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1.
Morphological characteristics, as well as ultrastructure of pollen grains, chromosome numbers and karyotype analysis have been used to establish a new species of Saussurea from the Qinghai–Tibetan plateau. The new species, Saussurea pseudograminea Y. F. Wang, G. Z. Du et Y. S. Lian is easily distinguished from the similar S. graminea Dunn by having 2–3 capitula, involucre 0.7–1.2 cm in diameter, smaller pollen grains, pollen surface with larger and denser spines, achenes 4.0–5.5 mm long, 32 chromosomes, and a karyotype formula 2n = 2x = 32 = 18m + 10sm + 4st, whereas S. graminea has solitary capitula, involucre 1.2–2.0 cm in diameter, larger pollen grains, pollen surface with smaller and sparser spines, achenes 3–4 mm long, 28 chromosomes and a karyotype formula 2n = 2x = 28 = 6m + 20sm + 2st. The new species is distributed in Dianzhangou, Awanchang, and Gamaliang mountain regions of Maqu county in Gansu province.  相似文献   

2.
3.
Nineteen populations of fifteen species ofGentiana sect.Chondrophyllae from China were observed cytologically.Gentiana alsinoides, G. anisostemon, G. asterocalyx, G. exigua, G. heterostemon, G. intricata, G. praticola, G. pseudoaquatica, G. spathulifolia, andG. subintricata all had the same chromosome number of 2n = 20 (or n = 10), whereasG. piasezkii had 2n = 36,G. squarrosa 2n = 38,G. prattii 2n = 18,G. aristata 2n = 14 (n = 7), andG. heleonastes 2n = 12. All these chromosome numbers are documented here for the first time, except forG. squarrosa, where it is a new number report. The basic numbers of x = 6, x = 7 and x = 19 are new for the section. Karyotype analyses of some species revealed that, except for a few cases, the species examined mainly had metacentric chromosomes. 2n = 20 = 2m(SAT) + 18m was found to be the main type of karyotype for the species with 2n = 20. Chromosomal evolution and its mechanism in this section are also discussed.  相似文献   

4.
以五叶草莓等6种野生草莓为试材,采用常规压片法对其进行了核型分析。结果表明,6种野生草莓的核型公式分别为:五叶草莓2n=2x=14=12m+2sm、黄毛草莓2n=2x=14=8m+6sm、绿色草莓2n=2x=14=10m+2sm+2st、东北草莓2n=2x=14=8m+6sm、森林草莓2n=2x=14=6m+8sm、西南草莓2n=4x=28=16m+12sm,6种野生草莓的核型类型均为"2A"型。供试6种野生草莓的进化顺序可能为:五叶草莓、绿色草莓、东北草莓、黄毛草莓、西南草莓、森林草莓。  相似文献   

5.
采用常规压片技术对分布于横断山区菊科(Compositae)风毛菊属(Saussurea DC.)的6种植物进行染色体数目和核型分析。结果表明:尖苞雪莲(S.polycolea var.acutisquama)核型公式为:2n=2x=32=20m+12sm,属2B型;球花雪莲核(S.globosa)型公式为:2n=2x=34=16m+18sm,属2B型;重齿风毛菊(S.katochaete)核型公式为:2n=2x=32=8m+18sm+6st,属3B型;柱茎风毛菊(S.columnaris)核型公式为:2n=2x=32=24m+8sm,属2B型;禾叶风毛菊(S.graminea)核型公式为:2n=2x=28=8m+18sm+2st,属3B型;长毛风毛菊(S.hieracioides)核型公式为:2n=2x=32=12m+16sm+4st,属2B型。6个种染色体中均未发现随体。其中尖苞雪莲和柱茎风毛菊染色体为首次报道。  相似文献   

6.
Aster saxicola W. P. Li & Z. Li, a new species of Asteraceae from southeastern Guizhou province, China, is described and illustrated based on morphological, molecular and cytological data. Morphological comparisons showed that A. saxicola is similar to A. oliganthus, but can be distinguished from the latter by its purple abaxial surface of the lower and middle cauline leaves, cordate‐ovate basal leaves with strigose hairs, outer three‐seriate phyllaries with purple or purplish apex, 9–14 ray florets and 10–18 disk florets. Phylogenetic analyses based on nrDNA ITS, ETS and plastid trnL–F DNA sequence data support that A. saxicola is a distinct species and belongs to Aster subgen. Aster sect. Ageratoides. Cytological observation shows that the new species is diploid with a karyotype formula 2n = 2x = 18 = 16m + 2sm. The new species should be considered endangered (EN) based on the IUCN red list criteria because of its restricted geographic range.  相似文献   

