【作者】 彭尽晖；

【导师】 周朴华；

【作者基本信息】 湖南农业大学 ， 植物学， 2010， 博士

【摘要】 绣球属(Hydrangea L.)植物是园林中重要的观赏植物,又具有多种药用价值,同时,由于其在绣球花亚科演化上处于一个中心位置,具有重要的分类学上意义。湖南省是绣球属植物的一个分布中心,也是遭受铝毒严重的省份。绣球属中的八仙花作为耐铝植物对铝毒表现出较强的忍耐能力和积累能力。论文通过对湖南省绣球属资源的调查收集,比较绣球属植物的耐铝特性和生理响应,以期筛选出高耐铝的种或品种,为揭示植物耐铝机理和防治铝毒提供理论基础和实践指导。目前国内外对绣球属铝胁迫下耐铝毒特性的研究少见报道。论文从以下几个方面对绣球属植物资源及耐铝特性进行研究,结论如下：1、首次对湖南省绣球属植物资源进行调查,并以南岳衡山风景名胜区、八大公山国家级自然保护区、大围山国家森林公园的绣球属植物资源为调查对象,实地勘察绣球属植物的典型自然群落及种类数量,得出湖南省绣球属种类丰富,共有绣球属植物15种3变种,占中国现有绣球属资源的39.1%。2、为探讨绣球属几种植物叶片气孔器和表皮毛特征与系统学的关系,首次采用光学显微镜和扫描电镜对绣球属植物叶片表面进行观察,结果表明：不同植物单位面积的气孔密度、气孔器形态有差别,八仙花、蜡莲绣球、圆锥绣球气孔呈长椭圆形,柔毛绣球呈卵圆形,气孔密度最大是柔毛绣球,为819.43个／mm2,最小的是圆锥绣球,286.05个／mm2,这可能与其抗逆性和生长势有关。表皮毛及附属物在外形上区别明显,蜡莲绣球表皮毛呈狭长的线状,毛上附属物为丘状突起；柔毛绣球表皮毛呈片状,附属物为乳突状突起；圆锥绣球表皮毛呈圆锥状,附属物为星状突起；八仙花无明显表皮毛,附属物为颗粒状蜡被物。从所观察的气孔器、表皮毛的形态特征及表皮毛上附属物形状等的变化,反映出来的突显差异支持了中国树木志绣球属的划分。3、采用单因素试验设计方法,首次建立了绣球属SRAP分子标记最佳反应体系为25μL:10×PCR Buffer2.5μL、DNA模板30ng、Mg2+浓度1.6mmol/L、dNTPs浓度0.6mmol／L、TaqDNA聚合酶3.5U、引物浓度为0.2μmol／L。从110对引物中筛选出14对引物组合,对19份绣球属材料进行了SRAP扩增,共扩增出233条带,其中多态性带为232条,多态性比率为99.7%。基于Nei&Li对19份绣球属材料的遗传相似系数进行分析,大部分材料的遗传距离比较远,在GS值分别为0.27和0.43处,所有材料聚为4类,其中1号伞形绣球单独聚为1类；第2类为除八仙花18号品种外的其余7个栽培品种；第3类为八仙花栽培种18号、蜡莲绣球、阔叶蜡莲绣球、长柄绣球、大枝绣球、紫背绣球、光柄绣球、柔毛绣球、柳叶绣球；第4类包括6号圆锥绣球和10号白背绣球。19份供试材料划分为3个系,即绣球花系(Ser. Petalanthae),由伞形绣球和八仙花7个栽培品种组成；腊莲系(Ser. Piptopetalae):由腊莲绣球、阔叶腊莲绣球、长柄绣球、大枝绣球、紫背绣球、柔毛绣球、光柄绣球、狭叶绣球和八仙花栽培种18组成；挂苦树系(Ser.Heteromallae),由圆锥绣球和白背绣球组成。4、首次对来源绣球属3个系的植物进行铝胁迫下光合特性比较。结果表明：随着Al3+浓度升高,几种绣球属植物的叶绿素含量和类胡萝卜素含量均呈先逐渐升高,而后逐渐降低。较低浓度的铝(≦0.15mmol·L-1)有利于绣球属植物叶绿素和类胡萝卜素的积累,对光合作用起到促进作用。随着Al3+浓度的升高,几种试材的净光合速率(Pn)、胞间CO2浓度(Ci)、蒸腾速率(Tr)、气孔导度(Cond)均呈先上升,而后逐渐下降趋势。而饱和蒸汽压(VpdL)则相反,呈先降后升的趋势。铝胁迫对叶室气温(Tair)和叶面温度(Tleaf)的影响较小。通过隶属函数法分析得出绣球属3个系的几种植物抗性的强弱顺序为柔毛绣球>腊莲绣球>圆锥绣球>八仙花。5、从铝吸收速率、吸收量、增加幅度三个方面对绣球属植物进行铝吸收特性研究,结果表明：八仙花、蜡莲绣球、柔毛绣球、圆锥绣球这四个植物材料Al元素的吸收速率与Al3+浓度的关系呈一元一次直线方程,且相关系数均在0.95以上,与Michaelis-Menten酶动力学方程不相符合。推断该4种绣球属植物对Al元素的吸收属于被动吸收。八仙花、蜡莲绣球、柔毛绣球和圆锥绣球在铝浓度为0.10 mmol.L-1溶液中连续培养一段时间,对Al3+的吸收速率随时间延长而下降,而对Al3+的吸收量随时间延长而增加,但增加幅度随时间延长而减少,在0-4h内增加幅度相对较大,4h以后,铝的吸收渐趋于饱和。6、Al3+胁迫下八仙花各品种的生理指标出现一系列的变化。随着Al3+胁迫液浓度的增大,其叶片组织内可溶性糖含量出现明显的增加；脯氨酸含量变化幅度较大；可溶性蛋白质含量的变化与铝胁迫浓度呈负相关;丙二醛的含量因品种不同,增加的速度有异；SOD酶、POD活性的活性呈现先上升后下降的单峰变化趋势；叶片细胞电解质伤害性外漏率(IL)与处理浓度呈正相关。更多还原

【Abstract】 Hydrangea is an important ornamental plant, which has high medicinal value. There also is an important taxonomic significance for its central position in the evolution of Hydrangeoideae.Hunan province is one of the distribution centers of Hydrangea as well as a province suffering serious aluminum toxicity. Hydrangea macrophylla is an Al-tolerant species, and showed a strong Al-tolerance and Al-accumulation ability. This paper studied Al-tolerance characteristics and physiological response of Hydrangea under Al-toxicity stress by collecting and investigated the resources of Hydrangea in Hunan province. The purpose of the study is to select a strong Al-tolerant species or varieties, and provide a theoretical basis practice comment for revealing plant Al-tolerance