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《植物生态学报》2017,(9)
水分是植物存活、生长和分布过程中的必需资源,阐明植物对干旱的应对和调节机制,是植物生理生态学和全球变化生态学的重要研究命题。植物对不同气候与土壤水分条件的长期适应会形成由一整套相关联的性状组成的水分调节策略,其中等水和非等水调节行为是两种典型的水分调节对策。区分并阐明植物的水分调节对策及其机制,不但在干旱地区植物育种、植被修复等实践中有广泛的应用前景,而且可为构建更精确的植被动态模型和预测气候变化情景下植被分布提供科学基础。该文首先阐述了等水和非等水调节行为的定义及3种定量分类方法:(1)基于气孔导度与叶水势的关系;(2)基于气孔导度与水汽压亏缺的关系;(3)基于黎明前叶水势与中午叶水势的关系。之后,从水力和碳经济性状两个方面比较分析了两种水分调节对策植物的种间差异。综合分析植物水分调节机制发现,水力信号与化学信号的相互作用是植物水分调节行为的主控因素。最后提出3个亟待开展研究的问题:(1)针对不同地区开展植物水分关系相关性状的测定,寻求可靠且普适的植物水分调节对策分类方法。(2)探索植物水分调节对策与水力、形态、结构、功能等性状之间的关联性,为改进植被动态模型提供可靠的参数。(3)加深理解不同时空尺度上植物水分调节过程,揭示植物对环境胁迫(尤其是干旱)的响应和适应机制。 相似文献
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中国典型地带陆生等足类的区系研究 总被引:7,自引:0,他引:7
通过对我国5个典型地带(热带、亚热带、暖温带、高寒带)20个样点进行陆生等足类的调查采集,共发现陆生等足类11科、29属、72种。由于各地带自然环境明显不同,造成了物种分布上的差异,其中热睡亚热睦区种类最多,分别为38种和47种,两地带物种共占总种数的80%以上;曙带和温带地区仅发现9种,而高寒带由于平均气温在0℃以下,不利于陆生等足类的生存,故迄今仅发现2种。其区系特点为:(1)区系分布的地带性 相似文献
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中国的鳄类只有两种:扬子鳄和湾鳄。分别产于长江流域与岭南,由于产地和属种的不同,其生活习性也有异,在我国古书中早已论述清楚了。 扬子鳄亦称鼍,过去盛产于皖、赣、苏、浙的长江沿岸沼泽地带,五十年代的九江、芜湖一带 相似文献
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东海浮游等足类和涟虫类的调查 总被引:1,自引:0,他引:1
根据1997~2000年东海(23°30′~33°00′N,118°30′~128°00′E)海域4个季节海洋调查资料,对东海浮游等足类和涟虫类种类的组成、数量变化及地理分布等特征作了探讨。结果表明,调查海域出现浮游等足类2种,其中圆柱水虱(Cirolanasp.)在东海等足类数量中具有绝对优势(占总丰度的98%),中国急游水虱(Tachaea chinensis)是稀有种。等足类主要在夏季出现,并分布在东海近海。浮游涟虫类主要分布在台湾海峡和东海南部海域。浮游涟虫类有4种,细长涟虫(Iphinoe tenera)和萨氏异涟虫(Heterocumasarsi)在3个季节出现,丰度和出现率较高,是东海涟虫类的常见种;无尾涟虫(Leueonsp.)在2个季节出现,丰度和出现率与前2个种相似,是次常见种。卵圆涟虫(Bodotria ovalis)仅出现在秋季,数量和出现率极低,是稀有种。细长涟虫、萨氏异涟虫和无尾涟虫都是暖水种。相比之下,无尾涟虫有更广泛的适温能力。卵圆涟虫在盐度较低的长江口出现,是一个近岸种。 相似文献
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本文用兔抗角蛋白抗体、豚鼠抗波形纤维蛋白抗体和抗角蛋白单抗AE1的间接免疫荧光抗体法比较了两个人体肝癌细胞系(BEL-7402和BEL-7404)和HeLa细胞中等纤维的分布式样,同时用SDS-PAGE法分析了上述细胞的中等纤维抽提物的多肽组成。结果表明:三种上皮细胞均含有两套不同类型的中等纤维系统:角蛋白纤维和波形纤维。但是,人体肝癌细胞和HeLa细胞的中等纤维分布式样和角蛋白多肽组成均有明显的差别。其中最明显的差别是HeLa细胞具有丰富的桥粒-张力纤维复合物和分子量为40 kd的角蛋白多肽,而在两个人体肝癌细胞系中看不到。 相似文献
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扬子鳄野生种群衰落探析 总被引:4,自引:2,他引:2
扬子鳄(Alligatorsinensis)属爬行纲、鳄目、鼍科、鼍属,是我国特有的珍稀物种。据张孟闻等考证,周秦时期扬子鳄数量相当可观,甚至到了“易而贱之”的地步。宗仁亲时苏颂的《图经本草》记载,扬子鳄“今江湖极多”。明嘉庆年间成书的《国宪家酞》记载:明初南京长江江岸生 相似文献
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Yan-Hui Wang David K. Ferguson Guang-Ping Feng Yu-Fei Wang Sergey G. Zhilin Cheng-Sen Li Popova-Tselenkova Svetlana Jian Yang Albert G. Ablaev 《Palaeogeography, Palaeoclimatology, Palaeoecology》2009,280(1-2):183-192
Elucidating the spatio-temporal distributions of terrestrial plants is a key for interpreting the origin of distribution patterns and the tempo of intercontinental disjunction. Nordenskioeldia was distributed in eastern Asia and North America from the Late Cretaceous to the Miocene. Its fossil record provides important information on former patterns of disjunction and dispersal in the Northern Hemisphere. New specimens from the Paleocene of China allow us to further extend the history of the group and provide the impetus to review its distribution in space and time. The comparative morphological survey on fossil Nordenskioeldia found in the Paleocene sediments in both eastern Asia and North America confirms that they belonged to the same morpho-species, which indicates a close floristic continuity between both continents due to land connection available during that time. The spatio-temporal distributions of Nordenskioeldia indicate that the taxon probably expanded eastward from eastern Asia into North America by the end of Early/Middle Maastrichtian, subsequently colonized Greenland, northeastern North America and Spitsbergen in the Early Paleocene, and finally became extinct in the Miocene. The fluctuations in its northern limits took place in response to climate changes: warming from the Paleocene to the Eocene, cooling during the Eocene–Oligocene and amelioration during the Late Oligocene–Mid-Miocene. 相似文献
