Mungbean (Vigna radiata L. Wilczek) is an important pulse crop in Asia due to its high nutritional value, rapid growth and ability to grow in a variety of environments. Despite its importance, mungbean production remains low due to a tiny genetic base and a lack of suitable parental lines for breeding operations. Using the line × tester mating design, this study investigated the combining ability and gene action for yield-related traits in mungbean. In summer 2021, at the Seed Breeding Farm, JNKVV, Jabalpur, Madhya Pradesh, evaluated forty crossings derived from ten lines and four testers. The tests were conducted using a randomised block design with 3 replications. The analysis of variance revealed significant variations between genotypes for all the traits, indicating a high level of genetic variation. For most features, the variance in specialised combining ability (SCA) exceeded the variance in general combining ability (GCA). This shows that non-additive gene activity has a significant influence. TJM 196, HUM 1, TMB 37, TJM 136, Kanika and Virat were identified as superior general combiners, while crosses TMB 37 × Virat, PDM 11 × Virat, TJM 3 × Kanika, SL 668 × Kanika, TJM 136 × Shikha, TJM 196 × Shikha, TJM 196 × Kanika and HUM 1 × Shikha exhibited high SCA effects for yield and its component traits. The predominance of non-additive gene action suggests that heterosis breeding or hybridisation, followed by selection in segregating generations, has the potential to greatly boost mungbean yields. These findings provide important guidance for the selection of promising parental lines and cross combinations in future mungbean enhancement initiatives.

Brassica juncea L. (Indian mustard) is a major rabi oilseed crop with a pivotal role in India’s edible oil economy, necessitating continuous genetic improvement for higher yield and quality traits. Therefore, the present study employs Line × Tester analysis to evaluate combining ability and gene action, aiming to identify superior parents and cross combinations for the development of high-yielding and resilient mustard cultivars. The study was conducted during the rabi season of 2025–26 at the Agricultural Research Farm of the Department of Genetics and Plant Breeding, Lovely Professional University, Phagwara, Punjab, India. A total of 40 genotypes comprising 12 parents (9 lines and 3 testers), 27 F1 hybrids, and one check were evaluated in a randomized block design. Analysis of variance revealed significant differences among genotypes, parents, and crosses for all traits, revealing substantial genetic variability and heterotic potential. Combining ability analysis revealed that both general combining ability (GCA) and specific combining ability (SCA) variances were significant for most traits, suggesting the involvement of both additive and non-additive gene actions. Additive gene action was predominated for traits such as days to 50% flowering, plant height, and siliqua-related characters, while non-additive gene action was more important for biological yield, seed yield, and harvest index. Among the parents, JD 6 and 45 S 46 emerged as superior general combiners among lines, while RK GOLD was identified as the best tester for yield and its components. Crosses such as HYOLA ADV 40 × RK GOLD, 45 S 46 × RK GOLD, JD 6 × RK GOLD, and NRCH-B1 × GSC 07 exhibited high SCA effects and were identified as promising hybrids. High heritability and predictability ratios for several traits indicated the effectiveness of selection, whereas traits governed by non-additive effects can be exploited through heterosis breeding.

A systematic evaluation of maize hybrid performance and combining ability was conducted to enhance resistance to maize lethal necrosis (MLN), drought tolerance, and grain yield (GY) in eastern and southern Africa. Thirty-eight early- to intermediate-maturing maize inbred lines, including MLN-tolerant and high-yielding genotypes with drought tolerance and resistance to multiple foliar and insect pests, were crossed with 29 single-cross testers to generate 437 testcross hybrids. These hybrids were evaluated under managed MLN inoculation, drought stress, and optimum conditions across multiple locations. Continuous variation in GY, disease severity, and agronomic traits confirmed quantitative inheritance, with strong positive correlations between GY and ears per plant and negative correlations between MLN severity and yield. Variance analyses revealed highly significant genotypic and genotype × environment interactions, with additive effects predominating across environments (Baker's ratios 0.85-0.99; heritability 0.69-0.88), supporting effective selection based on general combining ability (GCA). Superior MLN-tolerant hybrids, such as (CKLMARSI0037/CKLTI0139)//CKDHL120312, achieved up to 5.75 t ha ⁻ ¹ under MLN, exceeding commercial checks by over fivefold. Under optimum and drought conditions, top hybrids maintained high yield, foliar disease resistance, short anthesis-silking intervals, and delayed senescence. Specific combining ability (SCA) effects highlighted stress-specific non-additive interactions, particularly under drought, underscoring the need for targeted parental selection. GCA analyses identified across environment and environment-specific favorable parents, including CKDHL120312, CKDHL140910, CKLMARSI0037/CKLTI0139, and CML322/CML543, while GGE biplots confirmed tester discrimination and representativeness. These findings demonstrate that integrating MLN resistance, drought tolerance, and high yield is achievable without compromising other agronomic performance. The study provides a robust framework for selecting elite parents and testers, exploiting additive and non-additive genetic effects, and developing resilient, high-performing maize hybrids for sub-Saharan Africa.

