首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
UV-B辐射对南亚热带森林木本植物幼苗生长的影响   总被引:14,自引:0,他引:14  
研究了UV -B辐射对广东省南亚热带森林木本植物九节、鸭脚木、猴耳环、半枫荷、山乌桕和绿化树种大叶合欢幼苗生长的影响。实验结果表明 ,UV -B辐射降低叶片光合色素的含量 ;显著降低幼苗的净光合速率、蒸腾速率和气孔导度 ;降低干物质的增长 ;抑制大叶合欢幼苗根瘤的形成  相似文献   

2.
成都地区10种园林灌木叶片结构与抗旱性关系研究   总被引:2,自引:0,他引:2  
利用石蜡切片法和指甲油印迹法,对成都地区10种常见园林灌木叶片解剖结构的13个指标:主脉厚度、叶片厚度、上下表皮角质层厚度、上下表皮厚度、栅栏组织厚度、海绵组织厚度、下表皮气孔密度、气孔长度、气孔宽度、叶片结构紧密度、栅栏组织与海绵组织厚度比(栅海比)进行测定和分析,再用方差分析和主成分分析法选取有代表性的指标,结合隶属函数法对物种间的抗旱性进行综合评价。结果显示,13个指标的变异系数为17.40%~68.20%,在10种园林灌木间差异极显著。10种植物都属于异面叶,组织结构易于辨识(三角梅的下表皮角质层太薄,无法测出数据)。叶片结构紧密度、栅海比、气孔密度、气孔长、气孔宽、栅栏组织厚度可作为评价这10种园林灌木抗旱性的重要指标。抗旱性由强到弱依次为:红花继木、鸭脚木、红叶石楠、栀子、西洋杜鹃、海桐、山茶、雀舌黄杨、三角梅和金边大叶黄杨。其中红花继木、鸭脚木、红叶石楠和栀子属于强抗旱品种,可用于屋顶、边坡等区域种植。  相似文献   

3.
通过对香港大榄郊野公园森林群落的样地调查, 利用组平均法和除趋势对应分析两种方法, 对样方进行聚类与排序分析。把35个样地划分为11个植被类型, 森林群落可划分为台湾相思(Acacia confusa Merr.)林、红胶木(Lophostemon confertus(R. Br.) Peter G. Wils on ex J. T. Waterh.)林、木荷(Schima superba Gardner ex Champ.)林、柠檬桉(Eucalyptus citriodora Hook.)林、湿地松+鸭脚木(Pinus elliottii Engelm.+ Schefflera octophylla (Lour.) Harms .)林、土沉香(Aquilaria sinensis (Lour.) Spreng.)林、毛叶桉(Eucalyptus torel liana F. Muel l.)林; 灌木群落分为山油柑+越南叶下珠(Acronychia pedunculata (L.) Miq.+ Phyl lanthus cochinchinensis (Lour.) Spreng.)矮树灌丛、豺皮樟+桃金娘(Li tsea rotoundifol ia (Nees) Hemsl . var. ob longi folia (Nees) C. K. Allen+Rhodomyrtus tomentosa (Al ton) Hassk.)矮树灌丛、大头茶(Gordonia axillaris (Roxb. ex Ker Gawl .) D. Dietr.)矮树灌丛、桃金娘+芒萁(Rhodomyrtus tomentosa (Alton) Hassk.+Dicranopteris dichotoma (Thunb.) Bernh.)灌草丛。DCA排序结果反映海拔高度与各个森林群落的分布格局和物种组成关系不大, 而环境 湿度是影响森林群落物种组成的主要因素。多样性分析结果显示, 台湾相思林和土沉香林多样性指数最高, 说明台湾相思林逐渐向次生林演变, 除了红胶木林和少数郁闭度低的台湾相思林中有强阳生性树种外, 大部分人工林下植物以阳生性稍耐阴的树种为主。调查结果显示, 大榄郊野公园植物生长条件东部优于西部, 西部的物种丰富度和多样性指数较低, 主要以人工林和灌丛为主, 加上山火频繁发生, 导致长期处于先锋阶段。  相似文献   