7.
Karyomorphological comparisons were made of 16 native and cultivated species ofSelaginella in Japan. The somatic chromosome numbers are 2n=16 inS. boninensis; 2n=18 inS. doederleinii, S. helvetica, S. limbata, S. lutchuensis, S. nipponica, S. selaginoides, S. tama-montana, andS. uncinata; 2n=20 inS. biformis, S. involvens, S. moellendorffii, S. remotifolia, andS. tamariscina; 2n=30 inS. rossii; and 2n=32 inS. heterostachys. The interphase nuclei of all species examined are uniformly assigned to the simple chromocenter type. The metaphase karyotype of 2n=16 (x=8) is 8 m (=median centromeric chromosomes)+8(st+t)(=subterminal and terminal). The group of the species having 2n=18 (x=9) is heterogeneous karyomorphologically: The karyotype ofS. nipponica is 2n=18=6 m+12(st+t),S. tama-montana 10 m+2 sm(=submedian)+6(st+t), andS. uncinata 6 m+7 sm+5(st+t). Although the remaining five species have the common karyotype 8 m+4 sm+6(st+t), the values of mean chromosome length are variable. Another group of the specles having 2n=20 (x=10) is homogeneous, since all species have the same karyotypes 8 m+4 sm+8(st+t) and have similar chromosome size. The karyotype of 2n=30 is 12 m+6 sm+12(st+t) and is suggested to be a triploid of x=10, and 2n=32=16m+16(st+t), a tetraploid of x=8. Thus, three kinds of basic chromosome numbers, x=8, 9, 10 are present in JapaneseSelaginella examined, and their karyomorphological relationships are discussed.  相似文献   

8.
In order to gain better knowledge of the number and morphology of chromosomes in Aconitum subgen. Lycoctonum in China, 60 populations belonging to 20 species were cytologically studied. Chromosome numbers of six species (A. apetalum, A. finetianum, A. fletcheranum, A. longecassidatum, A. umbrosum and A. wangyedianense) are here reported for the first time. One species, A. fletcheranum, has 2n = 12, and thus is a diploid based on x = 6, a new base chromosome number for the genus Aconitum. Most of the remaining taxa are diploid (2n = 16) based on x = 8, but five taxa (A. angustius, A. brevicalcaratum var. brevicalcaratum, A. brevicalcaratum var. parviflorum, A.chrysotrichum and A. crassiflorum) are tetraploid with 2n = 32, and one species (A. apetalum) is hexaploid with 2n = 48, the highest ploidy level currently known in the subgenus. Disregarding differences in the presence or absence and number of satellites, the karyotypes of all the 2n = 16 species are quite uniform (2n = 2m + 6sm + 8st), but A. novoluridum, the only species of A. section Alatospermum, has an intrachromosomally less asymmetric karyotype (2n = 2m + 14sm), which lends further support for the primitive condition of its section as inferred from gross‐morphology. Chromosomal variation in the subgenus and the relationships of some of the species are discussed.  相似文献   

9.
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   

10.
Abstract Anaphalis is one of the largest genera of the Asian Gnaphalieae (Asteraceae) and is most diversified on the Qinghai‐Tibet Plateau. The chromosome numbers and karyomorphology of six species from seven populations were investigated for the first time for this region. Chromosome numbers have been newly documented for four species: Anaphalis deserti (2n = 56 = 24 median [m]+ 24 submedian [sm]+ 8 acrocentric [st]); Anaphalis plicata (2n = 56 = 26m + 30sm); Anaphalis xylorhiza (2n = 28 = 2 median point [M]+ 14m + 12sm); and Anaphalis rhododactyla (2n = 56 = 32m + 24sm). Two further counts are in agreement with the previously reported numbers, that is, Anaphalis royleana (2n = 28 = 4M + 6m + 18sm) and Anaphalis margaritacea (2n = 28 = 12m + 16sm). A new polyploid cytotype (2n = 56 = 26m + 30sm) was found in the Zougong population of A. margaritacea. Polyploidy is for the first time reported for Anaphalis, with four out of seven counts being tetraploid. Our cytological results suggest that polyploids might have played an important role in the evolution of Anaphalis on the Qinghai‐Tibet Plateau.  相似文献   

