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蔷薇科植物的起源和进化 总被引:1,自引:0,他引:1
俞德浚 《中国科学院研究生院学报》1984,22(6):431-444
Rosaceae. consisting of about 126 genera and 3200 species, is widely distribu-
ted in warm temperate and subtropical regions of the Northern Hemisphere, while more
than half of the genera are Asiatic and more then 80% of the total number of Asiatic
occur in China (Table 1). In this paper, the origin and evolution of Chinese genera is
discussed mainly. The principal tendency of the whole family is also described from
the point of view of evolution.
First of all, the systematic position of Rosaceae in Angiospermae is reviewed. Ac-
cording to the records of paleobotany, rosaceous plants occurred first in the Tertiary,
from the early period of Eocene (genera such as Spiraea and Prunus) to the late period
of Miocene (e.g. Crataegus, Malus amd Rosa). They have quite a long history in geolo-
gical data. Where has this big and old family originated and what steps does it stand in
the long course of evolution of flowering plants? There are several opinions and ex-
planations by different authors. In this paper, a general survey of the six prevailing
classical systems (Table 2) is made to give a brief idea of the position of this family
in the Angiospermae and of the relationships between the subfamilies and also the rela-
tionships between different genera in each subfamily. At the end of this paper, an at-
tempt is made to analyse and sum up the major evolutionary tendency of the whole fa-
mily.
As generally condidered, Rosaceae originated from Magnoliales, and woody plants
of the family still hold a dominant position. For instance, subfamily Spiraeoideae con-
sists of only one herbaceous genus (i.e., Aruncus) and subfamily Rosoideae only a few
herbaceous genera. All of these herbaceous genera are derived from the closely related
woody genera of the same subfamily.
In the course of evolution of Angiospermae, Rosaceae stands at the initial to the
middle stages of development. All parts of plant body in this family are at the chang-
ing and developing stages, with carpels, fruits and inflorescences being the most active.
The primitive types in this family, such as the members of subfamily Spiraeoideae,
usually have 5 and free carpels, the number of which are either reduced to 2-1 or in-
creased to 10-numerous. They have different levels of union and are either completely
free from each other or coherent at base. The carpels usually occur on the upper part of
the receptacle, because the shapes of receptacle are variable, sometimes disk-shaped, cup-
shaped, tube-shaped or even bottle-shaped. In the last case carpels grow inside the rece-
ptacle. Thus the position of carpels has changed from superior to inferior through half-
superior.
In accordance with the development of the carpels, various kinds of fruits are produ-
ced. The primitive types of fruit are follicles, with dry, dehiscent carpels opened along
different sutures. The next step, the carpels have developed into an indehiscent, I-celled
and l-seeded fruit, the so-caned achene. In different genera, the achenes have different
coat types and appendages to facilitate dispersing the seeds. Some of the achenes grow
upon the fleshy receptacle (like strawberry) and some of them inside the fleshy rece-
ptacle (like rose). Sometimes a few carpels are united with the receptacle and develop
into a pome (like apple and pear). Another direction of the fruit development is the
single carpel with fleshy exocarp and mesocarp, and a bony endocarp, then becoming a
drupe (like peach and plum).
In addition to fleshy receptacle of thickened fruit coats, they usually have showy
colour, fragrant smell and also plenty of sugars, acids, vitamins, etc. which are edible
and attract animals and human beings to assist the dispersion of seeds.
