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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.
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
3.
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
4.
Leonurus japonicus Houtt. [L. heterophyllus Sweet, L. artemisia (Lour.) S. Y.
Hu] is one of the most important traditional Chinese medicines used as a remedy for gynaeco-
logical disease since ancient times. A cytological investigation on the species was carried out
and the materials for chromosomal examination were collected from 26 localities in 20 provi-
noes and autonomous regions of this country. The number of chromosomes in root tip cell of
the species was found to be 20 on the whole (Tab. 1:1), agreeing with those reported by Ma and
al.[2] and probably by Chuang and al.[3] as well.
The genus Leonurus L. is variable in its chromosomes with an aneuploidy of x=9, 10 and
12. The present authors would propose that the primitive basic number of chromosome in the
genus is 9, and thus both 10 and 12 are derived, for: (1) among the 9 species (including 1 sub-
species) heretofore cytologically examined, x=9 occurring in 66.7%, x=10 occurring in 22.2%,
while x=12 occurring only in 11.1%; (2) in generaclosely related to the genus under considera-
tion, such as Panzeria, Galeobdolon and Lamium x=9 being the sole basic number.
But L. japonicus exhibits a mixoploidy of 2n=20 (occurring at the rate of 53.30% of the
total amount of cells examined), 2n=18 (30.70%), and 2n=16 (15.99%) in our work. (Table
1). Since the original basic number of chromosome of the genus is 9 as proposed above, 2n=
20 would be considered as a derived one and the occurrence of 2n=18 probably suggests an
early evolutionary trend of 2n=18→20 of the pecies in question. 相似文献
5.
6.
芍药属的研究(1)——国产几个野生种核型的报道 总被引：1，自引：0，他引：1
In the present paper 8 species with 15 populations of the genus Paeonia L. (if P.
papaveracea and P. japonica are recognised as species) were collected from Sichuan, Shaanxi
and Hebei provinces (see the Appendix for detail of the materials). The micrographs of their
somatic metaphase (also Mii in the case of P.veitchii) are shown in Plates 1-4, the karyo-
type formulae, ranges of chromosome length and classification of karyotypes according to Steb-
bins (1971) are shown in Table 5: the idiograms in Figs. 1-2, and the parameters of chromo-
somes in Table 1-4. The essential points are mentioned as follows:
(1) Chromosomes of the various species in the section Modan have so far been examined
and they are all diploid, the two species in the section Onaepia are also diploid, and thus
tetraploids exist only in the section Paeonia.
(2) Chromosomes in the genus Paeonia are relatively stable except for the differentiation
of ploidy. The karyotypes (Table 1-4) show no differences among different taxa in Sect.
Modan and the same can also be said about the taxa in Sect. Paeonia (Table 1). Not only
are the karyotypes very similar, but also among the members within either section have the
same parameters of chromosomes, and, differences, if occur, are not statistically significant.
Between the two sections, however, the situation is different. The arm ratios of the first pairs of
chromosomes in Sect. Modan are 1.53, 1.52 and 1.48 (Table 1), but those in Sect. Paeonia
are 1.12-1.28 (Table 2-4), 95% confidence limits are 1.46-1.60 for the section Modan and
1.07-1.28 (1.21-1.35 only for PB85078) for the section Paeonia, not overlapping, which indi-
cates that the two sections have differentiated in respect of the first pairs of chromosomes.
(3)The population PB85024, which belongs to the P. obovata complex, has a karyotype of
2B (stebbins, 1971), which is a new one in the genus Paeonia. This karyotype is a stable one,
for several individuals in the population are uniform in this respect, which shows that Steb-
bins’ (1971) generalization that all the species in Paeonia have 2A does not hold true.
(4) Three populations of P. obovata complex studied in this work from Sichuan and
Shaanxi are all tetraploids, and one from Hebei is a diploid. From the present work and
the previcus reports, the materials from Japan and Korea, no matter whether flowers are pink
or white, are diploids, those from Heilongjiang Province (with both pink and white flowers)
(Liu Ming-yuan, personal communication) and from Heibei Province (with pink flowers)
in China are also diploids, the one from Sakhalin (pink flowers) is tetraploid, those from
Priamur of the Soviet Union are a tetraploid (with white flowers) and a diploid (with pink
flowers), and those from Shaanxi (the Qinling Range) and western Sichuan (with both pink
and white flowers) are all tetraploids. As far as we have now known, ploidy in this parti-
cular complex is correlated with the geographical distribution: diploids are found in the cen-
tral part, tetraploids occur in the northern limits, and in the south letraploids are the only
cytotype.
(5) The materials of P. mairei from western Sichuan and Shaanxi (the Qinling Range)
are found all to be tetraploids, which shows that two cytotypes, diploid and tetraploid, exist in
this species, but the geographical distribution pattern of these two cytotypes is to be revealed
in the future investigation. 相似文献
7.
