【作者】 孙海菁；

【导师】 陈益泰；

【作者基本信息】 中国林业科学研究院 ， 林木遗传育种， 2007， 博士

【摘要】 本文针对杭州湾滨海盐碱地防护林和景观林带树种紧缺现状，围绕沿海防护林的树种选择，通过植被调查、树种评价和重要树种及其无性系的耐盐生理等三个方面展开研究，在树种资源现状评价的基础上，摸索了树种耐盐性评价指标体系建立方法，并对重要树种和洋白蜡(Fraxinus pennsylvanica)无性系盐胁迫后的生长、生理指标动态变化及其根、茎显微和超微结构的变化，耐盐指标和评价方法进行了讨论，为杭州湾沿海的耐盐树种选择奠定了理论基础。1、杭州湾沿海海岸带自然植被及防护林现状调查(1)典型新围垦海涂的调查发现高等植物种类简单，木本植物稀少；海滩主要群落有海三棱镳草(Scirpus mariqueter)和芦苇(Phragmites australis)，海岸以旱柳(Salix matsudana)、柽柳(Tamarix chinensis)灌丛植物群落为主，辅以少量草本群落；主要的促淤植被是海三棱镳草和芦苇。滩地没有形成有效的防浪林带，对滩地环境需保护并结合人工促进为主。(2)北部海岛的主要自然植被群落包括野梧桐(Mallotus，japonicus)、青冈(Cyclobalanopsis glauca)-石竹(Stellaria media)-鳞毛蕨(Dryopteris spp．)群落和红楠(Persea thunbergii)、青冈-石竹-鳞毛蕨群落等两种，并正在向地带性森林群落——以壳斗科植物为主(青冈林)的群落演替，海岛物种资源基础较为薄弱，需采用人工促进手段加速森林植被的自然演替进程。(3)杭州湾沿海现有保存林分种类较少，防护林带保存率较差，病虫害严重。在纯林中，杨树生长速度最快，水杉次之，刺槐较差，刺槐林下植被多样性较高；而混交林，其林分结构、蓄积量、抗风效果、病虫害均较纯林为优。杨树防护林保存率逐年减少，防风效果逐渐变差，在人为干扰的情况下，很难形成复层结构，必须采用人为措施对防护林加以改造，增加植被多样性，形成稳定的复层林型。2、沿海耐盐树种适应性评价与选择通过建立涵盖生长、抗逆、景观等多因子的综合评价指标，采用综合评价法对杭州湾慈溪新围海涂54个树种三年生林分和奉贤水、盐胁迫32个树种二年生林分的实验结果进行防护林和景观树种评价筛选，结果表明：慈溪新围海涂54个树种的表现共分4类：在0.2-0.4％盐土下表现良好的树种11种；表现尚好的树种13种；表现一般树种20种；不适宜树种10种。根据综合评价结果，推荐沿海防护林乔木树种15种：木麻黄(Casuarina equisetifolia)、旱柳、中山杉(Taxodium distichum×T．mucronatu)、弗栎(Quercus virginiana)、美国皂荚(Gleditsia triacanthos)、国槐(Sophra japonica L．)、香花槐(Cladrastis platycarpa)、黄连木(Pistacia chinensis)、墨西哥落羽杉(Taxodium mucronatum)、大叶女贞(Ligustrum lucidum)、洋白蜡、银荆(Acacia dealbara)、乌桕(Sapium sebiferum)、红千层(Callistemon rigidus)、栾树(Koelreuteria paniculata)；推荐沿海防护林灌木树种4种：夹竹桃(Nerium indicum)、珊瑚(Viburnum odoratissimum)、海桐(Pittosporum tobira)、海滨木槿(Hibiscus hamabo)。适宜做景观的树种与之差异不大，只是在选择顺序上略有变化。奉贤水、盐胁迫32个树种分为4类：表现良好的树种3种；表现尚好的5种；一般的6种；不适宜树种18种。根据综合评价结果，推荐水盐胁迫乔木树种5种，黄连木、乌桕、美国皂荚、侧柏(Platycladus orientalis．)、红叶椿(Ailanthus altissima)。水、盐胁迫灌木树种2种：胡颓子(Elaeagnus pungens)、海滨木槿。由于引种时间不长，其结果有待进一步观测。3、盐胁迫下弗栎等6个树种的生长、生理反应6个树种在盐胁迫后的生长、生理指标的研究结果表明：盐胁迫对不同树种生长性状抑制明显，大部分树种的细胞膜透性、脯氨酸、SOD活性、Na~+含量均随Nacl浓度的增加和处理时间的延长表现出逐渐增加的趋势；在中低盐度胁迫下增加趋势不明显，在高盐度胁迫下迅速上升；不同树种对于盐胁迫的响应浓度和时间有差异。利用主成分分析方法，筛选出苗高增长、脯氨酸、SOD活性、叶片盐害指数、生物量、相对电导率等6个指标作为树种耐盐性评价的指标，采用生长、生理指标与对照的比值，用座标综合评定法评定树种的耐盐性，依次为：旱柳、弗栎＞洋白蜡、美国皂荚、腊杨梅＞美国梧桐(Platanus occidenntalis)。4、盐胁迫下洋白蜡无性系生长、生理反应对水培条件下的洋白蜡无性系耐盐生长、生理动态的研究结果表明：盐胁迫下，洋白蜡无性系在苗高净生长、生物量、根系长、叶绿素、细胞膜透性，脯氨酸、丙二醛、Na~+含量的差异均达到显著水平；苗高、净光合速率、气孔导度、SOD活性等差异不显著。高盐对洋白蜡的生长和光合指标抑制明显，中、低盐度变化较缓；细胞膜透性，脯氨酸、丙二醛、Na~+含量随胁迫浓度和时间逐渐增加。无性系对盐胁迫的响应浓度、时间以及幅度上存在差异，在NaCl浓度4g／L～6g／L时，差异最大，在此浓度压力下选择效率较好，在盐胁迫下，其生物量模拟结果呈指数函数下降方式，不同无性系的下降速率有所不同。聚类分析的结果表明8个无性系可分为4类。在对指标进行相关、逐步回归、典型分析及主分量分析的基础上，选择苗高净生长、细胞膜透性、叶绿素a+b、Na~+含量4个指标进行生长和耐盐综合指数选择，入选无性系为4-20和1-17号。5、盐胁迫对洋白蜡根、茎显微和超微结构的影响光学和超薄切片技术结合透射电子显微镜清楚地显示了盐胁迫条件下根和茎的显微和超微结构变化。显微结构观测表明，盐胁迫对根和茎形成层细胞的活动和次生韧皮部和木质部细胞的分化产生显著影响。盐胁迫造成根和茎形成层带细胞不明显，未见新分化的木质部和韧皮部细胞。超微结构观测表明，盐胁迫使茎干形成层纺锤形细胞的中央液泡分裂成许多分散的小液泡，细胞质发生质壁分离现象，形成层纺锤形细胞形成条带状膜状结构，细胞质发生轻微的降解，细胞器结构不清晰，出现解体。更多还原

【Abstract】 Considering the shortage of tree species for Shelter-forest and landscape forest on the coastal area of Hangzhou Bay.and focusing on the issue of tree species selection, we conducted the vegetation investigation, tree species evaluation, as well as the tree and clone saline-resistance physiological research. Based on the current situation, the establishment method for saline-resistant tree species evaluation indicator system was discussed. The dynamic of growth and physiological indicators of Fraxinus pennsylvanica clones under the salt stress were studied. The micro-structure and ultrastructure of root and stem of Fraxinus pennsylvanica were observed. The indicators for saline resistance and evaluation method were discussed. The research results will lay a theoretic foundation for saline resistance tree species selection for sea front of Hangzhou Bay.1. Investigation for current situation