A Comparison of Seed Germination Ability between Exotic and Indigenous Weeds in Taiwan

台灣外來與本土雜草種子發芽能力之比較

徐玲明(Ling-Ming Hsu) ； 鄭榮順(Yoon-Suny Tee) ； 王慶裕(Ching-Yuh Wang)

《中華民國雜草學會會刊》 28卷1期 (2007/06) Pp. 98-111

https://doi.org/10.6274/WSSROC-2007-028(1)-098

摘要

本研究針對台灣五種外來雜草在不同環境下之發芽能力進行比較分析，包括紫花霍香薊(Ageratum houstonianum Mill.)、青葙(Celosia argentea L.)、小花蔓澤蘭(Mikania micrantha Kunth)、大白花咸豐草(Bidens pilosa L.)及三角葉西番蓮(Passiflora suberose L.)，並以本土雜草碎米莎草(Cyperus iria L.)爲對照比較其發芽潛力差異。在各種溫度處理下發現在20至36C範圍內六種雜草均可發芽，尤其三角葉西番連在24至32C溫度下有最適當之發芽率。然而菊科植物紫花霍香薊與大白花咸豐草則適合在較低溫度下發芽。研究發現所有雜草種子在滲透潛勢-0.4至-1.0 MPa範圍內，其發芽抑制程度均隨之增加，唯獨三角葉西番蓮不受影響。此外，當發芽環境pH值改變時，在pH 4.0至9.0範圍內所有雜草之發芽均不受影響，但在pH 9.0時本土雜草碎米莎草之發芽則受抑制程度達70%。雖然有四種雜草，包括紫花霍香薊、小花蔓澤蘭、大白花咸豐草、及碎米莎草之發芽必需光照，但也發現青葙及三角葉西番蓮在黑暗下其發芽僅受輕微抑制。於台灣氣候土壤環境下，顯然測試之五種外來雜草，尤其是三角葉西番蓮，其種子發芽競爭力高於本土雜草碎米莎草。

關鍵字

種子發芽 ； 環境 ； 外來 ； 本土 ； 雜草

並列摘要

The influence of environmental factors on seed germination ability between five exotic weeds, i.e., floss flower (Ageratum houstonianum Mill.), celosia (Celosia argentea L.), mile-a-minute (Mikania micrantha Kunth), beggarticks (Bidens pilosa L.) and passionflower (corkystemmed)(Passiflora suberose L.), and an indigenous weed flatsedge (Cyperus iria L.) in Taiwan was evaluated. While seeds of all six species germinated at temperatures between 20 and 36 C with the optimum for passionflower falling between 24 and 32 C, seeds of the two Compositae spp., floss flower and beggarticks, preferred lower temperature, with declining germination rate at increasing temperature. The germination of five weeds was inhibited with osmotic potentials increasing from -0.4 to -1.0 MPa, but that of passionflower was not affected by osmotic potential up to -1.0 MPa. Seed germination of all five exotic weeds was not altered much when pH of the moisture supply varied between 4.0 and 9.0, in contrast, that of the indigenous flatsedge was significantly reduced to 30% with pH increasing from 8.0 to 9.0. Although the seed germination of floss flower, mile-a-minute, beggarticks and flatsedge was light-dependent, that of celosia and passionflower was only slightly inhibited in dark. Under the climate conditions and soil environments in Taiwan, the five exotic weeds tested, especially passionflower, are expected to display higher seed germination ability than the indigenous weeds. Therefore, the invasion risk of exotic weeds should be closely monitored in both the field and non-farming lands.

並列關鍵字

seed germination ； environment ； exotic ； indigenous ； weeds