11.
对横断山区两种菊科植物圆齿狗娃花和细叶亚菊进行了染色体数目报道和核型研究,其中圆齿狗娃花为首次报道,2n=18=2x=18m(2SAT);而细叶亚菊的为新的染色体数目,2n=72=8x=56m+16sm,与之前报道的36不同。研究结果发现菊科植物这两个属在横断山及其它地区同时存在二倍体与多倍体。  相似文献   

12.
Carex sinosupina, a new species from Gansu, China is described and illustrated. This species is similar to C. aridula and C. ivanoviae, but differs by having broader leaves, 2.0–3.5 mm wide, perigynia 3–5‐veined abaxially and achenes concave at the middle of one lateral surface. Based on a field survey and SEM (scanning electron microscope) observation of the micromorphology of perigynia and achenes, the morphology and micromorphology of the new species, C. aridula and C. ivanoviae is compared.  相似文献   

13.
为探究凤仙花近缘种植物的细胞学和微形态学方面的亲缘关系,该文选取荔波凤仙花(Impatiens liboensis)及近缘种赤水凤仙花(I.chishuiensis)和管茎凤仙花(I.tubulosa)的根尖和叶表皮为实验材料,采用体细胞染色体常规压片法和叶表皮光学显微镜观察法对凤仙花近缘种植物进行染色体及叶表皮特征研...  相似文献   

14.
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   

15.
采用植物细胞学研究方法对主要采自中国西南地区横断山的6种植物:扁核木(Prinsepia utilis)、小叶金露梅(Potentilla parvifolia)、峨眉繁缕(Stellaria omeiensis)、金铁锁(Psammosilene tunicoides)、山卷耳(Cerastium pusillum)和独尾草(Eremurus chinensis)进行染色体数目和核型研究。研究表明:(1)6个种的核型公式和不对称性如下:扁核木2n=2x=30=1M+20m+9sm,2A;小叶金露梅2n=2x=28=21m+7sm,2B;峨眉繁缕2n=8x=72=1M+71m,1B;金铁锁在同居群下有倍性变化,2n=2x=14=14m,1A和2n=4x=28=28m,1A;山卷耳2n=2x=24=24m(2sat),1A;独尾草2n=2x=14=2m+2sm+8st+2t,4B。(2)讨论了染色体资料在这些物种分类和系统上的意义,支持扁核木为李亚科下的扁核木属;位于委陵菜属木本系的小叶金露梅主要以二倍体和四倍体为主,而草本系的委陵菜属植物多为多倍体。(3)该研究首次报道峨眉繁缕为八倍体,是繁缕属发现的最高倍性的物种;对比金铁锁属与蝇子草属的染色体研究发现,金铁锁属可能是由它们的共同祖先通过非整倍化产生;该研究首次发现山卷耳存在染色体数目2n=24的情况,且有1对随体;独尾草的研究进一步证明该物种可能为二型核。  相似文献   

16.
The present paper reports karyotypes in 4 species and 5 subspecies of Hippophae L. in China. It is found that all of the species and subspecies are diploid, with 2n=24, their complements are made of m and sm chromosomes and of them only H. thibetana has a pair of satellites. All of these karyotypes are symmetrical and primitive. It can be simplied as follows: Hippophae neurocarpa 2n = 2x = 24 = 18m+6sm, H. thibetana 2n = 2x = 24 = 14m (2sat)+ 8sm, H. rhamnoides L. ssp. gyantsensis 2n=2x=24= 18m+ 6sm, H. salicifolia 2n = 2x = 24 = 10m + 14sm, H. rhamnoides L. ssp. sinensis 2n=2x= 24 = 18m + 6sm, H. rhamnoides L. ssp. turkestanica 2n = 2x = 24 = 20m + 4sm; Hi. rhamnoides L. ssp. yunnanensis 2n = 2x = 24 = 14 + 10sm, H. rhamnoides L. ssp. mongolica 2n = 2x = 24 = 16m + 8sm.  相似文献   

