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Eight species in eight genera of Liliaceae from Zhejiang were cytotaxonomically studied in this work. The karyotypes of Chinese materials of these species
are mostly reported for the first time. The results are shown as follows (see Table
2-4 for chromosome parameters of them):
1. Disporum sessile D. Don Sixteen chromosomes are counted at metaphase of roottip cells.The Karyotype formula is 2n=16=2lm+2sm+4st+2sm+3sm+ 1sm(SAT)+2st
(Plate 1: 2-3, see Fig. 1:1 for its idiogram). The Karyotype belongs to 3B in
Stebbins’ (1971) karyotype classification, and consists of four pairs of larger chromosomes (1-4) and four pairs of smaller chromosomes (5-8). One SAT-chromosome is situated at the sixth pair. The chromosomes range between 4.85-16.63μm.
The karyotypic constitution is similar to that of Japanese material reported by
Noguchi (1974). Chang and Hsu (1974) reported 2n=14=13st+1sm and 2n=
16=2m + 13st + 1sm for the material from Taiwan under the name of D. shimadai
Hay. (=D. sessile D. Don). Compared with our result of D. sessile, the differences
are obvious.
2. Polygonatum odoratum (Mill.) Druce PMCs diakinesis shows eleven bivalents, n = 11, 5 large and 6 small (Plate 2:5). The meiosis is normal. The majority of reports of this species are 2n=20, with a few 2n=22 and 30 (see Table
1). The materials from southen Siberia and the Far East in USSR are all of 2n=
20. Our result is the same as recorded by Jinno (1966) in the Japanese material
and by Li (1980) from Beijing. Ge (1987) reported 2n=20 in the cultivated individuals of Shandong, China, showing that both 2n=20 and 22 exist in
China.
3. Scilla scilloides (Lindl.) Druce This species has the somatic chromosome
number 2n=18 (Plate 1: 4-6, see Fig. 1:2 for its idiogram), of which two
groups of chromosomes can be recognized, i.e. the 1 st -5 th pairs of large and
the 6 th-9th pairs of small chromosomes. A distinct character of the karyotype is that
two satellites are attached to the short arms of the 1st pair of chromosomes. The degree
of asymmetry is of 3C. The karyotype formula is 2n = 18 = 2sm (SAT) + 6st + 2t+
6m + 2sm. The chromosomes range from 2.02 to 11.93 μm. The Previous counts on
the species are 2n = 16, 18, 26, 34, 35, 36 and 43 (see Table 1). The present investigation confirms Noda’s and Haga’s results. The species is considered to be of
two genomes, namely A(x = 8) and B(x = 9). Our result shows a genome composition of BB, having a pair of large SAT-chromosomes. Chang and Hsu (1974)
reported 2n = 34 from a population of Taiwan, an amphidiploid (AABB), Karyotypes
of other Chinese populations are worth further researches.
4. Tricyrtis macropoda Miq. The chromosome number of somatic cells is
2n= 26, and PMCs MII shows 13 bivalents (n= 13) (Plate 3:1-3, see Fig. 1:3
for its idiogram). The karyotype formula is 2n= 26= 6m + 10sm + 6st + 4st (or
t), which is composed of chromosomes: 4L + 22S in size. The degree of asymmetry
is of 3B. No centromeres of the 12th and 13th pairs of chromosomes were observed
at metaphase, and the chromosomes may be of st or t. Nakamura (1968) reported
2n= 26(4L+ 22S)= 2sm+ 2sm-st+ 14st-sm+ 8st for T. macropoda Miq.
and 2n= 26(4L+ 22S)= 8m+ 2sm+2sm-st+ 2st-sm+ 12st for its ssp.
affinis, both from Japan. It is clear that the major character of their karyotypes,
i. e. 4L + 22S, is consistent with that reported here. Based on the previous and
present reports, all Tricyrtis species studied are remarkably uniform in the basic
karyotype, i. e. 4L + 22S.
5. Allium macrostemon Bunge. The present observation on the root-tip cells
of the species shows 2n = 32 (Plate 3: 4-5, see Fig. 1:4 for its idiogram). The
karyotype formula is 2n (4x)= 32= 26m + 6sm, which belongs to 2B, being of
high symmetry. Except the 6th, 10th and 13th pairs of chromosomes all the
are metacentric. Chromosomes of this species are large, ranging from 5.94 to 18.06
μm. Our result agrees with Kawano’s (1975) report under the name of A. grayi
Regel ( = A. macrostemon, Wang and Tang 1980).
6. Asparagus cochinchinensis (Lour.) Merr. Ten bivalents were observed in
PMCs MI, n=10 (Plate 1: 1). The present result confirms the number of a population of Taiwan recorded by Hsu (1971).
7. Ophiopogon japonicus (L. f.) Ker-Gawl. The species from Mt. Taogui,
Hangzhou, is found to have 2n (2x)=36=22m + 14sm (Plate 2: 1,5, see Fig.