mechanisms, preventing and remeding Al-toxicity. Up to now, there was few report about Hydrangea Al-tolerance characteristics.This paper studied the resource and Al-tolerance characteristic of Hydrangea. The results are as follows:1. An investigation on typical natural community, species and quantity of Hydrangea resources in Hunan Province was conducted by randomly set up a number of observation points in Nanyue Mountain Scenic Spots, Badagong Mountain National Nature Reserve and Dawei Mountain National Forest Park. The result showed that there were 15 species and 3 varieties in Hunan Province, account for 39.1%of total Hydrangea resources in China.2. To explore relationship between phylogenetic and the character of trichome and stomatal apparatus of leaves of some species of Hydrangea, the leaves surface was observed by using the optical microscope and scanning electron microscope. The result showed that stomatal density and stomatal apparatus shape among four species were differenct. The stomatal shape of H. macrophylla, H.strigosa, and H. paniculata’s stomatal were elongated oval, while H.villosa was oval. The stomatal density of H.villosa was the biggest (819.43/mm2), and the smallest one was H. paniculata(286.05/mm2), which may be related to the resistance and growth. Trichome modality differences were shown in the length, width, density and shape, etc., and its trichome appendage had obvious difference in appearance. H.strigosa’s trichome was long and narrow linear form, and trichome appendage were hill-like protuberances; H. villosa’s trichome was flaky, adjunct for the papilla-like protuberances; H. paniculata’s trichome was cylindrical cone, adjunct for the stellate protrusions; H. macrophylla had no obvious trichome, adjunct for granular material.The highlighting differences from the observed morphological characteristics of stomatal apparatus and trichome and the changing of appendage shape on trichome supported the classification published in《Chinese tree species》for the genus Hydrangea.3. The optimal SRAP system in Hydrangea was established with single factor’s experimental design for 25μL:10×PCR Buffer2.5μL, template DNA 30ng, Mg2+1.6mmol/L, dNTPs0.6 mmol/L, Taq enzyme3.5U, primer 0.2μmol/L. Fourteen out of 110 pairs of primer combinations were selected,233 SRAP bands were generated in 19 materials of Hydrangea, of which 232 were polymorphic, polymorphism rate is 99.7%.The genetic similarity coefficient based on Nei&Li of 19 materials of Hydrangea were analyzed, most of which had far genetic distance, and were classified into four groups at the GS(0.43and 0.27). Group 1 included H.umbellata; Group 2 included the other 7 cultivated species besides No.18; Group3 included No.18 and H.strigosa, H.strigosa var, H.longipes, H.rosthornii, H.strigosa var, H.villosa, H.glabripes, H.lingii; Group4 included H. hypoglauca and H. panciulata. The result of cluster analysis based on SRAP showed