4.
香港大榄郊野公园的植物组成与植被数量分类   总被引:1,自引:0,他引:1  
通过对香港大榄郊野公园森林群落的样地调查,利用组平均法和除趋势对应分析两种方法,对样方进行聚类与排序分析。把35个样地划分为11个植被类型,森林群落可划分为台湾相思(Acacia confusa Merr.)林、红胶木(Lophostemon confertus(R.Br.)PeterG.Wilson ex J.T.Waterh.)林、木荷(Schima superba Gardner ex Champ.)林、柠檬桉(Eucalyptus citriodora Hook.)林、湿地松+鸭脚木(Pinus elliottii Engelm.+Schefflera octophylla(Lour.)Harms.)林、土沉香(Aquilaria sinensis(Lour.)Spreng.)林、毛叶桉(Eucalyptus torelliana F.Muell.)林;灌木群落分为山油柑+越南叶下珠(Acronychia pedunculata(L.)Miq.+Phyllanthus cochmchinensis(Lour.)Spreng.)矮树灌丛、豺皮樟+桃金娘(Litsea rotoundifolia(Nees)Hemsl.var.oblongifolia(Nees)C.K.Allen+Rhodomyrtus tomentosa(Alton)Hassk.)矮树灌丛、大头茶(Gordonia axillaris(Roxb.ex Ker Gawl.)D.Dietr.)矮树灌丛、桃金娘+芒萁(Rhodomyrtus tomentosa (Alton)Hassk.+Dicranopteris dichotoma(Thunb.)Bernh.)灌草丛。DCA排序结果反映海拔高度与各个森林群落的分布格局和物种组成关系不大,而环境湿度是影响森林群落物种组成的主要因素。多样性分析结果显示,台湾相思林和土沉香林多样性指数最高,说明台湾相思林逐渐向次生林演变,除了红胶木林和少数郁闭度低的台湾相思林中有强阳生性树种外,大部分人工林下植物以阳生性稍耐阴的树种为主。调查结果显示,大榄郊野公园植物生长条件东部优于西部,西部的物种丰富度和多样性指数较低,主要以人工林和灌丛为主,加上山火频繁发生,导致长期处于先锋阶段。  相似文献   

5.
Effects of UV-B radiation (7.2 and 14.4 kJ d-1 m-2) on seedling growth of several woody species in the Southern subtropical forest in Guangdong Province were investigated. The species studied are: Psychotria rubra (Lour.) Poir., Schefflera octophyHa (Lour.) Harms, PitheceHobium clypearia Benth. , Pterospemwm heterophyllum Hance, Sapium discolor Muell. - Arg. and Albizzia lebbeck (L.) Benth. The results demonstrated that the content of photosynthetic pigments of the UV - B treated seedlings was lower than that of the control seedlings. The effect was more significant on content of chlorophylls than that of carotenoids. UV- B radiation markedly lowered net photosynthetic rate, and reduced stomatal conductance and transpiration rate of the seedlings. It also reduced accumulation of dry matter of the seedlings and inhib-ited the formation of root nodules of Albizzia lebbeck seedlings.  相似文献   

6.
不同溶液浸泡处理对鹅掌柴扦插繁殖的影响   总被引:4,自引:0,他引:4  
以清水对照,用多菌灵 福美双溶液和NAA IBA溶液对鹅掌柴插穗浸泡处理后扦插,试验对插穗的形态生长指标和生根过程进行了统计,并对插穗内源性激素IAA、ABA的含量进行了分析。结果表明:NAA IBA和适宜的多菌灵 福美双溶液均可提高插穗的生根率,促进根生长。经浸泡处理的插穗的成活率显著地高于对照(p<0.01)。多菌灵 福美双溶液浸泡插穗3h的理论最佳浓度为519mg/L。519mg/L多菌灵 福美双和200mg/LNAA IBA处理都提高了插穗IAA的含量,ABA的含量却有所降低。用519mg/L多菌灵 福美双和200mg/LNAA IBA分别浸泡插穗1.5h,成活率达到95.6%,比单独用200mg/LNAA IBA处理的成活率提高了10%(p<0.05);实验结果还表明,鹅掌柴的生根属混合生根型。  相似文献   

7.
福建观音座莲具有良好的观赏性状,室内适性优于橡皮树、鹅掌柴等、其习性喜凉爽、湿润、3m-80001x左右光强的半荫环境及酸性土壤。生长期要求有足够的水份供应,但忌花盆积水。  相似文献   

