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Growers may adopt a tomato hybrid if it is high yielder with good fruit quality and can withstand the bacterial wilt (BW) disease. A line × tester mating design was used to determine heterobeltiosis, combining ability and gene action for 15 characters in tomato. Most traits under study exhibited additive and non-additive gene action except days to 50% flowering, polar diameter of fruit, pH of fruit and lycopene content of fruit which were controlled by additive gene effect. Two genotypes, ‘Utkal Kumari’ and ‘CLN-2460E’ were identified as potential donors. The maximum, significant, heterobeltiosis was for disease incidence of BW followed by fruit yield per plant, fruit firmness, and fruits per plant. In the tropical tomato growing zones, two potential hybrids, ‘Utkal Kumari × CLN-2460E' and ‘Utkal Deepti × CLN-2460E', may fulfil significant horticultural requirements since they exhibited resistance against virulent biovars 3 and 6. More testing in a variety of edapho-climatic conditions is required to confirm the stability of the developed resistance and the hybrids’ resilience. Partial- to over-dominance reactions of fruit yield and other economic traits were reflected. Isolating pure lines from the segregating generation of heterotic F1s is another method to improve fruit yield and quality as well as disease resistance against bacterial wilt. [ABSTRACT FROM AUTHOR]

Information on gene action controlling the inheritance of quantitative traits is essential for selecting parents for hybridization and multiline varieties. Twenty hybrids obtained through 5 × 5 diallel mating with their parents were established on Teaching and Research Farm, Federal University of Agriculture, Abeokuta, Nigeria, in September 2018 using Randomized Complete Block Design in three replicates. The plants were observed for numbers of days to 50% flowering, plant height at flowering, stem girth, number of branches per plant, plant height at maturity, number of fruits per plant, fruit weight, fruit length, fruit width, and fruit yield per plant. Data were subjected to variance analysis, General and Specific Combining abilities were estimated, and gene effects and parameter ratios were done using Hayman’s method. Mid- and better-parent heterosis were estimated using Allard’s procedure. Genotype ‘NGB00356’ was the most desirable parent for earliness and the number of fruits per plant, while hybrid ‘NGB00347’ × ‘NGB00356’ was the best hybrid for fruit yield per plant. ‘NGB00356’, with its significant and positive general combining ability value for the number of fruits per plant, can be used as a parent in a hybridization program for yield improvement in okra. [ABSTRACT FROM AUTHOR]

Diallel analysis provides basic genetic information that is critically important to identify parents involved in hybridization breeding programs. This study was initiated to estimate combining ability effects and determine the type of gene action involved in inheritance of late blight resistance. Five tomato lines and 10F1 progenies produced by crossing of parents in a 5 × 5 half-diallel fashion were assessed for late blight resistance in field conditions. The combining ability ratio was greater than unity for all traits considered in this stud. At the same time, the degree of dominance was less than unity for all the traits, indicating a greater importance of additive gene effects for the inheritance of late blight resistance. The parents ’Eshete’ and ’Roma VF’ were general combiners, exhibiting significantadverse general combining ability effects for all studied traits. Specific combining ability effects of ’Roma VF × Eshete’ and ’Melkashola × Eshete’ were significantly negative for disease incidence, with all the lines exhibiting significant negative general combining ability effects for the trait, indicating transgressive segregants that are late blight resistant could be produced from crossing of these parental lines. These results, accordingly, indicated that the parents could be utilized in the crossing programme to develop late blight resistant transgressive segregant varieties. [ABSTRACT FROM AUTHOR]