Snake gourd (Trichosanthes cucumerina var. anguina) is an annual, day neutral climbing type herbaceous vegetable crop belonging to the Cucurbitaceae family with chromosome number of 2n = 2x = 22. Developing high yielding and well-adapted snake gourd cultivars is essential to meet the growing demands of a rising global population. This study was carried out using a line × tester mating design to assess the combining ability and genetic potential of diverse snake gourd lines for key morphological characteristics. The objective was to identify superior parental combinations and promising F1 hybrids with high specific combining ability (SCA) for further breeding programmes. A set of seven diverse snake gourd lines were crossed with two well-adapted testers. The resulting F1 hybrids, along with their parental lines, were evaluated for morphological traits, including growth parameters, flowering parameters, fruit parameters and biochemical parameters. Data analysis revealed significant differences among genotypes for all evaluated traits. General combining ability (GCA) and specific combining ability (SCA) effects were estimated and promising lines and hybrid combinations exhibiting high GCA and SCA for desirable traits were identified. The results of this study provide useful information on the genetic control of morphological traits in snake gourd and confirm that the line × tester analysis is an effective tool for identifying superior parental combinations for breeding programmes aimed at developing improved snake gourd cultivars with enhanced agronomic performance.

The development of early-maturing and high-yielding cotton varieties is a strategic priority in regions with limited growing seasons and increasing climate variability. This study investigates the genetic basis of earliness and evaluates the combining ability of selected cotton lines and cultivars using the Line x Tester hybridisation method. A set of lines (L-158, L-75, L-1703, L-1858, L-257) and testers (L-302, L-597, and the standard cultivar S-6530) were crossed to produce F1 hybrids and their F2 and F3 populations. Field trials were conducted under arid continental conditions in Uzbekistan using standard agronomic practices. The results revealed significant variation in the length of the vegetative period among parental lines and hybrids. General and specific combining ability (gca and sca) analyses showed that lines L-158 and L-1858 had the highest negative gca effects for the vegetative period, indicating their potential for breeding early-maturing genotypes. F1 hybrids displayed predominance and overdominance effects toward early-maturing original lines, while F2 and F3 generations exhibited wider-than-parental variation, leading to the identification of ultra-early recombinant lines. Several new breeding lines, including L-215, L-218, and L-178, demonstrated superior performance in earliness and agronomic traits. These findings provide a valuable framework for optimising selection strategies in cotton breeding programs and highlight the relevance of hybridisation for developing climate-resilient, early-maturing cultivars.

Rice (Oryza sativa L.) production is increasingly threatened by abiotic stresses, notably salinity and phosphorus (P) deficiency which constrain crop performance in vulnerable agro-ecosystems. The current study was designed to assess the combining ability of four Saltol 1 introgressed backcross inbred lines and two Pup1 introgressed testers through a Line × Tester mating design with the objective of identifying the nature of gene action of yield traits and superior parental genotypes and cross combinations for the genetic enhancement under stress-prone conditions. Eight F₁ hybrids along with six parental lines were assessed using a randomized complete block design with two replications during Rabi 2023-24. Analysis of variance revealed considerable genetic variability across all the traits studied. Combining ability analysis demonstrated that BIL 33, D5-1-3-2-1 and C16-1-2-8 were superior general combiners, particularly for grain yield and associated component traits while cross combinations such as BIL 33 × C16-1-2-8 and BIL 1102 × D5-1-3-2-1 exhibited significant specific combining ability effects reflecting the yield potential of hybrids. Variance component analysis further indicated that traits such as days to 50% flowering, plant height and grain yield were chiefly administered by additive gene action whereas traits viz., flag leaf length, spikelet fertility and grain number were influenced by non-additive action. These findings provide valuable insights into the genetic construction of key agronomic traits and offer a strong basis for breeding stress-resilient, high-yielding rice hybrids.

