Department of Radioecology, Institute for Environmental Sciences, 1-7 Ienomae, Obuchi, Rokkasho, Kamikita, Aomori 039-3212, Japan.
Division of Fruit Tree Production Research, Institute of Fruit Tree and Tea Science, NARO, 92-24 Nabeyashiki, Shimokuriyagawa, Morioka, Iwate 020-0123, Japan.
Radiat Prot Dosimetry. 2022 Sep 9;198(13-15):1004-1008. doi: 10.1093/rpd/ncac034.
Although fruit development primarily depends on photoassimilation by leaves, immature green fruits can also directly assimilate atmospheric CO2. To elucidate the process of C accumulation due to direct assimilation by fruit, we conducted a 13CO2 exposure experiment in an orchard in late June with immature 'Fuji' apples (Malus domestica). Four fruits from three trees were enclosed in transparent plastic bags and exposed to 13CO2 using an in-situ exposure system. Fruits were collected prior to and immediately following exposure in early July, late September and mid-November, and 13C concentrations in the peduncle, skin, flesh and core (including seeds) were measured. The higher assimilated 13C concentrations measured following exposure indicated that the fruits directly assimilated atmospheric 13C. The 13C concentration in fruit skin was higher immediately after exposure and in early July compared with that prior to exposure. In late September and mid-November, 13C concentrations were close to natural levels.
虽然果实的发育主要依赖于叶片的光合作用，但未成熟的绿色果实也可以直接同化大气中的 CO2。为了阐明果实通过直接同化积累 C 的过程，我们在 6 月下旬对未成熟的‘富士’苹果（Malus domestica）进行了 13CO2 暴露实验。从三棵树上选择四个果实，用透明塑料袋包裹起来，并用原位暴露系统对其进行 13CO2 暴露。7 月初、9 月底和 11 月中旬在暴露前后采集果实，并测量果柄、果皮、果肉和果心（包括种子）中的 13C 浓度。暴露后测量到的较高的同化 13C 浓度表明果实直接同化了大气中的 13C。暴露后立即以及 7 月初的果皮 13C 浓度高于暴露前。9 月底和 11 月中旬，13C 浓度接近自然水平。
