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Background Wheat plays a pivotal role in global food and nutritional security. To meet the growing demand for food, increasing wheat production through hybrid development remains an untapped avenue. However, the autogamy of wheat causes a significant challenge for hybrid development. Results The present study aimed to convert the elite bread wheat cultivars HD3086 and HD2932 into a cytoplasmic male-sterile (CMS) lines using the CMS donor parent (A-GW365) through a backcross breeding approach. Background analysis using 152 and 145 SSR markers confirmed ˃95% recovery of recurrent parent genomes (RPG) of the HD3086 and HD2932, respectively. The newly developed CMS lines were evaluated for pollen sterility and phenotypic similarity in comparison to recurrent parents. The cytological study and DUS characterisation of the converted A lines revealed complete sterility and similarity with the recurrent parent for morphological and agronomic traits. Further, two converted A lines, A-HD3086 and A-HD2932 and donor A line A-GW365 were crossed with six newly developed fertility restorer lines (R lines) in a line × tester breeding design. Combining ability analysis revealed positive general combining ability (GCA) for A-HD3086 and 955R across the three trials, and they were identified as the best tester and line, respectively, for grain yield. Furthermore, the genotype × environment interaction analysed through GGE biplot revealed that hybrids G1 (A-HD3086 × 908-3R), G2 (A-HD3086 × 917R), G4 (A-HD3086 × 955R), and G12 (A-GW365 × 1752R) were high-yielding and stable performers. Based on combining ability estimates, grain yield performance, and stability analysis, hybrids G4 (A-HD3086 × 955R) and G12 (A-GW365 × 1752R) were identified as the best-performing hybrids across the environmental trials. Conclusions The present study reported the conversion of agronomically superior cultivars to CMS lines and their practical utilization for the development of CMS-based hybrids.

A study using a (4 × 4) F 1 full diallel population of four parents: BARI Gom‐25 (P1), BARI Gom‐26 (P2), BARI Gom‐33 (P3), and Pavan (P4) was conducted following randomized complete block design with three replications under optimum and late sowing conditions to induce terminal heat stress to assess wheat ( Triticum aestivum L.) genotypes for heat tolerance and yield stability under normal and terminal heat‐stress conditions. Ten traits were evaluated for combining ability and heterosis analysis. Significant genetic variation was found among the genotypes for all traits. Combining ability analysis showed significant variations in both general and specific combining abilities. P1 and P4 under normal condition and P1 and P3 under terminal heat stress had the best general combining ability, while P1 × P2, P2 × P1, P3 × P4 under normal condition and P1 × P4, P2 × P3, P4 × P3 under terminal heat stress showed the best specific combining ability effects for yield per plant. The highest significant heterosis for yield per plant was exhibited by P1 × P2, P3 × P2, P3 × P4, P4 × P1, suggesting these combinations can be exploited for developing high‐yielding, heat‐tolerant wheat varieties. Based on heat tolerance indices, P1 × P3 and P1 × P2 were the most heat‐tolerant genotypes. Overall, the study highlights P1 and P3 as the most promising parents for use as genomic sources in developing heat stress–tolerant genotypes, while the combinations P1 × P3 and P1 × P2 emerged as the best crosses, offering both heat tolerance and stable productivity.