This research was conducted to determine the parents and hybrids with superior general and specific combining ability in 20 F1 hybrids including 5 female lines and 4 male testers. In study, 5 advanced lines were used as female parents and 4 registered varieties were used as male parents. The nine parents were crossed to procedure 20 F1 hybrids according to line x tester mating design during 2021-2022 growing season. The 20 crosses and 9 parents were evaluated in randomized complete block design with three replications during 2022-2023 growing season. According to results, it was determined that BC10 and BC22 lines in seed yield, Awassa tester in pod number per plant and seed yield had given the highest general combining ability. However, BC10 x Saryan, BC13 x Awassa and BC21 x Awassa hybrid combinations showed the highest specific combining ability in seed yield. It was stated that both additive and non-additive gene effects were efficacious for yield and some important yield components in the hybrid population studied. The promising hybrid combinations BC10 x Saryan (48.72**), BC21 x Awassa (126.74**) and BC13 x Awassa (127.83**) possessed positive significant heterosis for seed yield.

Background: Rapeseed (Brassica napus L.) remains a vital oilseed crop globally, yet local production in many regions, including Pakistan, falls short of rising edible oil demand. Hybrid breeding offers an effective pathway to improve yield and related agronomic traits, but its success relies on understanding the genetic contributions of parental lines. Combining ability and heterosis analyses provide essential insights into additive and non-additive genetic effects, enabling breeders to identify superior parents and productive cross combinations. Objective: To evaluate the general combining ability (GCA), specific combining ability (SCA), and heterosis of Brassica napus genotypes for plant height, primary and secondary branches, 1000-seed weight, and seed yield per plant using a structured line × tester approach. Methods: Five female lines and three male testers were crossed during the 2022–23 season to generate fifteen F₁ hybrids. These hybrids, along with their eight parents, were evaluated the following season under a randomized complete block design with three replications. Data from five quantitative traits were subjected to analysis of variance, followed by estimation of GCA and SCA based on established line × tester procedures. Mid-parent and better-parent heterosis were calculated to assess hybrid vigor. Results: Highly significant differences were observed among treatments for all traits, confirming substantial genetic variability. Parent vs. cross differences were significant for all traits except plant height. The line × tester interaction was significant for all traits. Additive genetic effects predominated for plant height, branching traits, and 1000-seed weight, whereas seed yield was more strongly influenced by non-additive effects. Several hybrids displayed strong positive SCA and expressed significant positive heterosis over the better parent for seed yield, indicating strong hybrid potential. Conclusion: The study identified valuable parental lines and promising hybrid combinations suitable for future rapeseed improvement. The results highlight the effectiveness of line × tester analysis in distinguishing superior combiners and support the development of high-yielding Brassica napus hybrids.

The present study was undertaken to assess heterosis for seed cotton yield, yield-contributing traits, fibre quality and biochemical characters in upland cotton (Gossypium hirsutum L.) using a Line × Tester design. Four lines, seven testers and their twenty-eight F₁ hybrids, along with the standard check GN.Cot.Hy-18, were evaluated in a Randomized Block Design with three replications during kharif 2024. Analysis of variance revealed significant genetic variability for all traits except seed index. Among the hybrids, 76-IH-20 × GISV-382 exhibited significant heterobeltiosis for seed cotton yield, while BC 68-2 × GISV-399 and 76-IH-20 × GISV-382 recorded the highest significant standard heterosis over the check. These hybrids also expressed desirable heterosis for major yield components such as bolls per plant, boll weight and ginning outturn, along with notable heterotic effects for fibre and biochemical traits. The hybrids BC 68-2 × GISV-399, 76-IH-20 × GISV-382, 76-IH-20 × GISV-399 and GSHV-112 × GISV-399 were identified as promising for exploitation of heterosis in cotton breeding programmes.