Improving grain yield and quality traits under low nitrogen (N) supply is a desirable goal for wheat breeders. Thus, genetic parameters in wheat crosses and use them in breeding programs under contrasting N environments were estimated during the 2020/21, 2021/22, and 2022/23 growing seasons at the Experimental Farm of the Faculty of Agriculture, Fayoum University. A total of 36 wheat genotypes consisting of six parents, fifteen F1, and fifteen F2 progeny generations were grown in two adjacent experiments, (i.e., low level (50 kg N/feddan) represents the 1st environment; E1 and recommended level (75 kg N/feddan) represent the 2nd environment; E2. Each experiment was laid out in a randomized complete block design with three replications. Information on combining ability effects were estimated for physiological and grain yield and its components. The genetic analysis was performed using Griffing Method 2 and Model 1. The results revealed that mean squares due to N levels, genotypes, and genotypes × N interactions were significant for almost all studied traits. This indicates that variability that existed among these genotypes seems to provide a chance for the appearance of good new combinations that can be isolated in the following generations. The mean squares of general (GCA) and specific (SCA) combining ability were significant for almost all studied traits, indicating that additive and non-additive gene action are important to inheritance for these traits. The crosses Sakha 94 × Sakha 95, Sakha 94 × Giza171, Sakha 94 × Sids 14, Sakha 94 × Misr 1, Sakha 95 × Misr 1, Sakha 95 × Misr 3, Giza 171 × Misr 1, Sids 14 × Misr 1 and Misr 1 × Misr 3 had favorable SCA effects and had high mean performance for grain yield/plant and some of the other traits. The best general combiner’s parents were Sakha 94, Giza 171, Sids 14, Misr 1, and Misr 3, who possessed high GCA effects for grain yield/plant and some of the other studied traits. It could be concluded that the use of a low nitrogen fertilizer level (50 Kg N/feddan); can minimize the chemical nitrogen and proved to be the best way to save about 30% of the chemical and avoid undesirable effects, then reduce the cost of production and pollution that could be accrued by the excessive use of chemical fertilizer. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is one of the most widely cultivated grain crops globally. In sub-Saharan Africa (SSA), it plays an important role in ensuring both food and income security for smallholder farmers. This study was conducted to (i) assess the performances of testcross hybrids constituted from maize lethal necrosis (MLN) tolerant doubled haploid (DH) lines under various management conditions; (ii) estimate the combining ability effects and determine the nature of gene action in the DH lines; and (iii) identify DH lines and testcross hybrids for resistance to MLN, high grain yield, and other important traits. Eleven DH lines were crossed with 11 single-cross testers using the line-by-tester mating design, and 115 successful testcross hybrids were generated. These hybrids, along with five commercial check hybrids, were evaluated across four optimum management conditions, two MLN artificial inoculations, and one managed drought environment in Kenya. Under each management condition, the effects of genotypes, environments, and genotype-by-environment interactions were significant for grain yield (GY) and most other traits. Hybrids T1/L3, T10/L3, and T11/L3 exhibited higher grain yields under at least two management conditions. A combining ability analysis revealed that additive gene effects were more important than non-additive effects for GY and most other traits, except for leaf senescence (SEN) and MLN disease severity score. DH line L3 exhibited a desirable general combining ability (GCA) effect for GY, while L5 was the best general combiner for anthesis date (AD) and plant height (PH) across all management conditions. DH lines L2, L6, and L7 showed negative GCA effects for MLN disease severity. Single-cross testers T11 and T10 were good general combiners for GY under all management conditions. Hybrids T2/L11, T9/L10, and T2/L10 demonstrated high specific combining ability (SCA) effects for GY under all conditions. This study identified DH lines and testers with favorable GCA effects for grain yield, MLN resistance, and other agronomic traits that can be used in breeding programs to develop high-yielding and MLN-resistant maize varieties. Better-performing testcross hybrids identified in the current study could be verified through on-farm testing and released for commercial production to replace MLN-susceptible, low-yield hybrids grown in the target ecologies. [ABSTRACT FROM AUTHOR]

Plant breeders are always in pursuit of desirable genes and gene complexes, leading to identification of potential and promising individuals/segregants often exhibiting traits with higher intensity. Identifying segregants with desirable combination of multiple traits would enable a breeder to develop superior cultivars. In this study, combining ability and multiple parent‐based approach was employed to derive segregants simultaneously superior for multiple traits. Single and double crosses were developed by crossing 11 parental lines in half diallel fashion and were evaluated under seven environments. To create crosses, the parental lines with the highest positive gca effects were selected in addition to desirable yield and fibre quality traits (SCYP, NOBP, BW, GOT, UHML and FS). The positive and significantly higher gca effects in these parents is an evidence of prominence of additive and additive × additive component of genetic variance. To identify desirable segregants, six F2 populations derived from four single and their two double crosses were evaluated by raising an optimal population size of 910–935 and 3040–3055 plants for single and double crosses, respectively. In each population, proportion of desirable and simultaneous transgressive segregants was estimated. A total of 19 (2.87%), 22 (3.32%) and 24 (3.60%) plants were transgressive in nature simultaneously for multiple traits in single crosses, namely, RAHH‐1755 and RAHH‐455, and double cross, namely, RHDC‐1933, of Group I, respectively. While in Group II, 22 (3.32%), 22 (3.32%) and 24 (3.60%) plants showed simultaneous transgressive segregation in RAHH‐1702, SHH‐818 and RHDC‐1940, respectively. The per cent simultaneous transgressive segregants were found to be higher in the double crosses compared with their respective single crosses, possibly for the reason that double crosses involve more number of parents owing to increased recombination. Hence, breeding for desirable segregating recombinants using diallel and multiple parent‐based approach paves the way towards directional selection based on combining ability making it more efficient compared with conventional means of hybridization followed by selection. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Marination is an important part of air‐dried beef processing, and traditional methods are inefficient and produce inconsistent results. Ultrasound, as a novel technology, can be combined with traditional marination methods. The study aimed to investigate the improvement of beef flavor by ultrasound‐assisted marination. At the same time, the potential relationship between the alteration of meat protein and flavor quality by ultrasound‐assisted marinating was further investigated to enable better flavor modulation and research.Headspace solid‐phase microextraction–gas chromatography–mass spectrometry revealed that the spice flavor of beef was significantly enhanced by 500 W ultrasound‐assisted marination. Meanwhile, the experimental results demonstrated that the ultrasound‐assisted marination promoted the unfolding of beef myofibrillar protein structure, which increased the number of hydrophobic and hydrogen bonding sites, enhanced the electrostatic effect and improved the functional properties of the protein. Ultrasound‐assisted marination significantly enhanced the binding ability of beef myofibrillar proteins to flavor compounds compared with conventional marination. An electronic nose confirmed that this resulted in a significant increase in the flavor of the marinated meat.Ultrasound‐assisted marination effectively enhanced the flavor of marinated meat, which was closely related to the development of protein conformation. The results of this study have important implications for the food industry and the role of protein unfolding processes in flavor modulation. In particular, the findings can be practically applied to improving meat flavor under ultrasound‐assisted marination. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