Tepary bean (Phaseolus acutifolius A. Gray) is an under‐utilized genetic resource with significant potential for food security and stress tolerance breeding. Expanding its cultivation in southern Africa requires high‐yielding, locally adapted and drought‐tolerant varieties. This study determined the combining ability and genetic components for seed yield and related traits in tepary bean genotypes under non‐stress (NS) and drought‐stress (DS) conditions. Seven parents were selected through rigorous phenotyping and crossed using a half‐diallel design. The 7 parents and 21 F2 progenies were evaluated in 2021/2022 season at Kasinthula and Bunda sites in Malawi under NS and DS conditions using a 4 × 7 lattice design with three replications. The specific combining ability (SCA) × location interaction effect was significant (p < 0.05) for DTF, NPP, and SY, suggesting that the genetic effects of crosses were influenced by the test locations. General combining ability (GCA) and SCA mean squares were significant for the number of seeds per pod (NSP) and SY under DS conditions, indicating both additive and non‐additive gene effects. Baker's ratio (BR) > 0.50 for NPP and NSP under DS conditions suggested a preponderance of additive gene effects. G40145, G40148 and G40150 parental lines were good combiners for NPP and SY. The F2 families from crosses such as Zimbabwe landrace/G40138, Zimbabwe landrace/G40150, G40059/G40145, G40059/G40148, G40138/G40150 and G40145/G40150 were identified as best specific combiners, with enhanced SY of 1.67 t/ha under DS conditions. The study recommends advancing high‐performing early‐generation families for selection across representative environments to facilitate variety release and commercialization.

 This research was aimed to study combining ability for growth, kernel yield, and its components, for maze (Zea mays L.) inbred lines, which evaluated in 8×8 diallel crosses. At two locations, Dukan and Qlyasan, at the Sulaimani region.  Significant genetic variability was found in all genotypes for all characters except no. of ears/plant. Highest significant general and specific combining ability were observed for most characters, revealing the importance of both additive and non-additive gene action, at the same time a low ratio of Ϭ2GCA/ Ϭ2SCA was recorded for all traits at both locations vice versa the average degree of dominance was more than one, this indicates to the high contribution of a non-additive gene effect. Heritability in broad sense was found to be high, while a narrow sense, it was low for all traits at both locations. Significant differences were noticed between both locations for kernel yield and most of its components, confirming the exceeding Dukan location.

Combining ability analysis can be used to preliminarily identify the advantages and disadvantages of combinations and parents in earlier generations, enabling breeders to reduce the range of material, save breeding time, and improve breeding efficiency. An approach for combining ability analysis through the hybrid crop breeding information management system is presented. The general combining ability prediction effect of parents and the specific combining ability prediction effect of combinations are calculated to analyze hybrid combinations using the hybrid crop breeding information management system. The results provide the basis for parent selection and combination selection. The plant breeding trial management function of the system can provide convenient diallel crossing trial design, field planting plan, and combining ability analysis. In the system, the genealogy of breeding materials is traced with the combining ability test crosses. The selection of high-generation breeding materials can be performed in accordance with the combining ability test results of early generation materials. The system has been successfully applied to a large Chinese seed company. The combining ability test function automates data analysis and eliminates days in the decision-making process. The efficiency of the combining ability test analysis and test report generation has improved to more than double by using the system.

