Influence of temperature and nitrogen on growth, photosynthesis and accumulation of non-structural carbohydrate in a tropical grass, Panicum maximum var. trichoglum.

Abstract

After an initial growth period on half-strength Hoagland solution at 25 deg C, plants of P. maximum var. trichoglume were transferred to N-free nutrient solution and an equal number were kept on half-strength Hoagland solution. Plants from both N treatments were grown under constant temperatures of 15, 20, 25, 30 or 35 deg . Leaf net photosynthetic rate, RGR and NAR/unit leaf area were affected to a similar relative extent with change in temperature or N, thereby precluding accumulation of very high percentages of total non-structural carbohydrates (% TNC). At low temperature and low N, changes in % TNC were inversely related to relative leaf area growth rate and also to some extent with dark respiration rate. In high-N plants, reduction in % TNC at higher temperatures was probably accentuated by the use of constant day/night temperatures. The influence of temperature on % TNC in low-N plants was slight. (Abstract retrieved from CAB Abstracts by CABI’s permission)