Adaptive strategies of reproduction in tropical fruit trees

为了阐明热带果树生殖系统的适应策略，本研究对以下四个方面进行了调查：（1）开花的季节性，（2）花部结构与授粉和受精的关系，（3）自交不亲和性和无融合生殖，（4）坐果潜力。气候条件，特别是降雨量在泰国是密切相关的生长周期在季节性结果的物种，但没有发现明确的关系，在印度尼西亚人工调控开花诱导反季节水果生产证明在商业果园应用生长调节剂在适当的土壤水分控制。在泰国，施用氯酸盐能特异性地诱导龙眼果实开花，目前已被商业化地用于反季节水果生产.详细研究了东南亚主要热带水果品种的发育过程和花部结构的独特特征。本文还介绍了传粉和受精系统以及媒介昆虫的作用。结果表明，似乎存在许多花部结构和开花方式适合异花授粉形成种子的果树种.两个榴莲品种在自交或异花授粉后花柱中的花粉管行为均未发现明显的自交不亲和性，但需要更多的品种进行试验来推广。以山竹和蓝桉（Langsat和杜克）为材料，对山竹无融合生殖种子形成和果实发育进行了研究，详细的形态学观察揭示了山竹无融合生殖的独特特征.由于干旱和雨季的交替通过土壤水分和光照条件影响了热带水果的发育，对几种热带水果的光合速率和同化物向果位的分配进行了比较研究。光合作用速率因品种而异，山竹生长缓慢与光合作用低有关。

To clarify the adaptative strategies of reproduction system in tropical fruits, the following four items were investigated ; (1) seasonality of flowering, (2) floral structure in relation to pollination and fertilization, (3) self-incompatibility and apomixis, and (4) fruit setting potential1. Climatic condition, especially rainfall in Thailand was closely related to growth cycle in seasonal fruiting species but no clear relationship between them was found in Indonesia Artificial regulation of flower induction for off-season fruit production was demonstrated in commercial orchard by application of growth-regulators under adequate soil moisture control. Chlorates application specifically induced flowering of longan fruits in Thailand, which is now commercially used for off-season fruit production.2. Developmental processes and unique features of floral structure in main tropical fruit species of Southeast Asia origin were investigated in detail. The system of pollination and fertilization and the role of vector insects were also described. It revealed that there seem to exist many fruit species whose floral structure and mode of flowering fit to form seeds by cross pollination.3. No clear self-incompatibility was found in two Durian cultivars in terms of pollen tube behavior in the styles after self- or cross pollination, but more cultivars should be tested to generalize. Apomictic seed formation and fruit development were surveyed with mangosteen and Lanceum(langsat and duke) and an elaborate morphological observation revealed the unique feature of apomixis in mangosteen.4. As alteration of dry and rain seasons influenced development of topical fruit through soil moisture and light condition, a comparative study of photosynthetic rate and assimilate assignment to fruiting position was conducted using several tropical fruit species. Photosynthetic rate varied with species and the slow development of mangosteen was specifically related to low photosynthesis.