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1.
A karyotypical analysis of Anemarrhena asphodeloides Bung. of the monotypic genus
Anemarrhena Bung. (Liliaceae) was carried out for the first time. The number of chromo-
somes in root-tip cell of the species was found to be 22, agreeing with that reported by Sato[12], although inconsistent in some other respects, such as position of centromeres, length of chromosomes, and nucleoli, etc. (Table 1 ). According to the terminology defined by Levan et al.［8］, the karyotype formula is therefore 2n=22=2sm (SAT)+2sm+18m.
Photomicrographs of the chromosome complements and idiogram of the karyotype are given
Fig. 1 and 2).
The karyotype of Anemarrhena asphodeloides shows explicitly to be asymmetrical, with three pairs of long chromosomes and eight pairs of short chromosomes. This specialized feature, when considered together with the rare occurrence of the basic chromosome number of 11 of the genus within the Tribe Asphodeleae of Liliaceae (see Table 1), suggests that the genus Anemarrhena is probably a rather specialized one, which has scarcely any intimate relationship with the other genera of the above tribe. The fact that this specialized karyotype is associated with certain trends of morphological specialization, such as flowers possessing three stamens only, gives support to the above suggestion. But, it is impossible to draw a more precise conclusion without a more thorough and comprehensive investigation of the species in question. 相似文献
2.
张芝玉 《中国科学院研究生院学报》1982,20(4):402-409
1. The present paper describes the observations of chromosome numbers and
karyomorphology of 2 species of 2 endemic genera and I endemic species of Chinese
Ranunculaceae: Asteropyrum peltatum (Franch.) Drumm et Hutch. 2n=16, x=8;
Kingdonia unifolia Balf. f. et W. W. Sm. 2n=18, x=9 and Calathodes oxycarpa Spra-
gue 2n=16, x=8. The chromosome counts of three ranunculaceous genera are repor-
ted for the first time.
2. The morphylogical, palynological and cytological date in relation to the syste-
matic postition of Asteropyrum, Kingdonia and Calathodes within the family Ranun-
culaceae are diseussed and resulted in following conclusions:
(1). On the basis of the basic number x=8 in Asteropyrum, it is further con-
firmed that this genus is distinct from the r elated genera such as Isopyrum, Dichocarp-
um and other allied taxa.
The comparison of Asteropyrum with Coptis shows that they are identical in short
chromosomes, with magnoflorina and benzylisaquinodine type of alkaloides, but dif-
ferent from coptis in the chromosome numbers (T-type), pantocolpate pollens, united
carpels and the dorsi-ventral type of petioles. In view of these fundamental morpho-
logical and cytological differences, Asterop yrum is better raised to the level of Tribe.
However Asteropyrum and Coptis may represent two divaricate evolutional lines of
Thalictroideae.
(2). The systematic position of the genus Kingdonia has been much disputed in
the past. We support the view of Sinnote (1914), namely, the trilacunar in leaf
traces “the ancient type”, appeared in the angiosperm line very early, while the uni-
lacunar of Kingdonia may be derived from the trilacunar. On the basis of the chromo-
some numbers and morphylogical observation, the present writer accept Tamura’s and
Wang’s treatment by keeping Kingdonia in Ranunculaceae instead of raising it to a
family rank as has been been done by Forster (1961). Kingdonia and Coptis are
similar in having short chromosome with x=9, but with one-seeded fruits; therefore it
is suggested that placed into Thalictroideae as an independent tribe, indicating its close
relationship with Coptideae.
(3). Comparing with its allies, Calathodes being with out petals, seems to be more
primitive than Trollius. But Calathodes differs from Trollius with R-type chromosomes in having T-type chromosome with x=8 and subterminal centromere. Those charac-
teristics show that it is very similar to the related genera of Thalictroideae. But as
Kurita already pointed out that most speci es of Ranunculus have usually large long
chromosomes but some species have compar ativelly short chromosomes, therefore we
regard T-type and R-type chromosomes appear independently in different subfamilies
of Ranunculaceae. According to Tamura, G alathodes seems to be closely related to
Megaleranthis, because of the resemblance in follicles. But due to lack of cytological
data of the latter genus, the relationship between the two genera still is not clear pen-
ding further studies. From the fact that the morphology and chromosomes of the
Calathodes differs from that of all other genera of the Helleboroideae, we consider
Calathodes may form an independent tribe of its own with a closer relationship withTrollieae. 相似文献
3.
