Effect of Temperature Regimes on Photosynthesis, Respiration, and Growth in Alfalfa

摘要: The influence of three temperature regimes (34/25, 21/8, and 12/2 °C with 14 hr day/10 night) on alfalfa (Medicago sativa L.) growth, photosynthesis, respiration, total nonstructural carbohydrate levels in roots was determined. plants were grown a greenhouse for 3 months, then the tops removed to crown. When growth from crown reached 5 8 cm height, placed chambers. Photosynthetic photon flux density 520 μmol m s during day-period. Plant shoot dry weight, leaf area greatest at 21/8 regime, followed descending order by those 34/25 °C. Root weight highest that concentration chlorophyll b leaves increased as increased. Net photosynthesis canopy 12.9 CO2 12 18.9 21 °C, but did not significantly increase 35 Shoot root respiration response an temperature. Total