An experiment was carried out to evaluate the level of heterosis and combining ability in cotton. Thirty five interspecific hybrids were generated by crossing five lines viz., GMS 14, GMS 17, GMS 19, GMS 21 and GMS 27 with seven testers namely CCB26, CCB51, DB1901, CCB2, CCB6, CO18 and Suvin in line x tester mating fashion. Twelve parents along with 35 hybrids and a standard check (DCH 32) were raised in a randomized block design with two replications to evaluate the combining ability and heterosis to identify good combiners and the best hybrids with high yield and fibre quality. The lines viz., GMS 14 and GMS 17 and the testers viz., CO 18 and Suvin were found to record significant gca effects for yield and fibre quality traits. Out of the 35 hybrids, GMS 14 x CO18, GMS 27 x Suvin and GMS 17 x CO18 recorded highly positive significant sca effects for most of the traits. The ratio between additive and dominant genetic variance was less than one for all the traits, indicating the preponderance of dominant gene action or non-additive gene action. The above three crosses also exhibited high heterosis over mid parent, better parent and standard check. Hence, these hybrids could be harnessed after analyzing their performance in yield trials. [ABSTRACT FROM AUTHOR]

The combining ability provides insightful information about the genetic mechanisms that govern the inheritance of traits and enables the identification of potential inbred lines; and promising hybrid combinations for crop improvement. However, most studies on quality protein maize (QPM) have focused on nutritional aspects, and very few are focused on their combining ability. In addition, studies on the adaptation, hybrid performance and stability of QPM in temperate areas remain scarce. Therefore, the present study sought to examine the combining ability of eight QPM inbred lines (QPM13, QPM14, QPM20, QPM21, QPM49, QPM50, VQL1, and VQL17). These 8 lines were subjected to half-diallel mating. Consequently, 28 crosses obtained were further evaluated in the temperate region of Kashmir against one check and parents in the RCBD, with three replications in a single row. The results revealed significant variances for general combining ability (GCA) and specific combining ability (SCA) for most of the recorded agronomic, yield, and quality traits. The crosses QPM49 × VQL1, QPM 13 × QPM14, QPM21 × VQL17, QPM13 × QPM50 and QPM50 × VQL17 were found to perform best in terms of earliness in tasselling (-1.842), silking (-1.204), days to mature (-2.654), highest yield (12.875 g)and protein content (1.113%), respectively. These promising crosses can be viable material sources for future QPM variety development programs in temperate regions. [ABSTRACT FROM AUTHOR]

Chili (Capsicum annuum L.) is an important functional food due to its main bioactive compound, capsaicin, and other nutritional phytochemicals. However, very few studies have been conducted to develop hybrids with a high content of nutritional phytochemicals. The present study involving six parents was conducted to identify superior hybrids with higher nutritional quality based on combining ability and heterosis following Griffing's diallel Method II Model I. A broad spectrum of genetic variation among the six parents and fifteen F1 hybrids was confirmed by analysis of variance. (H1/D)0.5 value indicated that partial dominance gene action controlled all the traits except capsaicin and total phenolic content. Based on general combining ability (GCA) results, parent P3 (PLP-2s) was the best general combiner for all the traits except K and Na, followed by the parents P6 (BU Capsicum 1), P5 (Morich-8), P4 (Chili Japan) and P1 (Red Chili). Specific combining ability (SCA), along with heterotic response, revealed that the F1 hybrid P3xP6 (PLP-2s x BU Capsicum 1) was the best hybrid, followed by the hybrids P4xP6 (Chili Japan x BU Capsicum 1) and P3xP4 (PLP-2s x Chili Japan), as they exhibited superiority for major nutritional components, such as capsaicin and ascorbic acid. Ultimately, the subsequent selection of the F1 hybrids would help develop better nutritional-quality hybrids. [ABSTRACT FROM AUTHOR]

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

Chili (Capsicum annuum) consumption is often suggested, and using functional food cultivars is the most effective strategy post COVID-19 pandemic. Controlling chili breeding activity is one of the most effective methods to produce new hybrid varieties. However, the general combining ability (GCA), specific combining ability (SCA), and heterotic effect of functional biochemicals (polyphenol content, antioxidant activities, and α-glucosidase inhibitory compounds) remain poorly known in C. annuum. This study aimed to estimate these parameters in C. annuum by using five different genotypes and their hybrid combinations based on growth characteristics, yield, yield components, and fruit functional biochemicals. The F1 and F1R progenies were obtained from crosses in a greenhouse with a full diallel mating design. Each parent used in this study had a GCA advantage for each characteristic. The hybrid combination of IPB074 × IPB005 and IPB435 × IPB367 displayed the best yield results. However, the results indicated the opposite regarding α-glucosidase inhibitory compounds. The heterotic effect of functional biochemicals was observed for traits related to genotypes, polyphenol content, antioxidant activity, α-glucosidase inhibitory compounds, and similar properties related to yield and yield components, indicating their use in hybrid chili production.