4.
In the work mitotic chromosomes in root-tips of 7 species native to Sichuan Pro-
vince were examined and their karyotypes were analysed based on 7-8 cells at mitotic meta-
phase, using Levan et al.'s (1964) nomenclature. The list of species and origin of the materials
used in this work are provided in the appendix. The micrographs of mitotic metaphase of all
the materials are shown in Plates 1 and 2; the idiograms in Fig. 1, 1-9, and the parameters
of chromosomes are provided in Tables 1-9. All the chromosome countings and karyotypes in
this paper are reported for the first time.
Characteristics of the karyotypes may be summarized as follows:
1. 2n=38 are found in all the materials except A. sichuanensis, which has 3 cytotypes, i.e,
2n=38+5B, 2n=38+lB and 2n=38+OB (Plate 2, 1-2, Fig. 1, 5-6).
2. The karyotypes are of two major types: the karyotype of A. flaviflora falls into 3C in
Stebbins's (1958, 197l) classification of karyotypes and those of all the other species into 2C.
The two types are also different from each other in the number of large and medium-sized
chromosomes pairs and morphology of the first pair of chromosomes (compare Plate 2, 5, Fig.
1, 9 with the other micrographs and idiograms).A. flaviflora with the karyotype 3C also differs
from the other species in a series of gross morphological characters: the species is of a yellow and
campanulate corolla.
3. The species with caespitose leaves (A. caespitosa and A. omeiensis) have essentially the
same karyotype, which is rather different from those of the species with scattered leaves. There
are two pairs of small sm chromosomes (arm ratio ≥1.90) in the former karyotype (Tables 1
and 3), but all the small chromosomes are m or sm with arm ratio <1.80 in the latter karyotypes. 相似文献
5.
中国特有的露蕊乌头亚属及铁破锣的染色体研究 总被引：3，自引：0，他引：3
商效民 《中国科学院研究生院学报》1985,23(4):270-274
The paper reports chromosomal number and chromosomal morphologies of
annual Aconitum gymnandrum endemic to China and Beesia calthifolia for the first
time. Of the two spcies, chromosome number is same (X=8, 2n=16) and chromosome
average lengths are 6.17μ , 10.73μ respectively. The longest chromosome 1, the short
chromosomes 3-5, 7 and the shortest chromosome 8 are metacentrical (m), the chro-
mosomes 2, 6 are submetacentrical (sm), and the pairs 4, 5, 8 have satellites in the
karyotype of A. gymnandrum. In B. calthifolia, all of the chromosome 1-5 are the
long m, the chromosomes 6, 8 are the short sm and the 7 is telocentrical (t). The pairs
3, 4, 6 have satellites.
According to the comparison of karyotypes of three subgenera—subgen. Para-
conitum, subgen. Aconitum and subgen. Gymnaconitum in Aconitum, the evolution trend
of chromosomes is further discussed.
Finally, the relationship between Aconitum and Beesia is also discussed in thispaper. 相似文献
6.
The fern Athyrium crenulato-serrulatum Makino is found in the whole of
Northeastern Asia embracing Northeastern China, Korea, Japan, Ussuri and the Far
East USSR. It is similar to the European Athyrium distentifolium, formerly known
as A. alpestre, in having exindusiate round or ovate sori, but differs in several
essential characters, such as the well-spaced fronds are biseriately arranged along a
thick and long-creeping rhizome, the base of stipe is thickened and not attenuated to-
wards the point of attachment, the deltoid-ovate lamina with the basal pinnae as long
as those next above, which all are distinctly petiolate and the rachis, costis and espe-
cially the costules of pinnules clad in fine pale-colored generally septate hairs under-
neath. All these clearly show that the fern in question is not an Athyrium sen. str.
neither Pseudoathyrium Newman to which latter the fern was referred by Nakai.
However, we have been long suspicious of its proper systematic position. In his recent
monograph on the genus Cornopteris (Acta Phytotax. Geobot. 30: 104. 1979.) Kato
has pointed out that C.crenulato-serrulata (Makino) Nakai “has the northernmost
destribution in the genus and exhibits a few characteristics similar to Athyrium, the
swollen base of stipes with projections and cartilaginous lamina margin. By these
characteristics the species is clearly discriminated from other species”. According to
Kurita (1964), Mitui (1970) and Karo (1978) the species in question has chromosome
numbers n=40, the base number of the subfamily Athyrioides instead of x=41, the
base number of the subfamily Diplazioides including Cornopteris Nakai. Since thefern in question fits no other athyrid genera, hence a new genus is proposed. 相似文献
7.
