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1.
描述了天南星科Araceae南星族Areae犁头尖属Tiphonium Schoa一新种——保山犁头尖Typhonium baoshanense Z.L.Dao & H.Li,它的叶形和佛焰苞形态与犁头尖T.blumei Nicolson & Sivadasan相似,但附属器下部,雄花序之上,有1-2轮不育雄花(退化雄蕊),雌花序圆锥形,附属器基部截形和佛焰焰苞檐部狭窄而易于区别。同域分布的犁头尖染色体数目为2n=52,本种染色体数目为2n=10,为天南星科的最低染色体基数。  相似文献   

2.
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 gynaecological 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 provinoes 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 subspecies) 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 consideration, 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   

3.
对荞麦属皱叶野荞麦(Fagopyrum crispatifolium J.L.Liu)及其近缘种细柄野荞麦[F.gracilipes (Hemsl.) Dam.et Diels]的染色体核型进行了分析.结果表明,2个野生荞麦的染色体数目均为2n=4x=32,但二者在随体数目、染色体长度等方面差异明显,染色体核型不同,皱叶野荞麦的核型公式为:30m(4SAT)+2sm,细柄野荞麦的核型公式为:32m,属首次报道.  相似文献   

4.
新船叶藓Neodolichomitra robusta(Broth.)Nog.为东亚特有种,其配子体茎尖细胞有丝分裂中期的染色体数为n=5,核型为K(n)=5=4V+1J或K(n)=5=4 m+1 sm,在核型分类中属于“2A”型。该研究结果为国内外首次报道。  相似文献   

5.
Mn(II) ions were used for probing the surfaces of porcine LDL1, LDL2 and HDL. From the intensity of the e.p.r. lines corresponding to the unbound Mn(II) the percentage of the ions bound to the lipoprotein surface is determined. From the titration curves the binding parameters, dissociation constant. Kd, and the number of binding sites, n, in all the three lipoproteins studied have been derived. There are at least two types of binding sites in each lipoprotein class. The ”weak’ binding sites are charaterized by approximately the same value of Kd (≈ 6.2 × 10?3 mol l?1 and different values for n (n = 114 for LDL1, n = 135 for LDL2 and n = 28 for HDL). Similarly, for the ”strong’ binding sites Kd ≈ 1.6 × 10?4 mol l?1 and the number of binding sites is 15, 20 and 5 for LDL1, LDL2 and HDL respectively. It is concluded that the binding sites are probably located in the protein part of the lipoproteins and that they are mainly associated with the negatively charged amino acids.  相似文献   

6.
黄牡丹七个居群的细胞学研究   总被引:11,自引:3,他引:8  
本文对产于云南中部至西北部的黄牡丹Paeonia delavoyivar. lutea 7个居群进行了细胞学研究。7个居群的染色体数目均为2n=10,核型都属“2A”型。在7个居群中,第二、第三和第五对染色体相对稳定,而第一和第四对染色体存在着变异。第四对染色体的变异较大,存在着结构上的杂合性,其杂合性不仅表现在其长度上,而且表现在臂比值上。这种结构上的杂合性可能与其形态变异有着相关性。在居群之间,随体和次缢痕的数目及位置也有着差异。  相似文献   

