| Abstract: | The effect of temperature between 0 °C and 51 °C oncold and heat resistance of chilling-sensitive plants has beenstudied in maize, cucumber and tomato growing in controlledgrowth chambers. It has been shown that the normal temperaturerange (the background range) specific for each species doesnot affect their thermo-resistance. Temperatures outside thisbackground range induced the development of cold and heat resistancein leaves (these are the temperature ranges of cold and heathardening). Temperatures below + °9C and above +49 °Cfor maize, +8 °C and + 40°C for cucumber and +6 °Cand +42°C for tomato resulted in a decrease in leaf thermo-resistanceand injury (these are the temperature ranges of cold and heatinjury). At gradually declining or rising temperatures the initialpoints of plant injury were shifted slightly towards more extremetemperatures. The time necessary for dehardening of plants dependedon the degree of hardening. Dehardening is complete only atthe background temperatures. It has been assumed that the responsesto temperature of chilling-sensitive and chilling-resistantgrowing species belong qualitatively to the same type. Key words: Temperature, Thermo-resistance, Plants |
