【作者】 张兴；

【导师】 车代弟；

【作者基本信息】 东北农业大学 ， 蔬菜学， 2012， 博士

【摘要】 榆树为榆科(Ulmaceae)榆属(Ulmus L.)植物的总称。在我国平原、盐碱地及沙荒地一直是用材林、防护林的重要树种。在园林绿化中可作为行道树、绿篱和庭院树种,如金叶榆和垂枝榆以其叶色鲜艳,树形优美等特点广泛应用于园林绿化中。全世界共有榆属资源30余种,我国有25种6个变种。目前,榆属植物的分布面积和种质资源正在逐年减少,原本属于榆树植被类型的丘陵地和沙地遭到严重的滥垦、过渡放牧等人为破坏。因此如何避免榆属植物资源进一步被破坏,更好的保护中国榆属植物,培育适合园林绿化的榆树新品种具有十分重要的意义。本研究通过对我国黑龙江省、山东省、浙江省及气候较干旱的甘肃省分布的榆属植物资源进行调查、整理、分析和评价,采用形态学标记和(?)ISSR分子标记对我国榆属资源亲缘关系进行研究,同时应用60Co-γ对白榆种子进行辐射研究,通过形态学观察,生理,分子生物学检测,以期获得观赏性状优良、抗性强的植株,为榆属植物资源的保护,育种和园林应用奠定基础。主要结果如下：1)此次调查共搜集我国70%的榆属植物,属于3组2系。搜集资源包括黑龙江省全部榆属资源,其中包括2个特有品种；山东省、浙江省、甘肃省的榆属野生种和栽培变种。采用层次分析法对榆属资源进行评价,园林应用范围中白榆、新疆大叶榆、旱榆、黄榆、榔榆、金叶榆和垂枝榆等为优良材料；经济应用中白榆、新疆大叶榆、春榆、太行榆、美国榆、多脉榆等为优良材料;抗干旱,耐盐碱的优良品种为圆冠榆、脱皮榆、旱榆。果实产油量大的品种为旱榆、黄榆、脱皮榆。抗虫性较好的品种为裂叶榆、太行榆和天优,其中裂叶榆叶部不感虫害,但易感天牛,在天牛可控区可作为优良树种；太行榆不仅生长季节幼叶颜色优美且不感病虫害,可作为优良城市绿化树种。2)对来源于黑龙江省和山东省的榆属资源进行形态学性状分类,选择28个表型性状作为分类信息进行编码,其中二元性状10个,有序多态性状10个,数值性状8个。Q聚类结果表明榆属栽培变种和半同胞家系聚为一组；榆属种间大部分聚类结果和传统分类吻合但白榆分类和传统不符。R型聚类结果表明各性状之间相对独立,28个形态学性状对品种的演化具有较独立的意义。主成分分析表明前5个主成分的累计贡献率达71.02%,果部性状和部分叶部性状是榆属的分类的主要性状.3)建立了榆属植物ISSR-PCR最佳反应体系；从93条ISSR引物中筛选出11条扩增条带清晰、多态性好的引物。11条引物共扩增出97条条带,其中多态性条带86条,占总扩增带数的88.66%;遗传相似系数分布在0.5490-0.9216之间,平均为0.7353。其中白榆半同胞家系白榆068、白榆0061遗传相似系数最大为0.9216；白榆34、古6遗传相似系数最小为0.6863。由ISSR聚类可知,榆属种间分类和传统分类相同；栽培变种红叶榆同其它各品种亲缘关系较远,单独聚为一类,钻天榆和榆组榆系亲缘关系较近,金叶榆同榔榆遗传相似性较高；半同胞家系和白榆聚为一组,且同各栽培变种垂枝榆、大叶垂榆、龙爪榆遗传关系紧密。由主坐标分析表明榆属资源分为三大组,组Ⅰ中栽培变种与白榆半同胞家系聚在一起；组Ⅱ中传统分类的榆属睫毛榆组中的美国榆和新疆大叶榆聚类,榆组榆系中的黄榆,裂叶榆聚类,并且睫毛榆组、榔榆组与榆组榆系的亲缘关系较近；组Ⅲ中传统分类榆组黑榆系中的东北黑榆、春榆、圆冠榆聚类。4)白榆种子60Co-γ射线辐射最佳半致死剂量为50Gy。60Co-γ辐射在幼苗生长前期起抑制作用,随着剂量的增加抑制作用增强。在生长过程中,小剂量的辐射抑制作用减轻,在苗高、鲜重等方面还具有促进作用(30-70Gy)；根系的生长量与辐射剂量成负相关,辐射能够抑制根系纵向伸长(顶端优势)促进侧根及须根的发育,扩大根系的分散度及营养面积。在30-90Gy范围内,能够促进地上部分生长；30-100Gy不同照射组别中均产生具有实用价值的观赏性状突变体。不同剂量的辐射,对榆树物候期具有一定的影响；对于展叶期30Gy-50Gy的辐射剂量对植株展叶有所促进,高于50Gy时展叶受抑制；辐射剂量为30Gy时皮孔形状为椭圆形,辐射剂量大于30Gy时皮孔恢复近圆形。5)低辐射剂量可以使白榆柱头膨大,对柱头的发育有刺激作用,而高辐射剂量则使柱头发育不良,对发育有阻碍作用；随着辐射剂量的增加花粉极轴与赤道轴比例呈递减的趋势；未经过辐射的白榆花粉外壁纹饰为细拟网状,随着辐射剂量的增加花粉外壁纹饰逐渐变的稀疏,小颗粒大小及疏密情况逐渐减小。不同辐射剂量对白榆叶片超微结构有一定影响,70Gy-100Gy叶片超微结构改变明显,叶绿体肿胀,双层膜消失,类囊体融合；线粒体双层膜消失,出现空泡变性,嵴断裂；核膜消失。6)叶绿素含量同辐射与辐射剂量之间呈负相关性；叶绿素a/b在70Gy处出现了一个跳变,叶色上表现为黄白色；在辐射剂量为100Gy叶绿素a/b的值和对照有明显差距,差异极显著,表现在叶色上为叶色变红色；SOD、POD酶活性随着辐射剂量的增加先升高后降低；CAT活性在30Gy剂量处升高到活性峰值后下降,50到100Gy稳步小幅上升。更多还原

【Abstract】 Elm is the general name of genus Ulmus L. It is one of the most important tree species which used as timberland and shelter forest in plains, saline-alkali soil and barren lands in China. There are thirty genus Ulmus species in the world and twenty-five species and six variants in China. Ulmus plants distribution area and Elm germplasm resources are decreasing every year. Originally hilly groud and sandy which belonged to Ulmus are serious of artificial destruction such as estrepement, overgrazing. It is significance to avoid Ulmus plant resources being further damaged, better protected of elm species in China and breeding new cultivars for landscaping.This study investigate the distribution of Ulmus in Heilongjiang, Shandong, Zhejiang and climate drier’s Gansu province. The genus Ulmus are investigated, collected, analyzed and evaluated. Secondly morphological markers and ISSR molecular markers are used to