A line x tester analysis was performed using three lines and eight testers, generating 24 hybrids, to evaluate the combining ability of parents for grain yield, yield-contributing traits, and zinc content in rice. Twelve traits were studied: days to 50% flowering, plant height (cm), panicle length (cm), effective tillers per plant, grains per panicle, length-to-breadth ratio, grain yield per plant (g), straw yield per plant (g), test weight (g), zinc content (ppm), protein content (%), and amylose content (%). The experiment was conducted in a randomized block design (RBD) with three replications at the Main Rice Research Station, Navsari Agricultural University, Navsari, during kharif 2024. The analysis of variance for combining ability indicated that general combining ability (σ²GCA) effects were significant for grains per panicle, while specific combining ability (σ²SCA) effects were significant for all traits except plant height and zinc content. The σ²GCA/σ²SCA ratio was less than one for all traits, suggesting that non-additive genetic variance played a predominant role in their inheritance.

Genetic variability and heritability estimates are essential for identifying promising genotypes and designing effective breeding programs in okra (Abelmoschus esculentus L. Moench). The present study was conducted to evaluate the extent of genetic variability, heritability, genetic advance, and the nature of gene action governing agronomic and nutritional traits using a line × tester mating design. Ten lines and five testers were crossed to generate fifty F₁ hybrids, which were evaluated along with their parents under four environments at the Department of Genetics and Plant Breeding, AKS University, Satna (M.P.). Analysis of variance revealed highly significant differences among parents and crosses for all traits, indicating substantial genetic variability in the experimental material. High genotypic and phenotypic coefficients of variation were observed for fruit yield per plant (12509.48 & 2535.96), total number of fruit per plant (38.48 & 38.95), and Plant height (34.20 & 34.80), suggesting ample scope for selection. High heritability combined with high genetic advance as percent of mean was recorded for Number of Branches per plant (97.69 & 25.10), Internodal length (99.42 &24.00) and Fruit Girth (99.33 & 42.82), implying predominance of additive gene action. Line × tester analysis revealed significant general and specific combining ability effects, indicating the importance of both additive and non-additive gene effects in the inheritance of yield and nutritional components. The study demonstrates the existence of substantial genetic variability and useful heterosis that can be utilized for developing high-yielding and nutrient-rich okra hybrids. Overall, the results provide insights into trait interrelationships and the genetic basis for simultaneous improvement of yield and nutritional quality in okra breeding programs.

The efficiency of the assignment of germplasm lines into heterotic groups is a prerequisite for obtaining useful heterotic patterns among germplasm lines. Therefore, this study was conducted to group lines into heterotic group besides assess the effects of both general and specific abilities. Fifteen white maize parental lines were crossed with two testers, i.e. parental line SK-12 and Single cross 120 at Agricultural Research Station in Sakha, Egypt during 2021 summer season. The resultant 30 crosses were evaluated along with four commercial hybrids in three locations during 2022. The parental inbred lines Sk5001/42, Sk5003/48, Sk5003/53, Sk5004/55 and Sk5004/56 recorded positive GCA effect on grain yield while Sk5001/41, Sk5002/46 and Sk5004/56 exhibited desirable GCA effects for earliness. Five single crosses viz. (Sk5003/53 × Sk12), (Sk5001/42 × Sk12), (Sk5004/55 × Sk12), (Sk5003/48 × Sk12) and (Sk5004/56 × Sk12) and two three way crosses (Sk5001/42 × SC.120) and (Sk5003/53 × SC.120) did not differ significantly against their respective check hybrids (SC 10 and TWC 321) though they outyield their respective checks. These hybrids could be subjected to further multi-location evaluation to assess the yield stability for commercial exploitation. Two groups of parental lines were created based on Heterotic Group Specific and General Combining Ability (HSGCA) method for grain yield trait. These groups might be employed in a breeding program to pick the best parents to make crosses in other combinations.

