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Background: Orobanche is an obligate parasite on faba bean in the Mediterranean region, causes considerable yield losses. Breeding tolerant faba bean genotypes to Orobanche is pivotal to sustain production and ensuring global food security, particularly considering the challenges posed by population growth. In the present study, seven faba bean lines and four testers were used in a line×tester mating design during 2020–2021 and 2021–2022 growing seasons. The eleven parents and their 28 F1 crosses were evaluated under Orobanche free and naturally infested soils. Results: The results demonstrated considerable variations among the evaluated genotypes, wide diversity among the parental materials, and heterotic effects for all studied agronomic traits under Orobanche-free and infested soils. Orbanche infestation displayed a significant adverse impact on all the studied agronomic traits. The genotypes Line1, Line2, Line3, and Line5 displayed superior performance under Orobanche-infested conditions and recorded the highest values of all studied agronomic traits. Additionally, Line1, Line2, Line3, Line5, and Line7 exhibited desirable significant GCA for most evaluated traits under the two infestation conditions. The obtained crosses displayed significant negative or positive heterosis for studied agronomic characters such as plant height, number of branches per plant, number of pods per plant, number of seeds per plant, and seed weight per plant were observed. Furthermore, specific cross combinations such as Line2×Sakha3, Line3×Nubaria5, Line7 × Nubaria5, Line6×Nubaria1, Line5×Sakha3, Line1×Sakha3, and Line1 × Nubaria5 exhibited superior performance in seed yield and contributing traits under Orobanche-infested conditions. Moreover, these specific crosses showed superior efficacy in reducing dry weight of Orobanche spikes. The results obtained from GGE biplot analysis closely aligned with those from the line×tester procedure, affirming the significance of GGE biplot as a valuable statistical tool for assessing genotype combining ability in line× tester data. Both additive and non-additive gene actions were reported to be predominantly involved in the inheritance of the studied agronomic traits in faba bean. Conclusions: The detected genetic diversity within the evaluated faba bean genotypes and their developed crosses exhibits substantial potential for improving faba bean productivity under Orobanche-infested conditions. The parental genotypes, Line1, Line2, Line3, Line5, and Line7, were identified as effective and promising combiners. Moreover, the developed crosses Line2×Sakha3, Line3×Nubaria5, Line7×Nubaria5, Line6×Nubaria1, Line5×Sakha3, Line1×Sakha3, and Line1×Nubaria5 could be considered valuable candidates for developing high-yielding and tolerant faba bean genotypes to Orobanche. [ABSTRACT FROM AUTHOR]

Background: As the most widely cultivated fiber crop, cotton production depends on hybridization to unlock the yield potential of current varieties. A deep understanding of genetic dissection is crucial for the cultivation of enhanced hybrid plants with desired traits, such as high yield and fine fiber quality. In this study, the general combining ability (GCA) and specific combining ability (SCA) of yield and fiber quality of nine cotton parents (six lines and three testers) and eighteen F1 crosses produced using a line × tester mating design were analyzed. Results: The results revealed significant effects of genotypes, parents, crosses, and interactions between parents and crosses for most of the studied traits. Moreover, the effects of both additive and non-additive gene actions played a notably significant role in the inheritance of most of the yield and fiber quality attributes. The F1 hybrids of (Giza 90 × Aust) × Giza 86, Uzbekistan 1 × Giza 97, and Giza 96 × Giza 97 demonstrated superior performance due to their favorable integration of high yield attributes and premium fiber quality characteristics. Path analysis revealed that lint yield has the highest positive direct effect on seed cotton yield, while lint percentage showed the highest negative direct effect on seed cotton yield. Principal component analysis identified specific parents and hybrids associated with higher cotton yield, fiber quality, and other agronomic traits. Conclusion: This study provides insights into identifying potential single- and three-way cross hybrids with superior cotton yield and fiber quality characteristics, laying a foundation for future research on improving fiber quality in cotton. [ABSTRACT FROM AUTHOR]

The hybrid between the female channel catfish (Ictalurus punctatus) and the male blue catfish (I. furcatus) is the best genetic type currently available for commercial catfish farming due to their superior traits. However, further genetic improvements can be achieved by selecting parents with increased combining abilities. Twenty female channel catfish and twelve male blue catfish were crossed in a partial factorial mating design, resulting in forty hybrid families. These families were evaluated for early growth in three different rearing systems, including ponds and aquaria. The early growth performance of hybrid catfish was significantly (p < 0.05) affected by the additive gene action of the female parent and the male parent. There were genotype–environment or genotype–age interactions affecting the combining abilities, both the amount and the type of genetic variation. Dam GCA was significant in all environments/ages; however, sire GCA was variable, and SCA was not significant. These findings suggest that reciprocal recurrent selection for growth could potentially improve the performance of F1 hybrid catfish. [ABSTRACT FROM AUTHOR]

