落羽杉优良种源选择研究

【作者】 柳学军；

【导师】 曹福亮；

【作者基本信息】 南京林业大学 ， 森林培育， 2006， 博士

【摘要】 落羽杉（Taxodium distichum（L.）Rich.）是古老的孑遗植物，原产北美，现已广泛引种到世界各地。落羽杉生长快、树形美、材质优良、适应性强，无论平原水湿地带或丘陵山区均能生长，适合我国广大地区作用材、防护及庭院观赏树种。本文对13年生16个落羽杉种源试验林不同种源之间的生物量生产、光合特性、木材物理化学性质，以及它们之间的相关关系进行了研究，以期揭示不同种源落羽杉在生物量生产、光合特性、木材物理化学性质等方面的差异，探讨各项指标之间的相关关系，并从生物生产力、木材物理化学性质等不同方面筛选出优良的落羽杉种源，为落羽杉的栽培推广提供理论依据。 研究结果表明：（1）不同落羽杉种源的树高、胸径、材积、地上部分生物量等均达到极显著差异水平，不同种源落羽杉形数的差异也较大，削度全都在强度削度以上；（2）落羽杉种群的广义遗传力变幅在5.99％～39.06％之间，其中胸径的广义遗传力最大，其次为单株材积、枝下高、冠幅和树高，而分枝角度和分枝数量的广义遗传力最小；（3）种源间的树高、胸径、材积、冠幅等生长指标间均呈现显著正相关。以材积为因变量，胸径（X₁）、树高（X₂）为自变量，建立了回归模型，Y=0.00577X₁+0.00436X₂-0.0628；（4）生长性状综合比较结果表明，12号、9号和6号种源生长最好；（5）16个不同落羽杉种源净光合速率、蒸腾速率、气孔导度、水分利用效率、光能利用效率、叶绿素初始荧光、最大荧光、可变荧光、电子传递速率、PS Ⅱ反应中心的潜在活力、光化学效率等光合特性指标均存在显著差异，但细胞间隙二氧化碳浓度差异不显著；（6）1-6个种源日进程曲线大致可以分为两类，4，5，6，7，12，，15，16，17和30号种源呈单峰曲线，而2，3，8，9，10，13，14号种源呈双峰曲线；（7）树冠不同层次净光合速率、水分利用效率、光能利用效率等的日变化进程及大小存在一定的差异；（8）测定的光合特性参数之间，以及光合特性参数与胸径生长之间存在一定的相关关系。以测定的各项光合特性参数为自变量，胸径为因变量，进行通径分析，表明胸径依各指标的多元线性回归方程极显著存在，但以Backward方法拟合最好，得到回归方程y=7.48602+4.53901X₇-0.06479X₈+490.25428X₁₁，其中光能利用效率(X₁₁)对胸径的生长影响最显著，其次为蒸腾速率（X₇）和气孔导度（X₈）；（9）16个种源落羽杉木材的微纤丝角、木材纤维形态、木材密度、顺纹抗压强度、纤维相对结晶度、综纤维素的含量、木素的含量、NaOH抽出物的含量和pH值等存在极显著差异，同时存在一定的径向和纵向变异规律，落羽杉木材性质部分指标之间的相关性达显著相关水平；（10）16个种源落羽杉依据木材微纤丝角和木材纤维长度2个木材材性指标可以分为4类，依据木材物理顺纹抗压强度、木材密度和木材纤维相对结晶度等可以分成3类，依据所有测定的木材物理化学性质可以分成3类。更多还原

【Abstract】 Taxodium distichum （L.） is a venerable and relic plant originating from North America, which now is introduced to being planted all over the world. Taxodium distichum have many virtues just like rapid growth and widely adapted planting, the graceful shape of tree, the excellent wood property and it can be planted not only under wetland areas but also highlands for the production of timber, shelter belt and ornamental in most of China. To elucidate the difference of the different Taxodium distichum provenances in the bio-productivity, photosynthetic characteristics, wood physical and chemical properties, this investigation was carried out to study the bio-productivity, photosynthetic characteristics, wood physical and chemical properties of sixteen provenances of thirteen year-old Taxodium distichum （L.）. In this paper, we also discussed the correlation coefficients of all indexes and screened out the fine provenances in order to provide the theoretic basis for widely planting Taxodium distichum.The results were as follows: （1） There were highly significant differences at 0.01 level among the Taxodium distichum provenances in growth traits of height, DBH （diameter at breast height） , tree volume and the above biomass. The differences of form factor among provenances were also greater and all the taper coefficients were more than the intensity-taper coefficients; （2） Broad-sense heritability among provenances varied from 5.99 to 39.06 percent. The broad-sense heritability of DBH was the biggest among all the genetic control of traits, and the broad-sense heritability of branch angle and branch number was the smallest; （3） There existed positive relationship at 0.05 level between growth traits such as height, DBH, tree volume and the width of tree crown. The regression equation based on the stem volume taken as attributive variable and the diameter at breast height （X₁） and height （X₂） taken as automatic variable was: Y=0.00577X₁+0.00436X₂-0.0628; （4） Synthetic result based on the compare with all the growth traits showed that the provenances of 12,9,6 were the best varieties; （5） There existed significant differences among 16 provenances in photosynthetic characteristics indexes like net photosynthetic rates, light use efficiency, transpiration rate, Stomatal conductance, transpiration rate, water use efficiency, initial fluorescence, maximum fluorescence, electronic transport rate, quantum efficiency of PS II and the primary light energy conversion of PSII, but the difference of intercellular CO₂ concentration was not obvious; （6） The diurnal courses of 16 provenances were distinguished two types: the provenances of the 4th, 5th, 6th, 7th, 12th, 15th, 16^th, 17th, 30th demonstrating single-peaked curve and the provenances of the 2nd, 3rd, 8th, 9th, 10th, 13th, 14th being dual- peaked curve; （7） There was a certain difference among the daily change and magnitude of net photosynthetic rates, water use efficiency and light use efficiency of 16 provenances in different layers of tree crown; （8） It showed the close correlation among the measured parameters of photosynthetic characteristics, between the parameters of photosynthetic characteristics and DBH. Path analysis based on the measured parameters of photosynthetic更多还原