The study was conducted during kharif (June–September, 2022) and rabi (October–December, 2022–23) at Agriculture Research Station, Madhira, Telangana, India to study on the combining ability analysis in blackgram for yield and its component traits through Line×Tester design. Twenty four crosses derived after crossing six lines and four testers were evaluated in line×tester analysis. Predominance of non-additive gene action was observed for most of the yield components except harvest index, which was under the control of additive gene action. Among the lines TU-94-2, MBG-207 and GBG-1 and testers IC-436638 and ABFBG-23RS were identified as good general combiners for days to 50% flowering, plant height, number of pods plant-1, pod length, number of seeds pod-1 and 100 seed weight. The crosses TBG-104×IC-436638, MBG-1070×LBG-20, TU-94-2×ABFBG-26RD and TU-94-2×LBG-20 have shown significantly favorable specific combining ability effects for seed yield plant-1 as well as yield attributes. Most of the crosses exhibiting high specific combining effects involved high×low combinations indicating additive×dominance, dominance×dominance type of gene interactions. Studies on heterosis indicated that majority of crosses showing high specific combining ability effects also exhibited high heterosis. The cross TBG-104×IC-436638 recorded high estimates of heterosis for seed yield plant-1 and also for number of clusters plant-1, pod length and biological yield plant-1. The superior crosses identified were TBG-104×IC-436638, TU-94-2×ABFBG-26RD and GBG-1×LBG-20 could be exploited for recombination breeding for development of varieties.

Maize (Zea mays L.) is globally recognized as the "queen of cereals" and is essential for food, livestock feed, and industrial raw material. Despite its importance, maize is vulnerable to numerous pathogens, with Turcicum Leaf Blight (TLB), caused by Exserohilum turcicum, posing a major global threat. This disease can result in severe yield losses, documented between 25% and 90% in various regions of India. Exploiting host plant resistance is recognized as the most effective and sustainable strategy for management, necessitating the evaluation of germplasm and identification of resistant genotypes through breeding techniques like line × tester analysis. The present study, conducted in Rabi 2024 at MRU, Hyderabad, utilized 5 lines and 10 testers to generate 50 F₁ crosses. The genotypes were subjected to artificial inoculation using the whorl drop method at 32 DAS to ensure consistent exposure to Exserohilum turcicum. Disease severity was recorded on a standard 1-9 scale at three crucial stages: tasseling, 20 days after tasseling, and maturity, followed by the calculation of the Per cent Disease Index (PDI). Evaluation revealed a marked decline in foliar disease resistance over time. While all 50 F₁ hybrids were classified as resistant (R) at tasseling, only 38% remained resistant by physiological maturity, with others shifting to intermediate or susceptible ratings. The inbred lines JLML-01888 and JLML-94333, along with testers JLSN-34 and JLSN-73, demonstrated the most stable and durable resistance across all stages, suggesting they harbor strong resistance genes or quantitative resistance loci (QTL). This temporal decline in resistance underscores the necessity of multi-stage screening to accurately capture hybrid performance. The identified resistant parental lines are critical germplasm for future breeding efforts focused on incorporating durable, multi-gene resistance to enhance stability.

Exploiting yield heterosis under low soil phosphorus (P) inputs is a possible strategy for enhancing rice productivity and resource use efficiency in the changing climate scenario. In the present study, Line (L) × Tester (T) analysis was conducted with five restorers, three maintainer lines and 15 derived hybrids. The hybrids and parents were evaluated for two wet seasons (Kharif- 2017 and 2019) across the graded levels of applied P (low—P20 kg ha−1; Moderate—P40 kg ha−1; Normal—P60 kgha−1). Pooled analysis across years revealed highly significant variances in the interaction of the General Combining Ability (GCA) of parents and the Specific Combining Ability (SCA) of hybrids with a predominance of non-additive genetic variance. Testers contributed higher variation for the key traits under graded P conditions. Among the parental lines, CRMS32B showed strong GCA effects for single plant yield (SPY) and number of productive tillers per plant (NPTP), while IR79156B was promising for spikelet fertility percentage (SFP). Among testers, ATR305 and TCP795 exhibited significant GCA effects for SPY, SFP and NPTP and early flowering. The Hybrids, H14 (CRMS32A × ATR226) showed the highest SCA effects for NPTP, SPY and SFP, while H10 (IR79156A × TCP795) exhibited significant SCA effect for earliness. Compared to standard check variety Kasalath, the hybrids demonstrated a 120 to 200% heterosis gain across the graded P levels for the key traits. AMMI analysis identified hybrids, H3 (APMS6A × ATR305), H13 (CRMS32A × ATR305) and H11 (CRMS32A × AYT21) as highly stable performers across graded P levels, while H14 (CRMS32A × ATR226) with moderate stability. The present findings highlight the breeding rice hybrids suited for low P conditions to improve phosphorus use efficiency and ensure yield stability under resource-constrained environments.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-20344-8.

