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题名	胡杨种子萌发和幼苗生长阶段生态学特性的初步研究
作者	李利
学位类别	硕士
答辩日期	2002
授予单位	中国科学院．中国科学院新疆生态与地理研究所．李利．
导师	张希明，中国科学院新疆生态与地理研究所
关键词	种子萌发
其他题名	The study on ecological characteristics of Populus euphratica in the stage of seed germination and seedling growth
中文摘要	胡杨是干旱荒漠区分布较广的乔木树种.在不同温度条件下,胡杨种子萌发和胚根生长对不同盐浓度(NaCl)和PEG(6000)的响应,以及自然条件下光照对胡杨小幼苗生长和生物量分配的影响进行研究,结果表明:胡杨种子的发芽率在10℃时为76%,在10--40℃时大于76%,在45℃时发芽率不到20%,但随后已发芽的种子就全部死亡;NaCl和PEG-6000溶液胁迫下,发芽率与水势呈显著线性负相关(R<'2>>0.89).并受到温度的微弱影响;在水势为-1.6Mpa时,NaCl处理条件下,发芽率分别为9%(20℃),7%(30℃),4.5%(40℃),PEG-6000处理条件下,发芽率均为0;在两种溶液胁迫下,胚根生长都比种子萌发受到的抑制强;光照对根冠比、叶面积比率和根重比率没有显著影响,光因子不改变胡杨幼苗生物量的分配状况,但能显著促进根的生长、叶面积的增加和生物量的积累.实验结果显示,胡杨种子萌发及胚根生长对盐分(NaCl)和干旱(PEG-6000)胁迫的忍耐力不强.大量的种子、较长和适宜的种子成熟期、迅速的发芽进程是胡杨在干旱荒漠区成功定居的重要策略,虽然冒险,却不失成功.The effects of sodium chloride (NaCl), polyethylene glycol-6000, temperature on germination and radicle growth, and the effects of light on early seedling establishment, growth and biomass allocation of Populus euphratica Olivier, were investigated. The species is mainly distributed in desert regions of north-western China, and occurs in sand dunes or the two sides of some rivers. Percentage germination of Populus euphratica Olivier, in 10℃ was 76% , all over 76% between 10-40℃, but it became 0 in 45℃ when it was nearly 20%. Total germination percentage had a negative linear relationship to water potential significantly in two stresses (R2>0.89), which was influenced lightly by temperature. In -1.6Mpa, the germination percentage of seeds in NaCl was 9%(20℃), 7%(30℃),4.5%(40℃), in PEG-6000 decreased to 0. In any cases radicle growth had more adverse response to saline or moisture stress than germination. Light can't significantly affect root shoot ratio, root weight ratio and leaf area ratio, and no biomass allocation is changed. High light is conducive to rowing of root, expanding of leaf area and assimilating of biomass. It was concluded that the species in the stages of germination and radicle growth had relatively low adaptability to salinity as well as drought, while shade has an adverse effect on seedling growth. The successful establishment of P. euphratica Olivier, in the early stage in desert regions was just dependent on a great number of seeds, the long and fit reproduction period, and the rapid development of germination and radicle growth. The species was an adventurer in germination types.
语种	中文
学科主题	植物生理学
公开日期	2010-11-12
页码	共41页
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/8342]
专题	新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据)
推荐引用方式 GB/T 7714	李利　. 胡杨种子萌发和幼苗生长阶段生态学特性的初步研究[D]. 中国科学院．中国科学院新疆生态与地理研究所．李利．. 2002.

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