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
8.
The vegetative characters of Ligusticum chuanxiong Hort. cv. Fuxiong
are described in comparison with L. chuanxiong Hort. and L. sinense Oliv. The chromosome
numbers and karyotypes of the three taxa were studied in root tip cells by Feulgen’s squash
method. Their karyotypes are determined as follows: L. chuanxiong, K(2n)=22=16 m+
4sm+2st (sat); L. chuanxiong cv. Fuxiong, K(2n)=33=24 m+6sm+3st (sat); L. sinen-
se, K(2n)=22=12 m+6sm+2sm (sat)+2st (sat).
The karyotypic similarities are found between L. chuanxiong and its cultivariety, butthe former is a diploid while the latter probably is a homologous triploid. 相似文献
9.
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
10.
中国种子植物特有属的数量分析 总被引：3，自引：0，他引：3
王荷生 《中国科学院研究生院学报》1985,23(4):241-258
Chinese flora with many endemic elements is highly important in the world’s
flora. According to recent statistics there are about 196 genera of spermatophytes, be-
ing 6.5% of total Chinese genera. These endemic genera comprising 377 species belong
to 68 families, among which the Gesneriaceae (28 genera), Umbelliferae (13), Compo-
sitae (13), Orchidaceae (12) and Labiatae (10) are predominant. The tropical type
containing 24 families and 80 genera is dominant. After it follows the temperate type
with 23 families and 50 genera. There are also 4 families endemic to China, i.e. Gin-
kgoaceae, Bretschneideraceae, Eucommiaceae and Davidiaceae. It shows that genera
endemic to China are obviously related to the tropical and temperate flora in essence.
The endemic monotypic genera (139) and endemic obligotypic genera (48) combin-
ed make up more than 95% of the total number of genera endemic to China. Phylo-
genetically more than half of them are ancient or primitive. The life forms of all ende-
mic genera are also diverse. Herbs, especially perennial herbs, prevail with the propor-
tion of about 62%, and trees and shrubs are the next, with 33%, and the rest are lianas.
Based upon the calculated number of genera endemic to China in each province and
the similarity coefficents between any two provinces, some conclusions may be drawn
as follows:
Yunnan and Sichuan Provinces combined are the distribution centre of genera en-
demic to China and may be their original or differentiation area, because numerous
endemic genera, including various groups, exist in these two provinces. The second is
Guizhou where there are 62 endemic genera. Others form a declining order, south
China, central China and east China. But towards the north China endemic genera de-
crease gradually, and the Qinling Range is an important distributional limit.
The largest simitarity coefficient, over 50%, appears between Shaanxi and Gansu
probably because of the Qinling Range linking these two provinces. But between any
other two provinces it is less than 30% and it is generaly larger between two south pro-
vinces than between two north provinces.
These characteristics mentioned above are correlated with topography and climate,
and they may be resulted from the diversification in geography and climatic influence
for a long time. 相似文献
11.
国产十种乌头的染色体研究 总被引：1，自引：0，他引：1
本文描述了我国产毛茛科乌头属的10个种的染色体数目和形态。 根据该属染色体基 数为8(x＝8)，可将这些种归为二倍体、四倍体、六倍体和八倍体种。 10种乌头的染色体在数目、大小、结构上表现出相关性。其中具根状茎而多年生的种多为二倍体，染色体形态较大，第3-7号多为近端着丝点(st)染色体, 具块茎而二年生的种多为多倍体，染色体形态较小，第3-7号多为近中着丝点(sm)染色体。染色体演化方向可能是二倍体→多倍体、大→ 小、st→sm。这进一步证明根状茎种较块茎种原始。根据染色体数目和形态，又可将这些种的染色体分为两类。这进一步支持了目前分类学上的牛扁亚属和乌头亚属的划分。本文还讨论了这些种的有关分类问题。 相似文献
12.
本文对国产葱属根茎组的8种植物进行了染色体研究，发现染色体数目2n＝16或32，核型属2A
或2B型，对称性较高。其染色体数目和核型分别为：Allium leucocephalum 2n(2x)＝16＝12m+2sm
+2st(2SAT); A，strictum 2n(4x)＝32＝16m+4sm+12st；A.ramosum 2n(2x)＝16=14m+2st
(2SAT); A．bidentatum 2n(4x)=32＝24m+4sm+4T;A．tenuissimum 2n(2x)=16=10m+4sm+
2st(2SAT)，A．anisopodium 2n(2x)＝16＝12m+2sm+2st(2SAT)；A．anisopodium var．zimmermanni
anum 2n(4x)＝32＝24m+4sm+4st(4SAT); A．condensatum 2n(2x)＝16＝14m+2st(2SAT)。多数种的染色体资料为国内首次报道。 相似文献
13.
