Twenty five CIMMYT inbreds were crossed with four elite tropical maize testers. Results exhibited that one inbred line tester can select the top best lines from a large number of CIMMYT lines and two testers gave more reliable results than one tester did. However, when line × environment interaction was significant, selected lines by one tester in one environment were not necessarily same as those selected at another environment indicating thereby that different testers should be used for selecting best inbreds at different environments. This study also showed that inbred lines from different maize heterotic groups did not show any significant differences in identifying best CIMMYT germplasm.

No abstract

No abstract

Maize (Zea mays L.) breeders currently exploit genetically narrow-base populations by deriving the recombination lines from F2 of commercial single cross hybrids. A mating design was proposed for maize hybrid evaluation as source germplasm. The commercial single cross hybrids, Hi Shell, DKC 7074 and PMZ 4, developed by the commercial company, Monsanto, were evaluated for their usefulness as germplasm. According to mating design three criteria were used: the percentage of inbreeding depression, the general combining ability and the specific combining ability. PMZ 4 had a lower percentage (21.9) of inbreeding depression, which was also combined with positive general combining ability (7.5) and negative specific combining ability. The estimated percentage of inbreeding depression was greater in DKC 7074 (31.4) and in Hi Shell (25.3). DKC 7074 also had negative general combining ability (35.5), while Hi Shell had positive specific combining ability (75.0). Therefore, evaluation through mating design showed PMZ 4 possesses more desirable genes and that it’s F2 may be a more profitable germplasm for developing elite inbred lines DOI: http://dx.doi.org/10.3329/bjb.v43i3.21615 Bangladesh J. Bot. 43(3): 363-366, 2014 (December)

No abstract