Seed Germination eco-physiology of Mikania micrantha H.B.K

假澤蘭種子萌發的生理生態學特性研究

楊期和(Qi-He Yang) ； 葉萬輝(Wan-Hui Ye) ； 鄧雄(Xiong Deng) ； 曹洪麟(Hong-Ling Cao) ； 張雲(Yun Zhang) ； 許凱揚(Kai-Yang Xu)

《Botanical Bulletin of Academia Sinica》 46卷4期 (2005/10) Pp. 293-299

https://doi.org/10.7016/BBAS.200510.0293

摘要

假澤蘭是華南地區危害嚴重的外來雜草。本文對其種子的生理生態特性進行研究以探討其入侵機制，結果表明：種子萌發的適宜溫度是25~30℃，15/30℃和室溫(24~23℃)。種子在黑暗中的萌發率低於10%，光強由0升至700勒克斯時，發芽狀況逐漸變好，當光強分別達到700和550勒克斯後繼續增大，發芽率和發芽指數不再有明顯變化。種子在白光、黃光和紅光下的發芽情況比在遠紅光、藍光和綠光下要好。種子在黑暗中浸泡的時間越長，光敏感性也越強；浸泡後的種子移至光下萌發，光量越大，發芽率越高。剛成熟的種子有休眠現象，經乾燥後熟後可解除。在室溫和15℃貯藏超過90d，或在4℃下貯藏超過120d，發芽率顯著下降，在室溫和15℃時下降速度比4℃和-5℃時要快。出苗率隨土壤深度的增加而降低，當土壤深度在粘土和沙土中分別超過1.5cm和1.75cm時，出苗率均為0。當土壤濕度由8%上升至20%，出苗率逐漸升高，當濕度超過22%，出苗反而受到抑制。假澤蘭種子萌發實驗結果表明它對華南地區有很強的適應性。

關鍵字

萌發 ； 光照 ； 假澤蘭 ； 種子 ； 土壤深度 ； 土壤濕度 ； 土壤類型 ； 溫度

並列摘要

Mikania micrantha H.B.K is an invasive alien weed in South China. To help understand the mechanisms of its invasiveness, we studied its seed germination ecophysiology. We found that the optimal temperatures for seed germination were 25, 30, 15/30℃ (night/day), and an ambient temperature (24-32℃). Germination percentage (GP) in dark was less than 10%, and it increased with increasing light intensity up to 700 Ix. However, GP and germination index (GI) did not change significantly when light was more than 700 and 550 lx, respectively. Germination was enhanced by white, yellow and red light more than far-red, blue, and green light. Light sensitivity and germination of seeds increased with increasing dark incubation time. Newly ripened seeds exhibited innate dormancy that was released by a two-month after-ripening period in dry storage. Except at a storage temperature of -5℃, seed GP decreased when storage time exceeded the after-ripening period, and this decrease was more pronounced from a storage temperature of 4℃ to 15℃ to ambient 24-32℃. Percentage seedling emergence was lower and slower when seeds were covered deeper in soil, and no emergence occurred when seeds were buried at 1.5 and 1.75 cm in clayey and sandy soil, respectively. With increased soil moisture content (MC) from 8% to about 20%, seedling emergence became increased and quickened. However, an MC greater than 23% reduced emergence. These responses of seed germination to various treatments indicate that this weed is well adapted to environments in South China.

並列關鍵字

Germination ； Light ； Mikania micrantha, Seed ； Soil depth ； Soil moisture ； Soil type ； Temperature.