tailieunhanh - Photosynthetic characteristics of red and green leaves in growing seedlings of Jatropha curcas

The use of Jatropha (Jatropha curcas L.) as a source of biofuel is documented. The physiological characteristics and growth studies of Jatropha have received less attention. In the present study, we measured leaf gas exchange with an infrared gas analyzer for red (immature) and green (mature) leaves of Jatropha curcas in response to various environmental conditions including photosynthetic photon flux density (PPFD), vapor pressure difference, and temperature. | Turkish Journal of Biology Turk J Biol (2014) 38: 457-468 © TÜBİTAK doi: Research Article Photosynthetic characteristics of red and green leaves in growing seedlings of Jatropha curcas 1, , 2 1 2 2 Munna SINGH * **, Sanjay RANJAN , Krishan Kumar VERMA , Uday Vashudav PATHRE , Pramod Arvind SHIRKE 1 Department of Botany, University of Lucknow, Lucknow, India 2 Division of Plant Physiology, CSIR-National Botanical Research Institute, Lucknow, India Received: Accepted: Published Online: Printed: Abstract: The use of Jatropha (Jatropha curcas L.) as a source of biofuel is documented. The physiological characteristics and growth studies of Jatropha have received less attention. In the present study, we measured leaf gas exchange with an infrared gas analyzer for red (immature) and green (mature) leaves of Jatropha curcas in response to various environmental conditions including photosynthetic photon flux density (PPFD), vapor pressure difference, and temperature. The seedlings were grown in pots for 45 days in a natural environment. Jatropha is a C3 plant based on its leaf–gas exchange characteristics. The optimal light-saturated photosynthetic CO2 assimilation, leaf conductance, and transpiration occurred in the range of 500–1000 µmol m–2 s–1 PPFD, depending upon the leaf positions and leaf types during growth. The net rates of photosynthesis, stomatal conductance, transpiration, and water-use efficiency were significantly affected by the leaf position and epigenetic variables, . temperature, vapor pressure difference, and irradiance. Key words: Jatropha curcas, photosynthesis, chlorophyll fluorescence, leaf position, water relations 1. Introduction Jatropha curcas is a perennial shrub that belongs to the family Euphorbiaceae. The plant grows up to a height of 3–5 m, but it can also reach heights of up to 8 m under favorable conditions. It shows .