共查询到19条相似文献，搜索用时 203 毫秒
1.
将太行榆 Ulmus taihangshaneasis S．Y．Wang并入脱皮榆U．lamellosa Wang ex S．L．Chang ex L．K．
Fu作为新异名；将毛叶朴Celtis pubescens S．Y. Wang et C．L. Chang并入朴树C．sinensis Pers．作为新异名。 相似文献
2.
3.
4.
本文测定了广义榆科 Ulmaceae s．l．及其近缘类群的trn K基因5′端内含子区序列。在尝试利用该内含子区进行榆科系统发育研究的同时，探讨了其在植物系统学研究中的应用前景。利用PAUP软件进行的系统发育分析仅得到1棵最简约树。该简约树的树长为665步，其一致性指数(CI)和保持性指数(RI)分别为0.7714和0.7965。分析结果表明：广义榆科为多系群；狭义榆科Ulmaceae s．str．为荨麻目rticales其他类群的姊妹群；大麻科Cannabacea嵌在朴科Celtidacea中，即朴科为一并系群；系统位置有争议的2个属——白颜树属Gironniera和糙叶树属 Aphananthe与朴科类群聚为一支。本研究还表明trnK基因5′端内含子区序列分析在植物较低分类等级(如近缘属间，属下种间)的系统发育研究中具有很好的应用前景。 相似文献
5.
6.
以呼包鄂榆城市群为研究对象,通过构建经济-社会-人口-生态系统指标体系,运用熵值法和耦合协调度模型研究城市群综合发展水平及耦合协调发展水平。研究表明,2007年～2016年呼包鄂榆城市群的综合发展水平呈现下降趋势,城市群及子系统的耦合协调程度较低。呼包鄂榆城市群应着力促进经济与人口,经济与生态的协调发展。 相似文献
8.
9.
10.
傅德志 《中国科学院研究生院学报》1992,30(6):515-528
竹柏科Nageiaceae是根据叶无中脉而具多数近平行细脉和雌性生殖器官接近原始的枝条状结构，
从裸子植物罗汉松科Podocarpaceae中分出的单属新科。 新科内有2个组，5个种，分布于太平洋西
海岸的东亚、南亚近海山地至新几内亚等南太平洋岛屿区域。 该科植物具有2个以上叶迹和无中脉的
多脉叶类型，在现存的裸子植物中十分特殊，仅与少数几个系统位置较为孤立或系统位置不甚清楚的
类群有一定相似之处，而与其他大多数具中脉叶类型的类群几乎没有任何过渡和联系。 古植物学证据
表明，自古生代以来，各不同地质时期均有这种多脉叶类型化石存在，同时，在某些古裸子植物化石
中，也存在接近Nageiaceae所具有的枝条状雌性生殖器官类型。 据此推测，在裸子植物系统发育中，
可能存在一条以叶具多脉为标志的M-演化线(multinerved-leaved evolutionary line)，这条演化线可追溯至古裸子植物科达类甚至更古老的类群。 相似文献
11.
李霞冰 《中国科学院研究生院学报》1985,23(4):259-263
This paper deals with the constituents of fatty acids from the seed oils of
Pinaceae in China, including 30 species belonging to 8 genera. Discovered are three
characteristic fatty acids, i.e. Cis-5,9-octadecadienoic acid, Cis-5,9,12-octadecatrienoic acid
and Cis-5, 11, 14-eicosatrienoic acid. Based on the data obtained, the distribution of the
three characteristic fatty acids in Pinaceae of China is also discussed. 相似文献
12.
Ashavaid T. F. Shalia K. K. Nair K. G. Dalal J. J. 《Indian journal of clinical biochemistry : IJCB》2000,15(1):1-5
The levels of cytotoxic aldehydic products in different culinary oils, with or without thermal stress, (routine domestic or
commercial frying) were determined by thiobarbituric acid method. The results showed that (i) thiobarbituric acid reactivity
was much higher in edible oils rich in polyunsaturated fatty acids than those rich in saturated fatty acids or monounsaturated
fatty acids, even without thermal stress, (ii) the lipid peroxide levels were in proportion to the duration of thermal stress,
(iii) nature of the container used (steel, iron or teflon-coated) had no significant effect on the extent of lipid peroxidation
under identical conditions of thermal stress and (iv) thermally stressed oils collected from hotels and roadside caterers
contained higher levels of cytotoxic aldehydic products, when compared to oils thermally stressed under domestic frying conditions.
These results suggest that dietary ingestion of thermally or autoxidatively stressed polyunsaturated fatty acid rich culinary
oils is more harmful compared with those similarly treated oils rich in saturated fatty acids and monounsaturated fatty acids. 相似文献
13.
