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Vegetative Growth Responses of Maize Genotypes to Simulated Natural Chilling Events 1
Author(s) -
Castleberry Ron M.,
Teeri James A.,
Buriel Joe F.
Publication year - 1978
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1978.0011183x001800040027x
Subject(s) - biology , hybrid , seedling , agronomy , growing season , anthesis , vegetative reproduction , horticulture , poaceae , cultivar
A series of three maize ( Zea mays L.) inbreds and five hybrids, selected to represent a range of adaptation to maturity zones in the United States and Canada, were subjected to simulated early season chilling events to determine whether seedling growth responses to chilling were related to maturity adaptation. Chilling periods (17/5 C day/night temperatures) of 4, 8, and 23 days were superimposed on a control temperature regime without cold periods. Early maturing inbreds and hybrids had greater rates of leaf area expansion and had higher seedling dry weights than late maturing inbreds or hybrids. However, the proportionate reduction in growth rate during chilling was approximately equal for early and late maturing genotypes. Selection for early maturity appears to have produced genotypes with high rates of leaf area expansion during vegetative growth but without specific adaptations which modify the direct detrimental effects of chilling. Significant treatment by entry interactions were found in which some hybrids had accelerated growth rates after chilling while other hybrids and the inbreds tested had rates which were equivalent to controls. For hybrids with accelerated growth, leaves which were expanded following chilling treatment were larger than the equivalent leaves on control plants. This may reflect a mechanism to maintain assimilatory area under intermittent chilling conditions. In addition, these results suggest that natural environmental variability may greatly affect relative ranking of maize genotypes for growth rate and limit comparisons of field and controlled environment studies, unless a wide range of environmental simulations is used.