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1.
三峡库区川鄂紫菀(菊科)的形态学和细胞学研究 总被引:5,自引:1,他引:4
对川鄂紫菀(Aster moupinensis (Franch.)Hand.-Mazz.)秭归居群进行了形态学和细胞学研究。形态学研究表明,川鄂紫菀存在居群间分化,但不足以划分变种。发现了一些被以前研究者忽视的重要性状,首次报道了川鄂紫菀的染色体数目和核型。其核型公式为2n=2x=18m。 相似文献
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采用常规压片法,对风毛菊属(Saussurea)5种植物的染色体数目和核型类型进行分析。结果表明:大耳叶风毛菊(S.macrota)核型公式为2n=2x=26=10m+12sm+4st,属2A型;长梗风毛菊(S.dolichopoda)核型公式为2n=2x=26=14m+8sm+4st,属2A型;川陕风毛菊(S.licentiana)核型公式为2n=2x=28=12m+16sm,属2B型;杨叶风毛菊(S.populifolia)核型公式为2n=2x=28=6m+18sm+4st,属2B型;尾叶风毛菊(S.caudata)核型公式为2n=2x=30=14m+14sm+2st,属2A型。这5种风毛菊属植物中,除大耳叶风毛菊染色体数目和核型类型与前人报道的一致外,其余4种植物的染色体数目和核型类型均为首次报道,并在川陕风毛菊中发现1对B染色体。 相似文献
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国产13种鸢尾属植物的核型研究 总被引:4,自引:0,他引:4
对中国产13种鸢尾属Iris植物进行了核型研究。其中中甸鸢尾I.subdichotoma、长葶鸢尾I.delavayi、大锐果鸢尾I.cuniculiformis为中国特有。大锐果鸢尾的染色体数目及核型为首次报道,核型公式为2n=22=4m 6sm 12st(2SAT)。长管鸢尾I.dolichosiphon的核型为首次报道,核型公式为2n=22=4m 12sm 6st。中甸鸢尾的染色体数目为新报道,核型公式为2n=42=20m 22sm。矮紫苞鸢尾I.ruthenicavar.nana的染色体数目为新报道,3个居群的染色体数目均为2n=42,核型公式分别为中甸居群2n=42=30m 12sm(2SAT),丽江甘海子居群2n=42=28m 14sm(2SAT),中甸尼西居群2n=42=36m 6sm(4SAT)。结合以往的细胞学研究结果,显示尼泊尔鸢尾亚属subgen.Nepalensis是一个染色体数目变化较大的类群,其中的中甸鸢尾可能是联系野鸢尾属Pardanthopsis与尼泊尔鸢尾亚属的重要类群。已报道的紫苞鸢尾I.ruthenica染色体数目为2n=84,与我们所研究的变种矮紫苞鸢尾(2n=42)呈倍性关系,通过与相邻类群的分析比较,认为紫苞鸢尾应是由二倍体类群演化而来。还对鸢尾属内染色体数目的变化和核型进化的趋势进行了探讨。 相似文献
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加拿大一枝黄花入侵的细胞学机制 总被引:2,自引:0,他引:2
对入侵植物加拿大一枝黄花(Solidago canadensis L.)和同属土著种一枝黄花(Solidago decurrens Lour.)的染色体计数,并对核型进行了分析.实验结果:加拿大一枝黄花染色体数目为2n=54,核型公式为k(2n)=6x=54=46m 8sm(0-6SAT),核型类型为2A型;一枝黄花染色体数目为2n=18,核型公式为k(2n)=2x=18=16m 2sm(0-2SAT),核型类型为1A型.通过对一枝黄花属(Solidago L.)植物染色体数目的统计分析,判断该属的染色体基数为9.通过对多倍体基因表达导致植物适应进化的讨论得出:多倍体是入侵植物特征,可能是植物入侵的内在机制. 相似文献
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报道了石竹科细蝇子草(Silene gracilicaulis)的染色体数目及核型。染色体数目2n=24,染色体核型公式为2n=2x=24=22m 2sm,属2A核型。 相似文献
8.