7.
The present paper reports the chromosome numbers and karyotypes of five species in Polygonatum from Anhui of China. The materials used in this work are listed in Table 1, Photomicrographs of somatic metaphase and karyograms of the five species of Polygonatum in Plate 1, 2, 3, the idiograms in Fig. 1-11 and a comparison of the karyotype of them is provided in Table 2. The results are shown as follows: 1. Polygonatum odoratum (Mill.)Druce Two materials were examined. One from Mt. Huangshan, Anhui, has 2n= 16 = 10m (3sc)+ 6sm (Plate 1 :A, B). The idiogram is shown in Fig. 1. The chromosomes range in length from 2.85 to 8.85 μm, with the total length 48.63μm and the ratio of the longest to the shortest 3.11, The karyotype belong to Stebbins’(1971) 2B. The two chromosomes of the first pair have arm ratios 1.01 and 1.29 respectively, and The first pair has one chromosome carrying a satellite attached to the short arm, showing heterozyosity .The chromosome num ber of 2n= 16 in P. odoratum and its karyotype are reported for the first time. The other from Langyashan, Chu - xian, Anhui, is found to have 2n = 18 = 10m (Isc)+2sm+6st(2sc) (Plate 1: C, D). The idiogram is shown in Fig. 2. The chromosomes range in length from 2.43 to 8.29μm, with the total length 46.67µm and the ratio of the longest to the shortest 3.41. The karyotype is also of 2B. In a somatic chromosome complement the 2nd pair have one chromosome carrying a satellite attached to the long arm, showing heterozygosity. 2. Polygonatum filipes Merr. Two materials were examined. One from the Huangshan, Anhui is found to have two cytotypes: 2n= 16 and 2n=22. This paper reports one of them. The karyotype formula is 2n=22=8m+8sm(2sc)+6st(Plate 3: Q, R). The idiogram is shown in Fig. 3. The chromosomes range in length from 2.55- 5.85μm, with the total length 45.01 μm and the ratio of the longest to the shortest 2.29. The karyotype belongs to 3B. The other material from the Fangchang, Anhui, is shown to have four cytitypes: 2n= 14, 2n= 16, 2n=20 (Plate 3: W) and 2n=22. This paper reports two of them. Type I: the karytype formula is 2n=14=10m+4sm (Plate 3: S, T). The idiogram is shown in Fig. 5. The chromosomes range in length from 2.59 to 7.61μm, the total length 37.44μm and the ratio of the longest to the shortest is 2.94. the karyotype belongs to 2B. Type II :The karyotype formula is 2n=16=8m+4sm+4st (Plate 3: U, V). The idiogram is shown in Fig. 4. The chromosomes range in length from 2.65 to 8.21 μm, the total length 46.01 μm and the ratio of the longest to the shortest 3.10. The karyotype belongs to 2B. The chromosome numbers of 2n=20, 2n= 14 and 2n=22, and karyotype of 2n= 14 and 2n=22 in P. filipes are reported for the first time. 3. Polygonatum cytonema Hua Two materials were examined. One from the Langyashan, Chuxian, anhui, is found to have 2n = 18 = 8m (2sc)+ 6sm+ 4st (Plate 2: K, L). The idiogram is shown in Fig. 7. The chromosomes range in length from 3.41 to 9.21 μm, the total length 56.34μm and the ratio of the longest to the shortest is 2.70. The karyotype belongs to 2B. The other material from the Huangshan, Anhui, has two cytotypes: 2n=20 and 2n= 22. Type I: The karyotype formula is 2n= 20= 8m+ 6sm+ 6st (Plate 2: M, N). The idiogram is shown in Fig. 8. The chromosomes range in length from 1.75 to 5.03μm, with the total length 32. 91μm and the ratio of the longest to the shortest 2. 87. The karyotype is also of 2B. Type II: The karyotype formula is 2n=22=6m+ 8sm+4st+ 4t (Plate 2: O, P ). The idiogram is Shown in Fig. 10. The chromosomes range in length from 1.75 to 4.95 μm, with total length 35.05μm and the ratio of the longest to the shortest 2.83. The karyotype brlongs to 3B. 4. Polygonatum desoulayi kom. The material from Xuancheng, Anhui, is found to have karyotype 2n = 22 = 10m (2sc) + 6sm (lsc) + 6st ( Plate 2. I, J). The idiogram is shown in Fig. 6. The chromosomes range in length from 1.86 to 5.61μm, with the total length 41.98μm and the ratio of the longest to the shortest 3.02. The karyotype is also of 3B. The first pair has one chromosome carrying a satellite attached to the long arm, showing heterozygosity. The chromosome number and karyotype of Chinese material are reported for the first time. 5. Polygonatum verticillatum (L.) All. The material from the Langyashan, Chuxian, Anhui is found to have two cytotypes. Type 1: the karyotype formula is 2n = 18 = 2m+ 2sm+ 10st+ 2t+ 2T (Plate 1: G, H). The idiogram is shown in Fig.9. The chromosomes range in length from 1.86 to 4.03μm, with total length 28.28μm and the ratio of the longest to the shortest 2.17. The karyotype classification belongs to 3B. Type II: The karyotype formula is 2n=24=6m+4sm+12st+2T (Plate 1: E, F). The idiogram is shown in Fig. II. The chromosomes range in length from 2.01 to 5.03μm, with total length 41.36μm and the ratio of longest to shortest 2.50. The karyotype is also of 3B. The chromosome numbers and karyotypes of Chinese material are reported for the first time.  相似文献   