تم إجراء هذه التجربة في موقع قلياسان، إقليم كوردستان - العراق، محطة البحوث الزراعية، كلية علوم الهندسة الزراعية - جامعة السليمانية، وفقًا لنظام التهجينات التبادلية النصفية و باستعمال سبعة أصناف من البازلاء (Avolla، Americana، Jeza، Joneor، Pack land، Arvena and Samara) مع هجنها 21 للجيل الرابع F4. تم زراعة التراكيب الوراثية وفق تصميم القطاعات الكاملة المقساة بثلاث مكررات. كانت متوسطات مربعات التراكيب الوراثية عالية المعنوية، مما يشير إلى وجود اختلافات كبيرة بين التراكيب الوراثية لجميع الصفات. كانت متوسط المربعات gca عالية المعنوية لجميع الصفات باستثناء عدد البذور لكل قرنة و دليل الحصاد التي كانت معنوية فقط. كانت متوسط المربعات sca عالية المعنوية لجميع الصفات باستثناء عدد البذور لكل قرنة و وزن مائة بذرة التي لم تكن معنوية. أعلى قيمة موجبة لقوة الهجين المقدرة كمتوسط انحراف الجيل الرابع عن معدل الآباء سجل بواسطة الهجين 2 × 6 و 4 × 5 لمعظم الصفات. سُجلَ أعلى قيم موجبة لتأثيرgca للصفات وزن البذور لكل النبات، الحاصل البيولوجي، و عدد القرون لكل نبات عن طريق الأب 4، بينما أظهر الأب 2 أفضل قيمة لبعض المكونات. وجد بأن الهجين 4 × 5 له القابلية الجيدة للأئتلاف خاص لوزن البذور لكل نبات و بعض مكوناته، منها عدد و وزن القرنات لكل نبات، و عدد البذورلكل قرنة. و كان نوع الفعل الجيني الذي يسيطر على توريث جميع الصفات هي نوع الفعل الجيني التفوقي عدا وزن مائة بذرة. درجة التوريث في معناها العام كانت عالية لجميع الصفات عدا عدد البذور لكل قرنة و التي كانت متوسطة، بينما درجة التوريث في معناها الضيق كانت عالية لصفة معدل وزن القرنة، طول القرنة، وزن البذور لكل قرنة و وزن مائة بذرة. The present study was carried out at Qlyasan locations, in Kurdistan Region-Iraq, Agricultural Research Station, College of Agricultural Engineering Sciences-University of Sulaimani, according to half diallel mating system using seven pea cultivars (1-Avolla, 2-Americana, 3-Jeza, 4-Joneor, 5-Pack land, 6-Arvena and 7-Samara) with 21 F4 crosses. The genotypes were planted in a completely randomized block design with three replications. Highly significant mean squares due to genotypes were recorded indicating the presence of sufficient variability among genotypes for all traits. The mean squares due to gca and sca were significant for all the studied traits. The highest positive heterosis values estimated as the F4s deviation from mid parental values recorded by the cross 2×6 and 4×5 for almost all traits. Maximum positive gca effect values for seed weight plant-1, biological yield plant-1 and pods number plant-1 were recorded by parent 4, while parent 2 showed the best value for some components. The cross 4×5 was the best sca combiner for seed weight plant-1 and some its components including pods number plant-1, pod weight plant-1 and seed number pod-1. The type of gene action as controlled the inheritance of all characters was over dominance except 100-seed weight. Heritability in broad sense was found to be high for all treats except seed number pod-1 which was moderate, while at narrow sense it was high for average pod weight, pod length, seed weight pod-1 and 100-seed weight.

Protection expired (ex-PVP) and off-patent maize ( Zea mays L.) inbred lines are publicly available to utilize, after being restricted through the U.S. Patent and/or Plant Variety Protection Act for 20 years. The purpose of this study was to assess the grain quality properties of ex-PVP maize short-season inbred lines. Three sets of North Carolina Mating Design II crosses were made with 12 NDSU lines, 24 ex-PVP lines, and seven current industry testers in the 2010 and 2010–2011 seasons. Hybrids and checks were arranged in partially balanced lattice trials across six ND environments in 2011 and 2012. Both general combining ability and specific combining ability were important for regulating most grain quality traits with the preponderance of additive genetic variance. However, there is still lack of interest for developing inbred lines and hybrids with top grain quality traits. If ex-PVP inbred lines do not have the potential to compete with current lines, still, those with good combining ability for grain quality could complement other germplasm sources when the market is ready to pay premiums for a better maize quality. Public breeding programs have the opportunity to increase the value of this particular commodity and complement industry efforts for a better and more profitable crop for U.S. farmers.