报道了水龙骨科丝带蕨属丝带蕨Drymotaenium mivoshianum Makino的染色体数目、核型及生殖方式.结果表明:丝带蕨体细胞的染色体数目为2n=72,核型公式为2n=2x=72=18m 26sm 24st 4T,核型为3B,核型不对称系数As.K=71.24%,丝带蕨的核型为首次报道.丝带蕨是有性生殖二倍体.结合前人的研究结果,讨论了染色体数目、核型在水龙骨科系统学研究中的意义. 相似文献
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百合属4种植物的核型研究 总被引:1,自引:0,他引:1
采用常规压片法对4种百合属植物野百合(L.brow n ii F.E.B row n ex M ie llez.)、兰州百合(L.d av id iiDuchartre var.un icolor(Hoog.)Co Hon.)、川百合(L.d av id ii Duchartre)、湖北百合(L.henry i B aker)进行了核型研究.结果表明,4种百合的染色体数目均为2n=24,核型除川百合为3A外,其余3种均为3B型.核型公式分别为:野百合2n(2x)=24=4m(2SAT) 2sm(2SAT) 4st 14t,兰州百合2n(2x)=24=2m(2SAT) 2sm 10st(2SAT) 8t 2T,川百合2n(2x)=24=2m(2SAT) 2sm 12st(3SAT) 8t,湖北百合2n(2x)=24=4m 18st 2t,其中湖北百合染色体核型为首次报道.通过比较发现,兰州百合与川百合的核型最为相似,亲缘关系相近;核型不对称性为兰州百合>川百合>野百合>湖北百合,以湖北百合的核型较为原始. 相似文献
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五种国产梾木属(广义)植物的核型 总被引:1,自引:0,他引:1
对分布于我国的木来木属CornusL .(广义 ) 4个主要类群的 5种植物进行了细胞学研究。结果表明 ,这 5种植物的染色体数目和核型分别为 :灯台树C .controversaHemsl.2n=2 0 =2m 8sm 1 0st;红瑞木C .albaL .2n =2 2 =8sm 1 2st 2t;毛木来C .walteriWanger.2n =2 2 =8sm 1 4st(0_2SAT) ;山茱萸C .officinalisSeib .etZucc .2n =1 8=8m 1 0sm (0_2SAT) ;四照花 (变种 )C .kousavar.chinensisOsborn 2n =2 2=2sm 6st (0_2SAT) 1 4t 相似文献
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山东10种植物的核型分析 总被引:6,自引:1,他引:5
对山东10 种植物进行了核型分析。茴茴蒜( Ranunculuschinensis Bge-) 染色体数目2n =16 , 核型公式K(2n) = 2x = 16 = 2 M + 2m + 2sm + 10st, “3A”类型; 五脉地椒( Thymusquinquecostatus Celak-) 染色体数目2n= 26 , 核型公式K (2n) = 2x= 26 = 8 M + 18m , “1A”类型; 蛇床( Cnidium monnieri(L-) Cuss-) 染色体数目2n= 20 , 核型公式K (2n) = 2x= 20 = 2M+ 16m + 2sm , “2B”类型; 波斯菊( Cosmos bipinnatus Cav-) 染色体数目2n = 24 , 核型公式K(2n) = 2x = 24 = 16m + 2m (sat) + 6sm , “2A”类型; 白车轴草( Trifolium repens L-) 染色体数目2n= 32 , 核型公式K (2n) = 4x = 32 = 32m , “1A”类型; 铁苋菜( Acalypha australis L-)染色体数目2n = 32 , 核型公式K (2n) = 2x= 32 = 32m , “1B”类型; 地构叶( Speranskia t? 相似文献
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几种重楼的染色体核型研究 总被引:7,自引:1,他引:6
作者对重楼属(Paris)的几个种:球药隔重楼(P.fargesii),毛重楼(P.mairei),花叶重搂(P.marmorata),黑籽重楼(P.thibetica),海南重楼(P.dunniana),巴山重搂(P.bashanensis),以及多叶重楼(P.polyphylla)的两个变种狭叶重楼(var.stenophylla)和华重楼(var.chinensis)的染色体核型进行了研究,发现种间及种内不同居群(population)间的核型都存在不同程度的差别。核型简式为:球药隔重楼K(2n)=2x=10=6m+2t(SAT)+2t+3bs,毛重楼K(2n)=2x=10=6m+4t+1bs,花叶重楼K(2n)=2x=10=6m+4t,黑籽重楼K(2n)=2x=10=2m+4m(SAT)+4t,海南重楼K(2n)=2X=10=6m+2t(SAT)+2t,巴山重楼K(2n)=2x=10=6m+4st,狭叶重楼K(2n)=2x=10=6m+1st+3t,华重楼K(2n)=2x=10=6m+4t。 相似文献
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开普芦荟和木立芦荟的染色体核型分析 总被引:4,自引:0,他引:4
对盆栽开普卢荟(Aloe ferox Miller)和木立卢荟(Aloe arborescens Miller)植物根尖细胞的染色体进行了观察分析。结果表明开普芦荟和木立芦荟的染色体数与已见报导的百合科(Liliaceae)中国芦荟(Alov vera var.chinensis)植物染色体数相同, 2n=14。染色体类型按Levan 方法分类, 没有近端部染色体和随体。开普芦荟和木立芦荟的染色体核型分析结果均为K(2n)=2x=4sm+10st。根据Stebbins 的核型分类标准, 开普芦荟的核型为"4C"型, 而木立芦荟的核型为"3C"型。两种芦荟染色体相对长度组成均为2n=14=6L+2M2+6S。根据核型研究, 可以确定百合科开普芦荟和木立芦荟的染色体基数为X=7。 相似文献
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The genus Lycoris (Amaryllidaceae) consists of about 20 species, all of which are
confined to temperate China, Japan and Korea.
