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题名	多枝柽柳（Tamarix ramosissima）两次开花现象的生殖生态适应性
作者	姬慧娟
学位类别	硕士
答辩日期	2009
授予单位	中国科学院．新疆生态与地理研究所
授予地点	北京
导师	尹林克，新疆生态与地理研究所
关键词	多枝柽柳
其他题名	Reproductive ecological adaptability of bi-seasonal flowering in Tamarix ramosissima
学位专业	植物学
中文摘要	以分布在准噶尔盆地的多枝柽柳（Tamarix ramosissima）自然种群和中国科学院吐鲁番沙漠植物园栽培种群为对象，对不同花期多枝柽柳种群的开花物候、结实特性、花部综合特征、繁育系统及种子萌发特性进行了观察研究，旨在探讨柽柳两次开花结实现象的生殖生态适应机理。主要结果和结论如下：不同生境的多枝柽柳具有相同的开花频率，每年均开两次花。在自然种群和个体中春花持续期分别为15d和11d，夏花持续期分别为77d和72d；栽培种群和个体春花持续期分别为11d和8d；夏花持续期分别为39d和35d，开花物候在不同生境的种群和个体水平上的差异可能由环境因素所引起。但不同生境、不同花期的单花花期均为1d。春花期表现为集中开花模式，而夏花期则表现为持续开花模式。多枝柽柳春花期的结实率和单个果实内的结籽数均大于夏花期的。多枝柽柳特殊的两次开花结实现象是对荒漠环境的一种适应。多枝柽柳散粉后花粉活力的动态变化趋势表现一致，花粉具有高活力的时间与柱头具有可授性的时间相吻合。P/O为649~1368，属于混合式繁育系统，与套袋实验的结果相一致。这种繁育系统可以避免荒漠生境多风、温湿度变化大等恶劣环境条件对其开花、传粉过程的影响，保障了繁殖成功。在两个观测地点，春花期种子的千粒重、长度和宽度均大于夏花期的；在5/15℃、5/25℃、15/25℃和25/35℃（暗/光=12/12h）四个温变周期下，除吐鲁番夏花期外，其它花期种子的萌发率均在90%以上，且彼此间差异不显著；在25/35℃条件下，多枝柽柳种子萌发迅速，初始萌发时间均低于4h；盐分浓度小于0.20mol/L时不抑制种子萌发，大于0.40mol/L时萌发率随盐浓度的增高而急剧降低，当浓度增高至0.80mol/L时，种子萌发率降低为零；多枝柽柳种子复水后恢复萌发率为0，表明NaCl处理后的种子永久地失去了萌发能力。综上所述，多枝柽柳具有在一定范围内稳定的两次开花特性、春夏花期不同的开花模式和持续结实特性、混合式的繁育系统类型、在较宽的温度范围内具有较高萌发率和耐盐萌发率，这些特点保证了多枝柽柳在多变的荒漠环境中各项繁殖过程的实现，为其在荒漠环境中成功定居繁衍提供了保证。Tamarix ramosissima is an excellent pioneer plant for sand control, taking natural and cultivated populations of T. ramosissima as study object, which distributed in Zhunggar Basin of Xinjiang and cultivated in Turpan Eremophytes Botanical Garden of Chinese Academy of Sciences respectively. In this paper, we observed the flowering phonology, characteristics of breeding system and seed germination in the different flowering periods of T. ramosissima. The main rusults were as follows: 1. T. ramosissima flowered twice a year under different environments and possessed the same flowering frequency. The duration of spring flower were 15d and 11d in natural population and individual respectively, while the summer flower were 77d and 72d; the duration of spring flower were 11d and 8d in cultivated population and individual respectively, while the summer flower were 39d and 35d. T. ramosissima flower lasted 1 day under different flowering periods and two different observation sites. In spring flowering belonged to mass-flowering pattern, while in summer flowering was extended-flowering pattern. Both the fruit set ratio and seed number in single fruit of spring flowering were more than those of summer folwering. Bi-seasonal flowering of T. ramosissima is adapted to the desert environment. 2. The survivoship(viability) curves for pollen were similar, the optimal pollination period was correlated with the period of stigma receptivity. The P/O ratios of T. ramosissima was 649~1368, the breeding system was facultative mixed, which was consistent with the results of bagging experiments. Thus, we concluded that the breeding system of T. ramosissima ensured reproductive success in the unpredictable environment of the desert. 3. Thousand seed weight, seed length and width of spring flowering were bigger than those of summer flowering respectively at two different observation sites. Except for the summer flowering period of Turpan, the final germinate percentage was basically more than 90% at four different thermoperiods (5/15℃, 5/25℃, 15/25℃ and 25/35℃), and were not significant different at other three flowering periods. At thermoperiod 25/35℃, seeds consistently germinated faster, the initial germination time were below than 4h. The seed germination was not affected by NaCl at concentrations below 0.20mol/L, but it was significantly decreased by NaCl at higher concentrations above 0.40mol/L, even fell to nearly 0 when NaCl solution concentration was 0.80mol/L. Seeds that were incubated in NaCl solution for 8d recovered after being transferred to distilled water and the percentage of recovery was 0, indicating that the NaCl-treated seeds may lose their ability to germinate. In a word, the special bi-seasonal flowering characteristics, different flowering pattern of spring flowering and summer flowering, consistently fruiting characteristics, the facultative mixed breeding system, the higher germination percentage and anti-salt germination percentage, those all ensured various reproduction process success of T. ramosissima in the unpredictable desert environment.
学科主题	植物生理学
公开日期	2010-11-12
页码	共59页
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/8438]
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	姬慧娟. 多枝柽柳（Tamarix ramosissima）两次开花现象的生殖生态适应性[D]. 北京. 中国科学院．新疆生态与地理研究所. 2009.

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