8.
Glycosmis longipetala F. J. Mou & D. X. Zhang is described from Guangxi and Yunnan provinces in southwestern China. The new species is similar to G. Cochinchinensis (Lour.) Pierre ex Engl. By its simple leaves, but distinguishable in having long-elliptic or oblanceolate (vs. Ovate) leaves, long-ovoid to ellipsoid (vs. Ovoid) floral buds, ovaries with many tubercles (vs. Smooth) and glabrous (vs. Pubescent) stamens. The pollen grains of the new species are 23.9±3.09 (20.8-27.0)×22.0±1.80 (20.4-24.4) μm in size with reticulate exine ornamentation in equatorial area and foveolate in polar area. The chromosome number of the new species is 2n=72.  相似文献   

9.
粗山羊草(Aegilops tauschii(Coss.)Schmal.,DD,2n=14)是普通小麦(Triticumaestivum L.,AABBDD,2n=42)D染色体组的供体。粗山羊草中含有丰富的抗病,抗虫,抗逆,优质等优异基因,因此粗山羊草是改良普通小麦的宝贵遗传资源。但有关普通小麦与粗山羊草杂交的研究报道较少。本文试图通过对普通小麦与粗山羊草杂种后代的细胞遗传学和染色体分离规律的研究,探讨转移粗山羊草优异基因的方法和途径。  相似文献   