8.
9.
We investigated the seedling survival of five evergreen tree species over 3 years inside and outside deer-exclusion fences in a warm temperate evergreen broad-leaved forest on Yakushima Island, Japan. Seedling survival was examined in relation to topography, herbivory by sika deer, and the soil surface environment (i.e., soil surface wetness, light conditions, slope inclination, and soil disturbance). The study species included Myrsine seguinii Lév., Syzygium buxifolium Hook. et Arn. (Group A: species distributed on the upper slope of the study site), Litsea accuminata (Bl.) Kurata, Schefflera octophylla (Lour.) Harms (Group B: species distributed on the lower slope), and Cleyera japonica Thunb. p.p. emend. Sieb. et Zucc. (Group C: species distributed on both slopes). The soil surface environment on the upper slope was drier, lighter, and more easily disturbed than the lower slope. Generalized linear model analyses indicated that seedling survival in fenced and unfenced quadrats was greater on the upper slope than on the lower slope for Group A and B species but not for Group C species. A micro-spatial scale analysis revealed that seedling survival was correlated with soil wetness, ground light conditions, and soil disturbance but not slope inclination. These results indicate that seedling survival was correlated with topography, sika deer herbivory, and the micro-spatial scale environment. Topography-related differences in seedling survival appear to adequately reflect the observed adult plant distributions for Group A and C species but not for Group B species.  相似文献   

10.
A bidesmosidic triterpenoid saponin from Schefflera octophylla.   总被引:1,自引:0,他引:1  
A new 3,28-bidesmosidic triterpenoid saponin was isolated from the leaves of Schefflera octophylla together with a new trisaccharide and oleanonic acid. Based on spectroscopic data and chemical transformations, the structures of the new constituents were determined as 3-epi-betulinic acid 3-O-beta-D-glucopyranoside 28-O-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)]-b eta- D-glucopyranoside and alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)-beta-D- glucopyranose.  相似文献   

11.
Amentotaxus formosana Li is a native, tolerant, and under-wood species in Taiwan. This particular species is only distributed around the Chachayalaishan and Dawushan areas. Because of its rarity, and the endangered and native properties of the species, we explored the regeneration process of the species in the native environment. This paper, therefore, aims to outline the age distribution and growth characteristics of A. formosana in the native stand using the techniques of tree ring analysis. An inventory was conducted in a site at the Chachayalaishan area from 2004 to 2006. According to the inventory, there are 67 trees in the sampling plot among which 16 individual A.formosana trees were counted. This is roughly 24% of the total population. This particular species is distributed around the understory space, while other species such as Litsea spp., Meliosma squamulata Hance, Schefflera octophylla Harms, Elaeocarpus japonicus Sieb et Zucc and Cleyera japonica Thunb are the major species whose canopy occupying the upperstory space of the stand. Results of tree-ring analysis suggest that the age of most of the trees in the sampling plot is between 31 and 90 years old with an average of 56. For the endangered species, A.formosana, age of the individuals varied from 14 and 126 years old and the average was 58 years old. Age distribution of the species was modeled using the Weibull probability density function and was statistically assessed using Sigmaplot statistical software. The estimate of shape parameter is 1.404 5 indicating a medium regeneration situation. The diameter growth rate of A. formosana is 0.32 cm and ranks 20th among the 26 species in the sampling plot. Using the age as a regressor variable, we can predict the diameter increment of A. formosana efficiently. The coefficient of determination, R2, is 0.832 2. The diameter growth among the trees of the upperstory and understory was competitive. Relationship between the growth change percentage of A. formosana and the surrounding hardwoods is negative.  相似文献   

12.
杨叶木姜子果实的挥发油成分分析   总被引:6,自引:0,他引:6  
本文采用GC-MS联用技术确定了杨叶木姜子Litsea populifolia(Hemsl.)Gamble果实挥发油的21种化学成分及相对含量,主要有:β-柠檬醛(β-citral)、α-柠檬醛(α-citral)、柠檬烯(limonene)、l,8-桉叶素(1,8-cinceole)、橙花醇(nerol)等,并与同属植物山鸡椒Litsea cubeba(Lour.)Pers的化学成分做了比较。  相似文献   

13.
Triterpenoids and their glycosides from the bark of Schefflera octophylla.   总被引:2,自引:0,他引:2  
A new triterpene and its glycosides were isolated from the bark of Schefflera octophylla together with asiatic acid and asiaticoside. Based on spectroscopic data, especially 2DNMR, and chemical transformations the structures of the new compounds were determined as 3 alpha-hydroxy-urs-12-ene-23,28-dioic acid and 3 alpha-hydroxy-urs-12-ene-23,28-dioic acid 28-O-[alpha-L-rhamnopyranosyl (1----4)-O-beta-D-glucopyranosyl (1----6)]-beta-D-glucopyranoside. For the first time asiaticoside was isolated from a plant other than Centella asiatica.  相似文献   

