Genetic Variation for Seedling Cold Tolerance in Short-Season Maize.

Early planted maize is often exposed to cold night-time temperatures and bright morning light, conditions that can damage photosynthetic tissues and reduce growth plant rates. Exposure of maize to cold temperatures can cause an increase in carotenoid levels relative to chlorophyll levels, an increase in anthocyanin levels, and a decrease in chlorophyll abundance.  In this study, a selection of maize inbred and hybrid lines were screened for seedling tolerance of chilling stress in a replicated controlled envronment experiment. Cold tolerance was quantified as the percentage of control plant dry weight maintained by seedlings exposed to a severe 3-day chilling stress.  Concurrently, we measured leaf spectral reflectance to detect changes in pigmentation caused by the cold stress.  We report on the extent of variation in cold tolerance, and the association of cold tolerance with novel reflectance indices.