Introduction and Objectives: Oilseed rape is one of the most important sources of vegetable oil in the world, and its seed contains more than 40% of oil, and the meal obtained from oil extraction has more than 35% of protein, and currently it ranks third among oil plants after soybean and oil palm. in the world. The existance of environmental stresses, such as drought stress, causes a significant decrease in oilseed rape yields. Therefore, breeding for drought tolerance is very important, and creating high yielding and early maturing or drought tolerant cultivars is one of the important goals of breeders. The purpose of this study was to determine the best general and specific combiners and the amount of heterosis compared to the superior parent in spring rapeseed using line×tester analysis in two conditions of normal irrigation and drought stress. Material and Methods: Seven high-yielding rapeseed lines were crossed with five testers with a range of early maturity in the 2018-2019. The first generation hybrids along with 12 parents (47 genotypes in total) were evaluated in the randomized complete block design with three replications in two conditions of normal irrigation and terminal drought stress (irrigation cut off at the beginning of podding stage) in the 2019-2020. The studied traits included physiological maturity date, plant height, number of pods per plant, pod length, number of grains per pod, height of the first pod from the ground, 1000-grain weight, seed yield, oil percentage and oil yield. Results: The results of analysis of variance in both normal irrigation and drought stress conditions showed a significant difference between hybrids for all investigated traits, which indicated a significant diversity between genotypes. In analyzing the effect of hybrids into the relevant components, the interaction effect of line × tester was significant for all the traits under normal irrigation conditions and also under drought stress conditions except for the height of the first pod from the ground, and oil yield. The effect of parents versus hybrids was significant in normal for all traits except the number of seeds per pod under normal irrigation conditions and except for plant height, pod length and number of seeds per pod in drought stress conditions, which indicates the existence of heterosis for these traits. For the trait of physiological maturing, among the lines, line 6 showed the highest negative general combining ability under normal irrigation and drought stress conditions, and tester 5 showed the highest negative general combining ability among the testers under normal irrigation and drought stress conditions. Tester 5 was contributed in early maturing T5×L3 hybrid under drought stress conditions. L1 and L5 in both conditions and T2, and L3 and L4 in normal irrigation conditions and T1 in drought stress conditions were identified as the best general positive and significant combiner for the number of pods per plant, and hybrids T5×L1, T1× L5, T2×L4, T4×L4, T1×L7, T1×L6, T2×L7, T3×L2, T5×L7, and T4×L3 were the best specific combiner to increase the number of pods per plant in both experiment conditions. T4 was the most significant positive general combiner under normal irrigation conditions and drought stress for the 1000-grain trait. Also, regarding the positive significant specific combining ability for this trait hybrids T2×L7, T3×L7 in both conditions, and in addition hybrids T1×L7 and T5×L4 under normal irrigation conditions and hybrids T1×L6 and T3×L5 under drought stress conditions showed the highest amount. The most significant positive general combining ability in grain yield was determined to T5 and L1 and L6 in both conditions. The best significant positive specific combining ability were T2×L7 and T3×L7 in both conditions. The highest positive and significant amount of general combining ability of the amount of oil, was given to T3 and T5 and L6 in both experimet conditions, and T4 and L7 in normal irrigation conditions and L5 in drought stress conditions. T1×L6, T5×L1, T2×L5, T3×L1, T5×L3 and T4×L4 were among the best hybrids in both conditions. In normal irrigation conditions, T2×L3, T4×L3, T5×L1, T4×L6, and T5×L3 and in drought stress, T5×L1, T2×L3, T2×L4, T4×L4, T4×L3, T4×L5 and T2×L7 had the highest amount of heterosis in the positive direction for the number of pods per plant. The trait of the number of grain per pods, T2×L3, T4×L3, T5×L1, and T2×L5 under normal irrigation conditions and T5×L6, T3×L6, and T5×L3 under drought stress condition had the highest amount of heterosis. Conclusion: The estimation of traits' combining ability showed that T5 and L1 and L6 were the best general combiners to increase grain yield. T3×L7 and T2×L7 hybrids were the best specific combiner for increasing grain yield under normal irrigation and drought stress conditions. Also for the 1000-seed trait, T3×L6, T4×L1, T5×L4 and T1×L1 hybrids under normal irrigation conditions and T3×L7, T1×L6, T2×L6 and T3×L3 hybrids under drought stress conditions have the highest amount of heterosis. The number of pods per plant and the number of grain per pods under normal irrigation conditions, T2×L3, T4×L3 and T5×L1 had significant positive heterosisTherefore, their parents can be suggested for hybrid varieties production programs. [ABSTRACT FROM AUTHOR]

Pearl millet (Pennisetum glaucum [L.] R. Br., 2n = 2x = 14) is a nutrient-dense and climate-resilient crop widely cultivated in the dry regions of Africa and Asia. In Burkina Faso, the actual mean yield of the crop is < 1 ton/ha compared with a potential yield of 3 tons/ha. Several constraints, including cultivar susceptibility to the noxious weed Striga hermonthica (Del.) Bentham (Sh) and severe and recurrent drought stress limit the potential productivity of the crop. Therefore, this study aimed to determine the combining ability effects and degree of heterosis for agronomic traits and resistance to Sh among complementary pearl millet genotypes to select promising parental lines and hybrids to develop and deploy farmer-preferred varieties. The narrow-and broad-sense heritability were relatively higher for Striga-resistance (≥ 70%) and low (≤ 23%) for grain yield. The general combining ability and specific combining ability ratios were less than unity for agronomic traits and Striga reaction indicating the predominance of non-additive gene action conditioning the assessed traits. The new experimental hybrids such as IP-11358 × ICMB177111, IP-11358 × IKMB18002, IP-10579 × ICMB177002 and IP-9242 × ICMB177002 are recommended for multi-environment evaluation and production in Sh-infested pearl millet cultivation agro-ecologies in Burkina Faso or similar agro-ecologies. [ABSTRACT FROM AUTHOR]

The investigation was conducted to calculate the superiority % for of the F1’s over commercial check hybrids, combining ability and genetic variability of eleven white maize inbred lines using a half-diallel design at Sids Agricultural Research Station in the 2022 growing season. The 55 crosses along with two commercial hybrids as checks; SC-10 and Hytech SC-2031 were evaluated in field trials at Sids, Sakha, and Gemmeiza Agricultural Research Stations using randomized complete block design with three replications in the growing season 2023. The results showed highly significant differences between three locations for all studied traits except GY and DTS traits. Mean squares for crosses and their interaction with locations were significant for all studied traits except for EHT. Also, variances of GCA and SCA were significant for all studied traits except EHT, indicating that additive and non-additive gene effects were important in the inheritance of most studied traits. However additive gene effects were more important than non-additive gene effects in the inheritance of all studied traits except for GY. Two inbred lines; Sd-4/2013 and Sk-12 had good general combining effects for GY. The best cross for SCA effects was Sd-63 × Gz-613 for GY; and Sd-1185 × Gz-613 for DTS. The cross Sd-2/2013 × Sk-9 was superior for grain yield and earliness than two checks. Also, four crosses; (Sd-2/2013 × Gz613), (Sd-41/2015 × Sk-13), (Sd-63 × Gz-613) and (Sd-1185 × Sk-9), were significantly superiority% relative to the two checks. These crosses will be further evaluated in the maize breeding program. [ABSTRACT FROM AUTHOR]

The latest study strategized to evaluate the maize populations by combining ability analysis under optimum and drought-stress environments to assemble the promising parental inbred lines and their hybrid populations with high productivity and resistance to drought stress. From the collection of the Trunojoyo Madura University, Indonesia, came five maize pure lines (UTM 2, UTM 7, UTM 10, UTM 19, and UTM 31) that received crossing in a complete diallel fashion to obtain 20 hybrid populations. The performance of five parental inbred lines and their 20 F1 hybrids' evaluation in crop season 2021 had a randomized complete block design with three replications under four each for optimum and droughtstress environmental conditions. Data recording ensued on grain yield and drought susceptibility index (DSI). The GCA and SCA variances revealed that grain yield had more influences from the dominant genes with maternal effects at the eight locations; hence, the parental lines have less stimulus on the hybrids' performance. The genotype UTM2 (G1) appeared resistant to drought-stress conditions based on the DSI value (0.70) and has positive GCA effects for grain yield. Therefore, it can better serve to improve drought resistance and grain yield. The results further exhibited that six maize hybrids, i.e., G3 (UTM 2 x UTM 10), G6 (UTM 7 x UTM 2), G10 (UTM 7 x UTM 31), G11 (UTM 10 x UTM 2), G22 (UTM 31 x UTM 10), and G24 (UTM 31 x UTM 19) were remarkable as commercial hybrids with high grain yield and resistance to drought stress. [ABSTRACT FROM AUTHOR]