study the genetic relationships among all Ulmus. Finally in order to obtain excellent ornamental characteristics and resistant plants, U. pumila seeds are radiated by60Co-γ. This research will lay a foundation of Ulmus breeding and landscape application. The main results are as follows:1)70%percent of Ulmus plants were collected and investigated which belonged to three sections and two series. It was included all Ulmus germaplasm resources in Heilongjiang among others there was two endemic species. Ulmus species and cultivars which distributed in Shandong, Zhejiang and Gansu province were also collected and investigated. Analsis hierarchy process(AHP) was used to evaluate Ulmus germaplasm. U.pumila L.、U.laevis Pall.、U.glaucescens Franch.、U. macrocarpa planch.、U. parvifolia Jacq.、U. pumila L. cv."jinye "and U.pumila L. cv."tenue" were excellent materials in landscape applications. U.pumila L.、U.laevis Pall.、U.propinqua Koidz.、 U. taihangshan-ensis S.Y Wang、U.americana L.、U.castaneifolia Hemsl.were excellent materials in economic applications. U.densa Litv.、U.lamellosa T.wang were excellent materials resistance to drought and salinity. U.glaucescens Franch., U. macrocarpa planch., U.lamellosa T.wang were excellent materials in fruit oil production. U.laciniata Schneid.、U. taihangshan-ensis S.Y Wang and ’TY’ were high resistance to insects. Among them leaves of U.laciniata Schneid. had less pests except for Alternatus, so it was a good tree species in Alternatus controllable area.’TH’ was not only had beautiful leaf color but also had less pests, so it was an excellent materials in landscaping.2) Ulmus species and varieties which collected from Heilongjiang and Shandong province were classified based on morphological traits. Twenty-eight morphological characteristics were encoded as classified information which including ten qualitative binary characters, ten qualitative polymorphic characters and eight quantitative characters. Q cluster showed that Ulmus varieties and half-sib families were in the same group. The results of cluster were similar to the traditional classification except siberian elm. The independence of each character was presented by R cluster. Twenty-eight morphological characteristics had independent significance in the evolution of Ulmus. The principal component analysis showed that first five principal components accumulative contributor ratio amounted to71.02%, and some representative characters which could be used in classification, such as fruit characters and leaf characters.3) The optimal ISSR-PCR reaction system were built.11ISSR primers which had clear bands and polymorphisms were select from93primers.97bands were produced after using11ISSR primers,86bands were polymorphic(88.66%). The range of genetic similarity coefficient was from0.5490to0.9216. The genetic similarity coefficient of siberian elm068and siberian elm061were the biggest (0.9216). The genetic similarity coefficient of siberian elm34and G6were the smallest (0.6863). The result of ISSR clustering was similar to the traditional classification in Ulmus. U. pumila