In: Phyton, 51 Fasc. 1 (2011), S. 115-132, with 4 figures


Key words: Carbon, global warming, dry season, CAM, citric acid, cerrado, Smilax goyazana.

Summary

Palhares D., Franco A. C. & Penteado Zaidan L. B. 2011. Photosynthetic responses of Smilax goyazana (Smilacaceae). – Phyton (Horn, Austria) 51 (1): 115–132, with 4 figures.

Smilax goyazana A. DC. (Smilacaceae) is a herbaceous species very common in the Cerrado. The gas exchange, the fluorescence of chlorophyll, the leaf water potential, the titratable acidity and the chlorophyll and carotenoid contents were measured in order to disclose its photosynthetic plasticity of responses to field conditions. The female plants tended to a higher degree of electron transport rate than the male plants. The maximum value of net CO2 assimilation and the transpiration rates were similar between male and female plants. The rates of CO2 assimilation, transpiration and electron transport on sunny days were stable throughout the day and also during the rainy and dry seasons. The leaf water potential is isohydric and constant even during the dry season. There was no difference in titrable acidity between dawn and dusk. The chlorophyll contents are typical of plants adapted to high levels of sunlight.