that the 19 materials of Hydrangea can be divided into 3 series, namely, Ser.Petalanthae, including H.umbellata and No12,13,14,15,16,17,19; Ser. Piptopetalae, including No 18 and H.strigosa, H.strigosa var, H.longipes, H.rosthornii, H.strigosa var, H.villosa, H.glabripes, H.lingii; Ser. Heteromallae, including H. hypoglauca and H. panciulata.4. The photosynthetic characteristics was studied. The result showed that chlorophyll and carotenoid content of several Hydrangea gradually increased first and then gradually decreased when the Al3+concentration increased. It was suggested that low concentration of aluminum (≦0.15mmol·L-1) was conducive to the accumulation of chlorophyll and carotenoids of Hydrangea, and played a positive role on photosynthesis. Net photosynthetic rate (Pn) and intercellular CO2 concentration (Ci) of several Hydrangea increased first with the increase of Al3+concentration, and then gradually declined, while the saturated vapor pressure (VpdL), by contrast, showed tendency to ascend first and then descend, Aluminum stress had little effect on Tair (leaves room temperature) and Tleaf (leaf temperature) of several Hydrangea. The ability of Al-tolerance was H.villosa.>H.strigosa>H.paniculata>H.macrophylla by Subordinate Function (SF).5. Aluminum absorption characteristics of Hydrangea were studied on the three aspects of aluminum absorption rate, absorption capacity and increase extent. The results showed that the absorption rate of Al in the four materials of H.macrophylla、Hstrigosa、H.villosa and H.paniculata was related with Al3+concentration as a linear equation in one variable, and the correlation coefficient was over 0.95, which didn’t match the Michaelis-Menten enzymatic kinetic equations. Therefore, we concluded that Al absorption of four Hydrangea were passive absorption. Continuously cultivated for some time in 0.10 mmol.L"1 solution of Al3+,the aluminum absorption rate of H.macrophylla,H.strigosa,H.villosa and H.paniculata descended with time, while the absorption capacity increased and increase extent descended. The increase extent was relatively large in the 0～4h, and after 4h the absorption of aluminum gradually saturated.6. Physiological characteristics of H.macrophylla changed a lot under Al3+stress, with the increase of stress, the soluble sugar content in leaf tissue of 7 H.macrophylla had significantly increased. The proline content of H.macrophylla was very sensitive to Al3+stress, with the stress increased, it changed in a big range. There was a negative relationship between soluble protein content in leaf and Al3+stress, while injurious electrolyte leakage rate (IL) was positively correlated. The MDA content under aluminum stress increased as the stress increased, but the rate of increase varied by species.Along with the stress increase,SOD and POD activity of 7 varieties first increased and then decreased in the manner of a single peak curve.更多还原