【作者】 陈燕；

【导师】 干友民； 刘伟；

【作者基本信息】 四川农业大学 ， 草业科学， 2008， 硕士

【摘要】 我国西南地区马蹄金资源丰富,本次试验以前期试验中筛选出的坪用景观价值和抗性强的野生马蹄金为研究材料,围绕马蹄金无性繁殖和有性繁殖特性,开展马蹄金无性系繁殖的最佳种植密度以及马蹄金开花习性和种子活力等的研究,并探求提高种子活力的方法,为推广优质野生马蹄金材料提供理论依据。研究结果表明:1.马蹄金无性系种群的扩展表现为前期主茎长度快速增加,尽可能的占据空间,增长率随时间推移而下降,主茎分株数与主茎长度之间呈显著的正相关以及间隔子动态变化规律,均揭示了无性系扩展形成的空间结构是聚集于源株周围空间一定范围内,扩展依赖于源株和先生分株、叶片对无性系的贡献。供试的马蹄金主茎的扩展表现出相同规律,但在相同时期有不同的数量表现特征。2.在环境充足的情况下,马蹄金无性系的扩展并不会出现主茎的“疯长”,而是保持方正型的生长格局。主茎和叶片增量的交替上升、无性系单位面积茎叶生物量随扩展距离的交替变化,以及供试材料无性系数量和生物量在空间上的分配和配置,均体现了无性系植株在生长和扩展功能之间的物质和能量的权衡,是马蹄金植株在不同阶段对环境的适应对策和植株生长过程中利用资源和环境的策略。3.供试材料在密度为D2的前期生长过程中,由于发生了克隆整合,资源和能量的分配和利用效率最高,呈现马蹄金植株的最佳生长状态。营养生长末期,材料单位面积茎叶生物量随密度的增加而升高,虽未出现恒值现象,但单株生物量随密度增加的递减已经体现出了密度制约的作用。4.在不同种植密度的影响下,马蹄金植株的克隆构型形态指标发生了有规律的变化:随着密度的增加,马蹄金间隔子长度递减,分枝角度增加,分枝强度减小;体现了马蹄金植株在密度影响下的可塑性变化,以及对环境的适应性表现。5.根据马蹄金的开花结实时间将野生材料分为三种开花结实物候:(1)全年未见开花结果,如材料SD200309和GD200503;(2)一年集中开一次花,开花时间集中在3～5月,结实时间为5～7月,如材料SD200303和SD200304:(3)除枯黄期外,全年开花结实,果期和花期高度重叠。同一匍匐茎上的开花顺序为从基部向匍匐茎扩展方向依次展花,个体开花时间异步,除SD200303、SD200304、SD200309和GD200503外,其他野生材料几乎都属于此类型。6.采用磨破种皮的物理方法处理马蹄金种子,磨破种皮后马蹄金种子的发芽势、发芽率、发芽指数和活力指数均较未磨破种皮的种子提高了2～3倍,但物理处理未能改变种子内部化学物质含量,所以未能促进幼苗的生长。7.采用赤霉素和PEG两种化学试剂处理马蹄金种子后,马蹄金种子活力提高,幼苗生长旺盛。综合分析:浓度为75ppm的赤霉素浸种4小时后,马蹄金种子的发芽率显著高于对照,效果最佳;20%的PEG浸种48小时,马蹄金种子发芽势、发芽率、发芽指数和活力指数提高最显著。更多还原

【Abstract】 There is rich resource of Dichondra repens Forst. in southwest of China, screening the materials which showed best turf landscape value and strong resistance on the pre-test, researched on the asexual reproduction and sexual reproduction characteristics, studied on the best plant density of the clone, flowering habit and seed vigor, and explored the way of improving the seed vigor, provide a theoretical basis of promotion of D.repens. The results show that:1. The main stolon of D.repens elongated as long as possible to occupied the ecological niche at first. But its increasing rate reduced varied with time. The positive correlation between the number of ramets and the length of main stolon as well as the dynamic change of spacer were all showed that the special structure of clone was gathered around origin plant and the extending of clone was due to the contribution of origin plant, lamina and the senior ramets. Although its number was different at one time, the main stolon elongated behaved the same rule.2. The main stolon elongated always keep the growth patern of matrix and not limitless in enough space. The main stolon length and leaf number increased by turns, the above biomass varied by turns and the allocation and structure of the clonal number and biomass show that there are mater and energy balance between the growth and the extending, also show the different environmental adaptation strategy of D.repens at different growth period.3. Because of the clone integration, D.repens made best ues of the resource and energy and behaved the best growth state under the density of D2. The above biomass of the stolon and leaf increased as density increased, but it did not come to a constant value. But the biomass per branch began to decreases as the density became bigger.4. The clone structure of D.repens varied under different densities: the spacer length descending, the interbranching angle increased and the branching density descending as well as the density increased; all the plasticity under different density indicated the environment adaptability of D.repens.5. All the wild D.repens divided in three bloom styles based on the bloom and seed time: (1)No bloom all the year,such as SD200309 and GD200503;(2) bloom once per year, peak flowering date focused from Mar. to May, seed date focused from May to Jul., it contained SD200303 and SD200304; (3)bloom all the year except the scorch period, the florescence and seed periods were laped over, bloom time were varied and it began at the originally stolon radicle and continued to the extended aspects, all the wild D.repens blonged to the style except SD200303, SD200304,SD200309 and GD200503.6. The Germination viability, germination capacity, germination index and vitality index were enhanced two to three times after the seed capsule frazzled; but the seeding growth was not advanced, as physics method can’t change the inside chemistry of seed.7. The seed vigor and the seedling growth of D.repens were enhanced after the chemistry gibberellin and polyethylene glycol soaking. Comprehensive analysis indicated that the seed germination rate was significantly higher after 75ppm of the GA soaking four hours; the germination viability, germination capacity, germination index and vitality index improved most significantly after the PEG of 20% soaking 48 hours.更多还原