Characterization of photosynthesis and transpiration in two rubber tree clones exposed to thermal stress

• Published in: Revista brasileira de botânica Vol. 41; no. 4; pp. 785 - 794
• Main Authors: Nóia Júnior, Rogério de Souza, Pezzopane, José Eduardo Macedo, Vinco, Jonas Souza, Xavier, Talita Miranda Teixeira, Cecílio, Roberto Avelino, Pezzopane, José Ricardo Macedo
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-12-2018; Springer Nature B.V
• Subjects: Amplitudes; Biomedical and Life Sciences; Botany; Carbon dioxide; Cloning; Conductance; Gas exchange; Hevea brasiliensis; Leaves; Life Sciences; Original Article; Photosynthesis; Physiological effects; Physiological responses; Plant Systematics/Taxonomy/Biogeography; Plantations; Reinforced reaction injection molding; Resistance; Rubber; Rubber trees; Seedlings; Stomata; Stomatal conductance; Temperature effects; Thermal stress; Transpiration; Trees; Thermal amplitude; Photosynthetic apparatus; Ecophysiology; Leaf temperature
• ISSN: 0100-8404; 1806-9959
• DOI: 10.1007/s40415-018-0495-3

Temperature is one of the most important factors influencing physiological responses of rubber trees, so much so that it is a limiting factor in the expansion of rubber tree plantations in Brazil. The aim of this research was to investigate the influence of thermal stress, characterized by different thermal amplitudes, on photosynthesis, stomatal conductance, transpiration and leaf temperature. Seedlings of two rubber tree clones, RRIM 600 and CDC 312, were exposed to three different environments which were characterized by the following daily temperature ranges: 25–30 °C (
E
1); 25–42 °C (
E
2) and 10–42 °C (
E
3). Gas exchange and leaf temperature measurements were performed during the experimental period. The results show that gas exchange was affected by higher thermal amplitudes (
E
2 and
E
3). Photosynthesis, stomatal conductance and transpiration were lower in
E
2 and
E
3 environments, being more pronounced in
E
3. It was also observed that, due to the higher thermal amplitude in
E
2 and
E
3, there was an increase in intercellular CO
2
concentration. Reduction in transpiration rates culminated in an increase in leaf temperature in
E
2 and
E
3, being more pronounced in the CDC 312 clone than in RRIM 600.