Interactions of Low Temperature, Water Stress, and Short Days in the Induction of Stem Frost Hardiness in Red Osier Dogwood

Abstract

The induction of stem frost hardiness by low temperature, water stress, short days, and their combinations in 2-and 4-month-old growing dogwoods ( Cornus stolonifera) were investigated. When plants were subjected to more than one factor, the increased hardiness was the sum of the effects of the individual factors involved. No interactions among these factors on hardiness were observed during a 3-week treatment. Results indicate that low temperature, water stress, and short days initially trigger independent frost-hardening mechanisms. Plant ages significantly influenced the change in low temperature-induced frost hardiness, but not the water stress or short day-induced frost hardiness.Frost hardiness in woody perennials can be induced by either low temperature (5-7), water stress (15), short days (4, 7), or their combinations (4, 6, 7). In red osier dogwoods: (a) short days alone induced frost hardiness to some extent (10, 13); (b) water stress also increased frost hardiness under either long day or short day regimes (2, 3); and (c) low temperature alone did not induce hardiness very effectively in long day regimes but was effective after growth cessation in short days (9, 13). There has been relatively little study on interactions of low temperature and water stress, or of low temperature, water stress, and short days in the induction of stem frost hardiness in red osier dogwoods. Therefore, a study was carried out and results are reported here. MATERIALS AND METHODSPlant Culture. Red osier dogwood plants, Cornus stolonifera Michx., were propagated by tip cuttings from the same genetic clones. Plants were then transplanted in 15-cm pots with a 3:2:2 mixture of soil, sand, and peat. Plants were maintained in a greenhouse under an approximately 16-hr-long day and 20/15 C day/night temperatures. Three weeks after transplanting, plants were trimmed to two leaders/pot to provide uniform experimental materials. After 2 months of growth, half of the plants were transferred to controlled environment chambers for treatments (trial I). The other half remained in the greenhouse for an additional 2 months of growth and were then transferred to growth chambers for treatments (trial II randomized design. This included (a) two photoperiods-16-hr LD2 and 8-hr SD; (b) two controlled water supplies-plants were watered once daily either to the point of saturation or with 30 ml of water/pot (WS); and (c) two temperatures-20/15 C day/night warm temperature and 5/5 C day/night LT. Each pot constituted an experimental unit and each treatment was replicated three times. Through the combining of LT, WS, and SD, eight treatments including a control were imposed. Prior to treatments, all plants were watered to field capacity and each pot was wrapped with a plastic bag to eliminate evaporation during the experiment (3). Hardiness determinations were carried out after 0, 7, 14, and 21 days of treatment. The status of soil moisture content and stem water potential under 30 ml/pot day WS was reported elsewhere (2).Evaluation of Frost...

Frost tolerance and hardening capacity during the germination and early developmental stages of four white spruce (Picea glauca) provenances

“…However, 1-week-old seedlings (no epicotyl, cotyledons only) were unable to increase their frost tolerance. Chen and Li (1978) also reported similar results for Cornus stolonifera Michx. seedlings, with the greatest frost tolerance occurring under a combination of low temperature and short photoperiod.…”

“…Brown and Bixby (1976) reported the same type of reaction for Robinia pseudoacacia L., in which 4-week-old seedlings were unable to react to a hardening treatment while 8-, 12-, and 16-week-old seedlings did, and their degree of frost tolerance increased with chronological age. Chen and Li (1978) also found that 12-week-old Cornus stolonifera seedlings had a greater response to a low-temperature treatment compared with 8-week-old seedlings. Neither of these studies, however, indicates the developmental stage of seedlings at the beginning of the treatment or when they were freeze tested.…”

Drought priming at vegetative stage improves the antioxidant capacity and photosynthesis performance of wheat exposed to a short-term low temperature stress at jointing stage

“…2, Table 3). Low temperature induced dehydration in plant tissues has been proved by molecular and physiological evidence (Chen and Li 1978;Mantyla et al 1995;Rajashekar and Panda 2014). In the present study, a short-term low temperature significantly reduced Ψ l , RWC, Ψ o and g s in leaves of both the drought-primed and non-primed plants (P<0.001).…”

Water stress is a component of cold acclimation process essential for inducing full freezing tolerance in strawberry

“…However, further decrease in water potential after 6 days of water withholding did not affect the freezing tolerance suggesting that the initial water stress was able to induce freezing tolerance. Thus, it is likely that water stress can trigger the cold acclimation process and can independently induce freezing tolerance in plants (Chen and Li, 1978). Mantyla et al (1995) compared freezing tolerance in Arabidopsis induced by water stress and cold acclimation treatment and found that water stress alone could induce freezing tolerance to similar levels as the cold acclimation treatment.…”