Genetic variation in maize for early seedling growth in a low temperature environment

Abstract

Full-sib, paternal half-sib, and S1 families derived from a tropical highland population of maize (Zea mays L.) were used to study genetic variability for time to coleoptile emergence, shoot weight, leaf number, and visual assessment of chlorophyll concentration at 24 days in a 15°c day/10°c night environment. Considerable genetic variation occurred for time to emergence, shoot weight, and leaf number. Part of the variation for shoot weight and leaf number could be attributed to initial seed weight, especially for shoot weight, but substantial variation occurred which was independent of seed weight but was related to time to emergence. Inbreeding depression of substantial magnitude occurred for time to emergence, shoot weight, leaf number, and chlorophyll concentration. The use of selected families from this population for the improvement of time to emergence, and hence early seedling growth, of maize cultivars under cool conditions was discussed.