TY  - SER
AU  - Mosa,H.E.
TI  - Estimation of combining ability of maize inbred lines using top cross mating design
KW  - Corn
KW  - Genetics
KW  - Breeding
KW  - Production
KW  - general combining ability
KW  - topcrossing
N1  - Includes references
N2  - Top crosses evaluation is used to determine the relative potential of maize inbred lines in a hybrid breeding program. Choice of tester is important for efficient selection among lines for their potential in hybrids. Nine new yellow maize inbred lines were top crossed with three testers i.e. two inbred lines (Gz653 and Gz654) and one single cross (Sk85)in 2007 growing season. Resulting 27 top crosses in addition to three commercial hybrids SC155, SCI62 and TWC352 (as check varieties) were evaluated at Sakha and Sids Agriculture Research Station farms during 2008 growing season. Data were. collected for number of days to 50% silking, plant height, ear height, grain yield and its components. Differences between the top crosses were found to be significant for all studied traits. Also, differences between check hybrids were significant only for days to 50% silking, grain yield, ear length and number of kernels/row. Meanwhile the contrast of top crosses vs. check hybrids was not significant for all traits. Mean squares of lines, testers and lines x testers interaction were significant for all traits except those of lines for ear length and of testers for ear diameter and number of rows/ear. The additive genetic effects was most responsible for controlling the inheritance of all traits. The inbred line tester Gz653 was capable of maximizing productivity of top crosses, express the widest range among crosses, best mean of the top cross and showed maximum variation in top crosses for most studied traits compared with other testers. Thus, the best tester for evaluating the inbred lines in top crosses for this study was the inbred line Gz653. Best parental inbred lines which revealed desirable GCA effects were Sk10 for days to 50% silking, grain yield, ear diameter and number of kernels/row; Sk5027 for grain yield, ear diameter, number of rows/ear and number of kernels/row; Sk5026 for plant height and ear height, grain yield and number of rows/car; Sk5002
UR  - http://nile.enal.sci.eg/EALE/2010/JARKU/3610/1/1.pdf
ER  -