Abstract Okra (Abelmoschus esculentus L. Moench) is a vital vegetable crop known for its nutritional and economic significance, especially in tropical and subtropical regions. Studying heterosis and combining ability in okra is crucial for enhancing its yield, quality, and resistance to pests and diseases. Heterosis can lead to superior offspring with enhanced traits while understanding combining ability helps in identifying the best parent combinations for breeding programs. Okra is an often cross-pollinated crop; therefore, exploiting heterosis is advantageous. The study was conducted from 2021 to 2022 at the Experimental Farm and Quality Analysis Laboratory, Department of Vegetable Science, College of Horticulture, Dr Yashwant Singh Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh, India to evaluate the heterosis and combining ability in okra to facilitate the development of high-yielding, resilient cultivars. The experimental material consisted of an F1 population of 30 crosses obtained from 10 parental lines crossed with three testers in a Line × Tester mating design, plus a standard check (Punjab-8). Estimates of heterosis (heterobeltiosis and standard heterosis) of the cross combinations UHFO-6 × Pusa Bhindi-5, UHFO-6 × Arka Anamika and UHFO-9 × Arka Anamika were high for inter-nodal distance, number of pods per plant, average pod weight, pod yield per plant, harvest duration, hundred seed weight, mucilage content, etc. Higher estimates of general combining ability (GCA) effects for pod yield per plant were observed in the parental lines UHFO-6 (123.47) and UHFO-9 (7.49). Among the cross combinations, UHFO-10 × Hisar Unnat (38.81), UHFO-2 × Pusa Bhindi-5 (38.29), UHFO-2 × Arka Anamika (17.42), and UHFO-5 × Arka Anamika (15.06) demonstrated higher estimates of specific combining ability (SCA) effects for pod yield per plant. The cross UHFO-2 × Hisar Unnat (160.00) exhibited the highest heterobeltiosis for mucilage content, while UHFO-10 × Arka Anamika (562.03) showed the highest standard heterosis for total polyphenol content. These cross combinations could produce okra with enhanced nutritional and medicinal properties. The highest GCA and SCA effects for pod yield per plant were observed in UHFO-6 (123.47) and UHFO-10 × Hisar Unnat (38.81), respectively. Identifying these parental lines and cross combinations based on their combining ability can result in the development of okra hybrids with substantially higher yields. In future, after multi-location trials, these parents and crosses can be released to replace existing okra cultivars (hybrids/varieties). Higher yielding and better quality okra cultivars can enhance the profitability for farmers, contribute to food security, and meet market demands more efficiently.

The present investigation was undertaken in brinjal (Solanum melongena L.) to estimate combining ability and gene action following a half diallel mating design using ten parents. The ratio of genetic variance components, σ2gca/σ2sca and σ2D/σ2A, showed dominant gene action, indicating the presence of non-additive genetic variance for days to 50% flowering, fruit yield per plant, total phenol, antioxidant activity and total soluble sugar. The traits fruits per plant, fruit girth, and fruit weight showed additive genetic variance. Among the parental genotypes, AB 15-08, ABSR 2 and AB 20-13 were found to be good general combiners for fruit yield, fruits per plant, and total soluble solids. The three highest-ranking hybrids were AB 15-08 × AB 20-13, AB 15-08 × AB 20-03 and AB 20-07 × GP BRJ 224. The above hybrids would be rewarding for harnessing heterosis.

Twenty F1s, parents and checks viz., MTU 1010 and RNR 15048 were assessed for grain yield and its contributing attributes to study combining ability and heterosis. The mean of hybrids was greater than that of the parents except for days to 50% flowering and plant height. For majority of the investigated characters, the analysis of variance indicated considerable variations among parents and hybrids. Degree of dominance was more than unity for majority of traits including grain yield. For the examined characters, SCA variances were equal to GCA variances, indicating the dominance of additive and non-additive gene activity. The traits days to 50 % flowering, plant height, panicle length, test weight, kernel length and kernel length/breadth ratio showed additive gene action whereas the remaining traits showed non-additive gene action. The gca effects revealed that among the lines IR 72 had significant gca effects in desired direction for yield and yield attributing traits. Among the 20 hybrids, MTU 1001 x Akshyadhan was found to be a good specific combiner for grain yield per plant. Similarly, the hybrids NLR 34449 x IR10N270 and IR 72 x IR10N270 were found to be good specific combiners for grain yield and yield contributing characters. The standard heterosis of these three hybrids was positively significant over the check varieties MTU 1010 and RNR 15048. Based on mean, sca and heterosis estimates, MTU 1001 x Akshyadhan, NLR 34449 x IR10N270 and IR 72 x IR10N270 were identified as promising hybrids.

