1. Physiological Characterization of Young ‘Hass’ Avocado Plant Leaves Following Exposure to High Temperatures and Low Light Intensity
- Author
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Itamar Neuberger, Shay Levy, Simon Chernoivanov, Or Shapira, and Lior Rubinovich
- Subjects
0106 biological sciences ,0301 basic medicine ,Stomatal conductance ,Photosystem II ,Leaf damage ,Hass avocado ,Plant Science ,01 natural sciences ,Article ,carbon assimilation ,leaf damage ,heat stress ,03 medical and health sciences ,Ecology, Evolution, Behavior and Systematics ,Ecology ,biology ,Chemistry ,Persea americana ,fungi ,Botany ,Sowing ,food and beverages ,biology.organism_classification ,Heat stress ,Horticulture ,Light intensity ,030104 developmental biology ,stomatal conductance ,QK1-989 ,subtropic ,Intensity (heat transfer) ,010606 plant biology & botany - Abstract
The worldwide demand for avocados has resulted in the planting of millions of young plants each year. However, global warming, resulting in high temperatures, sensed as heat stress, may severely damage these new plantings. The objective of this study was to assess the risks of heat stress on young avocado plants. We aimed to characterize different physiological parameters of young ‘Hass’ plant leaves following exposure to high temperatures under low light (LL) intensity and to pinpoint the temperature threshold for significant heat stress damage in these plants. To this end, young potted plants were subjected to different temperature gradients in a controlled-climate chamber. Minor and severe leaf damage was apparent in plants subjected to the 51 °C and 53 °C treatments, respectively. Minor and vast reductions in optimal quantum yield efficiency of photosystem II (Fv/Fm) values were observed in plants subjected to 51 °C and 53 °C, respectively. Heat stress treatments significantly reduced CO2 assimilation in plants subjected to 49 °C and higher temperatures. Stomatal conductance to water vapour and substomatal internal CO2 concentration were less sensitive to the heat treatments. These results imply that the heat damage threshold for young avocado plants under LL conditions is between 49 °C and 51 °C, whereas at 53 °C, severe and irreversible leaf damage occurs.
- Published
- 2021
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