10.
The present paper reports the chromosome numbers and karyotypes of eight species of Sect. Rhiziridium in Allium (Liaceae). The materials were all collected from their natural populations in east Inner Mongolia, China. The karyotype analysis is made on the basis of Li et al. (1985).The results are as follows (for chromosomes parameters, voucher specimens and localities, see Table 1 and Plate 1--2 the idiograms of the eight species in Fig. 1): (1) Auium leucocephalum Turcz. The somatic chromosome number and karyotype of this species is 2n=16=12m=2sm+2st (2SAT), in Stebbinsl(1971) kayotype classification, which belongs to 2A (Plate 1: 1; Fig. 1: 1). The range of chromosome relative length varies between 8.90--15.55%. Two small satellites are attached to the short arms of the 8th pair of chromosomes. (2) A. strictum Schrader has 2n (4x) =32=16m+4sm+12st, belonging to 2B (Plate 1: 2 & Fig. 1: 2). Satellites were not observed., and the range of chromosome relative length is between 3. 67-11.00%. (3) A. ramosum L. 2n=16=14m+ 2st (2SAT), belonging to 2A (Plate 1: 3 & Fig. 1: 3), Two small satellies are attached to the short arms of the 8th pair of chromosomes. The range of chromosome relative length is between 9.17-16.39%. The chromosome number and karyotype of this species are in accordancewith those reported by Li et al. (1982) with the material from Jinshan, Beijing. (4) A. bidentatum Fisch. ex Prokh. 2n (4x) =32=24m+4sm+4T, belonging to 2B (Plate 1: 4 & Fig. 1: 4). Satellites were not observed. A small median B-chromosome was found in root-tip cells of the population growing in sandy soil, and it is the first discovery (Plate 2: 9). The species has terminal chromosomes, which are seldom seen in Sect. Rhiziridium. The range of chromosome relative length is between 3.32—9.06%. (5) A. tenuissimu L. 2n=16= 10m+4sm+2st(2SAT), belonging to 2B(Plate 1:5 & Fig. 1:5). Two large satellites are attached to the short arms of the 8th pair of chromosome. The range of chromosome relative length is between 8.27--17.56%. (6)A. anisopodium Ledeb. 2n = 16 = l2m +2sm + 2st (2SAT), belonging to 2A (Plate 2:7 & Fig. 1: 7). Two large satellites are attached to the short arms of the 8th pair of chromosomes. In somatic cells of some plants of this species, a small submedian B-chromosome was found (Plate 2: 10, 11). The range of chromosome relative length is between 8.05-17.08 %. (7) A. anisopodium Ledeb. var. zimmermannianum (Gilg) Wang et Tang 2n (4x)=32=24m+4sm+4st( 4SAT), belonging to 2A (Plate 1: 6 & Fig. 1: 6). Four large satellites are attached to the short arms of the 15 and 16th pairs of chromosomes. The range of chromosome relative length is between 4.45--8.35%. This variety is similar to A. anisopodium Ledeb. in morphological characters, and their karyotype formulas are also very similar. The present authors consider that the variety is an allotetraploid derived from A. anisopodium Ledeb. (8) A. condensatum Turcz. 2n=16=14m+2st (2SAT), belonging to 2B (Plate 2:8 & Fig. 1:8). Two. small satellites are attached to the short arms of the 6th pair of chromosomes. In a few individuals of this species median (M) B-chromosome was discovered, and the number is stable (Plate 2: 12). The range of chromosome relative length is between 7.64--17.07%. In short, the chromosome numbers of the species studied in the present work are found to be 2n=16 or 32, and the karyotypes belong to 2A or 2B, highly symmetrical. The karyotypes of Chinese materials of these species are mostly reported for the first time. Threespecies have B-chromosomes.  相似文献   

11.
对苞萱草的核型研究   总被引:2,自引:0,他引:2  
孔红   《广西植物》1998,18(4):368-370
本文报道用光学显微镜观察对苞萱草Hemerocalisfulva(L.)L.var.op positibracteataH.KongetC.J.Wang,var.nov.的染色体,按全国第一次植物染色体学术讨论会建议的标准进行核型分析。研究结果表明,对苞萱草体细胞染色体数目2n=22,核型公式k(2n)=22=12m+6sm+4st,属于Stebbins核型的2B型。甘肃萱草属植物的核型可分为两大类群,对苞萱草的核型属于第二类群。对苞萱草与萱草H.fulva(L.)L.的核型较接近,为新变种的确立提供了细胞学方面的依据。  相似文献   

12.
A karyotypic analysis of Lycoris longituba Y. Hsu et Fan was carried out. The voucher specimen, Z. G. Mao 10501, is preserved in the Herbarium of Hangchow Botanical Garden. The chromosome number in root tip cells of the species is found for the first time to be 16, among which 6 are large, V-shaped with submedian primary constrictions, and the other 10 are short, rod-shaped with terminal primary constrictions. Photomicrograph of the chromosome complement and idiogram are given in Fig. 1-3 respectively. The karyotype formula of the species is therefore 2n=16=6m+6t+4t (SAT) in the light of the chromosomal terminology defined by Levan and al.[5] Based on the view stressed by Jones[3] and Brandham[4], successive fusion of the chromosomes should be taken as the essential mechanism for karyotype evolution and speciation in Lycoris. Reciprocal translocation, with the loss of one of the centromeres, might be the mechanism of origin for a V chromosome. It is, then, suggested that the decrease in chromosome number as a result of fusion of the rods with terminal or subterminal primaryconstrictions has taken place in the speciation of L. longituba.  相似文献   

