臺灣博碩士論文加值系統

本論文主要是以秈型（indica type）水稻（Oryza sativa L.）台中秈10號（TCS10
）為材料，分別以水耕幼苗及切離根培養系統探討ABA誘導水稻的耐冷性，以及Ca2+是否
參與ABA所調節之生理作用。試驗結果如下： 水稻TCS10為一不耐冷之水稻品種，5℃
低溫處理1天即對幼苗及切離根產生嚴重傷害，外加ABA處理確實可促進其幼苗及切離根的
耐冷性，10μM ABA即能顯著降低幼苗回溫後地上部的低溫傷害等級，但綜合各生理指標
則以50μM 的濃度對幼苗及切離根的處理效果最佳。 在水稻TCS10幼苗全株或根部低
溫處理的試驗結果發現，地上部的傷害程度在回溫期間扮演重要角色，當根部因低溫遭受
某一程度的傷害時，如果地上部受低溫的傷害不大，仍可在回溫後恢復植株的生長發育。
Ca2+抑制劑對於ABA促進水稻TCS10切離根耐冷性的抑制效果，以高濃度EGTA較明顯，
LaCl3和Verapamil則幾乎不具抑制效果。 根部形態的觀察上，ABA的處理會使水稻根
尖產生膨大，且膨大處有根毛增多的現象，回溫後增長的根徑顯著變粗，膨大處根毛增多
，分支根數目增加。高濃度EGTA可抑制ABA所造成的此一現象，而LaCl3及Verapamil則無
影響。綜合以上結果，ABA的施用在水稻對於低溫的抗性上確實有顯著的促進效果，而地
上部受低溫傷害的程度影響回溫後植株的回復情形；並且Ca2+可能參與ABA對切離根耐冷
性的促進及形態的改變，然而其機制仍有待進一步的研究釐清。

The objectives of this research were to study the ABA induced chilling tol
erance of rice, and the function of calcium in the physiological responses of
ABA regulation. Rice cultivar, Taichung Sen 10 (TCS 10), was used in this res
earch and was studied through the seedling and the excised root system. The r
esults were obtained as follows: TCS 10 is a chilling sensitive cultivar.
The seedlings and excised roots were injured seriously after being exposed to
low temperature (5℃) for 1 day. The chilling tolerance of seedling and excis
ed roots was improved by the pretreatment of exogenous ABA before chilling. T
he application of 10μM ABA could significantly reduce chilling damage of shoo
ts. However, 50μM ABA is the best concentration according to the summarizing
of several physiological indexes. Different response was found when the wh
ole seedlings or only the roots exposed to the chilling condition. The degree
of chilling injury in shoots was important to determine the recovery ability
of seedling after being reverted to 30/25℃. The growth and development of s
eedlings will be recovered if the shoots were injured only lightly, even the r
oots were seriously injured. Calcium inhibitor, EGTA in high concentratio
n, significantly diminished the chilling tolerance of ABA induced. The other
two calcium inhibitors, LaCl3 and verapamil showed little effects. In root
morphology, ABA could significantly induce root tip swelling and root hair fo
rmation. After being reverted to 28℃ from 5℃, the ABA treated roots grow ob
viously with enlarged diameter, flourishing root hairs and more branched roots
in the swelling area. High concentration of EGTA greatly decreased ABA actio
n. LaCl3 and verapamil had little effects. In conclusion, the pretreatment
of ABA could improve the chilling tolerance of rice significantly. The level
of chilling injury in shoots affected the growth recovery of seedlings after
being reverted to normal temperature. Calcium maybe involved in the ABA actio
ns to improve chilling tolerance and to change root morphology. Further stud
y is needed with this respect.