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Cold tolerance in sporobolus virginicus (L.) Kunth robust form, tissue cultures and whole plants
Author(s) -
STRAUB P. F.,
GALLAGHER J. L.
Publication year - 1989
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1989.tb02123.x
Subject(s) - rhizome , respiration , respiration rate , callus , biology , shoot , botany , carbon dioxide , horticulture , ecology
Sporobolus virginicus (L.) Kunth robust form, is a coastal C4 grass species in tropical and subtropical regions. An artificial freeze test was used to determine the response of tissue exposed to low temperature. The response was monitored by three methods: measuring respiration rates as carbon dioxide flux before and after freezing, conducting a triphenyl tetrazolium chloride (TTC) viability assay, and observing growth of tissue cultures and the regrowth of shoots and roots from rhizome buds. The TTC assay overpredicted the survival temperature in rhizomes, when based on a 50% of control as lethal value, but was a good indicator of survival in callus and suspension cultures. Respiration rates of callus tissue declined with low temperature exposure and paralleled the TTC results. Rhizome tissue however had a more complex respiratory response. High, post‐freeze, respiration rates during thawing of rhizomes at + 5.0°C were correlated with injury, detected both by a TTC assay and by the measurement of carbon dioxide flux. High respiration rates, measured after the thawing period, due to disabled rhizomes that were ultimately inviable, provide an explanation for the overprediction of the TTC assay. S. virginicus was found to be freeze‐sensitive, LT 50 = ‐ 2.5°C, with no hardening ability and it was concluded that cellular resistance defines the limits of freezing tolerance. However, avoidance of freezing strain through an underground perenniating organ probably allows S. virginicus to survive on the polar end of its range where episodic frosts may decrease temperatures to the lower limits of the cellular tolerance of a species.