Heterosis and combining ability in yellow maize (Zea mays L. ) over two locations (Sakha and Nubaria).

Abstract: ABSTRACT: Half diallel cross among eight inbred lines were made at Sakha Research Station during the growing season 2002. The eight parents i.e. (L-121, Gm-1004, SK-6241, SK-7266, SK-8249, SK-9074, SK-9108 and SK-9115) and their F1 crosses were evaluated at Sakha and Nubaria Agricultural Research Stations in 2003 growing season. Data were collected on silking date (days), plant and ear height (cm), grain yield (ard/fed.), ear length (cm), ear diameter (cm), No. of rows/ear, No. of kernels/row and weight of 100- kernels (gm).The data were genetically analyzed by using Griffing (1956) method-2 model I. Locations mean squares were highly significant for all studied traits and genotypes exhibited highly significant differences. The variances associated with general and specific combining abilities (GCA and SCA) were highly significant for all traits. High ratio of GCA/SCA mean square was detected for number of rows/ear and weight of 100-kernels/row indicating that the largest part of the total genetic variability associated with the two traits was a result of additive and additive by additive type of gene action, while, low ratio for the remaining traits were detected suggesting non-additive types of gene action. The interaction between locations and both types of combining abilities were highly significant for all traits except silking date. The inbred line L121 could be considered as the best combiner for grain yield (ard/fed.) and the inbred line SK7266 is the best combiner for earliness. The highest desirable SCA effects were detected in the crosses; (L121 x Gm1004) followed by (SK7266 x SK8249) for grain yield, (L121 x SK9074) for weight of 100-kernels, (Gm 1004 x SK9108) for number of kernels/row, (L121 x SK9074) for number of rows/ear and ear diameter and (Gm.1004xSK6241) for ear length. These crosses could be used as superior and promising hybrids in maize breeding program. Percentage of heterosis for grain yield in F1 hybrids relative to the check varieties S.C. 155 and S.C. 3080 and to the mean of all crosses ranged from (-28.24 to 45.42), (-26.52 to 48.90) and (-33.54 to +34.67), respectively. The cross (L121 x Gm 1004) surpassed by (45.42, 48.90 and 34.67) percentage relative to the three checks; S.C. 155, SC 3080 and mean of all crosses (over two locations). Five crosses out yielded the high check variety S.C. 155.
Key words: Maize, Combining ability, Heterosis, Gene action.
Publication year 2005
Pages 65-75
Availability location معهد بحوث المحاصيل الحقلية - مركز البحوث الزراعية - ش الجامعه – الجيزة
Availability number
Organization Name
serial title Egypt. J. plant Breed. 9 (1) : 65 - 75. Special Issue.
Author(s) from ARC
Agris Categories Agricultural research
Publication Type Journal
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