From standpoint of floristic division, Sichuan is located in the middle part
of Eastern Asiatic Region (Takhtajan 1978) or is the area where Sino-Himalayan Forest
Subkingdom and Sino-Japan Forest Subkingdom meet (wu 1979). Here exist many so-
called Arcto-Tertiary elements and newly originated species or races. In order to bring
the light the origin and differentiation of Eastern Asiatic elements, cytological investi-
gation on plants of this region are very significant. The materials of the following 5
species were collected on Mt. Emei in Sichuan Province. Voucher specimens are kept in CDBI.
1. Toricellia angulata Oliver var. intermedia (Harms) Hu
PMC meiotic examination revealed n = 12 at diakinesis (Pl. I fig. 9)
Toricellia, consisting of 2 spp., is endemic to Eastern Asiatic Region. Based on
our result along with the report of Toricellia tiliifolia (Wall.) DC. (2n=24) by Kuro-
sawa (1977), we argue that the basic chromosome number of Toricellia is 12. Many
authors, such as Airy-Shaw (1973), Dahlgren (1975, 1977), Takhtajan (1969, 1980),
Thorne (1983), have adopted Hu’s (1934) treatment erecting it as a monotypic family
Toricelliaceae. Its systematic position, whether closer to Cornaceae than to Araliaceae
or vice versa, has been in dispute. Cytologically it seems closer to Araliaceae, as shown
anatomically (Lodriguez 1971), because the basic chromosome number of Cornaceae s.
1. is x=11, 9, 8 (Kurosawa 1977), whereas that of Araliaceae is 12 (Raven 1975).
2. Cardiocrinum giganteum (Wall.) Makino
Somatic chromosome number, 2n=24 was determined from root-tip cells (Ph. I. fig.
8).
Cardiocrinum (Endl.) Lindl., consisting of 3 spp., is endemic to Eastern Asiatic
Region. C. giganteum (Wall.) Makino is distributed from Himalayan region to S. W.
China. The present report is in accord with the number reported by Kurosawa (1966)
who got the material from Darjeeling of India. However the karyotype of the present
plant is slightly different from that given by Kurosawa. In the present material, the
satellites of the 1st. pair of chromosomes and the short arms of llst. pair of chromoso-
mes are visibly longer than those of Kurosawa’s drawing (fig. 1, 2) The plants from
Yunnan, Sichuan and Hubei Provinces, named as C. giganteum var. yunnanense (Leit-
chtlin ex Elwes) Stearn, differ slightly from those of Himalayan region also in outer
morphological characters. The taxon needs both cytological and taxonomical further
studies.
3. Disporum cantoniense (Lour.) Merr.
PMC meiotic examination revealed n=8 at diakinesis (Pl. I. fig. 6)
This species is widely distributed from Himalayan region through Indo-China to
our Taiwan Province and Indonesia. Three cytotypes (2n=14, 16, 30) were reported for
the taxon including its variety, var. parviflorum (Wall) Hara, by various authors (Ha-
segawa 1932, Mehra and Pathamia 1960, Kurosawa 1966, 1971 Mehra and Sachdeva
1976a). Some authors consider D. pullum Salisb. and D. calcaratum D. Don as synonyms
of D. cantoniense. So D. cantoniense may be a species aggregate with different extreme
races. Sen (1973a, b.) reports that the somatic chromosome numbers of D. pullum
and D. calcaratum from Eastern Himalayan region are 14, 16, 28, 30, 32. He also
discovered that chromosome alterations in species of Disporum involve not only the num-
ber but the structure as well. He found that in species of Liliaceae where the reproduc-
tion is mainly vegetative, polysomaty often occurs. In China we have not only D. can-
toniense and D. calcaratum but also D. brachystomon Wang et Tang which is similar
to D. cantoniense var. parviflorum (Wall.) Hara. These taxa need further critical
studies.
4. Paris fargesii Franch.
PMC meiotic examination revealed n=5+2B (Voucher no. 112) or n=5 (Voucher
no. 62) at MI and AI (Pl. I. fig. 1. 4. 5.). This is the first report for the species. A
bridge and a fragment were also observed at AI.