An experiment was carried out to evaluate the level of heterosis and combining ability in cotton. Thirty five interspecific hybrids were generated by crossing five lines viz., GMS 14, GMS 17, GMS 19, GMS 21 and GMS 27 with seven testers namely CCB26, CCB51, DB1901, CCB2, CCB6, CO18 and Suvin in line x tester mating fashion. Twelve parents along with 35 hybrids and a standard check (DCH 32) were raised in a randomized block design with two replications to evaluate the combining ability and heterosis to identify good combiners and the best hybrids with high yield and fibre quality. The lines viz., GMS 14 and GMS 17 and the testers viz., CO 18 and Suvin were found to record significant gca effects for yield and fibre quality traits. Out of the 35 hybrids, GMS 14 x CO18, GMS 27 x Suvin and GMS 17 x CO18 recorded highly positive significant sca effects for most of the traits. The ratio between additive and dominant genetic variance was less than one for all the traits, indicating the preponderance of dominant gene action or non-additive gene action. The above three crosses also exhibited high heterosis over mid parent, better parent and standard check. Hence, these hybrids could be harnessed after analyzing their performance in yield trials.

Tomate de cáscara (Physalis ixocarpa Brot.) has great potential to generate hybrids and cultivars that present high yields. The objective of this work was to estimate genetic parameters using the REML/BLUP methodology and investigate selection strategies for F1 populations from a partial diallel, to increase fruit production. The crosses were carried out in 2020 and the evaluation of the parents and hybrids were carried out in 2021, using a randomized block design with three replications, and an experimental plot of 10 plants. Combining ability, heterosis, phenotypic correlations, correlation networks, path analysis, and selection indexes were estimated. Genetic variability was found for the descriptors fruit production, number of fruits per plant, fruit transverse axis, and soluble solids. Additive effects were predominant over non-additive gene action. The 92V and 173V parents were recommended to increase fruit production and the number of fruits per plant, due to their general combining ability values. PI02 and PI05 were the hybrids with the highest heterosis estimates for fruit production and number of fruits per plant. The negative correlation between fruit production and soluble solids stood out in the correlation study and trail analysis, thereby assisting in the strategy regarding the selection direction. The selection indexes selected the progenies: PI02, PI04, PI05, 92V and 173V. [ABSTRACT FROM AUTHOR]

Combining ability of nine sunflower inbreds (four cytoplasmic male sterile lines and five restorers) was tested in line x tester mating design. The material including parents and cross combinations were evaluated for nine agro-biochemical parameters. The inbreds viz., 67A and 47R were identified as good general combiners for seed yield and oil yield, 88A, 89A, 47R and GMU 1080 were identified as good general combiners for oil content and 67A, 179R and GMU 1080 exhibited good general combining ability for early maturity. Similarly, highest significant positive specific combining ability effects for seed yield were observed for crosses 38A x 179R followed by 89A x 179R and 88A x 159R. On the basis of positive significant SCA effects for oil percent the crosses 67A x GMU 1080, 89A x 159R and 88A x 150R were found to be superior. All the traits exhibited non-additive gene action and the proportional contribution to variability was maximum by crosses except for seed yield where lines contributed more towards variability. The crosses 67A x 47R, 89A x 179R, 38A x 179R and 88A x 150R recorded maximum average heterosis for seed and oil yield and the cross combinations 67A x 47R, 88A x 150R and 67A x GMU 1080 revealed maximum heterosis against better parent also for the above traits.

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

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

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

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

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

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

Maize is an important agricultural crop ensuring food and nutritional security throughout the globe. It is highly sensitive to many of the biotic and abiotic stresses, and among them, drought is the most severe abiotic stress limiting maize production. Climate change tends to worsen this scenario by changing precipitation patterns and decreasing water availability. Hence, the present study was undertaken to identify drought‐tolerant inbred lines under well‐irrigated and managed stress conditions in the field toward developing drought‐resilient maize hybrids. The initial in vitro screening of 65 agronomically elite maize inbred lines was undertaken at 15%, 20%, and 25% polyethylene glycol (PEG) concentrations. Subsequently, the 15 inbreds selected for their promising performance under varying concentrations of PEG were evaluated in the pot (100%, 60%, and 40% of field capacity [FC]) and managed field experiments (moisture stress). Various physiological, biochemical, and yield attributing traits were measured among the inbreds to assess their drought tolerance potential. The analysis of variance in the pot and field experiments indicated significant genotypic differences among the inbreds and genotype × treatment interaction for different traits considered. In the pot experiment, the phenotypic correlation analysis showed a significant positive association of shoot fresh weight with plant height (r =.71), number of leaves (r =.58), relative water content (r =.60), root fresh weight (r =.58), shoot dry weight (r =.60), and SPAD meter readings under (r =.71) moisture stress condition. In the field experiment, the grain yield had a significant positive association with plant height, relative water content, SPAD before stress, ear length, ear girth, kernel rows per ear, kernels per row, and per day productivity under stress. Proline accumulation in inbreds during stress was found to be higher compared to nonstress conditions. The inbred lines CML 505, CML 444, CML 451, CML 504, QM 11408, and MAI 214 were promising for most of the drought tolerance imparting traits. These six inbreds along with four inbreds having low DRI (SKV 50, MAI E2‐163, MAI 16, and MAI E2‐241) were crossed in half diallel manner, and crosses involving low × high or high × low DRI inbreds showed higher grain yield. The current study also revealed the need of combining various physiological and yield attributing traits in drought breeding programmes. [ABSTRACT FROM AUTHOR]