Maize breeding appears to be a key strategy to ensure global food security. Improving the grain yield and nutritional quality of maize can progress through breeding programs, where hybridization between two genetically contrasting inbreds might lead to producing superior hybrids. This phenomenon occurs as the developed hybrids are 100% heterozygous, and in consequence, expressing heterosis. However, to select parents for the ideal combinations, it is fundamental to understand the genetic status and the ability to combine the different inbreds. This review aimed to highlight the effectiveness of the general combining ability (GCA) and the specific combining ability (SCA) approaches to develop high-yielding and nutritionally enriched maize hybrids adapted to Malaysia's conditions. Maize breeders have applied various breeding methods, including the biofortification technique to augment the grain yield and nutritional quality of the crop. This technique is the most sustainable, feasible, and affordable one, as it offers more nutritious plants with the required micronutrients. Although a considerable amount of research has succeeded in identifying potential inbred combinations for specific traits and sites, the application of combining ability methods toward developing high-yielding and nutritionally enriched maize hybrids adapted to Malaysia's conditions has not been maximized. Therefore, it is important to understand the combining ability approaches to develop maize hybrids that could lead to the maximum output for combating the increasing maize global demand. [ABSTRACT FROM AUTHOR]

Breeding resistant wheat cultivars to Fusarium head blight (FHB), caused by Fusarium spp., is the best method for controlling the disease. The aim of this study was to estimate general combining ability (GCA) and specific combining ability (SCA) for FHB resistance in a set of eight genetically diverse winter wheat cultivars to identify potential donors of FHB resistance for crossing. FHB resistance of parents and F1 crosses produced by the half diallel scheme was evaluated under the conditions of artificial inoculation with F. graminearum and natural infection. Four FHB related traits were assessed: visual rating index (VRI), Fusarium damaged kernels (FDK), and deoxynivalenol and zearalenone content in the harvested grain samples. Significant GCA effects for FHB resistance were observed for the parental cultivars with high FHB resistance for all studied FHB resistance related traits. The significant SCA and mid-parent heterosis effects for FHB resistance were rare under both artificial inoculation and natural infection conditions and involved crosses between parents with low FHB resistance. A significant negative correlation between grain yield under natural conditions and VRI (r = −0.43) and FDK (r = −0.47) under conditions of artificial inoculation was observed in the set of the studied F1 crosses. Some crosses showed high yield and high FHB resistance, indicating that breeding of FHB resistant genotypes could be performed without yield penalty. These crosses involved resistant cultivars with significant GCA effects for FHB resistance indicating that that they could be used as good donors of FHB resistance. [ABSTRACT FROM AUTHOR]

Application of machine learning in plant breeding is a recent concept, that has to be optimized for precise utilization in the breeding program of high yielding crop plants. Identification and efficient utilization of heterotic grouping pattern aided with machine learning approaches is of utmost importance in hybrid cultivar breeding as it can save time and resources required to breed a new plant hybrid/variety. In the present study, 109 genotypes of sunflower were investigated at morphological, biochemical (SDS-PAGE) and molecular levels (through micro-satellites (SSR) markers) for heterotic grouping. All the three datasets were combined, scaled, and subjected to unsupervised machine learning algorithms, i.e., Hierarchical clustering, K-means clustering and hybrid clustering algorithm (hierarchical + K-means) for assessment of efficiency and resolution power of these algorithms in practical plant breeding for heterotic grouping identification. Following the application of machine learning unsupervised clustering approach, two major groups were identified in the studied sunflower germplasm, and further classification revealed six smaller classes in each major group through hierarchical and hybrid clustering approach. Due to high resolution, obtained in hierarchical clustering, classification achieved through this algorithm was further used for selection of potential parents. One genotype from each smaller group was selected based on the maximum seed yield potential and hybridized in a line × tester mating design producing 36 F1 cross combinations. These F1s along with their parents were studied in open field conditions for validating the efficacy of identified heterotic groups in sunflowers genetic material under study. Data for 11 agronomic and qualitative traits were recorded. These 36 F1 combinations were tested for their combining ability (General/Specific), heterosis, genotypic and phenotypic correlation and path analysis. Results suggested that F1 hybrids performed better for all the traits under investigation than their respective parents. Findings of the study validated the use of machine learning approaches in practical plant breeding; however, more accurate and robust clustering algorithms need to be developed to handle the data noisiness of open field experiments. [ABSTRACT FROM AUTHOR]

We used a 4×5 two-factor crossover design of fir advanced generation hybrid progeny in a forest farm in Kaihua County, Zhejiang Province, to study the growth traits, basic wood density, and trunk carbon content of 8 years old fir to estimate the general combining ability and special combining ability (GCA/SCA)effect values and relative importance of each trait, analyze the genetic control mode and correlation between traits, reveal the genetic effects of growth and timber traits in fir advanced generation hybrid progeny, and select high-performing hybrid combinations. We estimated the GCA/SCA effect values and relative importance of each trait and analyzed the genetic control mode and correlation between the traits. The results showed that the differences in height, diameter at breast height, volume of wood per plant, basic density of wood, and carbon content of the trunk of cedar trees were significant (P<0. 05) among the hybrid combinations, while the differences in carbon content were not significant among the combinations. Parent-parent fitness analysis showed that the maternal effects of tree height, diameter at breast height, volume of wood per plant, and trunk carbon content were greater than the paternal effects, with C25-3 having the greatest maternal effect and B109-3 having the greatest paternal effect. The hybrid combinations were mainly controlled by the effects of additive genes for each trait, and focusing on the selection of the parents for breeding tall fir tree generations is vital. Correlation analysis between traits showed that trunk carbon content and growth traits were significantly positively correlated. and two fast-growing and high carbon sequestration hybrid combinations (3211 and 3215)were jointly selected based on the 10％selection rate. The volume of wood per plant increased by>30. 91％compared with that of control check (CK), and the carbon content of the trunk increased by>26. 95％compared with that of CK, whereas the basic density of wood was weakly correlated or negatively correlated with the growth traits. Two hybrid combinations with high-performing wood traits (3218 and 3216) were selected, and the basic density of wood increased by>2. 17％compared with that of CK. [ABSTRACT FROM AUTHOR]

