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Title: | 雙子葉植物莖部第一圈周皮之起源 The Origin of the First Periderm in Some Dicotyledonous Stems. |
Authors: | 呂秀慧 |
Publication Year : | 1980 |
Degree: | 碩士 |
Abstract: | 本實驗共觀察雙子葉植物莖部之第一圈周皮,發現周皮通常各有固定的起源,在橫切面上,成圈排列,約平行於官束形成層和表層組織。 周皮之起源部位,以第一層皮層者(subepidermis)為最多,占83%,其餘依次為表層組織(epidermis)初生韌皮部(primary phloem)皮層較深部位……等;但是有些植物,例如黃楊(Buxus microphylla),其木栓形成層可從皮層之最內層彎延至表皮。 除少數例外之外,周皮之形成都在管束形成層開始活動之後。 「周皮之起源位置」與值物之習性和「分類地位」,有一共同趨勢,?草本與喬木,兩極端之植物群,都具有較淺層之周皮起源,可見「較進化」及「較原始」之植物群,具有較固定之起源部位。 一般之周皮,構造簡單,通常分成木栓形成層、木栓層(Phellem)和栓皮(Phelloderm)三部份,因木栓形成層以平周分裂所產生之細胞,大都分化成木栓層,很少分化成栓皮,故木栓層占的比例最大;若木栓層祇含一種細胞,則稱之為同型周皮(homogeneous periderm);不祇一種,稱之異型周皮(heterogeneous periderm),具同型周皮者較多,具異型周皮者只有九□、紫薇等三種。 1. This investigation deals with 80 species of the first periderm in dicotyledonous stems, reveals that the first phellogen usually has the definite origin in a given species and makes a continuous cylinder which is located nearly parallel to the vascular cambium and the plant surface. 2. The first periderm in the stem of about 83% plants observed in the present work originates in the subepidermal layers some in the epidermis itself, and still in some others, the first phellogen is differentiated in deeper cortical layers, or even in the primary phloem. But Buxus microphylla has its origin from the innermost layer to the epidermis. 3. It is apparent that both trees and herbs have their first phellogen originated in superficial tissues, such as: epidermis or subepidermis; on the other hand, the shrubs, which the first periderm is formed in either superficial or deeper tissues. The place of the first formed periderm is always the same among the genus. Both rather advanced and the primitive families in the taxonomic status always have superficial phellogen origin, whereas in others, show a more diversity situation. 4. The time of periderm formation is always later than the activation of vascular cambium. 5. Two out of 80 species studied, ie, Lagerstroemia subcostata Koehne and Lagerstroemia indica Linn. appear to be heterogeneous in structure. All others, 78 species are formed to be homogenous. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/76301 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 植物科學研究所 |
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