14.
遮荫对山麦冬生长特性和生物量分配的影响   总被引:12,自引:1,他引:12  
研究了不同遮荫水平(遮光率分别为:对照0%、 20%、50%、70%~75%、80%~85%、92.5%)对山麦冬生长以及生物量分配特性的影响。结果表明,随着遮荫程度的加重,山麦冬的生物量增量表出现先上升后下降的趋势,在遮荫50%水平下生物量增量达到最高;随光强减弱同化物分配发生改变,叶重比增加,根重比和根冠比下降。此外,遮荫还提高了植株的含水量和冠径。我们还观察到强光环境和深度遮荫均不利于花序、分蘖和块根的形成。因此,我们认为山麦冬作为耐荫植物对光环境具有一定的适应能力,强光或严重遮荫均不利于其正常生长发育。  相似文献   

15.
A sulphated triterpenoid saponin from Schefflera octophylla.   总被引:1,自引:0,他引:1  
T V Sung  G Adam 《Phytochemistry》1991,30(8):2717-2720
Dried leaves of Schefflera octophylla afforded a new sulphated triterpene glycoside. From spectroscopic data and chemical transformations the structure of the new constituent was determined as 3-epi-betulinic acid 3-O-sulphate 28-O-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl (1----6)]-beta-D-glucopyranoside.  相似文献   

16.
在编写《Flora of China》五加科Araliaceae时,发现两个新种,即拟榕叶罗伞Brassaiopsis pseudoficifolia Lowry&C.B.Shang和光华鹅掌柴Scheffiera zhuana Lowry&C.B.Shang。前者与榕叶罗伞B.ficifolia Dunn很相似,其区别在于,叶裂片数目较多,花序上具较多的伞形花序,花序轴具刺,主要分布于云南,广西偶见。后者与白花鹅掌柴S.leucantha R.Vig.相似,其区别在于,子房心皮数目较多,果时具明显的萼缘,花盘扁平,叶质地较薄,局限分布于西藏墨脱县。同时发现越南产的Brassaiopsis gaussenii Bui和中国产的细序鹅掌柴Scheffiera tenuis H.L.Li、球序鹅掌S.glomerulata H.L.Li均不能成立,处理为异名。  相似文献   

17.
白木香遗传多样性研究   总被引:2,自引:0,他引:2  
用ISSR分子标记技术对白木香(Aquilaria sinensis(Lour.)Gilg)的遗传多样性进行分析.结果表明,白木香物种水平的遗传多样性较高,而居群水平的遗传多样性相对较低,其中广东茂名居群的遗传多样性最高.白木香居群间存在较大的遗传分化,遗传分化系数G_(ST)=0.4425,表明居群内遗传分化大于居群间的分化.UPGMA聚类分析表明白木香分化为两个谱系,其中谱系Ⅰ由广东、福建、海南的5居群组成,谱系Ⅱ由广西、云南的3个居群组成.居群间的基因交流受到阻碍(Nm=0.6633<1),阻碍主要产生于两个谱系间,而谱系内部的居群间在较近的历史时期基因交流频繁(Nm分别为1.4382和1.2333),谱系分化的原因主要是地理因素,两谱系交界处有云开山脉等形成的天然屏障,阻碍物种的扩展和基因交流.  相似文献   

18.
我国大陆一新入侵种:七角星蜡蚧(半翅目:蚧总科:蚧科)   总被引:1,自引:1,他引:0  
七角星蜡蚧Ceroplastes stellifera(Westwood)是一种多食、热带广布害虫,2007年被列入《中华人民共和国进境植物检疫性有害生物名录》中。该虫在我国以前仅记录于台湾省,2013年10月下旬,发现该虫在云南省西双版纳地区危害鹅掌柴(Schefflera octophylla)和芒果(Mangifera indica),为我国大陆的新入侵害虫。本文介绍了其形态特征、地理分布、寄主植物、经济重要性等。  相似文献   

19.
对天门冬根尖细胞进行染色体常规制片,并进行核型分析。结果表明,天门冬染色体数为2n=20,核型公式为K(2n)=2x=20=8 sm+128m,其中中部着丝粒染色体(m)为4对,近中部着丝粒染色体(sm)为5对。核型类型为2B。  相似文献   

20.
首次系统地对短梗五加、糙叶五加、藤五加、窄叶藤五加四种五加属植物果实中的金丝桃苷、芦丁、槲皮素、山奈素、6,7-二甲氧基香豆素、紫丁香苷等6种活性成分进行了含量比较。采用RP-HPLC测定各个活性成分的含量。色谱柱为ODS C18柱,各活性成分的含量测定均选择最优的色谱条件和供试品溶液制备方法。结果显示:糙叶五加,藤五加,窄叶藤五加果实中除紫丁香苷外的其他活性成分含量均高于短梗五加,但尚未得到有效利用,具有相当好的开发前景。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号