【作者】 张华新；

【导师】 沈熙环；

【作者基本信息】 北京林业大学 ， 林木遗传育种， 1996， 博士

【摘要】 提高油松种子园种子产量和品质是种子园管理的核心,也是当前生产上亟待解决的问题。为此,于1985～1995年在河南卢氏和内蒙古宁城黑里河油松种子园,观测了雌雄球花在树冠中的空间分布特征,研究了光环境对雌雄球花空间分布的影响,探讨了树体修剪的原则;测定了无性系花粉数量和花粉生活力,并在球果分析的基础上,分析了无性系间、无性系内分株间及不同冠层和方位中球果性状的差异及其原因,讨论了球果性状与种子产量的关系;调查了31个无性系11年的雌雄球花量,分析了无性系雌雄球花量的变异和年份变化,从中分别筛选出20和22个雌、雄球花量稳定和超稳定的无性系;在连续3年授粉试验的基础上,检测了进入珠孔和珠心的花粉粒数,分析了不同授粉方式的授粉效率,证实油松符合“最先到达珠被臂的花粉,优先进入珠孔和珠心”的假设,并根据雌球花在可授期内的授粉效率,提出了开花频率计算中加权值的确定方法;在结实初期和盛期各3年,观察了两个种子园86个无性系的开花物候,了解了开花物候在无性系、同一无性系分株间和树冠不同部位的差异,分析了气候条件对开花物候的影响以及开花物候各性状间的相关性;研究了开花物候、配子数量与子代遗传组成的关系,讨论了开花同步性、配子产量和配置密度等对配子贡献的影响,并以配子贡献平衡为原则,按开花同步性、配子产量对无性系进行再选择,并估算了子代平均基因型值;观察了油松雌雄球花的分化时间,雌雄配子体的形成、受精和胚胎发育过程,在各个发育阶段败育胚珠的形态特征,以及不同无性系在球花发端和大小孢子发育进程上的差异,确定了雌雄球花促花处理的最适时期。 通过研究影响种子产量和品质的因素及其相互关系,得出遗传、营养、花粉数量、亲本间交配亲和性、自交和病虫害等因素是造成球果败育和胚珠败育的主要因素;树冠间交叠和郁闭可限制球花分布;开花同步性、配子数量、亲本间交配亲和性及自交等影响配子贡献;自交是空籽产生的主要原因,并降低种子发芽率、苗木保存率和生长量。无性系再选择、辅助授粉、营养管理、疏伐和树体修剪等是提高种子产量和品质的有效措施。并提出了将来的研究目标。更多还原

【Abstract】 The high genetic quality and ample yield are the key to seed orchard management, and also a urgent problem awaiting solution at present. Therefore, during 1985-1995 in seed orchards of Pinus tabulaeformis Carr., located in Lushi county, Henan province and Ningcheng county, Inner Mongolia autonomous region, continuous observations on the patterns of female and male strobilus distribution in crowns, female and male strobilus production, pollen amount and viability, pollen grains reaching micropyles and ovules, flowering phenology were carried out. The cone characteristics and the efficiencies of different pollination modes were analyzed. In addition, the female and male strobilus buds and ovules were observed under the microscope.The vertical distribution of female and male strobili in crowns varied with clones and years, the most of female strobili were borne in the middle part of a crown, while male strobili in the lower part, there was a tendency to distribute upward for both female and male strobilus in the crowns with ages. The female strobili bearing in the upper part of a crown were nearly equal in amount for all directions. There were much more female strobilus production on the shoots facing south than the other three directions in the middle and lower parts of the crown, while no male strobili nearly bearing in the upper part of the crown. About 90.4% of female strobili were concentrated outside the crown on 1-5 year-old branches of the first order, while male ones were mainly on weak branches inside the crown. Female and male strobili were terminally borne on the shoots .Vertically, the cone with filled seeds was mainly borne in the middle part of a crown, while less in the lower part. Horizontally, the cones facing the dominant wind directions during flowering produced more filled seeds. There were remarkable differences in cone characteristics for various clones in Lushi seed orchard, while no differences in Helihe. The variations among ramets within clone had no significance in the two seed orchards.There was a fluctuation in female and male strobilus production with about 4-year-cycle in Lushi seed orchard, and the fluctuations of cones with filled seeds among years coincided with male strobilus production. The variations of the cones with filled and emptied seeds did not tended to stable until abundant cone production. There were significant differences for the female and male strobilus production between clones, greater differences for strobilus production in a seed year than a lean year, and in abundant cone period than initial period, and the smaller differences between ramets within clone. The interactive effects of clone and year for the female and male strobilus production were significant. The 20 clones stable in production for female strobilus and 22 for male were selected from 31 clones.The first pollen grain arriving at the integument arms was preferentially engulfed over pollen approaching later during conelet receptive period. Controlled pollination carried out within 2-3 days after flowering gave the greatest efficiency with 54% of filled seeds. The repeated pollination during receptive period could not significantly increase seed numbers over single pollination. The 45-50% of filled seeds in cone could be produced when 0.2-0.4 ml of pollen was applied to one pollination bag. The mixtures of fresh pollen with dead pollen or talcum powder at the ratio of 1 : 1 could produce the same percentage of filled seeds as pure fresh pollen applied.The differences of flowering phenologies among clones, among ramets within a clone, at different positions within a crown were described, the relationship of flowering phenologyof the same clones in different years were analyzed. There were great differences in the average flowering synchronization indexes, and unbalanced contributions of female and male gametes for different clones in seed orchards were detected. The average synchronization indexes within a clone were larger than those among clones. The influences of flowering phenology on the indexes were as following order: for the mating pairs > mothers > fathers. There was a small fluctuation for unifonnity indexes estimated by female gamete production, while a great fluctuation by male gamete production among years, the uniformity of gamete contribution was improved in abundant flowering years than the initial period. The unifonnity of female gametes was more preferable to male ones. There was close relationship between the genotypic values of progenies and those of the pollen-clones.In general, the genotypic values of progenies were smaller than those of their mother-clones in initial years. The gamete contribution tended to equilibrate in abundant cone period, therefore, the average genotypic values of progenies were increased. Since the influence of gamete production on gamete contribution was greater than flowering phenology, the unifonnity of gamete contribution in seed orchard could be more effectively improved by adjustment of clonal female and male gamete production.The male strobilus differentiated in late June, while the female strobilus in middle July. The microsporogenesis occurred in late April of the next year. The mature pollen, which was pollinated from late April to middle May, was composed of 4 cells. The megasporocyte was formed in late April and early May of the next year and undertook meiosis to form megaspore in early and middle May. A female gametophyte developed from free nuclei, cell and archegonia phase to a mature egg cell. Fertilization took place in late May. The interval between pollination and fertilization was about 13 months. There were great differences in differentiation time of female and male strolibi and development process of microsporocyte and megasporocyte between clones. The optimal time for promotion of female and male strobilus was about a half month and one and a na’f month after the cessation of shoot growth, respectively.In addition, factors affecting seed production and quality and relationship among factors were discussed, among them, the genetic, nutrition, pollen amount, mating compatibility, selfing and insect pests were major factors causing conelet and ovule abortions. The close of canopy and overlap of branches between grafts hampered strobilus distribution and production. Selfing was main factor causing emptied seeds, decreased the gennination rate of seeds, survival and growth rate of seedlings. The degree of flowering synchronization, gamete numbers, mating incompatibility between parents and selfing affected gamete contribution;The clonal re-selection, supplemental mass pollination, nutrition management, roguing and pruning were effective measures increasing seed yield and quality.更多还原