Andhra Pradesh Agricultural University, Hyderabad
1Work conducted at the Maize Research Station, Hyderabad (A.P.) as part of the All India Coordinated Maize Breeding Scheme.
Four dent U.S. inbreds were used in a reciprocal back-crossing programme with four outstanding flint lines from the Indian Maize programme. The objective was to convert the dent character of U.S. lines into flint grain type, and if possible, enhance the combining ability of the lines and performance of the double cross (Kys X Cl 21E) (Tx 325 X Tx 203). Dent grain character was found to be partially dominant to flint grain character. One hundred and sixty seven flint lines recovered after two generations of reciprocal back-crossing were evaluated for their general combining ability. There was no improvement in the mean performance of recovered lines as compared to the four dent or four flint inbreds. The recovered lines of Kys, Cl 21E, Tx 325, KNR. 1, KT 41 and Eto-25A were at par with the original lines. The recovered lines of Tx 203 and Nar 330 were superior as compared to the original lines. In all, nine lines were significantly superior, 18 lines significantly inferior and 140 lines at par with their respective recurring parents.- The lines Cl 21E and KNR. 1 are considered to be the best as donor parents for improving general combining ability.