13.
Genetic variability in the federally endangered pitcher plant Sarracenia rubra ssp. alabamensis was assessed in eight Alabama populations using starch gel electrophoresis. Ten populations of the more widespread Sarracenia rubra ssp. rubra were sampled in the southeastern United States for comparison. Fifteen allozyme loci representing 13 enzyme systems were scored for each species. In contrast to S. oreophila and S. jonesii, two previously analyzed endangered pitcher plants, genetic diversity was high for both S. rubra subspecies. Within ssp. alabamensis the percentage polymorphic loci (Ps) was 80.0, the mean number of alleles per polymorphic locus was (APs) = 2.58, and expected heterozygosity (Hes) was 0.209. Genetic diversity was slightly lower for ssp. rubra (Ps = 73.3, APs = 2.91, and Hes = 0.177). The proportion of total genetic diversity found among populations was fairly low for both species (GST = 0.09 for ssp. alabamensis and 0.14 for ssp. rubra). Little genetic divergence has occurred between the two subspecies as indicated by the lack of diagnostic alleles, the proportion of total genetic diversity between taxa (GST = 0.09), and the genetic identity estimate (I = 0.90). The relatively high genetic diversity found for ssp. alabamensis indicates that the maintenance of its evolutionary potential is possible if population sizes are maintained or increased. Low levels of genetic diversity found within small Georgia ssp. rubra populations indicate that genetic erosion may increase extinction risks for these populations.  相似文献   

14.
The shape of the fitness function relating the decline in fitness with coefficient of inbreeding (f) can provide evidence concerning the genetic basis of inbreeding depression, but few studies have examined inbreeding depression across a range of f using noncultivated species. Futhermore, studies have rarely examined the effects of inbreeding depression in the maternal parent on offspring fitness. To estimate the shape of the fitness function, we examined the relationship between f and fitness across a range off from 0.000 to 0.875 for components of both male and female fitness in Cucurbita pepo ssp. texana. Each measure of female fitness declined with f, including pistillate flower number, fruit number, seed number per fruit, seed mass per fruit, and percentage seed germination. Several aspects of male fitness also declined with f, including staminate flower number, pollen number per flower, and the number of days of flowering, although cumulative inbreeding depression was less severe for male (0.34) than for female function (0.39). Fitness tended to decline linearly with f between f = 0.00 and f = 0.75 for most traits and across cumulative lifetime fitness (mean = 0.66), suggesting that individual genes causing inbreeding depression are additive and the result of many alleles of small effect. However, most traits also showed a small reduction in inbreeding depression between f = 0.75 and f = 0.875, and evidence of purging or diminishing epistasis was found for in vitro pollen-tube growth rate. To examine inbreeding depression as a maternal effect, we performed outcross pollinations on f = 0.0 and f = 0.5 mothers and found that depression due to maternal inbreeding was 0.07, compared to 0.10 for offspring produced through one generation of selfing. In at least some families, maternal inbreeding reduced fruit number, seed number and mass, staminate flower number, pollen diameter, and pollen-tube growth rate. Collectively these results suggest that, while the fitness function appears to be largely linear for most traits, maternal effects may compound the effects of inbreeding depression in multigenerational studies, though this may be partially offset by purging or diminishing epistasis.  相似文献   

15.
Fu Y  Dane F 《Annals of botany》2003,92(2):223-230
Allozyme genetic variation in 12 populations of the endangered Castanea pumila var. pumila (Allegheny chinkapin), sampled across the natural range of the species in the United States, was evaluated using 11 loci from seven enzyme systems. At the species level, the percentage of polymorphic loci (Ps) was 72.7 %, the mean number of alleles per locus (As) was 1.9, the mean number of alleles per polymorphic locus (APs) was 2.3, the effective number of alleles per locus (Aes) was 1.5 and the genetic diversity (Hes) was 0.296. At the population level, Pp = 49.2 %, Ap = 1.5, Aep = 1.4, APp = 2.1 and Hep = 0.21. Most of the allozyme variation (70 %) in C. pumila var. pumila occurred within populations. Wright's gene flow rate [Nm(W)] was as low as 0.57. Population differentiation along the species range was not detected. Populations of C. pumila var. pumila in Florida had the most variable levels of genetic diversity, but populations in Virginia and Mississippi also showed high levels. Based on the results of this study, conservation management strategies are discussed.  相似文献   