Exploitation of heterosis is one of the potential means for improvement of sweet pepper (Capsicum annuum var. grossum L.) that can further be utilized for identification of desirable recombinants. Promising hybrids could be acceptable to growers of tropical and subtropical climates if it is a high yielder with attractive fruit colour and blocky shape. Seven diverse parents were selected through multivariate analysis and were crossed in half diallel mating design to determine the extent of heterosis, mode of gene action, combining ability effects, and dominance estimates for 18 quantitative characters. Expression of fruit colour and shape at physiological maturity stage in the F1 generation indicated the dominance of red coloured group over other fruit colour groups and dominance of blocky fruit shape over elongate and round fruit shape. Preponderance of non-additive gene action for most of the characters under study suggested the usefulness of exploitation of hybrid vigour. Three genotypes, 8/4, C/4, and Baby Bell were found most promising donors. The hybrids, Arya×Baby Bell, 8/4×Baby Bell and C/4×8/4 were identified as promising based on per se performance, heterosis manifested, and relevance of specific combining ability effects, for possible commercialization under low cost protected structure of tropical and subtropical climates after critical testing. Partial to over dominance response in inheritance of most traits contributed to the genetic basis of heterosis. Isolation of pure lines from the segregating generation of heterotic hybrids emerged as a promising approach to develop line-bred variety having improved fruit yield and quality. [ABSTRACT FROM AUTHOR]

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Combining ability and heterosis were studied on 15 F1 hybrids and their parents to understand the inheritance of yield, its components and some grain quality traits for selecting superior genotypes. A line x tester mating design was conducted during 2021and 2022rice seasons at the Experimental Farm, of Sakha Research Station Kafr El-Sheikh, Egypt. The results revealed that GCA and SCA were highly significant for all studied traits except grain shape under both conditions. 11 L236 genotype was the best general combiner for number of days to 50% heading, number of filled grains/panicle, sterility% and grain yield/plant under normal and water deficit conditions. Also Giza 178 was the best general combiner for number of panicles/plant, grain yield/plant and hulling % under both conditions while, IR6500-127, Giza 178 and GZ1368-S-5-4 for head rice % and for amylose content Lines 11 L236 and tester Nerica7 under both conditions were good combiners for this trait. Crosses IR 69432 x Nerica7, IR 69432 x GZ1368-S-5-4, IR 12G3213 x Giza178, IR 12G3222 x Giza178 and IR 12G3222 x Nerica7 had high and significant SCA in desirable direction for most studied traits under both condition. Crosses IR6500-127 x Nerica7, 11 L236 x GZ1368-S-5-4, IR69432 x Nerica7, IR 12G3213 x Nerica7, IR 12G3222 x GZ1368-S-5-4 and IR 12G3222 x Nerica7 exhibited highly significant and desirable estimates of heterosis as a deviation from mid and better parent for most studied traits under both conditions. [ABSTRACT FROM AUTHOR]

ABSTRACT Elephant grass is an allogamous perennial forage crop with asexual propagation, allowing plant breeders to explore heterosis and develop hybrids. However, selecting parents for diallel crossing schemes is a major hurdle in the development of hybrids. In addition, this perennial crop has several harvests, which increases the dataset size and the complexity of the statistical analyses. Here, we propose a diallel analysis based on linear mixed models with repeatability information to identify parents and hybrids, and the optimum number of harvests. We performed a complete diallel crossing of 11 parents with data from five harvests for morphological traits and two harvests for nutritive value traits. The diallel model with repeatability information aids in the estimation of the genetic effect of diallel analysis to infer the ideal number of harvests and genotype × harvest interaction. We observed that the specific combining ability (SCA) is more critical for morphoagronomic traits, while the general combining ability (GCA) has greater importance for traits related to nutritive value. Furthermore, we detected that five harvests were sufficient for the morphoagronomic traits with a coefficient of determination (R2) of 0.8; however, ten harvests were required for an R2 of 0.9. The model is a promising single-analysis alternative for plant breeders to analyze a diallel with repeated measures and to estimate important parameters without incurring in additional financial costs.

In this experiment, F1s produced from a 7 × 7 half-diallel cross along with their parents were evaluated to develop high yielding and saline-tolerant barley lines. The investigation focused on the general combining ability (GCA) of parents, specific combining ability (SCA) of offspring, genetic action, and heterosis of eight quantitative variables. Genetic analysis and potence ratio suggested that different degrees of dominance controlling the inheritance of the studied traits. Significant GCA and SCA variances suggested the presence of both additive and non-additive gene actions controlling the traits. However, a GCA:SCA ratio lower than 1 indicated the preponderance of the non-additive gene action involved in the expression of the traits. The parents P5 and P6 possess the genetic potential favorable for early and short stature in their F1s. Conversely, P2 and P4 were more likely to produce short F1s with high yield potential. Based on the mean performance, SCA, and heterobeltiosis, crosses P2 × P3, P2 × P7, P3 × P4, P4 × P5, P5 × P6, and P6 × P7 were selected as promising F1s for earliness, short stature, and high yield potential. These crosses are recommended for further breeding to obtain early-maturing and high-yielding segregants. To identify saline-tolerant F1s, screening was conducted in saline media prepared in half-strength Hoagland solution. The salinity stress involved exposing F1s to 100 mM NaCl for first 10 days, and followed by an increase to 150 mM until maturity. Among the F1s, five crosses (P1 × P2, P2 × P3, P3 × P5, P4 × P6, and P4 × P7) exhibited promising signs of saline tolerance based on a comprehensive evaluation of healthy seed set, K+/Na+ ratio, root volume, generation of reactive oxygen species (O2•− and H2O2), and activities of key antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and glutathione reductase (GR). These crosses will undergo further evaluation in the next filial generation to confirm heritable saline tolerance.

Combining ability status of the inbred lines is crucial information for hybrid breeding program. Diallel or line × tester mating designs are frequently used to evaluate the combining ability. In the current study a modified diallel model was used, wherein the Griffing’s combining ability effects were further partitioned to understand the effects due to maternal and reciprocal. To do this, eight parental lines of maize were crossed in full diallel method and the generated hybrids along with parents were phenotyped. The field data on the quantitative traits was analyzed using both Griffing’s and the modified model to determine how well the parents’ and the F1 hybrids combined. For each of the traits, a sizable reciprocal and maternal variance was observed. The number of kernel rows per cob variable had a ratio of additive variance to dominance variance greater than one. All other traits including grain yield had a ratio close to zero, suggesting that non-additive gene action was primarily responsible for the genetic control of most of the traits. The narrow sense heritability was low to moderate for majority of the variables, except for number of kernel rows per cob. With the help of the improved model, it was possible to choose superior parents and cross-parent pairings with accuracy. Based on the modified general combining ability effects and maternal effects, the parental line P5 was recognized as a potential female parent and P7 as a good male parent for grain yield and yield-attributing characteristics. The cross combination of P8×P1 had the highest specific combining ability effect on grain yield. P5×P6 cross had the highest reciprocal effect. The correlation analysis implies that the Griffing’s general combining ability effects and specific combining ability effects were found to be less efficient in predicting F1 performance as compared to the modified model.

