黃金石斛蘭假球莖生長特性與內部構造觀察

The vegetative growth habits and internal structure observation of pseudobulb in Dendrobium aggregatum

陳建宇(Chien-Yu Chen) ； 沈榮壽(Rong-Show Shen)

《嘉大農林學報》 18卷1期 (2021/02) Pp. 39-58

摘要

本研究探討黃金石斛蘭（Dendrobium aggregatum Roxb.）之假球莖發育及其器官內部構造觀察。植株基本形態係由根被層發達之肉質根、肥厚假球莖與革質之厚葉組成的複莖叢生蘭。觀察其假球莖之生育可分成四個時期：分株繁殖4-6週後，開始有新生芽體萌發，進入新芽萌發期（Stage 0, S0），第7-8週進入假球莖發育期，可見葉片抽出展開（Stage 1, S1）；10-12 週後進入假球莖飽滿肥大期（Stage 2, S2），葉鞘膜漸呈銀白色；隔年進入假球莖成熟期（Stage 3, S3）之發育階段，並具開花之能力。具3個成熟假球莖的植株定植後每年可產生2-4個新假球莖，假球莖之肥大成熟週期約需一年；分株移植後新生第一代的假球莖，具移植休克短暫生長停滯現象，其葉片及假球莖的大小和母球相比皆有縮小的現象，需再經過二至三世代後，假球莖再快速發育肥大，且愈來愈大，重新形成的假球莖須經10-12週的肥大成熟期，再經天然冬季涼溫刺激，可見花梗萌出並進一步開花。

關鍵字

形態 ； 解剖 ； 假球莖 ； 週年生長

並列摘要

This study aimed to explore the basic growth habit, morphology observation and anatomy of pseudobulb, in order to understand the developmental characteristics of Dendrobium aggregatum. The basic morphology of an intact plant was composed of fleshy roots covered with velamen, well-developed root systems, enlargement and thickness pseudobulbs and leathery and hardness-thickness leaves. The growth pattern of pseudobulbs divided into four stages. After dividen from the mother plant, the firstfour to six weeks, new shoot begins to the sprouting stage (Stage 0, S0), and then enter the pseudobulb development stage (Stage 1, S1) at 7-8 weeks. It can be seen that the leaves are grew and unfolded (Stage 1, S1) during this atage. After ten to twelve weeks, it got into the pseudobulb enlargement stage (Stage 2, S2), and the membranes of leaves sheath turned into silvery white. The next year, the growth of pseudobulbs undergoes the last stage, called pseudobulb mature and stalk emergence stage (Stage 3, S3), in which pseudobulbs have the flowering competency. The growing model during annual cycle showed that the matured plant can grow 2-4 pseudobulbs per year, but it showed a decrease in size, compared with the leaves and pseudobulbs of mother generation. The newly formed pseudobulb after division showed transplantation shock with transient growth arrest. Subsequently, the development will become rapid after two or three generations of pseudobulb growth. Also, the size of the newly pseudobulbs will become larger and larger than the mother pseudobulbs. Based on the above investigated results, it showed that enlargement and maturity of each new pseudobulb needed 10-12 weeks. And after being stimulated by natural cool temperature in winter, it can be observed the stalk sprouts and then blooms.

並列關鍵字

Morphology ； Anatomy ； Pseudobulb ； Annual growth model