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Cedrelospermum Saporta is an extinct genus in the Ulmaceae with abundant fossil records in North America and Europe. However, so far, fossil records of this genus from Asia are sparse, which limits the interpretations of the morphological evolution and biogeographical history of the genus. Here we report well‐preserved fruits (Cedrelospermum tibeticum sp. nov.) and a leaf (Cedrelospermum sp.) of Cedrelospermum from the upper Oligocene Lunpola and Nyima basins in the Qinghai–Tibetan Plateau (QTP). This is the first fossil record of Cedrelospermum in the QTP, showing that this genus grew in this region during the late Oligocene. Cedrelospermum tibeticum fruits are double‐winged, morphologically similar to the Eocene and Oligocene double‐winged Cedrelospermum species from North America. This supports the hypothesis that Cedrelospermum migrated to Asia from North America by way of the Bering Land Bridge. Given that Cedrelospermum was a typical element of Northern Hemispheric flora in the Paleogene and Neogene, the presence of this genus indicates that the central region of the QTP was phytogeographically linked with other parts of the Northern Hemisphere during the late Oligocene. The morphological observations of C. tibeticum fruits and other double‐winged Cedrelospermum fruits suggest an evolutionary trend from obtuse to acute apex for the primary wing. Cedrelospermum tibeticum likely had warm and wet climatic requirements. This type of an environment possibly existed in the central QTP in the late Oligocene, thereby supporting the survival of C. tibeticum. 相似文献
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Mao‐Qin Xia Ren‐Yu Liao Jin‐Ting Zhou Han‐Yang Lin Jian‐Hua Li Pan Li Cheng‐Xin Fu Ying‐Xiong Qiu 《植物分类学报:英文版》2022,60(2):253-265
The genus Wisteria (Fabaceae) is disjunctly distributed in eastern Asian and eastern North American temperate deciduous forests, and it is widely cultivated around the world as spectacular garden plants. It is a member of inverted repeat-lacking clade (IRLC). The IRLC Species are characterized by the loss of an IR region in their plastomes, which has long been of great interest. In this research, we report whole plastome sequences from all four Wisteria species and a Wisteriopsis japonica, combining these with existing data to explore phylogenetic relationships and biogeography of Wisteria, as well as plastome evolution of IRLC species. Phylogenetic analyses recognized a clade containing Glycyrrhiza–Wisteriopsis–Wisteria as sister to the remaining genera of IRLC. North American Wisteria frutescens and the three Asian species formed reciprocal clades, and Wisteria brachybotrys was sister to Wisteria floribunda and Wisteria sinensis. Wisteria may have originated in Japan near the boundary of the Oligocene and Miocene. The disappearance of Bering Land Bridge in the late Miocene might lead to the Eastern Asian–Eastern North American disjunction of Wisteria. Allopatric speciation of Wisteria between the Japanese archipelago and the Asian continent in the Quaternary increased the species richness of eastern Asia in comparison with eastern North America. Synonymous substitution rates (dS) of protein-coding genes in the IRLC species were around 2-fold (SC genes) or 11-fold (IR genes) higher than those of non-IRLC species. For both SC and IR genes, herbaceous legumes have around 3-fold higher dS than woody ones. Both loss of one IR region and herbaceous habit elevated substitution rates of the plastomes. 相似文献