Paris polyphylla Smith is extraordinarily polymorphic species. Hara (1969) re-
gards all chinese extreme forms, such as P. fargesii Franch., P. violacea Lévl., P. pube-
scens (Hand. -Mzt.) Wang et Tang, etc. as infraspecific taxa of P. polyphylla. Need-
less to say, the various races of P. polyphylla Smith in China need further critical stu-
dies and are good material for further study to understand the speciation.
5. Reineckia carnea(Andr.) Kunth
Reineckia is a monotypic genus endemic to Eastern Asiatic Region. In the present
material somatic chromosome number in root-tip cells is determined as 2n=38 (Pl. I. fig.
7). According to the terminology defined by Levan et al., the karyotype formula is
2n=28 m+10 sm. The length of chromosomes varies from 14.28 μ to 5.5 μ. The idiogram
given here (fig. 3) is nearly the same as that presented by Hsu et Li (1984). The same
number has been previously reported by several authors, Noguchi (1936), Satô (1942),
Therman (1956). The karyotype is relatively symmetrical (2B, accorling to the classi-fication of stebbins 1971) in accord with the opinion of Therman (1956). 相似文献
8.
我国悬钩子属植物的研究 总被引：1，自引：0，他引：1
陆玲娣 《中国科学院研究生院学报》1983,21(1):13-25
The genus Rubus is one of the largest genera in the Rosaceae, consisting of more
than 750 species in many parts of the world, of which 194 species have been recorded
in China.
In the present paper the Rubus is understood in its broad sense, including all the
blackberries, dewberries and raspberries, comprising the woody and herbaceous kinds.
So it is botanically a polymorphic, variable and very complicated group of plants.
The detailed analysis and investigation of the evolutionary trends of the main organs
in this genus have indicated the passage from shrubs to herbs in an evolutionary line,
although there is no obvious discontinuity of morphological characters in various taxa.
From a phylogenetic point of view, the Sect. Idaeobatus Focke is the most primitive
group, characterized by its shrub habit armed with sharp prickles, aciculae or setae,
stipules attached to the petioles, flowers hermaphrodite and often in terminal or axill-
ary inflorescences, very rarely solitary, druplets separated from receptacles. Whereas
the herbaceous Sect. Chamaemorus L. is the most advanced group, which is usually
unarmed, rarely with aciculae or setae, stipules free, flowers dieocious, solitary, dru-
plets adhering to the receptacles and with high chromosome numbers (2n = 56).
Basing upon the evolutionary tendency of morphological features, chromosome nu-
mbers of certain species recorded in literature and the distribution patterns of species,
a new systematic arrangement of Chinese Rubus has been suggested by the present
authors. Focke in his well-known monograph divided the species of Rubus into 12
subgenera, while in the Flora of China 8 sections of Focke were adapted, but some im-
portant revisions have been made in some taxa and Sect. Dalibarda Focke has been
reduced to Sect. Cylactis Focke. In addition, the arrangement of sections is presented
in a reverse order to those of Focke’s system. The species of Rubus in China are
classified into 8 sections with 24 subsections (tab. 3) as follows: 1. Sect. Idaeobatus,
emend. Yü et Lu(11 subsect. 83 sp.); 2. Sect. Lampobatus Focke (1 sp.); 3. Sect.
Rubus (1 sp.); 4. Sect. Malachobatus Focke, emend. Yü et Lu (13 subsect. 85 sp.); 5.
Sect. Dalibardastrus (Focke)Yü et Lu (10 sp.); 6. Sect. Chaemaebatus Focke (5 sp.);
7. Sect. Cylactis Focke, emend. Yü et Lu (8 sp.); 8. Sect. Chamaemorus Focke (1 sp.).
In respect to the geographical distribution the genus Rubus occurs throughout the
world as shown in tab. 2, particularly abundant in the Northern Hemisphere, while
the greatest concentration of species appears in North America and E. Asia. Of the
more than 750 species in the world, 470 or more species (64%) distributed in North
America. It is clearly showm that the center of distribution lies in North America at
present time. There are about 200 species recorded in E. Asia, of which the species
in China (194) amount to 97% of the total number. By analysis of the distribution
of species in China the great majority of them inhabit the southern parts of the Yangtze
River where exist the greatest number of species and endemics, especially in south-
western parts of China, namely Yunnan, Sichuan and Guizhou (tab. 3. 4.). It is in-
teresting to note that the centre of distribution of Rubus in China ranges From north-
western Yunnan to south-western Sichuan (tab. 5), where the genus also reaches its
highest morphological diversity.
