Cultivar differences of photosynthesis and respiration in peanut leaves

摘要

To clarify the cultivar differences of photosynthesis and respiration in peanuts (Arachis hypogaea L.), thirteen cultivars were soil-cultured in natural-light phytotron during the summertime under conditions of 28/23 deg C, dayight cycle, ca. 60 percent RH and 380 ppm CO_2. Leaf discs obtained from the young, fully-expanded leaves were proviede for the measurement of photosynthesis and respiration with a gas-phase oxygen electrode. The cultivar differences in the rates of photosynthesis and respiration were within a range of mean values +-17 percent. The three cultivars (Jenkins Jumbo, Posados 64 and Satonoka) with high photosynthetic oxygen evolution (24percent higher than the mean ) had high ability of respiratory oxygen absorption (17 percent higher than the mean), and there was a weak correlation between photosynthesis and respiration when the thirteen cultivars were pooled. The specific leaf weight correlated with respiration but did not correlate with photosynthesis. The choice of the contrasting cultivars with high and low photosynthetic activities may be effective to demonstrate indigenous differences among cultivars.