Proceedings of the Fifth Asian Regional Maize Workshop - Search ...

correlated effects were not desi rable (Tables 3 and 4). Inbred-progeny recurrent selection in
852, 85TL, and 8516 was effective initially for grain yield, but response for increased grain
yield plateaued after the C2 and C3 cycles of selection. 852, BSTL, and 8816 included 50, 25 and
1~ exotic germplasm, respectively, and either the methods of selection used were not satisfactory
or the genetic load of the exotic germplasm was too great to real i ze long-term response to
inbred-progeny recurrent selection.
Effective population sizes (20 to 25) may have been too small, and too many alleles were
fixed either because of inbreeding and/or because of genetic drift. The lack of continued
response by inbred-progeny recurrent selection, however, is not limited to populations with
exotic germplasm because a similar response was obtained in BSK (Table 5), which is a strain
(Krug) of Reid YellCW