Background: Groundnut is one of the world's major food and oil crops. Being sources of nutrition and vegetable oil, rich in affordable and digestible protein, it is a strategic crop in Burkina Faso for food security, nutrition, and cash income. Understanding the nature of gene effect and genetic variation affecting yield and yield component traits will contribute to designing appropriate breeding methods for groundnut improvement and increase selection efficiency in Burkina Faso. Methods: In 2018, a total of 30 F2 progenies were generated through a 6 x 6 full diallel mating using six different and contrasting varieties. In 2019, parents and progenies were evaluated in a lattice square design in 3 replications at ICRISAT-Mali experimental field to assess the general combining ability (GCA) and specific combining ability (SCA) effects, the inheritance and the maternal and reciprocal effects for yield component traits (YCT) and oil content (OC). Results: Significant variabilities were observed among the parental genotypes and their F2 progenies for DTH, PSR, HPW, PL, PWD, SL, SWD, and OAC. Mean performance of the six parents were HPW (117.05g), HSW (57.24 g), PYH (1914.76), SYH (1312.73), PL (2.52), PWD (1,19), SL (1.38), SWD (0.83), OC (49.43), OAC (50.43) and LAC (33.61). Parent QH243C presented the highest value for SWD (1.02 cm) and OAC (60.76) while the parent ICGV09195 had the highest value of OC (50.36). Chalimbana presented the highest value of HPW (169.61 g), PL (2.98 cm), PWD (1. 41 cm), and SL (1.57 cm) while CG7 presented the highest value for HSW (75. 14 g), and SYH (1639.28 kg). Both YCT and OC are controlled by additive and non-additive gene effects with a predominance of additive gene action for HSW, SL, and SWD, whereas HPW, PL, PWD, and OAC were found to be more controlled by non-additive gene effects. Maternal effects as well as nuclear and cytoplasmic interaction effects were observed for both YCT and OC indicating that YCT and OC are influenced by a combination of genetic factors from both the maternal parent and the nuclear genome, as well as cytoplasmic factors such as mitochondrial DNA. Broad sense heritability ranged from 3.76 % to 91.56 %, and higher broad sense heritability values were recorded for pod length (91.56 %), hundred pod weight (83.71 %) and pod width (80.95 %). Conclusion: The study yields valuable insights into the inheritance of YCT and OC. The parents, Chalimbana and CG7, showed promise as good combiners for both yield component traits and oil content when used as male parents while TE3, Sh470P and QH243C can be used as female for the oil content and its components (oleic and linoleic content).

Erucic acid, more than 2 %, in mustard seed oil is considered unhealthy as edible oil, and also anti-nutritional for human consumption. The existing mustard varieties of Bangladesh contain 40–48 % erucic acid, which is a big concern for the country's nutritional, and food security and safety. Hence, to improve the seed oil quality of the existing variety, six popular cultivars of Brassica juncea mustard were crossed with a canola-grade line in 7 × 7 half diallel fashion, and the developed 21 F1 hybrids were assessed for yield contributing traits, and fatty acids composition. Variables with significant variations were found, while days to siliquae maturity, plant height, days to first flowering, and seeds per siliquae have moderate narrow sense heritability. The estimated gene action indicated that dominant or over-dominant gene action was more prominent in governing the traits. The parents, P1, P3, and P4 were discovered the best general combiners for early maturity and short phenology, whereas P2 and P7 were found to be the best general combiners for yield-attributing traits. Moreover, the hybrids P1 × P4, P1 × P6, P2 × P7, P4 × P6 and P3 × P5 were chosen as the promising hybrids due to their best specific combining ability, and desired heterotic effects on yield contributing traits. In addition, a significant decrease, on average 30–40 %, in erucic acid, but an approximately 20–25 % increase of oleic acid was found among the hybrids, in which the hybrids P1 × P6–S1, P5 × P6–S2 and P5 × P6–S4 demonstrated a better stability index. Overall, the obtained findings suggested that the hybrids, viz. P1 × P5, P1 × P6, P2 × P3, P2 × P7, P4 × P6, P5 × P6, and P6 × P7 were promising based on their early maturity, high-yielding, reduced erucic acid, and high oleic acid contents.

Understanding the combining ability effects, heterosis, and genetic relationships between parental lines would be helpful in the maize breeding program to develop high-yielding and genetically stable maize varieties for various contrasting environments. Hence, the objective of this study was to estimate combining ability effects, heterosis, genetic distance (GD) and associations for grain yield and other agronomic traits. Forty-five F1 diallel crosses, four commercial checks, and ten inbred lines were evaluated at Bako and Jima Agricultural Research Centers, Ethiopia. Significant differences were observed among environments, genotypes and genotype by environment interaction for grain yield and almost all studied agronomic traits. Combining ability analysis showed both additive and non-additive gene effects significantly controlled grain yield and all other studied traits. The preponderance of general combining ability (GCA) effects indicates the importance of additive gene action inheriting most agronomic traits. Lines L2, L7, and L9 were the best combiners for grain yield, whereas lines L3 and L4 had desirable GCA values to improve days to flowering and plant height. Among the top ten crosses, L6 × L9, L6 × L7 and L4 × L9 were good specific combiners and had 18.8 %, 17.2 % and 16.2 % grain yield advantage over the best check, BH546. These hybrids also had high mid and better-parent heterosis compared with other crosses. The associations of GD with mean of F1 and SCA effects were positive and highly significant for grain yield and some other traits. In contrast, correlations of GD with mid and better parent heterosis were non-significant for grain yield and most other traits. The results of this study are particularly useful for breeders who envisage combining conventional and molecular methods.