In this family, there are various types of flower arrangements, both indefinite inflo-
rescences including raceme, umbel, corymb and panicle, and the definite inflorescence,
such as solitary flower, cyme and compound cyme. In the evolution course, they tend
to change mostly from multiflowered compound inflorescence towards few-flowered sim-
ple inflorescence, and finally becoming a solitary flower: simultaneously with the decre-
asing of number of flowers on the inflorescence, the increasing of size of petals, which
become very showy for attraction of insects so as to guarantee pollination and fertiliza-
tion of the plants concerned. Another tendency, if the bisexual flowers change to uni-
sexual, either monoecious- or dioecious-polygamous, then they form a dense spike which
is beneficial to cross pollination. The abundance, diversity, and wide range of distribu-
tion of the species and genera of Rosaceae are considered mainly resulted from their
highly developed reproductive organs. 相似文献
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线粒体是真核生物重要的细胞器,为细胞提供大部分能量,同时也是活性氧(ROS)产生场所及细胞凋亡控制中心。线粒体来自与宿主共生的α-变形菌(α-Protobacteria),在形成细胞器的过程中α-变形菌蛋白组逐渐变小,将大部分遗传物质转移到核的同时与宿主建立了稳定的内共生关系。大多数现存真核生物的线粒体仍保留有少量来自α-变形菌的基因,其功能非常保守,仅编码线粒体蛋白合成相关的t RNA、r RNA、核糖体蛋白和氧化磷酸化复合物亚基蛋白。本文将从线粒体起源及蛋白含量进化进行综述。 相似文献
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桦本科植物的起源和早期演化 总被引:2,自引:0,他引:2
根据植物类群演化的时空统一观点,利用古植物学、地理分布和系统发育三个方面的研究结果,讨论了桦木科植物的起源和早期演化,认为:最早的桦木科植物生活在晚白垩纪桑托期,起源于中国中部地区,起源之后,一方面较缓慢地向欧洲散布,并在古新世到达欧洲;另一方面向中国东北地区散布,并迅速扩散到北极地区,通过白令陆桥在白垩纪最晚期到达了北美。 相似文献
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方振富 《中国科学院研究生院学报》1987,25(4):307-313
1. The distribution of Salix species among the continents. There are about
526 species of Salix in the world, most of which are distributed in the Northern Hemisphere
with only a few species in the Southern Hemisphere. In Asia, there are about 375 species, mak-
ing up 71.29 percent of the total in the world, including 328 endemics; in Europe, about 114
species, 21.67 percent with 73 endemics; in North America, about 91 species, 17.3 percent with
71 endemics; in Africa, about 8 species, 1.5 percent, with 6 endemics. Only one species occurs
in South America. Asia, Europe and North America have 8 species in common (excluding 4
cultivated species). There are 34 common species between Asia and Europe, 14 both between
Europe and North America and between Asia and North America, 2 between Asia and Africa.
Acording to the Continental Drift Theory, the natural circumstances which promoted speciation
and protected newly originated and old species were created by the orogenic movement of the
Himalayas in the middle and late Tertiary. Besides, the air temperature was a little higher in
Asia than in Europe and North America (except its west part) and the dominant glaciers were
mountainous in Asia during the glacial epoch in the Quaternary Period. Then willows of Eu-
rope moved southwards to Asia. During the interglacial period they moved in opposite direc-
tion. Such a to-and-fro willow migration between Asia and Europe and between and North
America occurred so often that it resulted in the diversity of willow species in Asia. Those
species of willows common among the continents belong to the Arctic flora.
2. The multistaminal willows are of the primitive group in Salix. Asia has 28 species of
multistaminal willows, but Europe has only one which is also found in Asia. These 28 species
are divided into two groups, “northern type” and “southern type”, according to morphology of
the ovary. The boundary between the two forms in distribution is at 40°N. The multistami-
nal willows from south Asia, Africa and South America are very similar to each other and
may have mutually communicated between these continents in the Middle or Late Cretaceous
Period. The southern type willows in south Asia are similar to the North American multista-
minal willows but a few species. The Asian southern type willows spreaded all over the conti-
nents of Europe, Asia and North America through the communication between them before the
Quaternany Period. Nevertheless, it is possible that the willows growing in North America
immigranted through the middle America from South America. The Asian northern type mul-
tistaminal willows may have originated during the ice period.
The multistaminal willows are more closed to populars in features of sexual organs. They
are more primitive than the willows with 1-3 stamens and the most primitive ones in the ge-
nus.
3. The center of origin and development of willows Based on the above discussion it is re-
asonable to say that the region between 20°-40°N in East Asia is the center of the origin and
differentiation of multistaminal willows. It covers Southern and Southwestern China and nor-
thern Indo-China Pennisula. 相似文献
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目前,古脊椎动物学中的世界性热点就是各大门类的起源和进化问题,近几年来,中国的古脊椎动物学家在这一方面获得了前所未有的重大发现。通过对这些发现的深入研究,为解决古脊椎动物学中的热点和难点作出了巨大的贡献。 相似文献
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多倍化是促进高等植物发生进化的重要力量。为了更清楚地了解多倍体在形成之后其基因组是如何进化的,利用38个随机引物对芸薹属Brassica L.禹氏三角(U’Triangle)中的多倍体物种及其祖先二倍体物种进行了研究。根据扩增出的273条带计算了遗传距离,并用UPGMA法进行了聚类分析。结果发现,二倍体物种B.campestris(AA)与B.oleracea(CC)的亲缘关系比与B.nigra(BB)的要近;异源多倍体B.napus(AACC)比起其二倍体祖先之一B.campestris(AA)与另一个 相似文献
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1956年美国科学家Arthur Anderson博士注目于辐射灭菌后的肉罐头而创造了一个惊人的发现。当用可杀死其周围的其它微生物的强烈的射线照射这种生长在肉上的细菌时.其外部形态不受任何影响.这种后来被取名为耐辐射奇球菌Deinococcus radiodurans微生物在10000戈瑞(Gy)也就是1000倍于广岛和长崎原子弹爆炸的辐射剂量下,这个 相似文献