Pearl millet has two major heterotic groups, HGB (Heterotic Group B) and HGR (Heterotic Group R), each with unique genetic backgrounds and traits. Leveraging appropriate genetic resources is crucial for enhancing the potential of these heterotic groups in hybrid breeding programmes. Testers are essential in this context, determining the combining ability of new breeding lines and accurately assessing the performance and potential of parental lines in hybrid combinations. Two sets of test crosses were produced using line × tester mating design: Set 1 with six HGB testers crossed with new restorer lines and Set 2 with six HGR testers crossed with new seed parental lines, evaluated at multiple locations in India. Testers were evaluated for their effectiveness using multiple criteria, such as rank correlation analysis for line performance in hybrid combinations, discrimination ability, general combining ability, per se performance and Biplot analysis. These assessments determined their relative ranking, with HGB1‐T3, HGB2‐T3, HGR1‐T1 and HGR2‐T1 identified as efficient testers. The genetic analysis helps identify efficient testers for selecting superior genotypes, thereby enhancing heterotic group performance by incorporating appropriate new breeding material. [ABSTRACT FROM AUTHOR]

Despite hybrid dominance contributing to the genetic improvement of crops, little is known about heterosis and inheritance patterns of endogenous substances in sorghum (Sorghum bicolor (L.) Moench) root bleeding sap. In this study, six sterile and six restorer lines of sorghum and 36 hybrid sorghum combinations formulated as incomplete double-row crosses were selected as test materials, and heterosis, combining ability, heritability, and their interrelationships of root bleeding sap endogenous substances in different hybrid sorghum combinations and their parents were investigated. The results showed that the root bleeding sap of the F1 generation of hybrid sorghum had a high heterosis in both soluble sugar content and amino acid content at the flowering stage, and the average high-parent heterosis was 129.34% and 74.57%, respectively. Indole-3-acetic acid (IAA), cytokinins (CTK), gibberellic acid (GA3), abscisic acid (ABA), soluble sugar, amino acid, and root bleeding intensity were mainly affected by non-additive genetic effects of the genes. Soluble protein was affected by additive genetic effects of the genes and had a high narrow heritability (75.50%), which could be selected at low generations in breeding. The combining ability analyses showed that the sterile lines 521A and 170A, and the restorer lines Ji318R and 0–30 were promising parents with high general combining ability. Correlation analysis showed that all endogenous substances of root bleeding sap were positively correlated with the sum of parental general combining ability (GCA) at highly significant levels, and IAA, CTK, GA3, ABA, soluble sugar, amino acid, and root bleeding intensity were positively correlated with male GCA at significant or highly significant levels. Therefore, the GCA of the restorer lines root bleeding sap endogenous material or the sum of both parents' GCA can be used to predict the performance of wounding endogenous material in the F1 generation of hybrid sorghum. Overall, this study results can help elucidate heterosis mechanisms of root bleeding sap endogenous material and improve sorghum quality. [ABSTRACT FROM AUTHOR]

The present studied carried out at Sakha Agricultural Research Station, Cotton Research Institute, Agricultural Research Center, Egypt, during 2022 and 2023 growing summer, during 2022 growing season, six cotton varieties of cotton belong to (Gossypium barbadense L.) were sowing and crossed in a half diallel mating design produce 15 F1 hybrids. The F1 hybrids and parents growing in 2023 season at randomized complete blocks design with three replications. The results showed that the squares of the genotypes, parents as well as crosses were highly significant for all traits studied with boll weight trait parents. The parental genotypes Giza 88 and Giza 92 gave significant (desirable) GCA effects for most fiber properties. Karshenky and Australy 13 showed GCA positive significant effects of most yield traits, this direction is desirable. Both of Giza 88 x Giza 86 and Australy 13 x Karshenky crosses recorded significant (desirable) SCA effects for most yield and fiber properties. Desirable relative to midand better-parent for some yield traits were found for the crosses, Giza 88 x Giza 86 and Australy 13 x Karshenky while, the crosses Giza 92 x Pima S7 and Giza 92 x Karshenky indicated desirable for some studied fiber properties. Non-additive genetic variances were larger than the additive genetic variance with respect to all traits studied. The broad sense heritability of seed cotton yield per plant was the highest value (93.91%) while the lowest value was recorded to boll weight (50.51%). Generally, Karshenky and Australy 13 could be used in breeding programs for improving high yielding varieties, while Giza 88 and Giza 92 could be considered as excellent parents for breeding programs to produce new varieties characterized with best fiber properties. [ABSTRACT FROM AUTHOR]