Pomato is a horticultural wonder plant, as tomato and potato can be produced from a single plant. This experiment explored the influence of diverse graft combinations of tomato scions grafted onto potato rootstocks on various growth and yield-attributing traits. The investigation outcomes confirmed the significantly positive influence of scion grafted onto rootstock on various yielding attributes of tomato and potato harvested from pomato grafts. Scion “Rakshita” grafted onto the rootstock of Kufri Himalini had the maximum fruit length. In contrast, the fruits harvested from the graft combination of Avtar grafted onto Kufri Khyati had the maximum number of fruits per cluster and the number of fruits per plant. The highest average fruit weight, fruit yield per meter square, and total fruit yield quintal per hectare were recorded with control “Avtar. The longest harvest duration was noticed with the graft combination of Heemsohna grafted onto Kufri Himalini. Moreover, on, rootstock Kufri Himalini with scion Rakshita resulted in maximum tuber length, and average tuber weight, while Kufri Himalini with Avtar had maximum fruit width. The maximum number of tubers per plant was also noticed with Kufri Pukhraj with Palam Tomato hybrid −1. The potato harvested from the rootstock of Kufri Pukhraj with Avtar had the highest tuber yield per plant, total tuber yield quintal per hectare, and tuber equivalent yield. The highest survival percentage of grafted plants was noted in Heemsohna onto Kufri Jyoti. In context to the cumulative yield of tomato fruits and potato tubers obtained from the pomato graft was found to be incremented in grafts of Avtar grafted onto Kufri Pukhraj followed by Rakshita grafted onto Kufri Rakshita, which also resulted in the maximum benefit-cost ratio with highest net return and gross return. The graft combination of scion Avtar and Rakshita onto Rootstock Kufri Pukhraj resulted in a positive increment in yield attributing traits of the pomato plant than of control of un-grafted tomato and potato.

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

Wheat (Triticum aestivum L.) is a staple food and major source of dietary calories in Pakistan. Improving wheat varieties with higher grain yield and disease resistance is a prime objective. The knowledge of genetic behaviour of germplasm is key. To achieve this objective, elite wheat varieties were crossed in 4 by 3, line × tester design, and tested in 2019 in a triplicate yield trial to estimate genetic variance, general and specific combining ability, mid-parent heterosis and stripe rust (Puccinia striiformis L.). High grain 3358 kg·ha–1 was recorded in F1 hybrid (ZRG-79 × PAK-13). Analysis of variance (ANOVA) revealed significant genotypic variance in grain yield. Broad sense heritability (H2) was recorded in the range of 28 to 100 %. General combining ability (GCA) significant for grain yield in parents except FSD-08 and PS-05 was recorded, while specific combining ability (SCA) was recorded to be highly significant for grain yield only in two crosses (ZRG-79 × NR-09 and ZRG-79 × PAK-13). Mid-parent heterosis was estimated in the range of –28 to 62.6 %. Cross combinations ZRG-79 × PAK-13 depicted highly significant mid-parent heterosis (62.6 %). Highly significant correlation was observed among spike length, spikelets per spike, plant height and 1000-grain weight. Rust resistance index was recorded in the range of 0 to 8.5. These findings suggest exploitation of GCA for higher grain yield is important due to the presence of additive gene action and selection in the filial generations will be effective with improved rust resistance, while cross combinations ZRG-79 × PAK-13 high GCA are best suited for hybrid development.

This article presents the findings of a study on the breeding of Indian Mustard, specifically focusing on heterosis and combining ability for seed yield and its component traits. The researchers evaluated 12 advanced lines/varieties of Indian Mustard and found significant differences among the treatments for various traits. Certain lines and cross combinations were identified as good combiners and showed high heterosis. The study provides valuable information for breeding programs aimed at improving seed yield and its component traits in Indian Mustard. [Extracted from the article]

The present study explores heterosis, combining ability, gene action and proportional contribution of lines, testers and their interactions for yield and its contributing traits in cabbage (Brassica oleracea L. var. capitata). Evaluating 30 F1 populations, 11 parents (6 CMS lines and 5 DH testers) and a standard check (Pusa Cabbage Hybrid-81) in RCBD during winter 2018, the results revealed that KTCB-836A, KTCB-50-1 and cross, KTCB-1A x KTCB-50-1 found superior for yield and its component traits based on GCA and SCA estimates respectively. Further, KTCB-836A x KTCB-51-19, KTCB-836A x KTCB-51-2, KTCB-836A x KTCB-50-3 and KTCB-836A x KTCB-51-6 identified as superior hybrids for yield per hectare based on estimates of standard heterosis and heterobeltiosis. The gene action studies indicated that non-additive gene action predominantly controls most quantitative traits, as the dominant variance (σ²D) was more than the additive variance (σ²A) and the variance ratio was less than one for most of the quantitative traits. While higher contribution of line x tester interactions also highlighted the effective role of testers. Heterosis breeding can thus be commercially exploited to develop superior cabbage hybrids. [ABSTRACT FROM AUTHOR]

Introduction and Objective: In crop breeding programs, comprehensive information is needed regarding the genetic structure of plant materials and their combinability. In this regard, the present study was carried out with the objectives of evaluating the general combining ability of parents and the specific combining ability of crosses, determining the nature and extent of gene action, and finally estimating the heritability of quantitative and qualitative traits of sugar beet hybrids by the analysis of line-tester crosses. Material and Methods: The study was conducted as a line-tester crossing using nine lines and two testers of sugar beet. For this purpose, maternal lines were planted in the middle lines and pollinator lines were cultivated in two lateral lines and all the crossings were done by observing the points related to isolation. A number of 18 hybrids obtained from the line-tester cross were cultivated and investigated in the agricultural research station of Shiraz in randomized complete block design with four replications during the crop season of 2019-2020. Results: The results of analysis of variance of root yield, sugar yield, white sugar yield, sugar content, white sugar content, sodium, potassium, harmful nitrogen, alkalinity coefficient, extraction coefficient of sugar and molasses sugar percentage showed that among studied hybrids, there is a significant difference at the 1% probability level in terms of all the traits except the two traits of sugar content and white sugar content. Line-tester analysis confirmed that the additive and non-additive effects of genes are involved in the expression and inheritance of root yield and sugar yield; However, in the genetic control of white sugar yield, sugar content, white sugar content, sodium, potassium, nitrogen, alkalinity coefficient, extraction coefficient of sugar and molasses sugar percentage, genes with non-additive effect have not played a role, and according to the significance of the general combining ability effect of the line or tester for the mentioned traits, only genes with additive effect are involved in the control. In total, from the used lines in the present study, 950123 and from the experimental testers, F-21121 had positive effects with regard to the improvement goals of sugar beet. S1-24 and F-21122 were associated with negative effects and caused a decrease in the breeding value of the traits. Conclusion: Overall, obtained results showed the existence of diversity among hybrids derived from crossing between lines and testers. Based on the results, genes with both additive and nonadditive effects are involved in the control of root yield and sugar yield, but in the inheritance of sugar yield, sodium, potassium, harmful nitrogen, alkalinity coefficient, extraction coefficient of sugar, and molasses sugar percentage, only genes with additive effect are involved. Considering that general combinability shows the additive effects of genes, so parents with high general combining ability also have a large additive effect that can be used in cultivar production. [ABSTRACT FROM AUTHOR]