U.S. Patent and Plant Variety Protection Act protect maize (Zea mays L.) inbreds and hybrids. The overall objective of this research was to assess the usefulness of patent expired maize inbred lines. Factorial crosses were made including North Dakota State University (NDSU) lines, ex-PVP lines, and top industry testers in the 2010 NDSU Fargo summer nursery and in the 2010–2011 NDSU New Zealand winter nursery. Hybrids were planted across six different ND environments in 2011 and 2012 following partially balanced lattice experimental designs. Combining ability analyses were performed following a factorial design with fixed parents. Our research identified ex-PVP inbreds PH207, Q381, PHP02, S8324, PHK76, CR1Ht, PHT77, LH205, LH54, and PHJ40 as above average lines in hybrid combinations to increase yield. Our trials suggest most ex-PVP lines are not useful directly for commercial purposes but could be used as potential breeding sources for short-season maize breeding programs. Improvements in intellectual property and re-thinking of breeding rights access are encouraged to explore more suitable hybrids for northern U.S. farms. Current industry lines have important trait weaknesses for northern U.S. climates that public sector breeders in strategic breeding locations could improve in order to develop better hybrids for farmers. Our preferred choice would be to partner with industry in order to improve current industry lines with known weaknesses, especially for northern U.S. and Canada environments.

Rice is staple food in Iran. Despite of high quality of local rice, their grain yield is low. In hybridization breeding programs, selection of suitable parents is an essential role for developing new combinations with broadens genetic diversity. Combining ability of local rice varieties namely ‘Hashemi’, ‘Sang Jo’ and ‘Tarom Deylamani’ and ‘Nemat’ was evaluated in a partial diallele analysis for agronomic traits in a randomized complete block design at Sari Agricultural Sciences and Natural Resources University. General combining ability (GCA) and specific combining ability (SCA) variances showed predominated role of additive gene effects in the inheritance of grain length. Both additive and non-additive components of genetic variances were important in the inheritance of traits like grain yield, plant height, panicle length, total grains per panicle, grain length and grain length to width. However, non-additive gene effects were seen for tiller number. Results showed that ‘Nemat’ was the best general combiner for most of characters followed by ‘Tarom Deylamani’. The cross of ‘Hashemi’ × ‘Tarom Deylamani’ was suggested to exploitation of heterosis breeding for increasing yield and its components in rice breeding programs. 

A diallel set of crosses, including selfs and some reciprocal crosses, was made between 15 parents, chosen for their fertility, from those included in a tetraploid potato (Solanum tuberosum subsp. tuberosum) breeding programme at the Scottish Crop Research Institute. The progenies were grown in randomised complete block trials with two replicates at a high-grade seed site from 1994 to 1996 inclusive and at a ware site in 1995 and 1996. The parents were included in the ware trials. Tubers were assessed for visual preference in all trials and for fry colour at both sites in 1996. Emergence and maturity were recorded in the ware trials and the tubers were assessed for yield, dry matter, size, appearance (regularity of shape), scab, uniformity, sprouting in store and keeping quality. There were very few growth cracks and very few internal defects. No reciprocal differences were found. Inbreeding depression was marked for emergence, yield, tuber size and appearance, and visual preference. In contrast, the selfs had a lighter fry colour than the parents and F^sub 1^s. Combining-ability analysis (selfs omitted) identified fry colour, emergence, maturity, yield, dry matter and sprouting resistance as traits for which the GCA (general combining ability) variance and narrow-sense heritability were high enough for good progress from full-sib family selection. Correlations between GCAs for pairs of traits were examined, including those from previously published seedling progeny tests. For fry colour, an unfavourable correlation with low yield (r = 0.596) was compensated by a favourable one with high dry matter content (r = 0.652), whereas unfavourable ones between foliage and tuber blight resistance and sprouting susceptibility (r = 0.578 and 0.596) were identified for monitoring. Clones with high GCAs were identified for use as parents in future breeding and the extent to which GCAs could be predicted from the parents, and the offspring means from the midparent means, was determined by regression and correlation analysis. The offspring-midparent regression was highest for fry colour, followed by dry matter, emergence and sprouting. Values were lower for scab due to environmental variation; for maturity, yield and tuber size due to SCA (specific combining ability); and for visual preference due to both factors. The implications for a breeding strategy are discussed.[PUBLICATION ABSTRACT]