SDS聚丙烯酰胺凝胶电泳揭示红豆杉属和白豆杉的种子蛋白主要多肽的分子量为31、
22和20千道尔顿(K)。穗花杉的多肽谱与上述两属相差较大，没有22K多肽，代之以一个33K
主要多肽。榧树属和穗花杉有很多共同的多肽，但没有44K这个红豆杉科多数种类共有的中
等含量的多肽，并出现一个36K主要多肽。三尖杉属一些种的多肽谱十分接近红豆杉属，竹
柏的种子蛋白与上述分类群也有一定程度的近似。
红豆杉科各属之间针叶过氧化物酶谱差别很大，但三尖杉属一些种与红豆杉属却有些类
似。
两种蛋白质资料一致说明红豆杉科内的进化趋势是从红豆杉属、经白豆杉属和穗花杉属
至榧树属。红豆杉属和三尖杉属之间蛋白质的近似，说明红豆杉科和三尖杉科之间的关系，可
能通过红豆杉属相联系的,述资料也说明红豆杉科应置于松柏目之下。 相似文献
14.
杜仲科的解剖学和胚胎学及其系统关系 总被引：1，自引：0，他引：1
本文作者用光学显微镜对杜仲科Eucommiaceae的木材解剖和胚胎发育过程进行了观
察，并与榆科Ulmaceae和金缕梅科Hamamelidaceae进行了对比分析。 根据木材和胚胎学的资料，并结合外部形态和化学方面的资料，讨论了杜仲科的分类系统位置。 相似文献
15.
豆科七种野生植物籽油脂肪酸研究 总被引：1，自引：0，他引：1
采用毛细管气相色谱法,对青海境内的豆科七个属的七种野生植物种子的含油率,理化常数和脂肪酸组成及相对含量进行了测定,结查表明,所测植物籽油中,主要为棕榈酸,硬脂酸,油酸,亚油酸和亚麻酸。 相似文献
16.
试论浙江省森林植物区系 总被引：6，自引：0，他引：6
王景祥 《中国科学院研究生院学报》1986,24(3):165-176
1. History of development of the forest flora Since the Cenozoic period, the number of forest tree species has steadily risen.
In the course of time, some of the archaic types slowly diminished and perished,
and new forms gradually evolved. During the palaeocene, the numher of the gymnospe-
rms (with the exception of conifers) and ferns drastically decreased, and that of con-
ifers, on the contrary, increased significantly, and meantime the broad-leaved tree spe-
cies also appeared. During the Neocene, the angiosperms expanded rapidly and the ve-
getation gradually shifted towards the mixed deciduous-evergreen forest. Shortly before
the Quaternary, there was a series of world-wide climatic fluctuations, as illustrated by
progress and retreat of glaciers, cold-resistant and warm-loving (thermophilic) plants
appeared alternately. In the post-glaciation period, the zonal distribution of forest ve-
getation in Zhejiang Province was essentially similar to that of the present time. Exca-
vations from Homu-tu, Yu-Yao County, reveal a luxuriant subtropical forest which
existed 7000 years ago.
2. Characteristics of the flora and vegetation
(1) Of ancient origin, with rich relic elements.
Archaic gymnosperms such as Ginkgo biloba, Amentotaxus argotaenia, Pseudotaxus
chienii, Torreya jackii, T. grandis, Taxus chinensis var. mairei, Podocarpus macrophyllus,
P. neriifolia, etc, are all found in the Cretaceous deposits. The occurrence of Ginkgo
can be traced hack to the Triassic. Most of the conifers, however, were found in the Ju-
rassic, and they have remained to the present time as the main elements of the needle-
leaved forests.
Among the primitive angiosperms, Magnoliaceae is represented by 19 species of 8
genera; Fagaceae and Lauraceae are the dominant evergreen broad-leaved tree species,
the former by 6 genera and 43 species, and the latter by 10 genera and 42 species. Ha-
mamelidaceae is represented by 10 genera and 18 species, while Ulmaceae, Tiliaceae, Elae-
ocarpaceae, by 21 species of 7 genera, 9 species of 2 genera and 6 species of 2 genera
respectively.
(2) Rich in species and consisting of diverse geographic elements, but domi-
nated by the tropical ones.
Throughout Zhejiang Province, there are over 1300 taxa of woody plants (includ-
ing varieties and cultivated ones) belonging to 109 families and 423 genera. Among
them, 8 families with 25 genera and about 45 species, are gymnosperms, and the rest, 101
families with 398 genera and about 1260 species and varieties, are angiosperms. The
major angiospermous families include Mognoliaceae, Fagaceae, Lauraceae, Theaceae,
Aquifoliaceae and Bambusoideae. Dominant families and genera are the tropical ones,
and next in the order, are the East Asiatic, the E. Asia-N. American, then the tempe-
rate, the cosmopolitan, endemic and other elements.
(3) Rich in endemic species, in monotypic and oligotypic genera.
