Comparative Study on the Energy Acquisition with Photosynthesis in Temperate and Tropical Fruit Trees

热带果树的光合速率低于亚热带和温带果树。特别是山竹等新热带果树的光能获取效率非常低。而苹果在高温强辐照条件下具有较高的光合能力。光合作用的反应在物种之间似乎是不同的。亚热带果树的光合速率受温度的影响，与温带果树的光合速率相当。在低温条件下，番荔枝和西番莲的光合速率随辐照强度的增加而增加。但在高温高光强条件下，速率较低。亚热带果树应在阴凉条件下生长，以最有效地利用光能。相反，高温有利于芒果、糖苹果等热带果树的光合效率。在气温下降的秋冬季节，热带和亚热带果树的光合速率急剧下降。在苹果中，当花青素色素在叶片中产生时，速率下降，叶片很快脱落。然而，在番石榴中，即使叶子变成红色，这种比率仍然相当高。热带果树可以通过在初冬时保持叶子在树上来获得大量的光能。CO_2导度对亚热带和热带果树的光合作用影响较大。遮荫条件下，通过提高CO_2导度，减少了番荔枝光合速率的下降。在不利条件下，芒果和西番莲CO_2电导的增加增加了光合作用，而在温带果树中没有这种现象。

Photosynthesis rate was lower in tropical fruit trees than subtropical and temperate ones. Especially the efficiency to acquire light energy was very low in neo-tropical fruit trees such as mangosteen. However, Sugar apple had high photosynthetic ability under high temperature and strong irradiance. The photosynthetic response seems to be different among species.Photosynthetic rate of subtropical fruit trees, which was comparative with that of temperate ones, was affected by temperature. In cherimoya and passionfruit, the rate increased with increase in irradiance level under cool condition. However, the rate was lower at high light intensity at high temperature. Subtropical fruit trees should be grown under cool condition to utilize the light energy most efficiently. On the contrary, high temperature was favorable for the efficiency of photosynthesis in tropical fruit trees like mango and sugar apple.From fall to winter during which air temperature decreased, photosynthetic rate of tropical and subtropical fruit trees drastically decreased. In apple, the rate decreased when the anthocyanin pigments were produced in the leaf and the leaves falled soon. In guava, however, the rate was still rather high even when the leaves truned to be red. Tropical fruit trees may obtain much light energy by keeping the leaves on the tree during early winter.The conductance for CO_2 greatly affected the photosynthesis of subtropical and tropical fruit trees. The decrease of photosynthetic rate was reduced by increasing to CO_2 conductance under shade condition in cherimoya. In mango and passionfruit, the increase in CO_2 conductance increasede the photosynthesis under unfavorable conditions Such phenomenon was not found in temperate fruit trees.