| 题名 | 三种柽柳科植物种子萌发对主要生态因子的响应 |
| 作者 | 孙红叶 |
| 学位类别 | 硕士 |
| 答辩日期 | 2007 |
| 授予单位 | 中国科学院．新疆生态与地理研究所 |
| 导师 | 张希明，新疆生态与地理研究所 |
| 关键词 | 温度 |
| 其他题名 | Response of three species seed germination of Tamarix L to key ecology factors |
| 中文摘要 | 本研究以三种柽柳科植物种子为研究对象，分析三种柽柳科植物种子萌发对干旱荒漠环境主要生态因子的响应，总结其在荒漠环境中的适宜萌发条件及适应特性，为当地的植被分布，植被格局研究以及荒漠地区植被自然更新提供资料。不同温度、盐分胁迫、干旱胁迫与光照条件对刚毛柽柳种子、塔克拉玛干柽柳种子、民丰琵琶柴种子萌发的实验结果表明：在5℃～35℃条件下，三种植物种子在25℃条件下的萌发率、萌发指数、累积萌发率均达到最高，萌发的适宜温度范围为l0～35℃，适应幅度较宽。10℃是萌发速度和萌发率发生变化的一个分异点，10℃以下的萌发速度和萌发率较低，10℃以上萌发速度和萌发率逐渐增大。刚毛柽柳种子萌发率高达80%以上，且种子可在3天内完成发芽过程，萌发速度较快。塔克拉玛干柽柳种子萌发率低于刚毛柽柳种子，在80%以下。民丰琵琶柴种子的萌发率为45.8%，萌发速度较慢，初始萌发率均在20%以下。刚毛柽柳种子、塔克拉玛干柽柳种子、民丰琵琶柴种子萌发率均随NaC1溶液浓度的增大而下降，种子发芽均受到抑制。相同水势PEG－6000溶液对三种植物种子萌发率的抑制作用均大于NaC1溶液。当水势为－0.5MPa，刚毛柽柳种子、塔克拉玛干柽柳种子在NaC1溶液和PEG－6000溶液中的萌发率曲线出现明显的分异。而民丰琵琶柴种子在NaC1溶液和PEG－6000溶液中的萌发率曲线趋势基本相同没有明显的分异。民丰琵琶柴种子在萌发期的耐盐性较另两者低，在0.3moL/LNaC1溶液中，种子萌发率即为0。在－0.9MPaPEG-6000溶液中，种子萌发率为0，其耐盐临界值为－2.385MPa，极限值为－5.67MPa；当NaC1溶液为0.7mol/L时，刚毛柽柳种子的萌发率仅为1.67%。，当PEG－6000溶液水势为－1.8MPa时，萌发率已急剧下降到0，其耐盐临界值为－3.972MPa，极限值为－7.78 MPa；塔克拉玛干柽柳种子在NaC1浓度达到0.7 mol/L时，萌发率仅为5%，在－2.3MPaPEG-6000中的萌发率完全为0，其耐盐临界值为－1.176MPa，极限值为－3.746MPa。刚毛柽柳种子、塔克拉玛干柽柳种子、民丰琵琶柴种子在NaC1溶液中的萌发恢复率随原处理液浓度的增大呈现两种变化趋势：刚毛柽柳种子萌发恢复率随NaC1溶液浓度的增大逐渐增大，在0.7mol/L时，萌发恢复率为60%；而塔克拉玛干柽柳种子和民丰琵琶柴种子的萌发恢复率随NaC1溶液浓度的增大先升高后降低。刚毛柽柳种子、塔克拉玛干柽柳种子、民丰琵琶柴种子在PEG－6000溶液的萌发恢复率随原处理液浓度的增大先升高后降低。但两种处理下三种植物种子的最终萌发率(全部萌发率)都低于在蒸馏水中的萌发率。根据三种植物种子在两种胁迫条件下各个萌发指标的分析，它们在萌发期的耐盐性顺序依次为：刚毛柽柳种子、塔克拉玛干柽柳种子、民丰琵琶柴种子。三种植物种子在萌发期的耐旱性顺序依次为：民丰琵琶柴种子、刚毛柽柳种子、塔克拉玛干柽柳种子。刚毛柽柳种子、塔克拉玛干柽柳种子、民丰琵琶柴种子无论在光照下还是黑暗中都能萌发，且光照和黑暗条件下的萌发率基本相同无显著差异（P>0.01）。光照和黑暗条件下的萌发率均在60%以上、萌发指数均在30以上。故三种植物种子萌发对光照的需求差异不大，光照和黑暗条件对种子的萌发无显著影响。The effects of different temperature, salts and drought stresses on the seed germination of three species were studied. The results show that the Tamarix hispida、Tamarix taklamakanensis and Reaumuria minfengensis seed germination percentage of suitable temperature is l0～35℃ at 7 different gradient of temperature , no difference was found between the germinability of theirs seeds under high and low temperature, meanwhile ,the Tamarix hispida seed germination speed is very fast and its germination percentage is basically exceed 80% among three species. 10℃ can affect the speed and ratio of germination to a certainty.Below 10℃ has distinctly effect. Different concentration of NaC1 restricted seed germination percentage significantly. The total tendency of seed germination percentage decreases with salinity increase of three species. In this experiment, we use polyethylene glycol 6000 to simulate water stress on the seed germination.The osmotic potential of polyethylene glycol-6000 has a strong restrict effect than in NaCl. Its seed germination percentage of every gradients are all lower than in NaCl .When the osmotic potential is -0.5MPa,the curve of Tamarix hispida、Tamarix taklamakanensis seed germination has obvious dividing plot,the tendency of two curves altered, so -0.5MPa is the threshold, except Reaumuria minfengensis a. After the non-germinated seeds from all the treatments are transferred to distilled water, the Tamarix hispida germination recovery percentage can increases to 60% with the increase of concentration of salts not including another two species. The three species germination recovery percentages in polyethylene glycol -6000 all have a tendency of first rise and then fall. But the total seed germination percentage of salts and polyethylene glycol-6000 are all lower than in distilled water. According to every index of germination in salt solution and polyethylene glycol 6000,also the germination recovery percentage of all treatments, the sequence of tolerace salinity among three species seeds is Tamarix hispida>Tamarix taklamakanensis > Reaumuria minfengensis.Meanwhile the ability of droughtness among three species seeds is Reaumuria minfengensis > Tamarix hispida>Tamarix taklamakanensis. On the condition of light and darkness, the germination ratio and index among three species seeds are not exist difference.Under the two gradients,the germination ratio and index are all above 60% and 30.Therefore, the requirement of this three species seeds under light and darkness has no difference. |
| 语种 | 中文 |
| 学科主题 | 植物生理学 |
| 公开日期 | 2010-11-12 |
| 页码 | 共65页 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.xjlas.org/handle/365004/7926]  |
| 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 | 孙红叶. 三种柽柳科植物种子萌发对主要生态因子的响应[D]. 中国科学院．新疆生态与地理研究所. 2007. |
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