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Amylose and resistant starch (RS) possess numerous industrial applications and health benefits. However, maize grains possess low amylose (<35%) and RS (<5%). To date, no information is available on the genetic variability of amylose and RS in subtropical maize. Here, 21 hybrids developed using half‐diallel mating design are evaluated for starch parameters at three locations. Analysis of variance (ANOVA) revealed a minor contribution for environments for amylose and RS. Amylose (22.2%–49.1%) and RS (1.02%–23.9%) showed wide variation among the hybrids. The experimental hybrids possessed significantly higher amylose (38.1%) and RS (20.9%) over the check hybrids (amylose: 29.1%, RS: 2.3%). PUSA‐AML‐H12, PUSA‐AML‐H18, and PUSA‐AML‐H16 are observed to be the most promising hybrids. Amylose and RS are positively correlated (r = 0.45), while total starch (TS) is negatively correlated with RS (r = −0.53). PMI‐AML‐147, PMI‐AML‐149, and PMI‐AML‐146 are the best general combiners for amylose and RS. Pusa‐AML‐H1, Pusa‐AML‐H12, and Pusa‐AML‐H5 emerged as the best specific combiners for amylose and RS. Both additive and nonadditive variances are important for amylose and RS. This is the first study of amylose and RS in a subtropical maize background, which could be significant in improving amylose and RS. [ABSTRACT FROM AUTHOR]

Soil acidity is one of the most important constraints to maize production in Angola, where both yellow and white maize is essential for food and feed requirements. In this study, four yellow acid soil tolerant donor lines from the International Maize and Wheat Improvement Centre (CIMMYT)—Colombia were crossed with ten yellow elite lines adapted to the mid-altitude climatic conditions developed by CIMMYT—Zimbabwe, in order to identify donor lines, which can be potential sources of acid tolerance genes in breeding programs in Angola and within the mid-altitude climatic zones. The two groups of parents were crossed using a line by tester mating design, yielding 36 crosses with sufficient seed, which were evaluated alongside six acid tolerant commercial hybrids, during the 2014–16 cropping seasons at nine sites, representing acid and non-acid soils in Angola and Zimbabwe. A significant (p < 0.05) line and line × tester effect for grain yield performance was observed across acid and non-acid conditions. Acid tolerance donor lines CY3 and CY1 showed the highest positive GCA effects for grain yield. In addition, crosses involving these two donor lines had the best yielding ability and stability under both acid and non-acid conditions. For instance, the crosses CH142464 (ZY2 × CY3) and, CH142447 (ZY2 × CY1) were the best combinations for grain yield performance under both acid and non-acid soil conditions, and were stable compared to the commercial check hybrids. Crosses involving the acid tolerant donor lines mostly flowered earlier than the commercial checks. Overall, the data showed the potential of tropically-adapted exotic yellow maize acid tolerance donor lines in improving productivity of sub-tropical maize under both low-pH and well-managed soil conditions. [ABSTRACT FROM AUTHOR]

Snap bean (Phaseolus vulgaris L.) is among the leading vegetables in Kenya that is mainly grown for export with the potential to increase household income. There are few programs in Kenya that focus on breeding new cultivars for increased production. The development of snap bean varieties that are resilient to the changing climate is crucial for sustainable agriculture in Kenya. To achieve this, knowledge of gene action, trait expression, and heritability is vital in effective breeding for quantitative traits like pod quality and yield. A study was conducted to investigate the inheritance of pod quality and yield traits in snap beans, which can inform the breeding of snap beans. A half diallel cross involving two indeterminate dry beans (G2333 and MCM 5001) and five determinate snap beans (Amy, Moonstone, Seagull, Serengeti and Vanilla) varieties was conducted. Data on pod traits (pod weight per plant, pod number per plant, pod length, pod diameter, pod wall fiber and pod suture string) were collected from 21 F1s and 7 parents grown in two locations (Embu and Kirinyaga Counties) in Kenya. The results showed significant genotypic and environmental effects (P < 0.001) for all traits, with significant genotype by environment (G × E) interactions for most traits. Additionally, general combining abilities (GCA) and specific combining abilities (SCA) were significant for all traits evaluated. The significance of GCA and SCA indicated the importance of both additive and non-additive gene effects in controlling the traits, although the additive gene effects were predominant. The study revealed that Vanilla and Serengeti had the highest GCA estimate for pod quality traits, while G2333 and MCM5001 had the highest GCA estimate for pod yield traits. Snap bean pod yield and quality are quantitative traits controlled by multiple genes and influenced by the environment. Therefore, the predominance of additive gene effects suggests that selection for these traits in segregating generations could yield satisfactory gains. The results of this study could impact the development of snap bean varieties that are more resilient to the effects of climate change. Thus, improving the sustainability and productivity of the agriculture sector in Kenya. [ABSTRACT FROM AUTHOR]

The article presents a study which estimated combining ability and heterosis of pearl millet hybrids for yield, and other yield components and identified superior pearl millet hybrids. Topics include analysis of variance for combining ability and estimation of variance components for grain yield and its components, estimates of general combining ability (GCA) of parents and specialized combining ability (SCA) effects of crosses, and estimates of SCA effects for eight characters in pearl millet.

