterosis and combining ability for kernel yield per plant and its components traits. The experiment was laid out in simple lattice design with two replications during kharif 2019 at Agricultural Research Station, Peddapuram, East Godavari District, Andhra Pradesh. Heterosis studies revealed that twelve out of fifty crosses exhibited significant positive heterosis over the mid-parent, five crosses showed significant positive heterosis over the better parent and one cross exhibited significant positive heterosis over the standard check, DHM117, for kernel yield per plant. The cross PDM1732 × BML6 recorded significant heterosis over mid parent, better parent and standard check in desirable direction for kernel yield per plant. Out of the 25 lines evaluated in the present investigation, the line PDM1733 for protein content and kernel yield per plant was found to be good general combiner in desirable direction and can be utilized as parent for production of good hybrids by crossing with other divergent lines and can also be employed in the development of synthetic varieties. None of the fifty crosses recorded significant sca effect for kernel yield per plant.

Combining Ability and Gene Action for Grain Yield and Attributing Traits in Maize (Zea mays L.) Subjected to Drought Stress

Background: Maize production is subdued by many impediments that cause yield minimization. Among various biotic and abiotic stress factors, one significant cause of yield reduction in maize is drought stress. Methods: A set of 15 inbreds which were crossed with 3 narrow base testers in line × tester mating design, and resulting 45 F1s along with the parent inbreds and 3 commercial checks were then, in RCBD, subjected to drought stressed and well-watered conditions to assess their genetic worth during spring 2021. Result: The ANOVA unraveled significant mean sum of squares due to lines, testers and line × tester in pooled analysis for all the ten traits. The inbred EI-2188-2 followed by EI-2448 and EI-03-3 contained fair per se performance and significant high GCA effects over the environments for grain yield/plant, proline content and cob length whereas the cross EI-2448-1 × EI-2156 was found most promising hybrid with significant and high SCA effects across the environments regarding grain yield/plant, proline content and cob girth. Prevalence of non-additive type of genetic variance in governing most of the traits suggests adoption of heterosis breeding will be rewarding for improving yield and drought tolerance. Heterotic pooling of the highlighted inbreds and utilization of the superlative hybrids in further breeding programmes for drought tolerance is proposed.

Assessment of Combining Ability for Yield and Associated Traits in Sunflower (Helianthus annuus L.)

The study was carried out at the Oilseeds Research Station, Latur. During kharif 2023, crosses were produced and during Rabi 2023–24, evaluation was conducted to assess the combining ability for seed yield and component traits in parents and hybrids in sunflower. In this study, 48 F1 hybrids were produced through Line x Tester mating design during Kharif 2023 using six CMS lines (DSF-2 A, CMS 148A, CMS 47A, CMS 597A, CMS 103A, CMS 112A) and eight testers (RHA-1055, EC-601951-1, EC-601924, R-274, LTRR-341, AKSF-15R, BK-R-1, R-856). These hybrids were assessed using a Randomized Block Design with two replications at the Oilseeds Research Station in Latur during Rabi 2023–24, together with their 14 parent lines and two commercial checks (LSFH-171 and KBSH-44). The observations were recorded on five randomly selected plants and the average value of these data was calculated for ten quantitative attributes. The analysis of combining ability (GCA and SCA) effect was came out by using the Line x Tester analysis method suggested by Kempthorne [1]. The significance of GCA and SCA effects was determined at the 0.05 and 0.01 level using the t-test [2]. All characteristics had substantial significant variance due to line x tester effects. The existence of non-additive gene action for days to maturity, head diameter, seed filling, 100 seed weight and seed yield per plant were recorded. The per cent contribution of testers towards total variance was greater than lines for all the characters except plant height. Among the parents, two lines CMS-597 A and CMS-47 A and four testers RHA-1055, EC-601924, R-274 and AKSF-15R were found to be superior general combiners for seed yield per plant and most of the yield contributing traits. On the basis of mean performance, SCA effects of crosses and GCA effects of the parents, the crosses viz., CMS-112 A x AKSF-15R, CMS-148 A x RHA-1055, CMS-597 A x R-856, CMS-47 A x R-274, CMS-597 A x LTRR-341, CMS-112 A x EC-601924 and CMS-597 A x EC-601951-1 recorded high SCA effect with low x high, low x high and high x high GCA status of parents for seed yield per plant.