The endemic species include Abies beshanzuensis, Ostrya rehderiana, Carpinus pu-
toensis, Carpinus tientaiensis, Celtis chekiangensis, Calycanthus chinensis, Machilus mi-
nutiloba, M. chekiangensis, Semiliquidambar caudata var. cuspidata, Acer aeutum, A.
yangjuechi, A. Changhwaense, A. elegantulum, A. pauciflorum, Ilex qinyuanensis, Sty-
rax zhejiangensis, Photinia zhejiangensis, Actinidia zhejiangensis, etc. The monotypic
and oligotypic genera are examplified by Ginkgo, Pseudotaxus, Pseudolarix, Fokienia,
Cyclocarya, Parakmeria, Pteroceltis, Sargentodoxa, Decaisnea, Aphananthe, Hemiptelea,
Zelkova, Fortunearia, Semiliquidambar, Polithyrsis, Ostrya, Heptacodium, Tapiscia,
Bretschneidera, Choerospondias, Kalopanax, Halesia, Hovenia, Emmenopterys, Eucom-
mia, Pileostegia, Platycrater, Alniphyllum, etc. The majority of the species mentioned
above are rare and precious ones.
(4) Introduced species gaining importance
Zhejiang Province is mainly situated in the mid-subtropical zone, and from Yukuan District and the Wenzhou Prefecture southwards it belongs to the evergreen broad-leaved south subtropical forest belt. A number of south subtropical species, such as Eucalyptus spp., Casuarina spp., Acacia mearnsii, have been successfully introduced into this region. The introduction of other species, such as Cinnamomum cassia, Grevillea robusta, Michelia alba, Canarium album, Litchi chinensis, Euphoria longan, Kandelia candel, are successful in certain areas. Small plantations of introduced species from S. W. China e.e. Cinnamomum glanduliferum, C. septentrionale have been established. In
addition, Metasequoia glyptostroboides, Ulmus pumila, several exotic Pinus species, Carya illinoensis, Robinia pseudoacacia, Amorpha fruficosa, etc. are widely planted throughout Zhejiang Province. In recent years, cold-temperate species such as Chamaecyparis obtusa, Thuja standishii, Thuja occidentalis, Abies firma have been introduced and planted in the mountainous areas. The forest flora of the province is thus being further enriched.
3. Geographical analysis of the forest flora
(1) The south part of Zhejiang lies in the transitional belt between the East and
South China Floristic Regions, its east part being on the north margin of the South
China Floristic Region, and its west part on the south margin of the East China Floristic Region.
(2) The north part of the province is weakly influenced by the temperate elements, but the influence may extend to the central part of this province as the elevation
there is higher.
(3) Diverse floristic elements such as those belonging to Japan, Taiwan (China),
C. China and S. W. China regions also occur in the province, especially in its western
and eastern parts. 相似文献
17.
用SDS聚丙烯酰胺凝胶电泳分析了杉科全部10属共13种植物的种子蛋白多肽。它们
都有分子量为32、24和10K(千道尔顿)的多肽。每个分类群一般只有2至4个主要多肽，构
成种子蛋白总含量的一半;而且其分子量都分布在24—26K及29—36K两个区域内。 因此，
杉科植物种子蛋白谱与红豆杉科、三尖杉科相似，而不同于松科。属内不同种之间，种子蛋白
组成和针叶过氧化物酶电泳谱都没有看到显著差别。根据这两种蛋白质资料，表明杉科各属除红杉、巨杉、落羽杉相互很接近外，其他各属间关系都比较远。但是还不能说杉科可以分立几个科。 相似文献
18.
Angela Godwin H. Ramachandra Prabhu 《Indian journal of clinical biochemistry : IJCB》2006,21(1):202-204
Fish and fish oils are the richest sources of ω-3 fatty acids. However, they are susceptible to lipid peroxidation due to
their high degree of unsaturation. In the present study, the level of thiobarbituric acid reactive material in various fish
oils available in the market with and without added Vitamin E was determined. The peroxide levels in fish oil heated to food
frying temperature of 180°C and the effect of addition of vitamin E has also been studied. The results indicate that the peroxide
levels in almost all the products available in the market were abnormally high irrespective of their Vitamin E content. This
might be due to the inefficient methods used for processing and storage of fish oils. Addition of vitamin E was found to have
a significant effect in lowering the rate of peroxidation of fish oil during thermal stress, showing that association of antioxidants
with ω-3 fatty acids lowers the rate of lipid peroxidation. 相似文献
19.
李秉滔 《中国科学院研究生院学报》1987,25(2):132-139
This paper is an outcome of taxonomic studies of Chinese Sauropus and
Cleistanthus. The former consists of two sections and 14 species of which three species are new; the latter is of 6 species, of which 3 species are first recorded from China. These two genera are mainly distributed in southwestern and south China. 相似文献