Abstract

A diallel cross was produced using diverse maize (Zea mays L.) germplasm of saline tolerant and saline susceptible maize lines as parents. Agronomic performance of the offspring of the diallel cross was examined. Eight germplasm lines bearing diversified agronomic traits of five known tolerant and susceptible lines were involved as parents of the diallel cross that was evaluated at three different ecological areas viz. Gazipur, Benerpota, and Kaliganj. CZ-29 and CZ-26 had positive and significant general combining ability (GCA) effects for yield in both the saline environments, where CZ-12 possessed negative and significant GCA effects for yield in the same areas but none of the parents exhibited either significantly positive or negative GCA in Gazipur location. Of the saline tolerant lines evaluated, CZ-29 was a good source for increased yield with significant and positive GCA values in both the saline environments that was also responsible for dwarfness and earliness in all locations. CZ-26×CZ-24 yielded well except at Benerpota with an additional benefit of shorter plant type across all environments. Hybrid CZ-29×BIL-65, however, was consistent and promising over the environments for bold seed and higher yield that ranked 2nd at Benerpota (4.81 t ha-1) and Kaliganj (6.73 t ha-1) and 3rd at Gazipur (7.40 t ha-1) location for yield having significant positive specific combining ability (SCA) effects at Gazipur and Kaliganj. Moreover, six hybrids either significantly or not consistently decreased yield over the locations with negative SCA. However, considering the overall performance of the hybrids, the involvement of saline susceptible or tolerant parents was not consistent in the present study. Crosses between saline tolerant lines did not produce any tolerant hybrids or dwarf parents did not produce dwarf hybrids except CZ-29×CZ-36 that was able to produce shorter hybrid for all the locations. Therefore, among the lines evaluated in this diallel cross having a distinct different genetic background, CZ-28 and CZ-29 contributed to earliness; CZ-29 and BIL-65 reduced plant height; CZ-12 increased seed size; CZ-26 and CZ-29 improved yield. Thus, these lines should be useful sources of alleles for pyramiding, earlier maturity, shorter plant heights, increased seed size and improved yield into desired breeding lines.

Key words: Diallel, maize, saline, environments, general combining ability, specific combining ability.