Praecitrullus fistulosus (Stocks) Pangalo is one of the nutrient-rich vegetables crops with proven therapeutic value. This study was designed to investigate the inheritance of important physiological and biochemical traits of Praecitrullus fistulosus. A set of 15 cross combinations were developed from five lines and three testers and evaluated for two years. The results depicted significant (p < 0.05) variation among the genotypes (parents and crosses) with respect to flavonoids, phenolic compounds, total carbohydrates, vitamin C, and carotenoids during both studied years. Data were analysed with traditional line × tester analysis for inheritance pattern, and the genotypes (parents and hybrids) were further analysed using polar plotsfor heterosis and gene action, and principal component biplot analysis for graphical explanation of combining abilities. The physiological traits, i.e., flavonoids, antioxidants, and total soluble proteins, showed significant means square values and general combining ability for genotypes, i.e., 20 and 47. The F1 hybrids 20 × 42, 8 × 63, and 20 × 40 showed high and significant specific combining ability for flavonoids, antioxidants, vitamin C, and carotenoids. GCA, SCA, and the PCA biplot also showed comparable results. The studies of heterosis using polar plots showed the preponderance of overdominance for the majority of traits. Conclusively, both conventional and graphical attribution of data using line × tester analysis could lead Praecitrullus fistulosus breeders to the selection of suitable breeding methods.

In wheat enhancement programs, the creation of new, high-yielding cultivars depends on understanding the genetic variation within the gene pool and its efficient application in breeding efforts. The Line × Tester mating design is a commonly employed method in plant breeding programs to assess genetic inheritance, evaluate the combining ability of parental lines, and identify superior germplasm for enhancing productivity and associated traits in progeny. To overcome yield limitations, one promising strategy for enhancing wheat productivity involves incorporating the gene pool of facultative winter wheat into spring wheat varieties. To achieve this objective, six diverse facultative winter wheat lines originating from semi-arid regions (FWWL-SA) were crossed with three spring bread wheat cultivars using a line × tester mating design throughout the 2021–2022. During the 2022–2023 growing season, six facultative winter wheat lines, three spring wheat testers, and their 18 resulting F1 hybrids were assessed using a RCB design with three replications. Substantial variations among genotypes were noted in traits such as maturity duration, height of plant, length of spike, grains spike-1 and grain yield per plant. The combining ability analysis demonstrated statistically meaningful variations across the lines, testers, lines × testers, lines vs. testers and parents vs. F1 progeny. According to combining ability, the line FAWWL-2 exhibited superior performance for early maturity, reduced plant height, and enhanced grain. Within the testers, 'Parula' emerged as the top performer for early maturity and shorter plant stature. In terms of grain yield, AARI-2011 demonstrated the highest general combining ability within the testers. The following hybrid combinations were identified as the most promising based on specific combining ability: FAWWL-1 × AARI-2011 for maturity duration, FAWWL-4 × Parula for plant height, FAWWL-6 × Punjab-2011 for spike length, and FAWWL-4 × AARI-2011 for grains spike-1. The FAWWL-4 × AARI-2011, FAWWL-2 × Parula, and FAWWL-6 × AARI-2011 were identified as the most effective specific combiners for grain yield. These crosses exhibited high general combining ability (GCA) influences in both the lines and testers. The GCA to SCA variance ratio demonstrated a dominant influence of non-additive gene action, additionally corroborated by the higher dominance variance relative to the additive variance. Moreover, the ratio of σ2A/σ2D was below unity, while the degree of dominance (σ2D/σ2A)1/2 exceeded one, implied a predominant role of non-additive genetic influences. "Findings from the present study indicate that, due to the prevalence of non-additive genetic influences, it may be more effective to postpone the chosen of diverse wheat genotypes until later segregating generations to develop superior lines for six key agronomic traits. Keywords: Additive gene action, combining ability, non-additive, gene action, gene pool, facultative winter wheat, spring wheat, genetic variability.