16.
王臣  路芳  关旸  张贵一 《植物研究》2001,21(2):215-221,T001,T002,T003
报道东北蒿属艾组12种植物的染色体数及核型资料,结果如下:宽叶山蒿(Artemisia stolonifera (Maixm.)Komar.)2n=4x=36=28m 4sm(4SAT) 4st(4SAT);野艾蒿(A.lavandulaefolia DC)2n=2x=50=40m 4sm 6st(6SAT); 矮蒿(A.lancea Van.)2n=2x=16=10m 4sm 2st;蒙古蒿(A.mongolica (fisch.ex Bess.)Nakai]2n=2x=16=14m 2st;红足蒿(A.rubripes Nakai)2n=2x=16=14m 2st;歧茎蒿(A.igniaria Maixm.)2n=2x=34=28m 2sm 4st(4SAT);柳叶蒿(A.integrifolia Linn.)2n=4x=36=20m 12sm 4st;线叶蒿(A.subula 4st(4SAT);柳叶蒿(A.integrifolia Linn.)2n=4x=36=20m 12sm 4st;线叶蒿(A.subulata Nakai)2n=2x=16=14m 2st;高岭蒿(A.brachyphylla Kitam.)2n=2x=18=14m 2sm 2st;林文稿[A.uiridissima(Komar.)Pamp.]2n=2x=18=14m 4sm;奄癌(A.keiskeana Miq.)2n=2x=18=16m 2sm;阴地蒿(A.sylvatica Maxim.)2n=2x=16=14m 2sm,核型对称性野艾蒿(A.lavandulaefolia)为2B型,其余均为2A型,依据核型资料对个别种的演化 分类进行了初步探讨。  相似文献   

17.
应用组织培养技术对川贝母(Fritillaria cirrhosaD.Don)进行多倍体诱导。结果表明:组织培养条件下,将川贝母愈伤口组织在培养基中添加一定浓度的和为水仙素处理一段时间,或者经一定浓度的和为水仙素浸泡一段时间后再培养,均可诱发川贝母多倍体的产生,但以前者效果较好。在秋水仙素浓度为1000mg/L。处理5d的条件下,诱导率最高达70%。细胞染色体鉴定结果为:四倍体染色体数为2n=4x=48,而二倍体的染色体数为2n=2x=24。  相似文献   

18.
三裂叶豚草和普通豚草的染色体核型研究   总被引:4,自引:0,他引:4  
祖元刚  沙伟 《植物研究》1999,19(1):48-52
本文对产自中国东北地区和南昌市的三裂叶豚草和普通豚草进行了染色体观察与核型分析,两种豚草的染色体数目分别为2n=24和2n=36,与前人的报导一致,染色体核型未见到报导。  相似文献   

19.
王恒昌  孟爱平  李建强  王勇  陶勇 《广西植物》2004,24(5):422-i008
对长江三峡库区特有濒危植物丰都车前(Plantago erosa var.fengdouensis)进行了细胞学研究,包括有丝分裂和减数分裂两方面.丰都车前可能为一异源四倍体。其核型公式为2n=4x=24=12m(2sat)+12sm(2sat),属于2A型.极端的环境压力尤其是季节性的水淹可能是此四倍体物种形成的主要原因。对同属内的另一物种车前(P.asiatica)进行了比较观察,确证车前为六倍体。该实验为丰都车前的保育遗传学研究提供了细胞学证据。  相似文献   

20.
中国芦荟染色体核型分析   总被引:8,自引:1,他引:7  
以中国芦荟为试验材料,按常规染色体压片法,观察中期分裂相并进行显微摄影。染色体类型按Levan方法分类,其核型为K(2n)=6st+8sm。  相似文献   

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