Selection of parental pairs when obtaining F1 hybrids of white cabbage with resistance to the tip burn of the inner leaves

Relevance. During the formation of cabbage heads, under certain conditions, white cabbage is damaged by a burn of the top of the inner leaves of the head, which abroad received the stable name “tip burn”. This disorder is interpreted as a physiological or non-infectious disease, the cause of which is a violation of calcium intake. The disease manifests itself inside the cabbage head, resulting from the interaction of environmental stress factors and the predisposed genotype. The most effective way to combat this disorder is to develop highly tolerant hybrids. This is especially true for the south of Russia, where the stress load on plants is maximum.Purpose of the study – to develop a principle for selecting parental pairs for developing hybrids that are resistant to the tip burn of the inner leaves of a cabbage head, and to identify promising hybrids. Materials and methods. In 2021-2022 in FSBSI "Federal Scientific Rice Centre", in the department of vegetable growing, 45 hybrid combinations obtained on the basis of 10 inbred lines were assessed under field conditions for the trait "burn damage to the inner leaves of the cabbage head." An analysis of the combining ability of lines according to Griffin, and an analysis of the inheritance of the trait according to Heiman were carried out. In 2023, a competitive test of promising hybrids was carried out.Results. In both years of research, 5 lines had negatively stable TCA for burn damage: Ten4270, Yas25p, Bs1f, Agr 82, 270Hn111. SCA of lines is more subject to changes from year to year. The effects of SCA in hybrids due to dominance, epistasis and overdominance in individual combinations significantly influence the manifestation of the trait in the direction of decrease or increase. The principle of selecting parental pairs to develop stable hybrids is based on a combination of lines with a negative SCA value; in some cases, it is permissible to include one line with an average SCA and low SCA. Analysis of genetic parameters according to Heiman confirms the prevalence of non-additive inheritance of the lesion; in unstable forms, the disorder is controlled by dominant polygenes and is highly heritable.

Study on gene action, combining ability and heterosis for different traits in Indian mustard (Brassica juncea L. Cxern & Coss)

Abstract Combining ability and heterosis was investigated in mustard hybrids obtained from 7 × 7 half diallel cross. Twenty one F1s along with seven parents were evaluated in Randomized Complete Block Design. The combined analysis of variance revealed very significant differences among the parents for all morphological variables with the exception of secondary branches and siliqua length, indicating wide diversity among the parental material used in the present study. Significant GCA and SCA variance indicated additive and non-additive gene action across all the characters. The SCA variance components were larger than the GCA variance components for most traits indicating the prevalence of non-additive gene effects. Jawahar mustard × PM-30, showed a significantly positive SCA and better parent heterosis for seed yield per plant whereas five hybrids (Kranti × PM-30, Gujarat Mustard-3 × Pusa Mahak, Jawahar Mustard × PM-30, Jawahar Mustard × Pusa Mahak and PM-30 × Pusa Mahak) exhibited significant positive SCA effect for number of siliqua/ plant. Jawahar Mustard × PM-30, Varuna×Jawahar Mustard, Gujarat Mustard-3 × PM-30, exhibited highly significant heterosis over the mid-parent. Keywords: Brassica juncea, GCA, SCA, gene action, Heterosis

Combining ability and gene action analysis in okra (Abelmoschus esculentus L. Moench)

The present research was conducted in Okra to study combining ability and gene action in a set of 28 F1s developed by crossing seven lines and four testers. The experiment was laid out in a Randomized Block Design with three replications and observations were recorded on 12 traits viz. days to 50% flowering, days to first picking, number of internodes, number of branches plant-1, fruit length at maturity and harvest, number of fruits plant-1, number of seeds fruit-1, seed index, fruit weight, yield per plant and plant height. The results revealed that two lines viz., VRO-4 and Sel-2 were excellent general combiners for most of the traits in both positive and negative direction as per desirable traits. Cross VRO-6 x Varsha Uphar recorded highly significant SCA effects for eight traits and GAO-5 x GJO-3 for yield trait. Variance due to GCA was less than SCA, and the GCA/SCA ratio was less than unity indicating preponderance of non-additive gene action for all the traits. This suggested the feasibility of exploitation of heterosis. Keywords: Gene action, Fruit yield, Okra, GCA and SCA

Exploitation of heterosis in chilli using genetic male sterile lines for red fruit yield with special reference to high rainfall conditions