In this region the characteristics of floristic elements of Rubus can be summarized
as follows: it is very rich in composition, contaning 6 sections and 94 species, about
66% of the total number of Chinese species; there are also various complex groups,
including primitive, intermediate and advanced taxa of phylogenetic importance; the
proportion of endemic plants is rather high, reaching 61 species, up to 44% of the
total endemics in China. It is noteworthy to note that the most primitive Subsect.
Thyrsidaei (Focke) Yü et Lu, consisting of 9 endemic species, distributed in southern
slopes of the Mts. Qin Ling and Taihang Shan (Fig. 4). From the above facts we may
concluded that the south-western part of China is now not only the center of distribu-
tion and differentiation of Rubus in China, but it may also be the center of origin ofthis genus. 相似文献
9.
We have described a new genus Taihangia, collected from, the south part of Taihang
Mountain in northern China. At the same time, comparative studies on Taihangia with its
related genera have been made in various fields including external morphology, anatomy
of carpels, chromosome and pollen morphology by light, scanning and transmission electron microscope. In addition, isoperoxidases of two varietier were analysed by means of polya-crylamide gel slab electrophoresis. The preliminary results are as follows:
Morphology: The genus Taihangia is perennial and has simple leaves, occasionally
with 1—2 very small reduced lobes on the upper part of petiole; flowers white, andromo-
noecious and androdioecious, terminal, single or rarely 2 on a leafless scape; calyx and cpicalyx with 5 segments; petals 5; stamens numerous; pistils numerous, with pubescent styles, spirally inserted on the receptacle in bisexual flowers, but with less number of abortive and glabrous pistils in male flowers.
In comparison with the related genera such as Dryas, Geum, Coluria and Waldsteinia,
the new genus has unisexual flowers and always herbaceous habit indicating its advanced
feature but the genus has a primitive style with thin and short hairs as compared with the genus Dryas which has long, pinnately haired styles, a character greatly facilitamg anemo-choric dissemination. The styles of Taihangia are slender and differ from those of the ge-nus Geum which are articulate, with a persistent hooked rostrum, thus adapting to epizo-ochoric dissemination to a higher degree.
The anatomy of carpels shows the baral position of ovules in the genus Taihangia like those in other related genera such as Dryas, Geum, Acomastylis, Coluria and Waldsteinia. This suggests that the new genus and its related ones are in a common evolutionary line as compared with the other tribes which have a pendulous ovule and represent a separate evolutionary line in Rosaceae. Dorsal and ventral bundles in carpels through sections are free at the base. Neither fusion, nor reduction of dorsals and vertrals. are observed. This shows that the genus Taihangia is rather primitive.
Somatic chromosome: All the living plants, collected from both Honan and Hopei
Provinces were examined. The results show that in these plants the chromosome number
is 2n= 14, and thus the basic number of chromosome is x=7. Such a diploid genus is first
found in both anemochoric and epizoochoric genera. Therefore, in this respect Taihangia is primitive as compared with herbaceous polyploid genus Geum and related ones.
Pollen: The stereostructure shown by scanning electron microscope reveals that the pollen grains of the genus Taihangia are ellipsoid and 3-colporate. There are two types of exine sculpture. One is rather shortly striate and it seems rugulate over the pollen surface; the other is long-striate. The genus Dryas differs in having only short and thick striae over the surface. The genus is similar to the genera Geum, Coluria and Waldsteinia in colpustype, but differs from them in that they all have long, parallel striae which are distributed along the meridional line.
