Variables influencing cold tests of cherry blossom buds

28 Aug 2024
2513

Temperature is one of the main environmental factors limiting plant growth, development and yield. One of the main abiotic stress factors that limit plant distribution, crop production and influence the suitability of locations for orchard planting is low temperature conditions.

Frosts can cause considerable economic losses and, therefore, limit the presence of orchards in areas subject to these phenomena. Differential Thermal Analysis (DTA) is a method often used to assess the cold resistance of plant organs to survive cold temperatures.

For example, flowers are mounted on thermoelectric modules and subjected to cooling temperatures to perform DTA. The water inside the biological tissue is supercooled and solidifies, releasing heat that is detected as low temperature exotherm (LTE). This is assumed to be equivalent to the temperature at which embryos suffer lethal damage.

The only critical aspect of this method is that the analyses must be carried out in the laboratory, and the timing and transport protocols can influence the values obtained. A more complete understanding of the comparison between lethal temperature measurements obtained through controlled freezing experiments with currently available instruments and those obtained with DTA is therefore needed.

The objectives of the study by the University of British Columbia and the Research and Development Centre in Summerland (Canada) were:

  1. to evaluate the impact of temperature, humidity and pre-test storage duration on the cold resistance of sweet cherry blossom buds measured over a period of time between 0 and 25 hours;
  2. to evaluate the impact of differences in DTA cooling rates on the cold resistance of measured cherry blossom buds;
  3. investigate the impact of various bud removal methods on the cold resistance of measured cherry blossom buds;
  4. compare cold resistance measurements obtained by DTA and controlled freezing tests. 

As evidenced by the production of low-temperature exotherms at warmer temperatures, researchers found that buds stored at warmer temperatures (12.5 °C and room temperature) for 2-6 h prior to differential thermal analysis or transported to the laboratory in a humid environment underwent biologically relevant alterations in their apparent cold sensitivity.

Through numerous tests, the researchers realised that the speed at which the temperature was lowered to achieve the low temperature exotherms also significantly influenced the results. It was seen that higher values corresponded to faster cooling. In general, the obtained low-temperature exotherms were similar between the buds, although the amount of plant material remaining attached to the base of the bud varied.

The results of this study indicate that measures of cold resilience obtained from DTA and controlled freezing experiments are generally comparable. The results of this study are relevant for researchers interested in performing cold hardiness measurements in sweet cherry. They emphasise the importance of maintaining consistency in DTA pre-test conditions and bud preparation in order to obtain reliable and comparable results between studies.

Source: Elizabeth Houghton, Kirsten Hannam, Denise Neilsen, and Louise M. Nelson. 2024. Factors that influence measurements of sweet cherry (Prunus avium) flower bud cold hardiness obtained using differential thermal analysis. Canadian Journal of Plant Science. 104(3): 204-216. https://doi.org/10.1139/cjps-2023-0087.
Image: Canadian Science Publishing

Melissa Venturi
University of Bologna (IT)


Cherry Times - All rights reserved

What to read next

Bacterial canker in cherries, bacteriophage viruses as allies

Crop protection

05 Apr 2024

Researchers from the Plant, Soil and Microbial Sciences Department at Michigan State University have been investigating the possibility of deploying bacteriophage viruses against bacterial canker for a few years now thanks to their specialisation in infecting bacteria.

Sweet and sour cherry varietal innovations and breeding program in Hungary

Breeding Varieties

06 Dec 2023

The latest releases are ʿPapillon®ʾ, a bicolor cherry that tastes sweet, ripens 3 weeks after ʿBurlatʾ and ʿKira®ʾ, an early-mid-season large, shiny, firm cherry, both are distributed by Artevos who supports the breeding program.

In evidenza

Cherry fruit cracking: an understanding of the physiological fundamentals is essential for devising an effective prevention strategy

Tech management

10 Nov 2026

Rain can trigger cherry cracking when water reaches microscopic fissures in the cuticle. Learn how fruit growth, cell walls, pectins, calcium and genetic differences contribute to the onset and spread of damage as cherries mature, and why similar fruits may respond differently.

Diaporthe eres in wild cherry: new discoveries about infection and defense strategies

Crop protection

10 Nov 2026

A Serbian study on Diaporthe eres shows how branch age affects lesion size and dieback in wild cherry. Older branches develop larger areas of necrosis, while tolerant trees generally show less extensive lesions and less frequent branch dieback, highlighting host tolerance.

Tag Popolari