【作者】 李晓梅；

【导师】 赵晓英；

【作者基本信息】 新疆师范大学 ， 植物学， 2010， 硕士

【摘要】 刺木蓼(Atraphaxis spinosa)和长枝木蓼(A. virgata)隶属于蓼科木蓼属,刺旋花(Convolvulus tragacanthoides)隶属于旋花科旋花属,这三种野生灌木是乌鲁木齐周边植被的重要组成种,是植被恢复的潜在候选植物种。论文通过野外观测和室内试验,对这三种植物种子的萌发、休眠的解除及萌发物候进行了研究并对其种子的萌发对策进行了探讨,主要结论如下:温度、水分和盐分对这三种野生灌木种子萌发的影响存在差异。刺木蓼在30/20℃的萌发率最高;长枝木蓼在30/20℃和20/10℃的萌发率高;刺旋花在所设温度下萌发率差异不大。它们的种子在-2.7MPa的水分胁迫和0.50mol/L的盐分胁迫下均能萌发,-0.3MPa的水分胁迫对两种木蓼种子的萌发起促进作用,0-0.2mol/L的盐胁迫对刺旋花种子萌发的影响不大。三种野生灌木的种子具有不同的休眠特性。刺木蓼和长枝木蓼种子分别经低温层积8周、6周及冬天野外自然层积均可解除休眠,同时室温干藏也能解除长枝木蓼种子的休眠,说明两种木蓼的种子均为非深度的生理休眠。刺旋花种子可以通过擦破种皮解除休眠,可知其为物理休眠。休眠解除后,种子萌发的最适温度降低。两种木蓼种子经过室温干藏后的萌发率高于低温干藏的,低温干藏提高了刺旋花种子的萌发率。经过埋藏后两种木蓼的种子全部萌发,刺旋花种子部分萌发。两种木蓼具有不同的萌发机制,产生不同休眠程度的种子,成熟早的刺木蓼种子休眠程度低,而长枝木蓼成熟晚的种子休眠程度低。刺木蓼种子在室温干藏的过程中,萌发率先降低后增加。室温干藏明显提高了长枝木蓼种子在15/6℃的萌发率,尤其是10月成熟的种子,10月和11月成熟的种子分别干藏9个月和6个月后解除休眠。休眠类型不同,萌发物候也存在差异。刺木蓼和长枝木蓼的种子在成熟的当年均未萌发,于第二年3月中旬开始萌发出苗,一直到4月出苗结束。刺旋花的种子在成熟的当年便开始萌发出苗,9月出苗结束,来年4月继续出苗。这三种野生灌木种子的萌发、休眠特性及萌发物候对于其在乌鲁木齐周边荒漠中成功定居与生长发育,物种的延续和种群的扩大具有重要的适应意义。更多还原

【Abstract】 Atraphaxis spinosa, A. virgata and Convolvulus tragacanthoides are native shrubs in Urumqi which have potential value in vegetation restoration. The germination, dormancy and germination phenology characteristics of them were observed and analyzed both in field and indoors, and the ecological adaptive germinative strategy of the species was discussed. The main results are as follows:The seed germination of the shrubs differ singnificantly in temperature, water stress and salt stress. The optimal germination temperature was 30/20℃for A. spinosa, 20/10℃and 30/20℃for A. virgata, respectively. The germination percentages of C. tragacanthoides are not significant in alternating temperature regimes from 10/6℃to 30/20℃. The seeds can germinate at -2.7MPa of water stress and 0.5mol/L of salt stress. PEG solution of -0.3MPa promoted seed germination of the Atraphaxis species. Salt stress hardly inhibit seed germination of C. tragacanthoides.The dormancy characteristic of the seeds are different. Dormancy break of Atraphaxis spinosa and A. virgata seeds by cold stratification at 5℃for 8 weeks and 6 weeks, also at the habitat in winter. The seeds of the Atraphaxis species were shallow non-deep physiological dormancy. The seeds of C. tragacanthoides were physical dormancy, because the dormancy was broken by scarification.The seeds were treated by dry storage at room temperature, dry storage at 5℃and burying storage for 9 months. The seed germination of the Atraphaxis species achived higher after dry storage at room temperature than that of at 5℃, in opposition to C. tragacanthoides. The Atraphaxis species seeds all germinated after buried. And the seeds of C. tragacanthoides had lower germination after buried.Two Atraphaxis species have different mechanisms of germination. Their seeds have different level of dormancy. A. spinosa fruits twice a year, in June and September. A. virgata has a long florescence last out two months. A. spinosa seeds were collected in June and September, while A. virgata were collected in October and November. The seeds of A. spinosa maturating earlier have higher germination comparing to matured later. Dry storage significantly increased germination percentage of A. virgata at 15/6℃, the percentage of increment was greater in October than that in November. A. spinosa seeds matured in October were break dormancy after 9 months and the seeds matured in November after 6 months in the situation of dry storage.Germination phenology of the seeds are different due to the dormancy types. No seedlings emerged after sowing of two Atraphaxis species seeds. In the next spring, the seedlings were recorded. The seeds of C. tragacanthoides emerged after sowing, and continued to germinate in April the next year.The seed germination, dormancy and germination phenology characteristics of the shrubs have significant ecological consequences in development of seedling, population persistence and expansion in desert around Urumqi.更多还原