The recent experiment on "Line × Tester analysis for seed yield &amp; its components in linseed (Linum usitatissimum L.)" during Rabi Year I, 2021-2022, was carried out. These F1’s, along with their parents, including check, RLC- 148, were planted in a randomized block design during Year II, Rabi 2022-2023, at the Department of Genetics and Plant Breeding Research-cum Instructional Farm at the College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh. The screening for wilt, powdery mildew under natural field conditions was found to be recorded as resistant for IC0564661, IC-0564654, IC-0498589×RLC-92,IC-0564661×RLC-92,IC-0564654×RLC-92,IC-0564661× RLC-133,IC-0076542×RLC-148,IC-0564661×RLC-148,IC-0525968×RLC-153. Resistant to wilt check variety is RLC- 92 and susceptible to wilt is RLC-133.

An experiment was conducted to evaluate the genetic potential of bitter gourd genotypes and their hybrids for yield and mosaic virus resistance using a line × tester analysis. The study utilized six high-yielding lines (L1-L6) and three mosaic virus-tolerant testers (T1-T3) to generate 18 F1 hybrid combinations. These genotypes were evaluated for 19 traits, including yield components and biochemical markers associated with defense responses, such as Peroxidase (PER), Polyphenol Oxidase (PPO), and Phenylalanine Ammonia Lyase (PAL). The present study was undertaken to identify superior hybrids with high yield and resistance to mosaic complex viruses. Analysis of variance (ANOVA) revealed significant genetic variability among the parents and hybrids for most traits. The general combining ability (GCA) analysis identified lines L3 and L5 as superior for earliness and enzyme activity, while tester T3 was the best general combiner for both yield and biochemical resistance traits. Specific combining ability (SCA) analysis highlighted strong non-additive gene action, with several crosses exhibiting significant effects. Notably, the hybrids L5 × T2 and L3 × T3 demonstrated exceptional performance, combining high yield potential with enhanced resistance to the mosaic virus complex, as indicated by elevated biochemical marker expression. Conversely, some high-yielding crosses like L1 × T3 and L2 × T3 showed poor resistance, making them unsuitable for mosaic-prone environments. The study concludes that the hybrid combinations L5 × T2 and L3 × T3 are promising candidates for developing new bitter gourd varieties that are both high-yielding and tolerant to mosaic viruses.

The present study intends to estimate the nature and magnitude of gene action and combining ability for yield and related traits in CMS based rice hybrids developed by crossing three CMS lines with 14 testers in Line × Tester mating design. During kharif 2023, 42 F1’s were developed which were evaluated along with their 17 parents in Randomized Block Design (RBD) with three replications during kharif, 2024 at the Rice and Wheat Research Centre, Malan, Himachal Pradesh. The observations were recorded for various characters viz., days to 50% flowering, days to 75% maturity, plant height at maturity, effective tillers per plant, panicle length, spikelets per panicle, grains per panicle, grain yield per plant, spikelet fertility, 1000-grain weight, grain length, grain breadth and L:B ratio. The analysis of variance for combining ability showed that Lines × Testers had significant differences for all the characters studied which indicated presence of sufficient amount of variation for yield and its component traits. Combining ability analysis revealed that among testers, HPR 2143 and among lines, IR 58025A exhibited desirable general combining ability (GCA) effects for grain yield and majority characters. IR 58025A × HPR 2612 reflected desirable significant specific combining ability (SCA) effects for majority characters studied. Preponderance of non-additive gene action was found in the inheritance of characters which was validated by higher values of SCA variances than their corresponding GCA variances. The study revealed the potential parents and promising cross combination(s) which could be further exploited for heterosis breeding. However, Multi-environment trials will be needed for efficient selection because they help to understand the true genetic potential of genotypes.