L. cv.sp was far away from other cultivars. The genetic relationships of U. pumila L. cv.’Pyramidalis’ and genus Ulmus were relatively close. The Genetic similarity coefficient of U. pumila L. cv.’jinye’ and U. parvifolia Jacq was relatively high. Half-sib families and U.pumila were clustered in the same group. U.pumila L was close to U.pumila L. cv.’tenue’, U.laevis Pall, U. pumila L. cv.’pendula’. Ulmus species were divided into three sections. Cultivar varieties and U.pumila L. were in the same clustering. U.americana L.and U.laevis Pall were belonged to the same clustering in section Ⅱ. The relationship of U. macrocarpa planch, U.laciniata Schneid and U. parvifolia Jacq was relatively close. U.davidiana Planch. U.propinqua Koidz and U.densa Litv were belonged to the same clustering in section III.4) The optimal60Co-γ lethal dose of U.pumila seeds was50Gy.60Co-γ had negative effection on young plant growing, the more dose, the more damage. Low dose(30-70Gy) had positive effection on plant height and plant fresh weight.60Co-γ increase growing of Lateral root, but inhibit main roots. Radiation between30-90Gy was helpful to the growth of plants. Radiation between30-100Gy could produce mutation on ornamental traits.60Co-γ can also effect phenophase of Ulmus, Radiation between30-50Gy was useful to leaves growth. leaves were inhibited when radiation was over50Gy. Lenticel shape was ellipse when radiation was30Gy and Lenticel shape became almost round when radiation was over30Gy.5) Low radiation dose can enlarge the stigma of white elm, which has stimulatory effect to the development of stigma. While high radiation dose made the development dysplasia, acted inhibition effect to the development of stigma. The ratio of pollen axis and equator was decrease following the increase of preirradiation dosage. The ornamentation of pollen exine were fine quasi reticular with no radiation, the reticular became sparse and the size of small particles became smaller and spare following the increase of radiation dosage. There were some effects on leaf ultrastructure of elm under radiation with different dose, the changes to leaf ultrastructure was obviously at radiation dose of70to100Gy. The structure of chloroplast became intumesced, double-layer membrane disappeared and thylakoid fused; the double-layer membrane of mitochondria was disappear and occurred vacuolar degeneration and cristae fragmentation; the nuclear membrane was also disappeared. 6) There were negative correlation between chlorophyll content and radiation, radiation dose; the value of chlorophyll a/b has a jump at70Gy and showed on leaves with yellow-white colour; when the radiation dose was100Gy, there were extremely significant difference of chlorophyll a/b between treatments and control and showed on leaves with red colour; the activities of SOD and POD increased at first and then decreased following the increase of radiation dose. The activities of CAT has the top value at the peak with radiation dose of30Gy and then decrease, there were a steadily and slightly rises at radiation dose50to100Gy.更多还原