本文报道了原产我国北方的7种常见野生耐寒花卉的染色体数目或核型，即猫儿菊、二月兰、大 花剪秋萝、地黄、华北蓝盆花、长白山罂粟与细叶毛萼麦瓶草。 后三种为首次报道。 相似文献
14.
本文对安徽南部贝母属的5种植物的核型进行了研究，结果如下：祁门贝母Fritillaria qimenensis
D C.Zhang et J．Z．Shao：2n=24+4Bs=3m+lsm+8st(2sc)+12t(2sc)+4Bs。铜陵黄花贝母F．monantha
Miq．var．tonglingensis S．C.Chen et S．Ｆ．Yin本文报道2个细胞型，细胞型I：2n=24+5Bs=4m+8st
(2sc)+12t(2sc)+5Bs；细胞型II：2n=24=2m+2sm+8st(2sc)+12t(2sc)。窄叶小贝母F.xiaobeimu Y．K．
Yang，J．Ｚ．Shao et M．M．Fang：2n=24=2m+2sm+10st(4sc)+lot。宁国贝母F．ningguoensis S．C.
Chen et S．F．Yin：2n=24=2m+2sm+8st(2sc)+12t。浙贝母F.thunbergii Mig．：2n=24=2m+2sm+8st(2sc)+12t(2sc)。除浙贝母外，其余均是近年发表的新种或新变种，其染色体数目和核型均为首次报道。 相似文献
15.
秦岭地区10种百合科植物核型报道 总被引：1，自引：0，他引：1
本文对秦岭地区的Polygonatum的2种，Hosta的2种和Smilax discotis，Cardiocrinum
giganteum，Asparagus filicintus，Reineckia carnea，Tupistra chinensis，Rohdea japonica做了核型分析。其中有4种的核型为国内首次报道。本义对不同产地的玉竹gonatum odoratum)的核型进行了对比，讨论了其核型进化的可能途径。 相似文献
16.
黄精属5种植物的核型研究 总被引：2，自引：0，他引：2
本文报道了安徽省黄精属Polygonatum Mill．5种植物的染色体数目和核型。玉竹P. odoratum
(Mill.)Druce黄山材料2n=16=10m(3sc)+6sm，滁县琅琊山材料2n=18=10m(1sc) +2sm+6st(2sc)，二者均属2B核型．
长梗黄精P．filipes Mirr. 黄山材料2n=22=8m+8sm(2sc)+6st，属3B核型，安徽繁昌材料2n=14=10m+4sm和2n=16=8m
+4sm+4st，二者均属2B核型。多花黄精(P.cyrtonema Hua)安徽黄山材料2n=20=8m+6sm+6st和2n=22=6m+8sm
+4st+4t，二者均属3B核型，安徽滁县琅琊山材料2n=18=8m(2sc)+6sm+4st，属2B核型。长苞黄精(P．desoulayi kom．)
2n=22=10m(2sc)+6sm(1sc)+6st，属3B核型；轮叶黄精(P．verticillatum(L．)All．)2n=18=2m+2sm+10st+2t+2T和2n=24=6m+4sm+12st+2T，二者均属3B核型。其中玉竹2n=16，长梗黄精2n=14和2n=22，长苞黄精2n=22，轮叶黄精2n=18的染色体数目和核型均为首次报道。 相似文献
17.
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
18.
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
19.
本文对睡莲科6属6种代表植物的核型进行了研究，并探讨了它的分类学位置。结果如下：莲2n＝16=9sm+4m+3st;王莲2n＝24=8sm+8m+8T，蓝睡莲2n＝28，可配成14对，染色体小，第l号染色体上有2条随体；萍蓬草2n＝34＝18m+16sm；芡实2n=58，可配成29对，染色体小，第l号染色体有2条随体，莼菜2n＝72，可配成36对，染色体按大小可分成大，中、小三个类别。除莲外，其它5种植物的核型为首次报道。莼菜的体细胞染色体数目2n＝72和国外报道的2n＝80不相一致。莲的染色体以及形态学特征和其它睡莲科分类群显著不同，可将其从睡莲科中独立出来，并成立莲科和莲目。原归属于睡莲科的分类群仍组成睡莲目，并分别置于莼菜科和睡莲科。 相似文献
20.
本文报道浙江产菝葜属smilax 7个种的染色体数目和核型。S．nipponica有两种核型，2n＝
26和2n=32，均为3B型，但后一种细胞型的雄株的第一对染色体大小不等，可能为性染色体；S.
riparia 2n=30，属3B型；S．siebodii n＝16；S. china有两个染色体数目，2n＝96 和n＝15；
S. davidiana 2n=32，属3B型，对减数分裂MI的观察发现n＝16；S．glabra 2n=32，亦属3B
型：S. nervo-marginata var．liukiuensis 2n=32，属3C型。讨论了种间在核型上的差异、属的基数、
核型演化趋势和性染色体等问题。 相似文献