In addition, under transmission electron microscope, the exine in the Taihangia and related genera Acomastylis, Geum, Coluria, Waldsteinia and Dryas has been shown to be typically differentiated into two distinct layers, nexine and sexine. The nexine, weakly statined, appears to consist of endoxine with no foot-layer, in which the columellae are fused, and which is thicker beneath the apertures. The sexine is 2-layered, consisting of columellae and tectum. Three patterns of tectum can be distinguished in the tribe Dryadeae: the first, in the genera Taihangia, Acomastylis, Geum, Coluria and Waldsteinia, is tectate-imperforate, with the sculpturing elements both acute and obtuse at the top and broad at the base; the second, in the genus Dryas, is semitectate, with the sculpturing elements shown in ultrathin sections rod-like and broader at the top than at the base or as broad at the top as at the base, and the third, tectate-perforate, with the sculpturing elements different in size. From the above results, the herbaceous groups and woody ones have palynologically evolved in two distinct directions, and the genus Taihangia is related to other herbaceous genera such as Acomastylis, Geum, Coluria and Waldsteinia, as shown in the electron microphotographs of ultrathin sections. The genus Taihangia, however, is different from related herbaceous genera in that the pollen of Taihangia is dimorphic, i.e. in addition to the above pattern of pollen another one of the exine in Taihangia is rugulate, with the sculpturing elements shown in the ultrathin sections being obtuse or emarginate and nearly as broad at the top as at the base.
The interesting results obtained from the comparative analysis of morphology, ana-
tomy of carpels, chromosome countings, microscopic and submicrosocopic structures of pollen may enable us to evaluate the systematic position of Taihangia and to throw a new light on evolution of the tribe Dryadeae. It is well known that the modes of dissemination of rosaceous fruits play an important role in the expansion and evolution of the family. The follicle is the most primitive and the plants with follicles, like the Spiraeoideae, are mostly woody and mesic, while the achene, drupe and pyrenarium are derived. In Rosoideae having a achene is a common feature. Particularly in the tribe Dryadeae, which is distinguished from the other related tribes by having orthotropous ovules, the methods of dissemination of fruits have developed in three distinct specialized directions: anemochory with long, plumose styles (e.g. Dryas), formicochory or dispersed by ants or other insects, with the deciduous styles (e.g. Waldsteinia and Collria),and epizoochory with the upper deciduous stigmatic part and the lower persistent hooked rostrum, an adhesive organ favouring epizoochory dissemination (e. g. Geum and related taxa). Taihangia is a genus endemic to mesophytic
forest area of northern China. Due to its narrow range and specific habit as well as pubescent styles, neither perfectly adapted to anemochory nor to epizoochory, the genus Taihangia might be a direct progeny of the ancestry of anemochory. Maintaining the diploidy and having an ntermediate sculptural type of pollen, the new genus might probably represent a linkage between anemochory and zoochory (including epizoochory and dispersed by ants).
Experimental evidence from isoperoxidases shows the stable zymograms of root and
roostoks. The anodal isozyme of T. rupestris var. rupestris may be divided into 6 bands:
A, B, C, D, E, F, and T. rupestris var. ciliata into 4 bands: A, B, C, G. The two varietiesof the species share 3 bands: A, B, C. However, D, E and F bands are characteristic of var. rupestris and G band is limited to var. ciliata. As far as the available materials are concerned, the analysis of isoperoxidases supports the subdivision of the species into two varieties. 相似文献
10.
The present paper deals mainly with the karyotype analysis of five
materials in Angelica dahurica collected in Yanbian of Jilin, Anguo of Hebei, Yuxian of
Henan, Hangzhou of Zhejiang and Suining of Sichuan. They are under the names
“Dongbeidahuo”, “Qibaizhi”, “Yubaizhi”, ”Hangbaizhi” and “Chuanbaizhi” respe-
ctively. Among then “Dongbeidahuo” is a wild plant, which occurs in northeastern
China, and the others are cultivated as important crude drugs in some provinces. “Qi-
Baizhi” and “Yubaizhi” have been identified as conspecific with the wild Baizhi-“Do-
Ngbeidahuo” (A. dahurica) according to the external morphological features, whereas the
other cultivated ones, “Hangbaizhi” and “Chuanbaizhi”, treated as a variety (A. dahu-
rica var. formosana).
The results of karyotype analysis are shown in Plate 1, 2, with the formula 2n=22
=12 m+2 mSAT+4sm+4st. The karyotypes described here are constantly characterized by
satellites attached to the fourth pair of metacentric chromosomes and differ from the pu-
blished reports on the other species of the genus. It is reasonable to say that the five
materials collectively named “Baizhi” are taxonomically closely related to each other
and could be regarded as conspecific. Since the second chromosome pair is submetacen-
tric in “Dongbeidahuo”, it may be justifiable to separate the wild plant from the cul-
tivated ones and treat them as two separate varieties. 相似文献
11.
