ESTIMATION OF SPECIFIC COMBINING ABILITY EFFECTS USING TWO METHODS AND THEIR RELATIONSHIPS WITH MEAN PERFORMANCE AND HETEROTIC GROUPS IN MAIZE | ||||
| Egyptian Journal of Plant Breeding | ||||
| Volume 28, Issue 3, November 2024, Page 281-299 PDF (550.4 K) | ||||
| Document Type: Original research | ||||
| DOI: 10.12816/ejpb.2024.393185 | ||||
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| Abstract | ||||
| The specific combining ability testing is used to identify pairs of inbred lines capable to produce the best hybrids. A line × tester analysis involving 45 hybrids obtained from crossing between 15 inbred lines and three testers was performed. The experiment was conducted at three locations for grain yield in 2023 summer season. The objectives of this study were to compare between estimation of specific combining ability effects by Kempthorne and Yang methods, classify the inbred lines into heterotic groups and identify the superior hybrids for high grain yield. A randomized complete blocks design (RCBD) with three replications was used at each location. Analysis of variance indicated significant mean squares due to lines (L), testers (T), (L×T) and their interactions with locations (Loc) for grain yield. The results showed that grain yield was mainly controlled by non-additive gene effects. The inbred lines Sk27, Sk31, Sk32 and Sk36 had desirable general combining ability effects (GCA) for grain yield. The two hybrids (Sk24×Sk1) and (Sk27×Sk1) were significantly out-yielded the check hybrid SC168. The results showed that numbers of SCA effects of hybrids which showed positive or negative significance according to Yang method were more than those estimated by Kempthorne method, which means that Yang method is better for explanation of SCA effects. Furthermore, SCA effects of Yang were more correlated with mean performance of hybrids than SCA effects obtained by Kempthorne method, hence Yang method is more practical to the breeders. Heterotic groups HSGCA method which estimated using GCA effects plus SCA effects of Yang was more efficient than HSGCA that estimated using GCA effects plus SCA effects estimated by Kempthorne for classification of inbred lines into heterotic groups. This study concluded that Yang method to estimate SCA effects is more beneficial than Kempthorne method for the maize breeders in selection of superior hybrids. | ||||
| Keywords | ||||
| Zea mays; Hybrids; GCA; SCA; Additive; Non-Additive; Gene effects; Classification; HSGCA | ||||
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