【作者】 李燕；

【导师】 操国兴；

【作者基本信息】 四川农业大学 ， 森林培育， 2010， 硕士

【摘要】 近年来,对植物繁殖生态学的研究己成为生态学领域的热门之一,而对植物繁殖器官—花的研究成为繁殖生态学研究的基础。目前对各种植物花期配子数量及果期结实率、种子数变异的研究较多,对引起变异的机制,不同研究的结果不同。本研究以四川碧峰峡(N28°51′10″～30°56′40″,E101°56′26″～103°23′28″)为实验地,以多年生多次生殖草本植物紫萼为研究对象,采用野外试验控制法,通过去叶和去花蕾处理等方法探讨了紫萼花期花序内引起配子数量变异的结构效应及其对不同资源条件的反应情况,并尝试对引起这种变异的可能机制进行合理的解释。经过一年多的野外试验和室内实验,数据整理分析,得出以下一些主要结论：1.紫萼个体、花序内各部位胚珠数、花粉数均随花序大小增大显著增加(p<0.05),中部花粉除外(r=0.261,p=0.087)；花粉：胚珠比与花序大小无显著相关关系(p>0.5)；去叶后个体及顶部的花粉数与花序大小的显著相关性消失(p=0.095,0.780),仅基部花粉随花序大小显著增大(r=0.329,p=0.047),随之个体和顶部的花粉：胚珠比随花序大小增大显著降低(r=-0.382,-0.401；p=0.023,0.014)。胚珠较花粉与花序大小的相关性更强、更稳定；个体、基部和顶部花粉较中部花粉与花序大小的相关性更强,基部花粉与花序大小的相关性更稳定。2.紫萼花序内每花配子数存在着位置依赖性,这种显著性差异表现为基部较中部和顶部有更大的资源分配,花粉数、胚珠数以及花粉：胚珠比均由基部到顶部逐渐降低；花粉和花粉：胚珠比从基部到中部降低的幅度小于从中部到顶部降低的幅度,而胚珠却相反；紫萼去叶后个体花粉数和胚珠数均较对照显著增加,花粉：胚珠比不变,花序内各对应部位配子数不变,顶部花粉除外(显著增加,p=0.039)；去叶后花序内从基部到顶部的配子数降低幅度均有所减小,但差异不显著,去叶不影响花序内部位间的资源配置。3.所有不同资源处理下顶部花胚珠数均随花序大小增大而增加(p<0.001)；对照不结实、对照结实、去叶结实花序大小与顶部花花粉数显著正相关(p<0.05),与花粉：胚珠比不相关(p>0.1)；去叶不结实和去花蕾花序大小与顶部花花粉数不相关(p>0.5),与花粉：胚珠比显著负相关(p<0.05)。4.去花蕾后顶部花花粉数较对照顶部显著降低,胚珠数不变,但胚珠数较对照基部显著降低；基部和中部花结实后顶部花花粉、胚珠数不变；但去叶后基部和中部花结实后顶部花的花粉、胚珠数显著降低。5.综合来讲,紫萼花蕾早期营养生长与繁殖生长竞争同一资源库,去叶后,个体显著增加了对繁殖配子的资源投入；紫萼花期花序内由基部到顶部的配子数显著降低由花序自身发育的结构效应引起；不去叶时,果实和花发育竞争不同的资源库,花序内不存在果实发育和花发育的资源竞争,去掉叶子后,果实和花发育共同竞争同一资源库,花序内存在果实发育和花发育的资源竞争。但结构效应起主要作用。更多还原

【Abstract】 Recently, the study on plant reproduction has become one of the most important in ecology, and the study on flowers, the reproductive organs of plant is the basic of plant reproductive ecology. Now, the study focus on variation of gamete number, fruit set and seeds of different species; and to the reasons of variation, different studies had different answers. This study located in Bi Feng Mountain((N28°51′10″～30°56′40″, E101°56′26″～103°23′28″), Ya’an, Sichuan, China, and Hosta ventricosa (Liliaceae),a perennial herb was selected for study material, defoliation and debud treatments were applied in the field experiment, to explore the architectural effects of variation on gametes and response on different resource treatment, and try to get the reasonable explanation. Over more than one year of field experiment and data analysis, the results were as follows:1. Ovule and pollen number increased with inflorescence size significantly at plant and inflorescence level in Hosta ventricosa (p<0.05),but not pollen of Middle position(r=0.261,p=0.087); there is no significant correlation between p:o ratio and inflorescence size(p>0.05); After defoliation, the significant correlation between pollen number and inflorescence size disappeared at plant and Top position (p=0.095,0.780),and just the pollen number of Bottom increased with inflorescence size significantly(r=0.329,p=0.047); with the disappear of significant correlation between inflorescence size and pollen number of plant and Top position, the p:o ratio decreased significantly with inflorescence size(r=-0.382,-0.401;p=0.023,0.014). There was a more stable and stronger correlation between ovule number and inflorescence size than pollen, and stronger at plant, Bottom and Top position, more stable at Bottom position for pollen.2. There was a position-dependent gamete production within inflorescence in Hosta ventricosa, the plant allocated more resources to Bottom than Middle and Top position, pollen, ovule and p:o ratio decreased significantly from Bottom to Top position; pollen and p:o ratio decreased greatly from Middle to Top than from Bottom to Middle position, ovule was inverse; defoliation significantly increased the pollen and ovule number of plant,but no significant variation in p:o ratio; there was no significant variation of gamete at the same position between control and defoliation, except the pollen of Top position(pollen of Top increased significantly after defoliation, p=0.039); after defoliation, the gamete production decreased slower from Bottom to Top position, but not significantly, defoliation didn’t change the resource allocation to different positions within inflorescence.3. Ovule number of Top position increased significantly with inflorescence size at all treatments with different resource treatments(p<0.001);there was a significant increased correlation between pollen of Top and inflorescence size for control-unfruiting, control-fruiting and defoliation-fruiting(p<0.05),but not p:o ratio(p>0.1); and a significant decreased correlation between p:o ratio of Top and inflorescence size for defoliation-unfruiting and debud(p<0.05),but not pollen number(p>0.5).4. After removing the flower buds of Bottom and Middle position, the pollen of Top position decreased significantly, there was no variation in ovule,but to the Bottom of control the ovule decreased significantly; the fruiting of Bottom and Middle flowers didn’t change the gamete production of Top position;After defoliation, fruiting of Bottom and Middle flowers significantly decreased the gamete production of Top flower.5. There was resource competition between vegetative growth and reproductive growth, defoliation significantly increased the resource allocation to reproductive gametes;The decreased of gamete production from Bottom to Top within inflorescence was due to Architectural effects; undefoliation, there was no resource competition between developing fruit and flower within inflorescence because of different resource sink, with defoliation, there was resource competition between developing fruit and flower within inflorescence because of the same resource sink. But architectural effects was the main.更多还原