Cytological investigations, including a reexamination of the karyotypes of 14 taxa, measurements of relative nuclear DNA content, and meiotic configuration observations on some specific
forms and interspecific hybrids, have been carried out by the present authors in order to re-evaluate the mode of karyotype evolution and the role of hybridization in the speciation of Lycoris.
These have resulted in a new theory for explaining the karyotype evolution in the genus, which
will be considered elsewhere. The present paper deals with observations on karyotypes of 11
species, 1 variety and 2 artificial hybrids.
Results obtained through karyotype analysis, as shown by the data in Table 1, Plates I-VI
and Figs. 1-2, reveal that: (1) the karyotypes of Lycoris rosea, L. radiata var. pumila, L. sprengeri, L. haywardii, L. caldwellii, L. squamigera and L. radiata are, on the whole, consistent with
those reported by the previous authors[1,2,3,4,5,8,10,12];(2) the I (rodshaped) chromosomes of L.
chinensis and L. longituba are all T’s (telocentric) instead of t’s (acrocentric) or t(Sat)’s;
(3) the three materials of L. aurea of different sources have shown a karyotypic differentiation:
one with 2n=14=8m+6T, and the others with 2n=16=6m+10T: (4) both of the karyotypes
of L. straminea and L. albiflora are 2n=19=3V+6I, inconsistent with 2n=16=6V+10I for the
former and with 2n=17=5V+12I for the latter as reported by Inariyama (1953), Bose and
Flory (1963) and Kurita (1987).
The following aspects are worthwhile discussing:
1. The types of chromosomes.
Karyotype analyses reveal the existence of three major chromosome types in Lycoris: (1)
m (metacentric) chromosomes: (2) t (acrocentric) chromosomes, with short arms, (3) T (telocentric) chromosomes, sometimes with dot-like terminal centromeres. To distinghish t’s from
T’s is of paramount importance for solving the problem of karyotype evolution in Lycoris.
Bose (1963) pointed out that in the species with 2n=22, all I chromosomes were t’s, while in
species with 2n=12-16, all I chromosomes were T’s. Our results of chromosome observations
are consistent with Bose’s remarks. Some authorst[3,6] have probably mistaken the dot-like terminal centromeres of T’s of L. longituba and L. chinensis as the short arms of t’s.
2. The significance of Robertsonian change in karyotype evolution.
Although chromosome numbers and karyotypes are very variable in Lycoris, as shown in
Table 1, the total number of arms of a chromosome complement of any species is always multiples of 11. Hence, it seems likely that Robertsonian changes have taken part in karyotype
alteration, The genus has a series of basic chromosome numbers: 6, 7, 8 and 11. But which is
the most primitive one? It is uncertain whether a successive decrease in chromosome numbers
as a result of Robertsonian fusion or a gradual increase in chromosome numbers brought about
by fission (fragmentation) has been the essential mechanism for karyotype evolution and speciation in Lycoris. These problems are of crucial importance and will be discussed in our
subsequent papers.
3. The origin of polyploids.
As evident from Table 1, there are two levels of ploidy differentiation in Lycoris: (1) di ploids with 2n=22 or the equivalent of 22, (2) triploids with 2n=33 or the equivalent of 33.
The most common way of origination of triploids in plants is the hybridization of diploids with
Tetraploids. But tetraploids have never been found in Lycoris. Thus, it is suggested that the
triploids have originated from the combination of an unreduced gamete of a diploid with a
normal gamete of another diploid.
4. The role of hybridization in speciation.
Results of karyotype analyses show that hybridization has taken an important part in the
speciation of Lycoris. Two types of hybrids have been found: (1) 2n=19= 3V+ 16I, L. straminea, L. albiflora and the two artificial hybrids L. sprengeri×L. chinensis and L. haywardii×
L. chinensis all possess this karyotype. It could be seen from the above chromosome number and
karyotype that this sort of karyotype is exactly half of the total sum of 2n=22I and 2n=16=
6V+10I. It is, therefore, quite evident that taxa possessing this karyotype are all diploid
hybrids of 2n=22 and 2n=16, (2) 2n=27=6V+21I, L. caldwellii and L. squamigera possess
this karyotype. It is reasonable to assume, too, that they are segmental allotriploids and have
arisen from the combination of an unreduced diploid gamete of 2n=16 and a normal haploid
gamete of 2n=22. The origin of the hybrid karyotype 2n=17=5V+12I reported by Inari-
yama (1953) is similar to that of 2n=19, except that one of the parents possesses 2n=12=
10V+2I instead of 2n=16=6V+10I. The origin of the other hybrid karyotype 2n=30=3V+
27I reported by Bose (1963) is similar to that of 2n=27, but the diploid gamete comes from
taxa possessing 2n=22 instead of 2n=16. 相似文献
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