A half-diallel cross study of seven melon inbred lines was carried out. The seven parents and their 21 F1 hybrids were evaluated for precocity of maturity, average weight per fruit, and fruit quality (fruit size, rind thickness, and soluble solids). The Diallel analysis was investigated for breeding values of these melon genotypes via general and specific combining ability, relationships between general and specific combining ability, and heterosis for the evaluated traits. The analysis of variance of the traits evaluated indicated highly significant differences among genotypes, suggesting the presence of adequate genetic variation for breeding. Additive genetic effects were most important with respect to fruit weight, while genetic dominance and epistasis effects mainly controlled fruit quality traits (fruit size, rind thickness, and TSS). Parent 1 (P1) and parent 3 (P3) had significant positive general combining ability effects for fruit weight. Also, P3 had positive general combining ability effects for fruit length and diameter, and cavity diameter. P3 was found to show maximum significant GCA in the desirable direction for all the traits except for TSS. Evaluation of heterosis (%) revealed that hybrid P1 × P3 can be considered as the best-performing hybrid for average fruit weight, TSS, and precocity, which also exhibited the highest positive and significant SCA effect for these traits. These results suggested that, among the melon genotypes studied, there is the potential to generate superior new varieties in hybrid production. [ABSTRACT FROM AUTHOR]

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

Information on the inheritance of adaptive traits to high plant density (HD) and low N (LN) in maize is a prerequisite for breeders to develop tolerant varieties to these stresses. The objective of the presented study was to estimate additive and dominance variances, heritability, and genetic advancement of the adaptive traits of tolerance to HD and LN stresses. Eight diverse maize inbred lines tolerant to HD and LN were options for diallel crosses. Parents and F1 crosses sustained evaluation in two seasons under nine environments, viz., three plant densities (high = HD, medium = MD, and low = LD) × three N levels (high = HN, medium = MN, and low = LN). A randomized complete block design with three replications functioned in each environment. Both additive and dominance variances were significant; dominance was appreciably higher than the additive variance in most cases. The degree of dominance was more in the over-dominance range. The highest heritability, along with the highest genetic advance, succeeded from the environment stressed for both HD and LN for leaf angle, penetrated light at the bottom of the plant, and leaf area produced 1g grain, and from the environment stressed for HD for plant height and 100-kernel weight. Moreover, the results suggested that heterosis breeding is the method of choice for the genetic improvement of most studied traits. [ABSTRACT FROM AUTHOR]

The present study was conducted to find out high yield and good quality cucumber hybrids which can further be released for cultivation in the tropics under open filed conditions. Therefore, five lines (2 gynoecious, 1 each predominantly gynoecious, parthenocarpic gynoecious and predominantly gynoecious and parthenocarpic) and 11 testers (monoecious) were crossed in a line × tester mating design to develop 55 F1 hybrids at Vegetable Research Farm, Punjab Agricultural University, Ludhiana. All the 71 genotypes were evaluated during spring–summer 2021 under open field conditions for 11 quantitative traits. Gene action study revealed the predominant role of non-additive genetic variance for all traits except for fruit length. On the basis of GCA (general combining ability) effect, lines PK-1, PBRK-11 and 25–46 VNR and testers Punjab Naveen, Pusa Uday and PMC-1were found to be best for fruit yield, quality and earliness which can be utilized as donor parents in future breeding. The maximum heterobeltiosis was recorded for fruit yield followed by fruit number per plant, fruit weight, fruit length and fruit diameter. The significant and positive correlation between GCA and mean of parental lines was observed for fruit yield, fruit number per plant, fruit length, and days to first fruit picking. Exploitation of the top performing hybrids 'PK-1 × AVCU-1205, PK-1 × Swarna Ageti, PK-1 × PMC-1 and PBRK11 × Punjab Naveen', after critical evaluation, could be recommended for commercial cucumber open field production in the tropics. Promising hybrids could also be exploited in segregating generations to identify pure lines having high yield with good fruit quality. [ABSTRACT FROM AUTHOR]

Pansy is one of the most important bedding winter annual for sub-tropical climatic conditions. Twenty-eight F1 hybrids of pansy were evaluated in randomized block design with three replications, to study the combining ability for vegetative and floral characters. The analysis of variance indicated significant variability among all the genotypes for all the characters. The ratio of genetic component of variance indicated the equal importance of additive and non-additive gene action in governing the flower yield and its component traits of pansy. Estimates of general combining ability effects showed that parents Pa-64-1-5-14, Pa-62-4-12-18, Pa-63-1-7-25 and Pa-32-8-7-6 were good general combiners for most of the traits except stalk length and flower size. The specific combining ability effects showed that for yield traits the best cross combinations were Pa-64-1-5-14 x Pa-62-4-12-18, Pa-13-1-2-3 x Pa-47-1-3, Pa-11-1-3-7 x Pa-62-4-12-18, Pa-64-1-5-14 x Pa-63-1-7-25 and Pa-11-1-3-7 x Pa-64-1-5-14. The study on gene effect of different characters indicated the predominance of non-additive gene effects for most of the characters. The gca variances was higher for branches number, flower size, days from bud initiation to flowering and flowers number than sca variances, indicating additive gene action, and progeny selection will be effective for the genetic improvement of these traits. [ABSTRACT FROM AUTHOR]