of natural vegetation and protection forest on the coastal area of Hangzhou Bay.The higher plant species is not rich in the investigation site in newly-enclosed tidal flats in Cixi, with the total species of 59 under 45 genera and 21 families. The main community is Scirpus mariqueter-reed, the natural vegetation are mainly the shrubs of Salix matsudana Koidz and Tamarix chinensi. There is a few herb communities. The main driving vegetation for silt-forming are Scirpus mariqueter and reed. There is no effective wave-provention forest belt, and the bottomland environment need to be protected by artificial promotion.The main natural vegetation in Dainshan Island include MalIotus japonicus, Cyclobalanopsis glauca (Thunb.) Oerst-Stellaria media (L.) Cyr.- Dryopteris spp and Persea thunbergii, Cyclobalanopsis glauca (Thunb.) Oerst.- Stellaria media (L.) Cyr.-Dryopteris spp. They are on succession for regional forest community with the species in Fagaceae as the dominance. Due to the weak natural basis on the sea island, it is necessary to accelerate the natural succession process with artificial method.The remaining stand type is few on the coastal area of Hangzhou Bay with low survival rate and serious diseases and insect pests. The investigation for the protection forest with different tree species and type as well as poplar protection forest with different age Showed that the poplar grows the fastest, followed by Metasequoia glyptostroboides and Robinia pseudoacacia in pure forest. The undergrowth biodiversity in Robinia pseudoacacia forest is high. The structure, volume, wind-shield and disease and pest attack of mixed forest are better than those of pure forest. The remaining rate of poplar decreases year by year, with the wind-shield effect weakening. With the human disturbance, it is difficult for the poplar protection forest to form multiple-layer structure. It is necessary to improve the forest with artificial measurement, increase the biodiverty and form stable multiple layer structure.2. The comprehensive evaluation and selection of salt-resistant trees on Coastal Shelter-forest of Hangzhou BayBy means of establishment of comprehensive evaluation index, including tree-growth, tree-resistance capacity and sight-view etc., method by Analytical Hierarchy Process and factor weight, 54 tree species in Cixi county, Hangzhou Bay and 32 tree species which were under water-salt stress experiment in Fengxian county, Shanghai, the pro-tection forest and sight-view forest were evaluated as follows: the 54 tree species under salt stress of 0.4% content in Cixi could be divided into four categories, 11 tree specie were excellent, 13 tree species were good, 20 tree species were suitable and 10 tree specie were not suitable. Based on the comprehensive evaluation result, the following 15 tree species, which were recommended as arbor tree of protection forest, were Casuarina equisetifolia, Salix matsudana Koidz, Taxodium distichum×T.mucronatu, Quercus virginiana, Gleditsia triacanthos, Sophrajaponica L., Cladrastis platycarpa, Pistacia chinensis Bunge, Fraxinus pennsylvanica, Ligustrum lucidum, Taxodium mucronatum, Acacia dealbara Link, Sapium sebiferum, Callistemon rigidus R.Br, Koelreuteria paniculata. The following 4 trees species which were recommended as shrub tree of protection forest, were Nerium indicum Mill., Viburnum odoratissimum, Pittosporum tobira (Thunb.) Ait., Hibiscus hamabo. There was no significant difference among these tree species for sight-view, except the selection sequence. The 32 tree species in FenXian county were divided into four categories, 3 tree specie were excellent, 5 tree