【作者】 张卓文；

【导师】 傅廷栋； 包满珠；

【作者基本信息】 华中农业大学 ， 植物学， 2005， 博士

【摘要】 杉木是我国特有树种,也是我国最重要的用材树种。育种是杉木研究最活跃的领域之一。我们在福建林学院杉木种源林、临天杉木林分、长乐1代杉木种子园、姥山1代杉木种子园及崇阳1.5代杉木种子园等试验林分内,对杉木生殖生物学特性进行了较为全面而深入的研究工作,结果表明:杉木物候可明显地划分为12个物候期;种子园内杉木无性系物候与其种源原地理位置相关。无性系许多物候期与其原地理位置杉木物候相比较,由于长时间异地引种栽培原因出现“趋同”现象;本方首次提出以cb/xb比值作为无性系雌雄球花开花同步性分类标准,并对各无性系进行了分类。分类方法与结果能客观在评价杉木种子园雌球花可授粉期与雄球花散粉期同步性。从同步性的角度并提出种子园建立与改造对无性系植株选择与配置,达到减少自交概率的目的。以植株雌球花及雄球花在不同时间内开花百分率为指标将无性系划分为早花型、中花型及晚花型;以雌雄球花开花同步性,将杉木各无性系分为雄先雌后型、雄雌同步型及雄后雌先型;杉木球果发育过程与发育时间符合对数函数,但其残存率与发育时间则呈负线性函数;病虫害及灾害性天气是球果致死的主要原因;杉木花粉散发有其特有的日变化规律及时段变化规律;杉木种子园内花粉在垂直空间的分布方式为集群分布,种子园内花粉在水平空间上呈现出均匀分布状态,而花粉量在园外则随传播距离的增大而减小并呈现出线性相关;风速是影响杉木花粉散发最重要的因子,花粉在静条件下作匀速沉降运动,风、地形等因子也影响其运动,如果遇到气流,花粉则随气流上升混合,这种混合有利于种子园内不同无性系植株杂交而减少自交;杉木无性系雌球花和雄球花在树冠中的分布出现明显的分层现象,雄球花主要分布于树冠中下部,雌球花一般分布于树冠中上部,种子园因为密度小而使得雌球花在树冠中的分布范围达整个树冠;杉木雌雄球花及花粉对风作为花粉传播媒介出现适应性变化;同一杉木无性系植株单位花粉囊内的花粉数差异没有达到显著性水平,而不同无性系间单位花粉囊花粉差异达到极显著性水平;雌雄球花数量与其配子比例不同年份及无性系间差异显著或极显著;本文首次提出以Rm及Rc作为客观定量地评定种子园授粉效率的标准,并对现实种子园内的授粉水平进行了评述。Ra为授粉期间种子园内单位面积上花粉累积数与适宜单位面积上花粉累积数比值,Rm为授粉高峰期间种子园内单位面积上1天中最大花粉累积数与适宜单位面积上一天中最大花粉累积数比值。根据授粉期间单位面积上累积沉降的花粉数目人们能客观定量地评定授粉水平,正常年份情况下应该维持授粉期间累积花粉量3—5粒/mm2,在所研究的各种子园内授粉水平过高,Rc达4—56倍,对此应该进行改造,增加偏雌植株的比例或采取促进雌球花分化的技术措施以提高单位面积种子产量;杉木花粉为近球体,赤道轴为39.87μ更多还原