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Xiang QY Manchester SR Thomas DT Zhang W Fan C 《Evolution; international journal of organic evolution》2005,59(8):1685-1700
Data from four DNA regions (rbcL, matK, 26S rDNA, and ITS) as well as extant and fossil morphology were used to reconstruct the phylogeny and biogeographic history of an intercontinentally disjunct plant group, the cornelian cherries of Cornus (dogwoods). The study tests previous hypotheses on the relative roles of two Tertiary land bridges, the North Atlantic land bridge (NALB) and the Bering land bridge (BLB), in plant migration across continents. Three approaches, the Bayesian, nonparametric rate smoothing (NPRS), and penalized likelihood (PL) methods, were employed to estimate the times of geographic isolations of species. Dispersal and vicariance analysis (DIVA) was performed to infer the sequence and directionality of biogeographic pathways. Results of phylogenetic analyses suggest that among the six living species, C. sessilis from western North America represents the oldest lineage, followed by C. volkensii from Africa. The four Eurasian species form a clade consisting of two sister pairs, C. mas-C. officinalis and C. chinensis-C. eydeana. Results of DIVA and data from fossils and molecular dating indicate that the cornelian cherry subgroup arose in Europe as early as the Paleocene. Fossils confirm that the group was present in North America by the late Paleocene, consistent with the DIVA predictions that, by the end of the Eocene, it had diversified into several species and expanded its distribution to North America via the NALB and to Africa via the last direct connection between Eurasia and Africa prior to the Miocene, or via long-distance dispersal. The cornelian cherries in eastern Asia appear to be derived from two independent dispersal events from Europe. These events are inferred to have occurred during the Oligocene and Miocene. This study supports the hypothesis that the NALB served as an important land bridge connecting the North American and European floras, as well as connecting American and African floras via Europe during the early Tertiary. 相似文献
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Elizabeth J. Hermsen 《The Botanical review》2013,79(1):1-47
Itea is a genus of about 20 species of trees and shrubs that are today native to southeastern North America, eastern Asia, and eastern Africa. In this paper, I review the fossil record of Itea, which is based on four types of fossils: diporate, psilate pollen attributed to Itea or the dispersed pollen genus Iteapollis; carpofossils representing fruits and seeds attributed to Itea europaea; flowers preserved in amber and assigned to Adenanthemum iteoides; and leaf impressions attributed to Itea. The distributions of these fossils indicate that Itea was present in western North America from the early Eocene to Miocene, in eastern North America beginning no later than the early Miocene, and in western Eurasia from the late Eocene to Pliocene. Only one datapoint is known from eastern Asia; it is early Miocene in age. Based on the fossil record, it can be inferred that Itea crossed between continents over both the Bering Land Bridge and North American Land Bridge, and that it reached Africa from Europe via Anatolia. Thus, it is predicted that the sole extant North American species, I. virginica, may be most closely related to the sole extant African species, I. rhamnoides. The potential application of Itea fossils to calibrating phylogenetic trees generated from molecular sequence data is also discussed. 相似文献
