In recent years maize breeders have become more aware of the importance of some abiotic stresses such as drought and low N. Such traits exhibit genetic variation which can be manipulated in a variety of ways for affecting improvements. A few of the more important strategies will be classified as Direct, Indirect, Alternate and Integrated strategies. Direct strategies emphasize selection directly under specific environments. Indirect strategies, in contrast, involve screening of elite maize germplasm especially inbreds and hybrids under those specific stresses. The alternate strategies make use of inbreeding and high densities as a means to reflect improvements in abiotic stresses. The integrated strategy uses recurrent selection procedure, and makes use of inbreeding, and high densities in different stages of completing a breeding cycle. All strategies will result in improving the trait(s), however, from the standpoint of resource efficiency and effectiveness, some alternate and indirect strategies may be expected to provide rapid advances. Cyclic improvement procedures in general will be slow but by emphasizing selection for secondary traits and reducing time to complete a cycle the progress can be increased. The results from various studies and strategies will be reported to show progress. Indirect and alternate strategies also helped to identify lines tolerant/resistant to drought or low N which had no previous history of selection for tolerance to such traits.

English

0208|AGRIS 0201|AL-Maize Program|R01PROCE

Juan Carlos Mendieta

CIMMYT Staff Publications Collection