GENETIC DIVERGENCE IN COMBINING ABILITY AND MAIZE HYBRIDS | ||
| Journal of Plant Production | ||
| Article 10, Volume 30, Issue 7, July 2005, Pages 3787-3807 PDF (3.43 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jpp.2005.237422 | ||
| Authors | ||
| M. E. Nassr ,1; E. A. El-Absawy2; A. A. Gulrqis1 | ||
| 1MolecuJar Biology. Dept., Genetic Engineering and Biotechnology Research Institute, Mi,nufiya University. | ||
| 2Bloinforrnatics Dept., Genetic Engineering and Biotechnology Research Institute, Mtnufiya Unlversity. | ||
| Abstract | ||
| To estimate the genetic parameters for a local maize population (Zea mays L.J. Halt diallel cross mating design was used. The data showed the best crosses (M1 OxM 11) and (M11 xM 18) for grain yield /plot: and (M10xM12) tor plant height and days to tasseling; (M11xM16) for too-kernet weight; (M15xM18) for number of rows/ear, number of kernels/row and 100·kernel weight; (M12xM16), (M13xM15) and (M 14xM 18) for plant height (towards shortness) and ear height (towards low ear placement); and the cross (M16xM18) for days to tasseling towards earliness and grain yield/plot. Generally, most studied traits showed significant differences for G.C.A mean squares except, number of rows/ear and plant height at the two years and combined data. Highly significant specific combining ability (S.C.A) mean squares, were found for most studied traits. For crosses x years interaction mean squares show highly significant differences for most studied traits wer,::; found. while for number ot rows/ear. plant height. and days to tasseling non- significant differences were observed For G.C.A x years mean squares the dat.l showed divided between the seven traits under study. For S.C.A x years -nean squares, highly sig,!1ificant differences for most studied traits were foun.j ";'re ratio between K2G.C.A / K'S.C.A. was found to be less than unity at the comr-r.ed data for most studied traits except for days to tasseling indicating that. the uommance genetic variance controlled the .behavior of most studied traits rathr-: .ian the additive ones. Generally the best inbred line was M 18 for ear diameter a: the two growing years and the combined data. for lCO-kernel.weight at the second year and combined data, and ptant height (toward shortness) at the first year and combined data. The best crosses were (M11xM16) for 100-kernRI·weight (M13xM1S) for ear height (towards low ear placement) at the two years and combined data. The percentages of economic heterosis of F I hybrids relative to the check variety (S.c155) were ranged from (1.60% to 33.66%) positive desirable values and from (·5.78%) to (-6.40%) negative desirable values at combined data. Heterosis could not be considered as a function of genetic divergence. Moreover. genetic distance based on morpho-agronomical markers was not significantly correlated with specific combining ability, heterosis and the mean performance. Hence, it is impossible to predict the hybrid performance from genetiC distance itself. | ||
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