TOPCROSS ANALYSIS AND COMBINING ABILITY FOR GRAIN YIELD AND OTHER ATTRIBUTES IN MAIZE (Zea mays L.) | ||||
| Journal of Plant Production | ||||
| Article 2, Volume 1, Issue 5, May 2010, Page 673-688 PDF (701.04 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jpp.2010.86392 | ||||
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| Authors | ||||
| M. E. M. Abd El-Azeem; A. M. M. Abd El Aal; A. M. K. El-Galfy | ||||
| Maize Res. Dept., Field Crops Res. Inst., Agric. Res. Center (ARC), Egypt. | ||||
| Abstract | ||||
| Nineteen selected S’3 inbred lines families from white maize were topcrossed with each of the two the commercial inbred line testers, viz. Sd-34 and Gz-629 at Sids Agric. Res. Stn during 2008 growing season. Forty entries (38 topcrosses and two white commercial single crosses checks; SC. 10 and SC. 129) were evaluated at Sakha and Sids Agric. Res. Stn in 2009 growing season for days to 50% silking, plant and ear heights, grain yield and grain yield per plant. Obtained data revealed that, mean squares due to crosses, lines, and testers were significant for all studied traits at both locations and over locations. Line x tester interaction was significant for all of the studied traits, except days to 50% silking and plant height at Sakha, and days to 50% silking at Sids. Highly significant differences were detected among locations for all of the studied traits, indicating that the two locations differed in their environmental conditions. In addition, Location x tester interaction was significant for all studied traits, except for ear height and grain yield per plant. The four top-crosses (L-4 x Sd 34), (L-7 x Sd 34), (L-8 x Sd 34) and (L-9 x Sd 34) significantly outyielded the best check (SC. 129) by 15.1, 19.7, 12.1 and 23.8%, respectively in the combined data. The best GCA effects for grain yield were recorded for lines L-4, L-6, L-7, L-8, and L-9. However, L-10 and L-19 exhibited the highest GCA values for earliness, whereas, inbred lines 7 and 3 exhibited the highest GCA values for plant and ear height. These lines should be directly utilized in breeding program to develop high yielding hybrids. Results showed also that the cross L-9 x Sd-34 was the best positive and significant SCA effects for grain yield in ard/fed and per plant. The magnitude of σ2GCA for lines was high for all studied traits, except for silking date at Sakha, silking date, plant height and ear height at Sids and the combined data. The interaction σ2GCA x Loc for lines was higher than that of σ2SCA x Loc for only plant height and ear height, indicating that the additive type of gene action is more affected by environmental conditions than the non-additive type of gene action. | ||||
| Keywords | ||||
| maize; top crosses; combining ability; type of gene action | ||||
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