閉鎖系内で蓄積する微量ガスに関する研究 サラダナのエチレン放出特性

Abstract

In order to obtain basic data of evolution of ethylene from lettuce plant (Lactuca sativa L. cv. Okayama), ethylene concentration was measured in a closed chamber in which the plants were cultivated under controlled environment (25°C air temperature, 60-70% relative humidity, 200μmol m-2 s-1 photosynthetic photon flux density (PPFD), continuous lighting, 400μL L-1 CO2) . Ethylene release rates of intact lettuce plant on a fresh weight basis (Ef) and on a dry weight basis (Ed) ranged from 0.1 to 0.25 nmol g-1 h-1, and from 1.2 to 3.1 nmol g-1 h-1, respectively. These rates gradually decreased as the plant grew. The ethylene release rates on a leaf area basis (E1) remained constant (0.6 nmol dm-2 h-1), independent of leaf area. Ethylene release rates of intact lettuce plant were affected by cultivation conditions such as ambient CO2 concentration, light intensity and light/dark period. Ed and E1 of lettuce plant cultivated at 2000μL L-1 CO2 were 1.4 times and 1.7 times, respectively, as much as those of the plant cultivated at 400μL L-1 CO2. Ed of lettuce plant was slightly higher in 300μmol m-2 s-1 PPFD than in 150μmol m-2 s-1 PPFD. E1s were similar to each other in both PPFD. Ed and E1 of lettuce plant cultivated at 12 h light/12 h dark period were 1.9 times and 1.7 times, respectively, as much as those of the plant cultivated at continuous lighting.