本文对浙江产的Disporum sessile， Tricyrtis macropodo， Scilla rcilloides，Ophiopogon japoni-
cus,Liriope platyphylla和Allium macrostemon的核型作了分析，并报道了Polygonatum odoratum
和Asparagus cochinchinensis 的单倍体染色体数目。其中绝大多数为国产材料的首次记载。 相似文献
12.
本文报道了我国黑龙江产桔梗科沙参属的10种1变种的染色体数目和核型，对其中
7种作了减数分裂行为的观察。 其中6种1变种为首次报道，并发现2n=68的4x种。该
属染色体基数多为17(x＝17)，但Adenophora trachelioides和A．remotiflora的基数为18
(x=18)，为该属独特基数。核型的共同特征是：小型，以中部(m)、近中部(sm)着丝点
染色体为主，至少具一对近端着丝点染色体和一对随体染色体。该属染色体的演化处于二种
水平： 数目变化(包括多倍化和非整倍体变化)和结构变异。 多倍化是该属物种形成的主要
途径之一。结合其它性状讨论了这些种的分类，并确立1个四倍体新种(A. amurica)和1个新组合(A．pereskiifolia ssp．alternifolia)。 相似文献
13.
本文报道了东亚植物区系中双子叶植物9个种的体细胞染色体新计数，其中6个是属的新计数，并对这些资料与有关的科或属在系统学和进化上的意义作了讨论。 相似文献
14.
重楼属Paris有19种，分布于欧亚大陆。根据对本属所有种的染色体研究，重楼属染色体基数为5，核型的基本结构有两种形式：热带核型K2n＝2x=10=6m十4t和温带核型K2n=2x=10＝6m+4st或 6m+2st十2t。 热带核型的种(13种)分布在亚洲大陆的热带和亚热带；温带核型的种(6种)则出现在欧亚大陆的温带地域。重楼属的多倍体种的核型属温带核型，为本属的边陲种。四倍体种四叶重楼Paris quadrifolia分布在本属分布区的西端(欧洲)；日本重楼P.japonica是八倍体种，局限在属分布区的东端(日本)。全部热带核型的种都是二倍体种。其中海南重楼P.dunniana等较原始种类都集中在华南和中南半岛北部。作者认为，亚洲大陆北纬18°至北回归线的热带地域是重楼属的起源地，云贵高原至邛崃山地域拥有14种重楼和9种核型结构式(全属有13种核型结构式)，是重楼属的多样化中心，即现代分布中心。 相似文献
15.
万寿竹六个居群的核型研究 总被引：1，自引：0，他引：1
本文研究了在云南境内的万寿竹Disporum cantoniense (Lour．)Merr．从滇东南经滇中到滇西
北不同居群间的核型变异。该种的染色体数目较为稳定，2n=14，没有观察到不同数目的变异。六个
居群的不对称性均属于3B型，但各个居群的核型结构表现出一定的差异，核型间随体位置和数目的不
同以及同源染色体的杂合性是居群间变异的主要特征，这种种内不同居群间核型的变异或许与该种的地理分布及生境有一定的相关性。 相似文献
16.
傅德志 《中国科学院研究生院学报》1988,26(4):249-264
本文对人字果属Dichocarpum W．T．Wang et Hsiao．的形态、花粉和染色体等性
状，以及地理分布进行了系统研究。确认了该属在毛茛科Ranunculaceae中的地位，并认为可
能与星果草属Asteropyrum Drumm．et Hutch．关系较密切, 证实了该属内存在三沟和散沟两
种花粉类型。该属的染色体基数可能为x=6，产于东亚大陆的种为4倍体，日本的种为6倍
体，原始的2倍体种已灭绝。中国西部山地可能为该属的分布中心，日本的种可能是在第三纪由中国大陆迁移过去的。本文按该属内各种之间可能的亲缘关系，作出了系统排列。 相似文献
17.