High-quality red/dry chilli for spice, pharmaceutical and medicinal purposes is a major goal in chilli breeding. The male sterile lines have greater potential for the exploitation of heterosis in chilli to achieve this objective. Genetic male sterile lines with special traits like destalking and ability to withstand high rainfall were involved in heterosis breeding to identify hybrids for commercial and industrial purposes. Forty F1 hybrids were developed by crossing 4 diverse GMS lines with 10 testers using Line × Tester mating design to estimate heterosis, combing ability and gene action. The experiment involving 14 parents and 40 F1s, along with standard variety ‘CH-27’ was laid out in α-lattice square design in three replications during summer 2020 and 2021. The GMS lines MS 9-2 and MS 26-1 along with testers DPCh 10, VVG, DPCh 40 and Him Palam Mirch-2 showed significant GCA for marketable red/dry fruit yield and majority of their component traits. Ten F1 hybrids were identified with superiority for fruit yield based on mean performance, significant heterosis and SCA effects, providing an opportunity to utilize them in value-added products and dried spice purposes viz., MS 9-2 × HPM-2, MS 11-2 × DPCh 40, MS 9-2 × DPCh 40 and MS 9-2 × DPCh 101 with erect fruiting habit and that of MS 9-2 × DPCh 10, MS 26-1 × DPCh 10, MS 9-2 × PBC 535, MS 26-1 × VVG, MS 29-2 × DPCh 10 and MS 26-1 × DPCh 22- C with pendent fruits. The non-additive gene action was predominant in the expression of fruit yield, total red fruits/plant, oleoresin and capsanthin. A significant positive correlation among SCA, economic heterosis and per se performance is an indicative to identify superior hybrids. Multi-location testing of these hybrids shall pave way to exploit them commercially by making them available to the farmers.

Studies on combining ability of half diallel derived rice hybrids generated using landraces x advanced breeding lines of North East India

North East (NE) India, the centre of origin of rice is blessed with landraces like Kala Joha, Chakhao Poireiton (CP) and Mynri, Jwain from Assam, Manipur, and Meghalaya respectively. NE India is a hotspot for rice blast disease and it can cause a loss in grain yield from 30-100%. Rice breeding in NE India should focus on developing rice varieties/ hybrids utilizing the local landraces and their diverse gene pool. Hence, six landraces and four advanced breeding lines were crossed in half diallel fashion and the F1s were evaluated for ten agro-morphological and two rice blast disease related traits. Half-diallel analysis using Griffing's numerical method was adopted to obtain combining ability effects. Significantly high general combining ability (GCA) effects for grain yield per plant (GYPP) were observed in Mynri (2.7**) and CAUS107 (2*), whereas it was negative for CP (-2.2**). Crosses between landraces and advanced breeding lines gave high GYPP like, CAUS103 x Kasalath (24.3±4g) and CAUS107 x Kala Joha (21.4±1.5g), they also showed higher SCA effects of 10.3 and 6.4 respectively. Lowest disease affected spikelets per panicle (DSPP) was observed in Mynri x CAUS126 (0.2±0.03) and lowest leaf blast (LB) scores (1) were recorded in Jwain x CAUS107, Blm x CAUS107 and Blm x CAUS103.

Assessment of Combining Ability and Gene Action in F1 Generation for Quantitative and Qualitative Traits of Pigeonpea [Cajanus cajan (L). Millsp.

To estimate combining ability and nature of gene action, twenty four pigeonpea crosses were developed from ten parents in Line × Tester fashion during Kharif 2022-23 and were evaluated in Randomized Block Design with three replications during Kharif 2023-24. The estimates of σ2gca were lower than the corresponding σ2sca for all the twelve characters studied indicating the predominance of non-additive gene action. Among the parents, the line GJP 1915 was found to be good general combiner for seed yield per plant and its yield contributing characters like plant height, number of primary branches per plant and pod length. The tester GJP 1820 was also good general combiner for seed yield per plant and its component traits like plant height, number of primary branches per plant, number of secondary branches per plant, number of pods per plant and 100-seed weight. The cross BDN 2013-41 × UPAS 120 had registered the highest sca effect for seed yield per plant. The sca effect in this cross combination was also accompanied by significant and desirable standard heterosis and high per se performance for days to maturity, reproductive phase duration, number of secondary branches per plant, number of pods per plant and number of seeds per pod and significant and desirable heterobeltiosis for days to maturity, reproductive phase duration, number of primary branches per plant, number of pods per plant and 100-seed weight. The cross GJP 1915 × BLACKTUR had registered significant and positive sca effect for seed yield per plant which was also accompanied by highest per se performance for pod length. These cross combinations can be potentially utilized in future breeding programmes for exploitation of hybrid vigour.

Integrating Antixenosis Against Helicoverpa armigera (Lepidoptera: Noctuidae) and Micronutrition in Kabuli Chickpea (Cicer arietinum L.) Genotypes