1:5 for its idiogram) which belongs to 2B. The karyotype is composed of 2
medium-sized chromosomes with metacentric centromeres and 34 small chromosomes,
ranging from 1.34 to 4.92 μm. The populations from Mt. Tianzhu and Mt. Yuling,
Zhejiang, are found to be aneuploids at tetraploid level (2n=64-70). It is interesting that Nagamatsu (1971) found the karyotypes of Japanese materials to be 2n=
67 and 68, also showing unsteady 4x karyotypes of this species. In the previous.
reports (see Table 1), the chromosome numbers of this species are mainly 2n = 72,
besides 2n = 36 recorded by Sato (1942) from Japan.
8. Liriope platyphylla Wang et Tang The somatic complement of the species
collected from Mt. Tianzhu, Hangzhou, is 2n = 36 (Plate 2: 3-4, see Fig. 1:6
for its idiogram). The karyotype is 2n(2x) = 36 = 16m + 20sm, belonging to 2B
type. The chromosomes are small except the medium-sized, 1st pair and the
range is from 1.27 to 5.19μm. The material from Mt. Yuling, Zhejiang, is found
to have a variety of chromosome numbers (2n= 60-71), as observed in Ophiopogon
japonicus. Hasegawa (1968) reported the karyotype of 2n = 72 (4x) from Japan
The 2x karyotype is first recorded.
This genus is closely related to Ophiopogon. Based on the Hasegawa’s and present studies, all the species in these two genera are remarkably uniform in karyo-type. Therefore, the taxonomy of the two genera is worth further researches. 相似文献
245.
湾区是世界一流滨海城市的显著标志,生态安全是湾区可持续发展的基本保障。以浙江大湾区为研究区域,基于生态安全评价,采用探索性空间数据分析(ESDA)和地统计分析(GA)方法揭示生态安全的空间相关性与异质性。结合大湾区生态安全空间特征、未来土地利用管理和行政单元的空间分布提出生态保护的差异化管理策略,为大湾区经济社会发展及生态安全保障提供理论支撑。结果表明:(1)生态安全呈现出“北低南高”的分布格局,生态安全区占比71.7%,生态系统整体较安全。(2)生态安全莫兰指数Moran′I值达0.878,“热点”区域占比50.65%,空间正相关性显著。结构性变异在生态安全空间分布中占据主导,宁波、绍兴受结构性变异和随机性变异的综合影响,人口密度、产业布局是影响生态安全空间异质性的主要随机因素。(3)城市发展类型分为优先发展区、综合开发区和生态保护区,其中优先发展区和综合开发区是大湾区经济发展重点区域,生态保护区是保障大湾区生态安全的关键区域,未来城市管理者应对生态环境分区管理,落实差异化管控措施。 相似文献
246.
作为社会复合生态系统的重要理论,城市生态位一直是研究重点,但缺少尺度效应的深入观察。以浙江省为例,首次将地市-区县-乡镇三个尺度进行横向对比,构建了多个尺度适用的城市生态位评价模型。研究通过生态位宽度、生态位重叠度、生态位分异指数和引力模型方法,对825个乡镇,71个区县和11个地市的3个尺度的生态位进行了探讨。研究结果表明:从生态位宽度来看,浙江省的生态位发展不均衡,地市尺度呈现反"C"结构,衢州市和丽水市生态位宽度最小,杭州市、湖州市和宁波市生态位宽度最大。且研究尺度越大、生态位宽度越大,则尺度效应作用越大。从生态位分异程度来看,随着尺度的缩小,分异程度逐渐增大,其中社会生态位分异程度最大。表明尺度效应在发展越不平衡的生态位维度中作用力越大。从生态位重叠度和引力模型来看,生态位宽度小的区域往往面临竞争难以摆脱困境,而生态位宽度大的区域更容易将竞争转化为合作。出现强者越强,弱者越弱的两极分化现象,丽水市和衢州市竞争最激烈而杭州市和宁波市合作更为便利。浙江省各地市可以通过资源再造、协同发展和借力帮扶策略优化区域发展。 相似文献
247.
AbstractThe aim of this study was to quantify the pollution level of toxic elements, their ecological risk and human health hazard in the agricultural soil of Tiantai County, Zhejiang province. A total of 2651 soil samples were collected and analyzed for 13 toxic elements using different analytical techniques. The concentration of Cd, Pb, Hg, Mn, and Zn was higher than the Zhejiang background value in more than 50% of samples. Enrichment factor showed that As, Cd, Hg, Mo, Pb, Se, V, and Zn were anthropogenically loaded and most of the toxic elements showed poor spatial distribution. Nemerow pollution index showed that Chicheng, Shiliang, Pingqiao, Tantou, and Youngxi towns were seriously polluted by toxic elements. Principal component analysis and cluster analysis showed that Co, Cr, Ni, and Cu, whereas, Cd, