Browsing by Subject "Gene action"

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Combining ability and hybrid breeding in Tunisian melon (Cucumis melo L.) for fruit traits
(2024) Chikh-Rouhou, Hela; Kienbaum, Lydia; Gharib, Amani H. A. M.; Fayos, Oreto; Garcés-Claver, Ana; Chikh-Rouhou, Hela; Regional Research Centre on Horticulture and Organic Agriculture (CRRHAB), LR21AGR03, University of Sousse, Sousse 4042, Tunisia; Kienbaum, Lydia; Institute of Plant Breeding, Seed Science and Population Genetics, University of Hohenheim, 70599 Stuttgart, Germany; Gharib, Amani H. A. M.; Department of Vegetable, Medicinal and Aromatic Plant Breeding, Horticulture Research Institute (HRI), Agricultural Research Center (ARC), Giza 12613, Egypt; Fayos, Oreto; Department of Plant Science, Agrifood Research and Technology Centre of Aragon (CITA), Avda. Montañana 930, 50059 Zaragoza, Spain; Garcés-Claver, Ana; Department of Plant Science, Agrifood Research and Technology Centre of Aragon (CITA), Avda. Montañana 930, 50059 Zaragoza, Spain; Wang, Huasen; Miao, Li
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.
Heterosis and combining abilities in a diverse seven-parent pearl millet population diallel tested in West Africa
(2021) Dutta, Sonali; Sattler, Felix T.; Pucher, Anna; Drabo, Inoussa; Issaka, Ahmad; Sy, Ousmane; Sanogo, Moussa D.; Angarawai, Ignatius I.; Haussmann, Bettina I. G.
Pearl millet [Pennisetum glaucum (L.) R. Br.] is an important food-security crop to smallholder farmers in West Africa (WA). Breeding for high yield and stability is a major challenge in the harsh environments of WA but could be tackled by a more systematic exploitation of hybrid vigor and heterosis in breeding of both open-pollinated varieties (OPVs) and different types of hybrids. Knowledge of combining ability patterns and quantitative-genetic parameters is required for an efficient development of hybrid vigor and heterosis in breeding programs. Hence, our objectives were to complement other existing studies and estimate the combining ability of seven unique, highly diverse Sahelian pearl millet populations from Senegal, Mali, Benin, Burkina Faso, Niger, Sudan and Nigeria and the heterosis and stability of their 42 diallel-derived population hybrids (or hybrid populations) to inform pearl millet OPV and hybrid breeding. The materials were evaluated in six environments in WA in 2007. Grain yield (GY) exhibited an average panmictic mid-parent heterosis of 24%, ranging from − 1.51 to 64.69%. General combining ability (GCA) was significant across test environments as reflected by high heritability estimates and high GCA:SCA variance ratios. Thus, early selection for parental per se performance would be rewarding. The parental population from Sudan (IP8679) had strongly negative GCA for GY. Its lack of adaptation contributed to the predominance of additive effects in the present germplasm set. Parental populations PE02987 (Senegal), PE05344 (Mali) and ICMV IS 92222 (Niger) showed large positive GCA for GY. Their offspring, especially PE02987 × PE05344 and Kapelga × ICMV IS 92222, exhibited a high and stable GY across all test environments. Tapping the regional pearl millet genetic diversity and preselecting the crossing parents seem beneficial for OPV and hybrid breeding to increase pearl millet productivity in WA.