- 期刊
有水坑台灣杉種子園內空粒種子之形成原因
The Reasons for the Failure of Seed Production of Taiwania Cryptomerioides Hay.At YEOU-SHOEI-KENG Clonal Orchard
摘要
台大實驗林溪頭有水坑台灣杉種子園於1966年以成熟母株枝條之嫁接苗建立，迄今所生產種子皆為空粒，未能達到預期目標。為瞭解種子不稔除了因花粉敗育外，雌毬花胚珠健康狀況是否也有關，乃調查全園內種木之花粉生產能力及胚珠的發育，並利用人工授粉方式測試種子生產能力。結果發現1999-2000年所生產之天然授粉種子仍為空粒，2001年觀察園內種木發現有35.33％的種木著生雄毬花，卻在成熟前凋萎未能生產花粉。雌毬花之一部分胚珠的微細構造發育良好且分泌授粉滴，授粉滴也具有聚集花粉之能力。2001年12月1日收集不同授粉處理之成熟毬果，發現經人工授粉處理（控制授粉及輔助授粉）之有效種子雖僅佔3.25及4.11%，發芽率卻高達90及94%，且4個月大之苗木生長良好，外觀正常；而未授粉處理（對照組及開放授粉）的種子全為空粒。上述結果顯示雌毬花至少有一部份胚珠的健康狀況足以生產種子，故本種子園無法生產種子園的原因為花粉敗育及鄰近缺乏花粉源所致。
並列摘要
The Taiwania cryptomerioides clonal orchard at Yeoi-Shoei-Keng, the Chi-Tou District of the Experimental Forest of National Taiwan University was established with grafting in 1966. It has not been able io produce filled seeds since then. The objective of this study was to observe the pollen production ability and the development of ovules. In addition, we took artificial pollination to examine the function of ovules and seed production ability of a sampled tree. During 1999-2001 all open pollinated seeds in the orchard were empty. The proportion of trees that initiated male strobili was 35.3%. However, all male strobili withered before maturation. Microstructures of ovules were sound and secreted pollination drops which functioned normally to catch the pollens. We collected mature cones induced by different pollination treatments on December 1, 2001. Although the proportion of full filled effective seeds produced from two artificial pollination treatments were only 4.11% and 3.52%, those were higher than 0% of two unartificial pollination treatments. The germination percentages of effective seeds were 94% and 90%, respectively. The morphology and growth performance of 4-month-old seedlings were similar to the control seedlings. Therefore, we claim the reason of the failure of seed production of the seed orchard is caused by the abortion of male strobili in the orchard and without mature tree around the orchard.