Effect of leaf age and position on light-saturated CO2 assimilation rate, photosynthetic capacity, and stomatal conductance in rubber trees

Kositsup Boonthida, Kasemsap Poonpipope, Thanisawanyangkura Sornprach, Chairungsee Naruenat, Satakhum Duangrat, Teerawatanasuk Kannikar, Améglio Thierry, Thaler Philippe. 2010. Effect of leaf age and position on light-saturated CO2 assimilation rate, photosynthetic capacity, and stomatal conductance in rubber trees. Photosynthetica, 48 (1) : 67-78.

Quartile : Q3, Sujet : PLANT SCIENCES

Résumé : Shoots of the tropical latex-producing tree Hevea brasiliensis (rubber tree) grow according to a periodic pattern, producing four to five whorls of leaves per year. All leaves in the same whorl were considered to be in the same leaf-age class, in order to assess the evolution of photosynthesis with leaf age in three clones of rubber trees, in a plantation in eastern Thailand. Light-saturated CO2 assimilation rate (Amax) decreased more with leaf age than did photosynthetic capacity (maximal rate of carboxylation, Vcmax, and maximum rate of electron transport, Jmax), which was estimated by fitting a biochemical photosynthesis model to the CO2-response curves. Nitrogen-use efficiency (Amax/Na, Na is nitrogen content per leaf area) decreased also with leaf age, whereas Jmax and Vcmax did not correlate with Na. Although measurements were performed during the rainy season, the leaf gas exchange parameter that showed the best correlation with Amax was stomatal conductance (gs). An asymptotic function was fitted to the Amax-gs relationship, with R² = 0.85. Amax, Vcmax, Jmax and gs varied more among different whorls in the same clone than among different clones in the same whorl. We concluded that leaf whorl was an appropriate parameter to characterize leaves for the purpose of modelling canopy photosynthesis in field-grown rubber trees, and that stomatal conductance was the most important variable explaining changes in Amax with leaf age in rubber trees.

Mots-clés Agrovoc : Hevea brasiliensis

Mots-clés géographiques Agrovoc : Thaïlande

Classification Agris : F62 - Physiologie végétale - Croissance et développement

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

• Kositsup Boonthida, Kasetsart University (THA)
• Kasemsap Poonpipope, Kasetsart University (THA)
• Thanisawanyangkura Sornprach, Kasetsart University (THA)
• Chairungsee Naruenat, Kasetsart University (THA)
• Satakhum Duangrat, Kasetsart University (THA)
• Teerawatanasuk Kannikar, RRIT (THA)
• Améglio Thierry, INRA (FRA)
• Thaler Philippe, CIRAD-PERSYST-UPR Ecosystèmes de plantations (FRA) ORCID: 0000-0002-9924-4309

Source : Cirad - Agritrop (https://agritrop.cirad.fr/554915/)

Métriques

[ Page générée et mise en cache le 2024-11-03 ]