17.
以2份角堇与4份大花三色堇自交系为试验材料,采用染色体常规压片方法,观察和分析了它们的细胞染色体数目、相对长度、平均臂比等核型指标,以明确两种植物细胞学特点,为分类以及育种提供理论依据。结果表明:(1)2份角堇自交系染色体数目均为2n=2x=26,染色体基数为x=13,染色体核型公式分别为2n=2x=26=8m+12sm+6st、2n=2x=26=4m+16sm+6st,核型不对称系数为67.20%~70.10%,核型分类均属于3B。(2)4份大花三色堇自交系均为四倍体,其中2份(EYO-1-2-1-4、DSRFY-1-1-2)染色体数目为44,核型公式为2n=4x=44=4m+16sm+6st、2n=4x=44=16m+24sm+4st;2份(G10-1-3-1-4、XXL-YB-1-1-1-1)染色体数目为48,核型公式分别为2n=4x=48=8m+20sm+20st、2n=4x=48=4m+36sm+8st,核型不对称系数为66.74%~71.77%,核型分类属于2B、3B。  相似文献   

18.
中国甘草属植物的核型分析   总被引:15,自引:2,他引:13  
本文对国产甘草属11种,1变种进行了染色体核型分析,2n=2x=16,并对其种间关系进行了讨论。  相似文献   

19.
Two species of Sarcandra and nine of Chloranthus in the Chloranthaceae from China were investigated cytologically. The basic chromosome number of both genera is x=15. In Sarandra the two species studied are diploid, and in Chloranthus seven species are diploid, one tetraploid ( C. fortune;, 2n = 60) and one hexaploid (C. henryi, 2n = 90). Chromosomes are medium-small to small, ranging in length from c . 6.0 μm to 1.O μ m. The katyotype formulas are as follow: S. glabra 2 n= 10m+ 10sm + 8st + 2stc; & hainanensvs 2n = 8m+ 12sm + 8st+2stsat; C. spicatus 2n=12m+8sm + 6st + 4stsat; C. erectus 2n= 12m + 4sm+ 12st + 2stsat; C. serratus 2n=16m + 12sm + 2stsat; C. sessilifolius 2n= 14m + 8sm + 6st+2stsat; C. nervvosus 2n = 8m + 4sm + 6st + 2stsat; C. angustfolius 2n = 20m + 6sm + 2smsat+ 2stsat; C. japonicus 2n = 18m + 8sm + 4stsat; C. fortunei 2n= 48m+4sm + 4st + 4stsat. Karyotype asymmetries are of type 3B in C. erectus and C. nervosus and 2B in the other species. Based on these results, combined with the evidence from comparative morphology, anatomy, palynology and embryology, the relationship between Sarcandra and Chloranthus is discussed.  相似文献   

20.
Santolina ageratifolia Barnades ex Asso is a natural autohexaploid (2n = 6x = 54, 54 + 1B), endemic to Teruel Province, Spain and inhabits a substrate derived from sandstone, red limolite and quartzite. Three chromosome formulae are found: 30m + 12sm + 12st, present in 52% of the descendants (52 metaphase), 24m + 5m‐1sm + 18sm + 6st in 39% of the descendants (39 metaphase) and 24m + 5m‐1sm + 18sm + 6st + 1B in 9% of the descendants (9 metaphase). Chiasmata are mostly interstitial rather than terminal, giving rise to the formation of cruciform structures. The predominance of bivalent configurations in the meiosis and the exclusively bivalent formation in four individuals indicate that this species has a strong tendency towards diploidization. Secondary association of bivalents is observed in the number of 2, 4–6 chromosomes associated, the average being 4.21 ± 1.20 chromosomes. The variation in the chromosomal characteristics suggests chromosome translocation and/or inversions. This species is partially sterile, with a mean pollen fertility of 40.56% and a mean fructification of 34.24%. The frequencies of multivalents and pollen fertility have a strongly significant effect on fructification percentage. Phenotypic variation in habits is not correlated with karyotype characteristics. The cytogeography of the polyploid taxa of the Santolina rosmarinifolia aggregate is discussed. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 797–807.  相似文献   

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