对葱属粗根韭的3个地方居群的核型分析结果表明,3个居群的核型表现出很大的差异。西藏
达孜居群为2n=2x=20=4m+10sm+2t(2SAT)+4T;四川乡城居群为2n=2x=20=10sm+6t
(2SAT)+4T;四川理县居群为2n=2x=20=6m+1Osm+2t(2SAT)+2T。虽然它们之间在核型上存
在差异,但除达孜居群的植株较矮小外,3个居群的植物在形态上却非常一致。理县居群的核型被认为
是原始类型,由它通过染色体结构变异,分别演化出更不对称的达孜居群和乡城居群。葱属中,目前只
发现4个种的染色体基数为10,除本种外其余3种分别是A．decipiens Fisch．;A．kujukense Vved．和
A．chelotum Wendelbo。根据这4个种的核型特征和分布格局,基数10可能有不同的起源,至少粗根韭
的起源与其余3种不同,而且起源最晚。粗根韭的核型特征及它与染色体基数为11的宽叶韭A．hook-
eri Thwaites在核型上的相似性,表明它们很可能共同起源于基数为10但现已绝灭的祖先种。此外,还探讨了该祖先种的起源问题。 相似文献
18.
杨亲二 《中国科学院研究生院学报》2001,39(5):405-422
研究了国产毛茛属Ranunculus L.11种及其4个近缘属——美花草属Callianthemum C．A．Meyer、
侧金盏花属Adonis L．、碱毛茛属Halerpestes E．Greene、水毛茛属Batrachium S．F．Gray 5种植物的染色体
数目和形态。发现美花草C.pimpinelloides(D．Don)Hook．f.et Thoms.、川滇毛茛R．potaninii Kom．、深
齿毛茛R．popovii var．stracheyanus(Maxim．)W．T. Wang、高原毛茛R．tanguticus(Maxim．)Ovcz．、石龙
芮R．sceleratus L．、西南毛茛R．ficariifolius Lévl．et Vant．、褐鞘毛茛R．sinovaginatus W．T. Wang、三裂碱毛茛H．tricuspis(Maxim．)Hand．-Mazz．和碱毛茛H．sarmentosa (Adams) Kom．9种植物为染色体基数x
＝8的四倍体(2n=4x＝32)；短柱侧金盏花A．brevistyla Franch．、丝叶毛茛R．nematolobus Hand.-Mazz．、
棱喙毛茛R．trigonus Hand．-Mazz．、茴茴蒜R．chinensis Bunge 4种植物为染色体基数x＝8的二倍体(2n＝
2x＝16)；毛茛B．japonicus Thunb．、黄毛茛R．laetus Wall．2种植物为染色体基数x=7的二倍体(2n＝2x
＝14)；水毛茛R．bungei (Steud．) L. Liou 有二倍体(2n＝2x=16)和三倍体(2n＝3x=24)两种细胞型。根 据染色体资料，讨论了上述5属的属间关系和毛茛属中一些种的种间关系。 相似文献
19.
本文报道了中国苹果属Malus Mill．21种36类型的核型和6个多倍体类型的减数分裂联会构
型。 (木+多)(木+衣)海棠组Sect．Docyniopsis和花楸苹果组Sect．Sorbomalus中的滇池海棠系Ser．
Yunnanenses 属2A型，陇东海棠系Ser．Kansuenses中的变叶海棠M．toringoides和花叶海棠M．
transitoria属2A、2B则，三叶海棠系Ser．Sieboldianae属2B型，苹果组Sect．Malus中的苹果系
Ser．Pumilae和山荆子系Ser．Baccatae除小金海棠M．xiaojinensis 2B型外，均属3B型。减数分
裂观察结果有同源四倍体，节段异源三倍体和异源三倍体类型。本文还讨论了种类间在核型上的差异、栽培种的起源，核型的演化趋势以及无融合生殖类型的分类学处理。 相似文献
20.
本文对国产葱属Allium 8个种的14个居群的染色体进行了研究。其染色体基数均为x=8，其中7个居群为二倍体(2n=2x=16)，6个居群为四倍体(2n=4x=32)，1个居群为多倍体复合体(2n=4x=32，2n=6x=48，2n=8x=64和2n=9x=72)。并发现随体染色体十分活跃，在多倍体中其数目并不都与其倍性相对应，并有“串状随体”现象出现；在有些类群中其形态变异较大，而随体染色体杂合形式的多态现象也较普遍。本文重点讨论了随体染色体的数目、形态变异及杂合现象在葱属进化中的作用，认为随体染色体形态变异及杂合现象的出现是葱属中遗传变异的重要源泉之一。并对葱属中的染色体基数及种内多倍性问题进行了初步讨论。 相似文献