Effects of Altitude and Season on Glandular Hairs and Leaf Structural Traits of Nepeta nuda L.

海拔高度及氣候因子對直齒荊芥的腺毛及葉部構造特徵之影響

George Kofidis ； Artemios M. Bosabalidis

《Botanical Studies》 49卷4期 (2008/10) Pp. 363-372

摘要

本文研究海拔高度（950公尺，1,480公尺及1,760公尺）與季節（四月到十月）對直齒荊芥的葉片形態（含腺毛）、解剖及超微結構特徵的影響。在直齒荊芥植物的營養生長期，生長於1,760公尺處的植株明顯小於位於較低海拔生長者。以上三個不同海拔，葉的最大面積都在七月，秋季產生的葉子小於夏季者。三個不同海拔的直齒荊芥之葉片厚度在生長季裡有明顯的變動。葉下表面的氣孔密度高於上表面者；就海拔而言，長在1,480公尺處的植物葉片的氣孔比長在高於此處及低於此處海拔植物的氣孔數目為多。葉上表面非腺毛的密度較下表面為高（三處不同海拔的族群植物樣本並無顯著差異），然而在整個取樣期間，生長在海拔950公尺的植物葉片下表皮被毛少於其他海拔者。直齒荊芥的腺毛有兩種類型：頭狀毛（由一個基部細胞、一個柄細胞及一個頭細胞組成）及盾狀毛（由一個基部細胞、一個柄細胞及四個細胞形成的大頭組成）。由春天到秋天，所有測試族群植物葉部兩面的頭狀毛之密度都有增加的傾向；盾狀毛在葉下表面非常多，但在上表面則不容易見到；位於海拔950公尺的植物在初夏時葉面盾狀毛的密度遠高於較高海拔者（1,480公尺與1,760公尺），但時至晚夏初秋則反是。分布在三個不同海拔的植物之夏季葉其表皮細胞中均含有酚類化合物，然而入秋後似乎就都檢測不到這種物質。似此差異亦見於三個不同海拔族群植物葉肉組織的葉綠體：自夏天至秋天，這三個不同海拔的族群植物澱粉粒在葉綠體基質含量少時，澱粉粒的相對容積也隨之下降；但在此時期，每個葉綠體之基粒的相對容積比例則上升。

關鍵字

海拔高度 ； 葉綠體 ； 腺毛 ； 葉片結構 ； 直齒荊芥 ； 季節

並列摘要

The effects of altitude (950, 1,480 and 1,760 m) and season (April to October) on some morphological (including glandular hairs), anatomical, and ultrastructular leaf traits of Nepeta nuda were studied. During the whole vegetative period, plants at 1,760 m were significantly shorter than plants at the lower elevations. At all altitudes, the leaves obtained their maximal surface in July. Leaves emerging in the autumn were smaller than summer leaves. Remarkable fluctuations were noticed in leaf thickness at the three altitudes during the growing period. Stomata occurred in higher density on the abaxial leaf surface than on the adaxial one. As related to altitude, leaves of 1,480 m plants possessed more stomata than leaves of plants at the two altitudinal extremes. Non-glandular hairs were denser on the adaxial leaf surface (no significant differences were noticed between plants of the three populations). However, leaves at 950 m were the less pubescent on the abaxial leaf surface during the whole sampling period. Glandular hairs of N. nuda were of two morphologically distinct types, i.e. capitate hairs (composed of a basal cell, a stalk cell and a head cell) and peltate hairs (composed of a basal cell, a stalk cell and a voluminous head of 4 cells). The density of capitate hairs tended to increase from spring to autumn on both leaf surfaces, in all populations examined. Peltate hairs were numerous on the abaxial leaf surface, but they could hardly be observed on the adaxial one. Leaves of 950 m had significantly higher peltate hair density on early summer compared to leaves of the higher altitudes (1,480 m and 1,760 m), but later on, in late summer and early autumn, just the opposite held true. At all three altitudes, summer leaves contained phenolics in their epidermal cells while autumn leaves seemed devoid of such substances. Differences also existed in mesophyll chloroplasts of plants at the three populations. In all altitudinal populations, the relative volume of starch grains became decreased from summer to autumn, when starch grains occupied only a small portion of the chloroplast stroma. On the other hand, during the same period, the relative volume percentage of grana per chloroplast increased.

並列關鍵字

Altitude ； Chloroplasts ； Glandular hairs ； Leaf structure ； Nepeta nuda ； Season