ABSTRACTThe leguminous chickpea is a good source of protein, but its yield potential is frequently constrained by biotic stresses, primarily Helicoverpa armigera, a major havoc for cultivation of the crop. To develop host plant resistance for minimizing the losses due to the pod borer, five kabuli parents with desired traits for pod borer tolerance were crossed in diallel mating design to produce 10 crosses which were analysed for traits related to pod borer and nutrition. Based on correlation studies, trichome density was found positively correlated with phenol content, but both the traits were negatively associated with number of damaged seeds. Therefore, the tolerant genotypes were identified on the basis of phenol content, trichome density, number of damaged seeds and field rating. Among parents ICC 12197 was found superior in terms of yield and borer tolerance features with an intermediate pest resistance susceptible rating in addition to higher Fe content. However, significant sca effects for higher phenol content and seed yield in ICC 11764 × ICC 14190 were recorded with reduced number of damaged seeds in addition to higher Fe and Zn content. It was observed that the specific combination involved good and poor combiners for each trait. The same cross also showed significant standard heterosis in desirable direction for phenol content, trichome density, number of damaged seeds and seed yield. Additionally, the ratio of σ2 GCA to σ2 SCA revealed nonadditive gene action in controlling the expression of phenol content, trichome density, number of damaged seeds and Fe and Zn content. Thus, breeder may focus efforts on desirable cross utilizing selection in further segregating generations for higher phenol content, trichome density and Fe and Zn content in addition to yield‐related traits while lesser number of damaged seeds per plant to concentrate for development of pod borer resilient high yielding kabuli genotypes to combat micronutrient deficiency.

General and Specific Combining Ability for Fruit Yield Using Diallel Population of Ridge Gourd (Luffa acutangula (Roxb.) L.)

An experiment was conducted using 7 x 7 diallel population of ridge gourd to study the general and specific combining ability (GCA and SCA) of parents and their hybrids for 17 yield traits in a randomized complete block design with three replications. Data on 17 characters were subjected to analysis of GCA and SCA variances and their effects. The GCA and SCA variance were found highly significant for all the characters except days to first female flowering. Low magnitude of σ²g/σ²s ratio was observed for all the traits other than days to first male flowering, days to first female flowering, fruit length (cm), fruit width (mm), individual fruit weight (g). On the other hand, σ²g/σ²s ratio was more than 1.0 for days to first male flowering, days to first female flowering, fruit length (cm), fruit width (mm) and individual fruit weight (g). The general combining effects (GCA) of the parents revealed that none of the parent was found to be good general combiner for all the characters. However, in the present investigation, parent P3 was observed to be one of the best general combiner as it has shown significant GCA effects in desirable direction for number of fruits per plant and fruit yield per plant. It also observed significant GCA effects for parameters related to earliness viz., days to first male flowering, node number of first female flower and days to first harvest. Similarly, parent P5 was also good general combiners for fruit length, fruit width and individual weight of fruit, parent P6 and P7 were also good general combiners for fruit length, individual weight of fruit except fruit width. The parent P2 and P4 were also good general combiners for number of fruits per plant. The estimate of SCA effects revealed that none of the crosses was consistently superior for all the characters. The highest yielding hybrid (P3 x P4) had registered the highest SCA effect for fruit yield per plant. Similarly, the cross combinations P6 x P7, P3 x P6, P3 x P7, P1 x P5, P2 x P6, P4 x P5 were observed as good specific combinations for fruit yield per plant. The hybrid P2 x P6 was good specific combiner for days to first male flowering, hybrid P3 x P4 for sex ratio followed by P4 x P5 and P5 x P7. Hybrid P1 x P4, P6 x P7, P3 x P6 and P2 x P4 were found as good specific combinations for fruit length, P4 x P6 and P3 x P4 for fruit width. The hybrids P3 x P6, P6 x P7, P3 x P4, P2 x P4 and P1 x P5 were observed as good specific combinations for individual fruit weight.

Combining Ability and Heterosis for Yield and Yield Attributing Traits in Bitter Gourd

A study was conducted during Rabi 2022 and Kharif 2023 at the Department of Horticulture, University of Agricultural Sciences, Bangalore to develop 49 F1 hybrids through the utilization of line × tester mating design. The parents and developed hybrids along with standard check (Pusa Hybrid 6) were evaluated in Randomized Complete Block Design) and Alpha lattice design, respectively, for yield and yield attributing traits. The combining ability analysis revealed that among 14 parents, Pusa Rasdar, Pusa Do Mausami, Pusa Vishesh, Hirkani and Pant Karela 4 were identified as best general combiners for most of the studied yield and yield attributing traits. The estimates of heterosis revealed that the hybrids, Konkan Karali × Pant Karela 4 (45.45%), Konkan Tara × Pusa Do Mausami (23.48%), Pusa Rasdar × Phule Green Gold (126.87%) and Hirkani × Pusa Do Mausami (46.20%) were top performing hybrids over standard check for fruit length, diameter, average weight and number of fruits per vine, respectively. Similarly, Pusa Rasdar × Pant Karela 4 (127.06%), Priya × Pusa Do Mausami (101.05%), Punjab 14 × Pusa Do Mausami (100.53%) and Pusa Rasdar × Pant Karela 3 (97.61%) were top performing hybrids over standard check for yield per vine. These hybrids also recorded highest significant sca effects hence, considered as good specific combiners.