Resumen

PEREZ-COLMENAREZ, Alberto et al.  Mass selection for adaptation to temperate climate of tropical and sub-tropical races of mexican maize. Bioagro [online]. 2007, vol.19, n.3, pp.133-141. ISSN 1316-3361.

Mexico is the place with the major genetic diversity of maize (Zea mays L.); however, plant breeding programs have been limited to the obtainment of improved open pollinated varieties and hybrids from races adapted to specific agricultural regions, so the adaptation of exotic germplasm is an option to broaden the genetic variability of breeding programs. Visual mass selection (VMS) using the plant and ear aspect as selection criterion is an important strategy in maize breeding programs to adapt exotic germplasm. Considering the potential value that the exotic germplasm has to improve maize, in 1989 three subtropical and seven tropical mexican maize races were submited to VMS for adaptation in Montecillo, México, where temperate climate conditions prevail. The original varieties, eight or nine VMS cycles of each race plus five local varieties were evaluated for yield in the 1998 spring-summer period at Montecillo and Tecámac, México, in a randomized completely block design with four replications. In general, the last cycle of selection surpassed the yield of local varieties, suggesting that VMS was an effective method to adapt exotic germplasm. The mean genetic advance per VMS cycle for ear yield per plant was 24.6 % in Pepitilla, 18.2 % in Olotillo, 12.5 % in Nal-Tel, 10.2 % in Tabloncillo, 9.1 % in Tepecintle, 6.6 % in Tuxpeño, 5.6 % in Comiteco, 4.5 % in Zapalote Chico, 3.7 % in Vandeño, and 2.5 % in Celaya

Palabras clave : Genetic advance; plant breeding; exotic germplasm; Zea mays.