Intermating between genetically diverse tomatoes could provide information on the underlying biology as a source of new alleles for phytonutrient contents and tomato leaf curl virus (ToLCV) disease tolerance in cherry tomato [Solanum lycopersicum var. cerasiforme (Dunnal) A. Gray]. The study determined combining ability effects, heterosis and gene action for conditioning 19 quantitative traits involving crosses between anthocyanin rich (Aft gene) tomato (Solanum lycopersicum L.) lines and 7 breeding lines of nutritionally rich cherry tomato [S. lycopersicum var. cerasiforme (Dunnal) A. Gray]. An overwhelming response of non-additive gene action in controlling expression of most traits was evident. Purple tomato line "Bidhan Purple" and the cherry tomato lines "Cherry Round Yellow Big Fruit" and "18/ToCVAR-2" could be potential genitors for cherry tomato breeding. Based on combining ability, average heterosis, and mean performance, the promising hybrids: "Alisha Craig Aft ×18/TOCVAR-2," "Bidhan Purple × 18/TOCVAR-2" and "Alisha Craig Aft × Cherry Round Yellow Big Fruit" were identified in terms of phytonutrient contents and ToLCV disease tolerance. Partial, to over-dominance, reaction in inheritance of most traits reflects the genetic basis of heterosis. Promising cherry tomato hybrids could be exploited following appropriate testing or could be used in segregating generations to produce line-bred cultivars that are ToLCV disease-tolerant and high in phytonutrient contents. [ABSTRACT FROM AUTHOR]

Heterosis is a method of increasing productivity and is used in many crops. In cotton, heterosis is mainly related to yield and fiber length. Two male-sterile cotton lines ms 273 and ms 274 were included in crosses with five modern varieties: Chirpan-539, Natalia, Rumi, Helius and Nelina. Heterosis manifestations were found for productivity/plant (7.4-63.8%) and fiber length in the F1 hybrids. The cultivar Chirpan-539 and Rumi variety, with high GCA for fiber length and high variances of SCA, emerged as suitable for heterosis selection of this trait. The crosses 273 × Nelina and 274 × Nelina, with the highest productivity\plant (39.5-42.1 g) and the highest heterosis (61.9-63.8%), the second one with high SCA effects, are of interest for the heterosis selection of productivity. The crosses 274 × Chirpan-539 and 274 × Natalia, with the longest fibers (28.9-29.3 mm) and heterosis (2.1-3.5%), the first one manifested high SCA effects, are of interest for the heterosis selection of fiber length. The results obtained are encouraging for the development of heterotic selection and practical use of heterosis in cotton based on male sterility. [ABSTRACT FROM AUTHOR]

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Salinity is a major abiotic constraint in majority of the rice cultivation areas of the world and improving grain yield in rice under such circumstances is one of the important breeding objectives. In the current study, combining ability estimates for twenty-four hybrids developed by crossing six lines with four testers were used to determine the genetic make up of 11 morphological traits under coastal-saline conditions. The aim of this study was to determine the combining ability, gene action and proportional contribution of cross components in rice genotypes. The experiment was conducted in the experimental farm, Department of Genetic and Plant Breeding, Faculty of Agriculture, Annamalai University. The analysis of variance for combining ability showed that specific combining ability (SCA) variances were larger than the corresponding general combining ability (GCA) variances for all the characters studied, which suggested that predominance of nonadditive gene action for the target traits. The proportional contribution of testers was observed to be higher than that of the lines and interactions of line x tester, revealing the higher estimates of GCA variance due to presence of additive gene action among the testers used. The best general combining parents for grain yield and its component characters were found to be ADT 37, ADT 43 and ADT 38 among the lines and CSR 36 and FL 478 among the testers based on per se and gca effects. The hybrids ADT 43 x CSR 36, ADT 42 x CSR 36 and ADT 37 x CSR 36 were considered to be superior crosses due to the superior performance for the majority of the economic characteristics examined along with early maturity and low stature plants. Highly significant sca effects for grain yield and its component traits were found to be suitable for heterosis breeding. The crosses viz., ADT 46 x CSR 36 and ADT 45 x CSR 36 were identified with high mean and negatively significant sca effects for yield and could be exploited for recombination breeding. [ABSTRACT FROM AUTHOR]

Given the increasing problems of water and soil contamination with cadmium (Cd), it is necessary to investigate the genetic and physiological mechanisms of tolerance to this metal in different crops, which can be used for the development of effective crop management strategies. This study aimed to assess the potential of grafting as a strategy to increase Cd tolerance and reduce absorption in tomato by evaluating the contribution of the root system and aerial parts for tolerance mechanisms. To this end, reciprocal grafting and diallel analyses were used to examine the combining ability of contrasting tomato genotypes under exposure to 0 and 35 µM CdCl2. Roots and above-ground parts were found to have specific mechanisms of Cd tolerance, absorption, and accumulation. Grafting of the USP15 genotype (scion) on USP16 (rootstock) provided the greatest synergism, increasing the tolerance index and reducing the translocation index and Cd accumulation in leaves. USP163 exhibited potential for breeding programs that target genotypes with high Cd tolerance. In tomato, both Cd tolerance and accumulation in aerial parts are genotype- and tissue-specific, controlled by a complex system of complementary mechanisms that need to be better understood to support the development of strategies to reduce Cd contamination in aerial parts. [ABSTRACT FROM AUTHOR]

The market value of cotton in exporting countries, such as Burkina Faso, depends on the quality of major fiber properties. A lack of variation among the genetic resources available in Burkina Faso hinders breeding progress to meet fiber quality demands in future cultivars. F1 populations from a half diallel crossing scheme between lines developed at Texas A&M AgriLife cotton breeding program at Lubbock and germplasm accessed from Burkina Faso were evaluated for fiber property enhancement. Crosses exclusively within common origin materials did not result in highly enhanced hybrids. Hybrids within American materials expressed significant SCA effects undesirable for future cultivars in Burkina Faso. Five hybrids within the Burkina Faso material expressed significant SCA effects: two of them implicating FK37 as the better parent in transmitting superior targeted fiber traits to its progenies. Hybrid FK37xE9 significantly enhanced UHML, Str, UI and SFI but not Mic and Rd. Inter-program hybrids with at least one significant SCA effect were crosses with female American lines and male Burkina Faso parents. Hybrids E53x16-2-216FQ, E53x15-10-610-7 and E32x15-10-610-7 showed significantly improved Str and UI for the most economically important traits, which also include Mic, UHML, SFI, Rd and +b. Together, the GCA and SCA effects, heritability and correlations showed more additive than non-additive gene actions. Therefore, knowledge of the best combiners and hybrids could be used in the cultivar development process to enhance value with improved fiber characteristics. [ABSTRACT FROM AUTHOR]