【Abstract】 Chinese fir is the most important timber tree in south part of China, and the research of flowering characteristics and its breeding is one of the most active research area. We have carried out a series of research into Chinese fir flowering characteristics in 1.5 generation Chongyang seed orchard, 1 generation Laoshan seed orchard, lgeneration Zhangle seed orchard, Lintian forest and Jujian Forestry College provenance forest, the results show that Chinese fir Phenology can be divided into 12 phases, there is a relationship between the Chinese fir clone Phenological phase in a seed orchard and its original geographical location. Because of a long time of introduction, many Phenological phase among clones appear " going to the same". We have proposed the ratio of cb/xb as index to estimate the time of male and female flowering coincidence. Using the ratio of female to male cones, the clones can be classed into mainly female clones, female and male clones and mainly male clones. Using flowering percentages of female and male cones among different clones at different dates, clones can be divided into early, mid and late flowering clones. Based on the time of male and female flowering coincidence, clones can be grouped into early female flowering late male flowering clones, coincident male and female flowering clones and late female flowering early male flowering clones. The regression between Chinese fir female cone developing course and date is a logarithm, the regression between Chinese fir survival rate and date is negative linear, and diseases, insect pests and disaster weather are the main factors which lead cones to death. The pollen dispersal has its own release pattern and day-night cycle. Vertical pollen distribution is as a cluster one, horizontal pollen distribution in seed orchards and in normal forest is a uniform distribution type, outside seed orchards and normal forest pollen distribution is diffusible. Wind speed is the most important factor for pollen dispersal. The relationship between pollen quantity and distance to a seed orchard is linear. When a pollen leaving from its pollen sac, the pollen makes a evenly sedimentation movement and the wind, topographical factor can effect this movement as well, which make pollens ascend and mix with wind to decrease self-fertilization rate. Male cones and female cones have their own distribution regions in tree crowns, male cones are located in the middle to top and female cones the middle to bottom part of tree crown, and because of lower density for mother trees in seed orchards than that of in a stand, female cones are distributed over the whole of the mother tree crown in seedorchard. Chinese fir male cones and female cones appear to be very well adapted for wind as the pollination mechanism. There are no obvious differences for the number of pollen grains produced by one pollen sac among trees in the same clone, but there are obvious differences among clones. There are obvious differences both among clones and between years in female cone number, male cone number and their ratio. We have proposed the index of Rm and Rc as the pollination level in a seed orchard. The accumulation pollen during pollination period (Rc) should be 3-5 pollen grains / mm2 to guarantee fertilization. Chinese fir seed orchards in this study produce too much pollen, which is 4-56 times as Rc, and could be improved by increasing the number of mother trees which produce more female cones or stimulation more female flowers in these seed orchards in order to produce more seeds. Chinese fir pollen is almost like a ball with an equator axes length 39.9μm, a pole axes length 37.4μm, a volume of 30219μm3 and a weight of 1.98x10~-5mg. The pollen number produced by 1 sac of a Chinese fir tree is 2300-12000 grains, and the average pollen number per tree 7.8311x10~9, about 1.5539xl05mg, the average ovule number 39240.55. One mother tree in seed orchard can produce pollen 2.1891x1010, about 4.3438xl05mg and ovule 53199.25. On the pollen surface there are lot of Wu-body pattern, and there is a aperture on pollen surface as well, and the aperture varies very much among provenance Chinese fir. The pollen wall is composed of 2 layers, i.e. exine and inxine, the exine can be divided into sexine and nexine else. We can find Golgi-body, endoplasmic reticulum( ER), mitochondria, nucleolus and so on inside pollen. The useful way for the vigour test is to dye pollen with ink, the dyeing time for clones is from 12.65 to 30.17 minutes. Boron is very important for pollen germination, without it in the culture medium, pollen germination is restrained, with the culture medium of 1-50 ppm boron acid a pollen germinates well. Apart from the normal germination pollen tube morphology, there are abnormal morphological types. The are differences of peroxidase isozyme among Chinese fir provenance pollens. There are obvious differences for morphological characteristics both male cone and female cone, the distributions of male cone and female cone morphological characteristics are not normally distributions. There are different types for both male cone and female cone. In Chongyang seed orchard the average female cone diameter, female cone length, macrosporophyll number, macrosporophyll width, macrosporophyll length, total seed number, good seed number, empty seed number, Se-seed number and the one-thousand grain weight of clones are 26.53mm, 30mm, 52.30, 12.45mm, 14.86mm, 72.90, 17.73, 19.72, 35.33 and 9.41g respectively. The correlation coefficients are reach to significant level for the follow items: between female cone diameter and length, among each kind seed, and among macrosporophyll items. There are obvious differences for every kindseed number in a cone and female cone morphological items among clones. This information tells us that clone composition plays a very important role for seed production in a seed orchard. We can obtain three components by means of varimax with Kaiser normalization rotation factor analysis and name: macrosporophyll factor, female cone-seed factor, and seed factor. With good seed number per cone all clone female cones can be classed into 4 groups by means of Hierarchical cluster. There are obvious differences for 1000-grain weight, purity and vigour among families, and the family seeds can be divided into 3 quality groups by means of K-means with purity, 1000-grain weight, seed moisture content, vigour, Se-seed, empty seed and germinating.Based on the characteristics of Chinese fir flowering, we make some suggestions for Chinese fir seed orchard establishment or improvement: in order to decrease or perish self-fertilization rate we can do by increasing the clone number, increasing mother trees which produce more female cones or stimulating mother trees to yield more female cones. To chose clones with high female cone yield and high seed quality when we set up a new Chinese fir seed orchard. To carry a artificial pollination according to pollination regulations during the pollen dispersal season when it needs. To manage the Chinese fir seed orchard intensively to decrease abortion rate for both female cones and seeds.更多还原