Combining ability of new yellow maize inbred lines under two different locations.
Abstract: ABSTRACT: This investigation was carried out at two different locations (Gemmeiza and Mallawy).New seventeen yellow inbred lines of maize were top crossed to two line testers (Gm. 1021 and Gm. 1002) to produce thirty four top crosses in summer season of 2004 and evaluated in addition with two checks (S.C. 155 and S.C. 3084) in summer season of 2005 under the two locations. Highly significant differences were recorded between the two locations. Moreover, mean squares of crosses and their partitioning lines, testers and lines x testers interaction were significant and highly significant for most studied traits. Based on the combined analysis of the two locations, the non-additive genetic variance was more important than the additive genetic variance in the inheritance of all studied traits except, ear position and number of rows/ear. The inbred line Gm. 376 gave positive significant and desirable GCA effects for grain yield, number of kernels/row and ear length, while, four inbred lines gave significant and desirable GCA effects for grain yield only. The inbred lines Gm. 377, Gm. 379 and Gm.381 exhibited negative significant and desirable GCA effects towards earliness and dwarfness. The inbred lines Gm. 373, Gm. 381 and Gm. 383 showed significant and desirable GCA effects for resistance to late wilt disease. On the other hand, the line tester Gm 1002 showed negative significant and desirable GCA effects towards earliness, dwarfness, while, it showed positive significant for ear length and grain yield. On the other side, the line tester Gm. 1021 exhibited desirable GCA effects for resistance to late wilt disease, ear diameter and number of rows/ear. Five top crosses exhibited desirable SCA effects for grain yield, i.e., (Gm.371 x Gm. 1021) , (Gm.377 x Gm. 1021) , (Gm.378 x Gm. 1002), (Gm.381 x Gm. 1021) and (Gm.386 x Gm. 1002), while, the single cross Gm. 386 x Gm. 1002 gave highly significant and desirable of SCA effects for grain yield, ear length, number of rows/ear and number of kernels/row in addition to five top crosses i.e. Gm 382 x Gm 1021 (31.9 ard/fad.), Gm 385 x Gm 1021 (31.6 ard/fad), Gm 383 x Gm. 1021 (31.5 ard/fad.), Gm. 385 x Gm. 1002 (31.4 ard/fad) and Gm 387 x Gm 1002 (31.4 ard/fad) out yielded than the commercial crosses S.C. 155 (28.7 ard/fad.) and S.C. 3084 (31.2 ard/fad) for grain yield and most agronomic traits. The relative increasing percentage of grain yield (ard/fad) for the top crosses with inbred line Gm 1021 as tester, ranged from -35.9% to 2.2%and from -30.3% to 11.2% relative to S.C. 3084 and S.C. 155, respectively. The highest percentage values of the relative increasing for the top crosses with inbred line Gm 1021 as tester were obtained from the two crosses (Gm.385 x 1021) and (Gm382 x 1021). The relative increasing percentage of grain yield for the top crosses with inbred line Gm 1002 as tester, ranged from -57.4% to 0.3% and from -53.7% to 9.1% relative to SC 3084 and SC 155, respectively. The highest percentage values of the relative increasing for the top crosses with inbred line Gm 1002 as tester were obtained from two crosses (Gm387 x 1002) and (Gm385 x 1002). These results are of great utilization for maize breeder to be involved in breeding program to improve grain yield and its contributing characters.
Key words: Maize, Zea mays L, Line x tester, Combining ability ,Top crosses.
Publication year 2007
Pages 185-201
Availability location معهد بحوث المحاصيل الحقلية - مركز البحوث الزراعية - ش الجامعه – الجيزة
Availability number
Organization Name
serial title Minufiya J. Agric. Res. 32 (1): 185- 201.
Author(s) from ARC
Agris Categories Agricultural research
Publication Type Journal
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