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The eastern Asia-North America disjunction is one of the most interesting biogeographical patterns, but its formation is still in much debate. Here nucleotide sequences of five cpDNA regions, nrDNA ITS and two low-copy nuclear genes (LEAFY, 4CL) were employed to reconstruct the phylogeny and to explore the historical biogeography of Thuja, a typical eastern Asia-North America disjunct genus. High topological discordance was observed between chloroplast and nuclear gene trees, even between different nuclear gene trees, suggesting that Thuja could have a reticulate evolutionary history due to multiple interspecific hybridization events. The eastern Asian species Thuja koraiensis might have obtained its chloroplast genome from the eastern North American species T. occidentalis by chloroplast capture, while the western North American species T. plicata is very likely to have inherited a recombinant cpDNA. Based on the phylogenetic analysis of multiple genes, DIVA-reconstruction of the distribution history, molecular clock estimation and fossil data, we inferred that Thuja could have originated from the high-latitude areas of North America in the Paleocene or earlier with subsequent expansion into eastern Asia through the Bering Land Bridge. The two eastern Asia species T. standishii and T. sutchuenensis have a sister relationship, and their split could have occurred in the Oligocene or early Miocene. In the present study, the selection of molecular markers in biogeographic studies was also discussed. Since most previous studies on the eastern Asia and North America disjunction are based on uniparentally inherited cpDNA and (or) directly sequenced nrDNA ITS data, the historical reticulate evolution in the studied groups might have been underestimated. Therefore, we suggest that multiple genes from different genomes, especially low-copy nuclear genes, be used in this research area in the future. 相似文献
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A new species, Altingioxylon hainanensis, is described from the Eocene Changchang Formation of the Changchang Basin on Hainan Island, South China. It is the first
record of a fossil wood assigned to Altingiaceae found in China, and the most ancient evidence of wood for this family in
eastern Asia. The new species is similar to A. rhodoleioides, known since the Miocene in India and Java Island, and to Altingia
hisauchii from the Miocene to Pliocene of Japan. The close resemblance between these species and Liquidambar sp., known from the Middle Miocene of western North America, provides additional evidence for the migration of their ancestors
from Asia to North America across the Bering land bridge during the Miocene. Distinctions in ray sizes between the eastern
Asian specimens and their contemporaries from Europe to Kazakhstan is suggested as a result of the divergence between the
large eastern Asian clade and the North American–west Asian clade within Altingiaceae during the Eocene–Oligocene. The presence
of crystals in ray cells may be considered an ancestral condition that persists in the eastern Asian lineages up to the extant
Altingia and Semiliquidambar, but which was lost in other Altingiaceae in the course of evolution. 相似文献
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西藏新生代秋乌组孢粉化石的发现及其初步研究 总被引:7,自引:0,他引:7
本文首次报道西藏雅鲁藏布江缝合带附近秋乌组含煤沉积中的孢粉化石。孢粉植物群主要由Quercoidifes,具孔类及三孔沟类花粉组成,包括12科26属及一些未定类群。组合中产有少量的Graminidites及Tsugaepollenites。植物群的总体特征显示其时代可能为渐新世至早中新世。秋乌组沉积早期的环境比较温暖。 相似文献