CLASSIFICATION OF MAIZE INBRED LINES INTO HETEROTIC GROUPS USING SPECIFIC COMBINING ABILITY EFFECTS FOR GRAIN YIELD | ||
| Egyptian Journal of Plant Breeding | ||
| Volume 29, Issue 1, April 2025, Pages 1-15 PDF (621.84 K) | ||
| Document Type: Original research | ||
| DOI: 10.12816/ejpb.2025.424188 | ||
| Abstract | ||
| In the maize hybrid development program, understanding general and specific combining ability of the inbred lines and their hybrids, forming and exploiting meaningful heterotic groups are key aspects for success. Twelve new yellow maize inbred lines, derived from four different genetic sources were used in this study. Two testers inbred lines; (Sk15 and Gz658) were crossed with the twelve inbred lines at Sakha Agricultural Research Station in 2022 summer season. A total of 24 F1 crosses plus one check (Pioneer Single Cross 3444) were evaluated in a randomized complete block design with three replications at three Agricultural Research Stations in 2023 summer season for grain yield. The mean squares due to crosses and their partitions; lines, testers and lines × testers interaction were highly significant for grain yield. Also the results showed that non-additive gene effects were more important than additive gene effects in the inheritance of this trait. The two crosses (Sk5009/50 × Gz658) and (Sk5009/51 × Gz658) were significantly superior to the check for grain yield. The desirable inbred lines for general combining ability (GCA) effects were Sk5009/50, Sk5009/51, Sk5006/44 and Sk5006/45 for grain yield. The results showed that the best genetic source to isolate the desirable inbred lines for grain yield was the improved population Sk9 (C2). The correlation coefficients between mean performance of crosses and their specific combining ability (SCA) effects based on Kempthorne and SCA effects based on Yang methods showed that the two methods were going in same direction, however the SCA effects of Yang method was higher for corresponding with mean performance than Kempthorne method, hence SCA effects of Yang method is more practical for maize breeder to selection. The best breeding efficiency for classifying the twelve inbred lines into heterotic groups was obtained by SCA effects based on Yang (74.0%), whereas SCA effects based on Kompthorne showed the lowest breeding efficiency (66.7%). Hence SCA effects of Yang proved particularly successful in classifying inbred lines of maize into heterotic groups. | ||
| Keywords | ||
| GCA; SCA; Additive gene effects; Non-additive gene effects; Heterotic group; Crosses; Population; Breeding efficiency | ||
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