The success of developing prominent hybrids directly depends on the selection of parents with good combining ability which can transfer desirable genes with additive effects to their progeny. The data of 42 hybrids generated using 7 × 7 full diallel design; their seven parents along with three check hybrids were subjected to combining ability analysis from the experiment that was carried out during rainy season 2019. The analysis of variance showed significant general combining ability, and specific combining ability mean sum of squares for all the thirteen characters studied. It is obvious from the results that three lines (SC Sel 2, SC Sel 1 and SC Sel 3) showed high overall general combining ability status, suggesting these lines as good general combiners across traits. Eighteen hybrids had high overall specific combining ability status, while nearly 52% (22 hybrids), 57% (24 hybrids) and 47% (20 hybrids) of crosses showed high overall mid-parent, better-parent and standard heterosis. The unique superiority of crosses involving high overall general combiner parent in the crosses highlighted the importance of using such parents to realize high heterotic crosses. A non-linear relationship between high overall specific combining ability status and heterotic status of hybrids was noticed. The probability of obtaining a cross with high standard heterosis was more with employing parents with high general combining ability status. [ABSTRACT FROM AUTHOR]

Development of tomato hybrids with stable tolerance against tomato leaf curl virus (ToLCV) disease is necessary in the tropics and sub-tropics. Genotypes having a broad genetic base and phenotypic diversity were chosen as parents and crossed in a 4 × 3, line × tester fashion without reciprocals to produce 12 F1 tomato hybrids to determine manifestation of heterosis and gene action for characters. The predictability ratio exhibited a desired response for non-additive gene action in controlling expression of most traits including percent disease index (PDI) of ToLCV, but not for days to first flowering, locule number, fruit pH, fruit lycopene content and fruit yield per plant which were controlled by both additive and non-additive gene action. Specific gravity, titratable acidity and polar diameter of fruit were controlled by additive gene effect. Maximum heterobeltiosis in the desired direction was recorded for fruit yield per plant followed by lycopene content of fruit, retinol activity equivalent, and PDI of ToLCV. Two genotypes, "AVTO-1315" and "2016 Res/1" were promising genitors and may be utilized in future breeding. Hybrids "AVTO-1424 × 16 RES 1" (Ty-2, Ty-3, ty-5 + Ty-2) and "AVTO-1315 × 2016 Res/1" (Ty-1/Ty-3, Ty-2 + Ty-2) carrying multiple genes were considered promising for high yield with some field tolerance against ToLCV disease. Pyramiding multiple genes possessing at least Ty-2 and Ty-3 into tomato hybrids may be effective in managing ToLCV disease for tropical and subtropical regions. [ABSTRACT FROM AUTHOR]

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

Abstract: The breeding of Physalis peruviana is incipient in Brazil and is shown to be the most promising alternative for the development of productive genotypes with fruit quality. Therefore, the objective was to evaluate the combining ability between inbred lines of P. peruviana, thus indicating the selection of hybrids with fruit quality. Therefore, four populations from different origins were selfed for three generations and crossed in controlled hybridizations, resulting in 28 P. peruviana populations. The hybrid in relation to the parent performance, based on the effects of general and specific combining ability, was compared in a full diallel mating design (Griffing Method 1). In the analysis of variance, the factor genotype was partitioned into the following causes of variation: i) parents and F1 hybrids, ii) selfed generations and iii) Genotype × environment (GE) interaction. There were significant differences between Parents and F1 hybrids for the trait fruit polar diameter. Still, the interaction between specific combining ability x environment and, reciprocal effect x environment, was significant. However, for the Xanxerê environment, there was a reduction of approximately 3.0 mm in the polar diameter of the fruit in the hybrid Colombia x Peru and a reduction of 4.5 mm for the reciprocal (Peru x Colombia). In the comparison of the selfed generations S0 with S1, the fruit weight of the Lages population decreased by 0.380 g. There was also a reduction of 974.5 kg.ha-1 in the fruit yield of the Peruvian population. Thus, the performance of the P. peruviana populations in hybrid combinations is unpromising, indicating the existence of only one P. peruviana gene pool, with a restricted genetic basis.

Developing popcorn genotypes that are adapted to water-deficit conditions is crucial due to the significant impact of this abiotic stress on grain yield. This study aimed to assess the combining abilities of preselected popcorn lines for agronomic and root traits under well-watered and water-stressed conditions. A circulating diallel analysis was conducted to investigate the effects of the general and specific combining abilities of 10 lines and their respective hybrids for various traits, including productivity, popping expansion, expanded popcorn volume, 100-grain weight, ear length, ear width, support root angle, crown root angle, number of support roots, number of crown roots, density of support roots, and density of crown roots. Non-additive action genes predominantly influenced the agronomic traits under both water conditions. In contrast, the root traits displayed a greater proportion of additive action gene expression under both conditions, despite being significantly affected by the environment. Lines L61, L71, and L76 demonstrated positive and high effects for general combining ability. The hybrids L65/L76, L71/L76, and L61/L75, in addition to exhibiting satisfactory effects of their specific combining ability, also displayed the most favorable phenotypic responses for most agronomic and root traits, making them ideal candidates for inclusion in popcorn breeding programs aiming to develop drought-tolerant genotypes.

Abstract Background For the purpose of utilising hybrid vigour to produce possible hybrids with a suitable level of stability, the knowledge of gene activity and combining ability is a crucial prerequisite before choosing desirable parents. The present study was carried out with six parents crossed in full diallel fashion and generated 30 F1 hybrids. These hybrids were evaluated in two replications in Randomized Block Design at Department of Cotton, TNAU for combining ability and gene action. Diallel analysis was carried out according to Griffing’s method-I (parents + F1 + reciprocals) and model-I and Hayman’s graphical approach by using INDOSTAT software. Results Analysis of variance for combining ability indicated that mean square values of GCA, SCA and reciprocals were highly significant for all the traits except for the uniformity index. RG763 and K12 showed highly positively significant GCA effects for most of the yield traits while PA838 and K12 for fibre quality traits, so they were found as best general combiners. PAIG379 × K12 and PDB29 × K12 for yield traits, and PDB29 × PA838, RG763 × PA838, and CNA1007 × RG763 cross combinations for fibre quality traits could be recommended for future breeding programms. Conclusion The results of both Griffing’s and Hayman’s approaches showed that non-additive gene action predominates as SCA variance was bigger than GCA variance, so heterosis breeding is thought to be a more fruitful option for enhancing GCA of many traits.