species were good, 6 tree species were no bad and 18 tree specie were not suitable. Based on the comprehensive evaluation result,, the following 5 tree species which were recommended as arbor tree of water-salt resistant forest, Pistacia chinensis Bunge, Sapium sebiferum, Gleditsia triacanthos, Platycladus orientalis (L.) Franco., Ailanthus altissima Swingle v. and two shrub trees, which were Elaeagnus pungens Thunb, and Hibiscus hamabo, but due to short introduction period, further observation was suggested.3. Growth and Physiology reaction of 6 tree species under salt stressIt was found that growth was inhibited apparently in all species. Permeability of cell membrane, Proline content, SOD activity, soluble protein and Na+ content increased under the stress of NaCl in most species. They were obviously elevated with higher Na+ concentration, but not with lower Na+ concentration. However, there were differences among the species in response time. Through PRLNCIPAL Component analysis, factors such as height growth rate, Proline content, SOD activity, index of salt harm, biomass, relative conductivity could be used for selection of tree species under salt stress. Based on Analysis of growth rate and physiology indexes, tree species were arranged in ordering according to their tolerance as Salix matsudana Koidz., Quercus virginiana, Fraxinus pennsylvanica, Gleditsia triacanthos, Myrica cerifera and Platanus occidenntalis.4. Growth and physiology reaction of Fraxinuspennsylvanica clones under salt stressThe tolerance of Eight clones of Fraxinus pennsylvanica were analyzed using solution curare system. It was showed that there were obvious difference among the clones in Biomass, chlorophylls content, electrolyte leakage, Proline content, MDA content, Na+ content and root characters. However, no apparent differences were observed in net photosynthetic rate, stomatal conductance and SOD activity. Growth and photosynthesis decreased significantly under higher salinity. In contrary, permeability of cell membrane, Proline content, MDA content and Na+ content increased with salt treatment, the most variances appeared among Fraxinus pennsylvanica clones when the concentration NaC1 increased to 4g/L～6g/L. As the result, it was sutible to select clones in the salinity zone The best model was exponent equation for biomass decrease with salinity. 8 clones could be classified into 4 families by Cluster analysis, indexes of net growth, permeability of cell membrane, chlorophylls content and Na+ content could be used for selection. 4-20 and 1-17 were the best clones.5. The changes of root and stem in Fraxinus pennsylvanica under salt stress on microscopic structural and untrastrueturalIn the research on microscopic structural and untrastructural changes of root and stem in Fraxinus pennsylvanica under 6%Nacl stress, the cambium activity and secondary tissues differentiation were observed by light microscopy (LM) and transmission electron microscopy (TEM), respectively. The present results indicated the remarkable impact of salt stress on cambium cell activity and secondary xylem cell differentiation of both root and stem. In comparison with control samples, cambium cells of salt treated materials appeared low activity without any new differentiating phloem and xylem cells under LM. In the samples under salt stress, TEM observations shown the large central vacuole in active cambial cells divided into smaller ones and apparent plasmolysis. Protoplast of fusiform cell formed into strip membrane structure with slight degeneration. The fine structure of cell organelles appeared rough and unclear, and even disaggregating.更多还原