人工授粉對番荔枝與鳳梨釋迦著果之影響

Effect of Artificial Pollination on the Fruit Set of Sugar Apple (Annona squamosa L.) and Atemoya (A. cherimola x A. squmosa)

番荔枝不同品種之雄蕊花藥開裂時間不同，大部份自上午02:30至08:30間，其中以‘軟枝種’最早，其花藥開裂時間不論夏期果與冬期果，大部份集中於上午02:30至04:30間；其次為‘粗鱗種’與‘紫色種’大部份夏期果與冬期果之花藥開裂時間於上午04:30至06:30間；‘台東一號’之夏期果與冬期果之花藥開裂時間很一致，有95%集中於上午06:30至08:30間；另‘大目種’品系之花藥開裂時間與‘台東一號’很接近。而鳳梨釋迦冬期果之花藥開裂時間主要約於下午4時至6時間，受氣候因素影響，高溫及低溼情況，有小部份於下午6時至8時間花藥開裂。番荔枝各品種不論夏期果或冬期果平均花藥數約為199只／朵，重量為11 mg／朵。鳳梨釋迦冬期果為229.5只／朵，重量為13 mg／朵。將番荔枝與鳳梨釋迦均具兩性花，雌雄異熟，且雌蕊先熟；將開花期間花朵之花瓣發育形態分為五個時期，其中番荔枝以瓣開期之授粉著果率最高，為88-89.7%，而鳳梨釋迦冬期果亦以瓣開期之97.1%為最高。亦即以尚無花藥可供授粉之瓣開期具有最大受粉著果能力，而在能產生花藥之受粉期形態之受粉著果率卻偏低。因此，番荔枝及鳳梨釋迦兩產業在開花期間授粉期時進行採集花藥（花粉），而於瓣開期時施行授粉作業，即進行人工異花授粉作業，可提升著果率，穩定產量。 This study investigated the time of anthers dehiscence, number of anthers and their total weight, pollination capability of petals at different developmental stages, and different pollination techniques and their effects on the fruit set among atemoya and five different cultivars of sugar apple; namely 'Roan-Jy', 'Tsu-Lin', 'Tai-Tung No. 1', 'Do-Mo', and 'Tzy-She'. An optimal operation model was also established to enable the industry to stabilize yield and enhance fruit quality. Different sugar apple cultivars had different anther dehiscence time, varying between 2:30 and 8:30 a.m. The 'Roan-Jy' had the earliest anther dehiscence time among all of the cultivars with majority of them dehiscence between 2:30 and 4:30 a.m., which was followed by 'Tsu-Lin' and 'Tzy-She' between 4:30 and 6:30 a.m. and then 'Tai-Tung No. 1' with the latest anther dehiscence time between 6:30 and 8:30 a.m. In atemoya, most of the anthers dehisce between 4:00 and 6:00 p.m., except for a few of them, which dehisce between 6:00 and 8:00 p.m., due to the effect of high temperature and low RH. The average number of anthers and the average weight of an anther per flower for sugar apple were 199 and 11mg, respectively, and those for atemoya were 229.5 and 13 mg, respectively. Based on the morphological changes during the development of a flower, it was categorized into five different stages; namely close bud stage, petal split stage, petal development stage, petal opening stage, and pollination stage. Irrespective of the cultivars of sugar apple or atemoya, the maximum pollination capability and fruit set occurred at the petal opening stage, under which, anthers were not fully mature. Conversely, fruit set was low at the time when anthers were fully mature. This result showed that the petals of both atemoya and sugar apple were hermaphroditic, belonging to dichogamy. As such, artificial cross pollination was necessary to enhance fruit set, stabilize productivity and increase the commercial values of atemoya and sugar apple by producing fruits that are big, round and symmetrical.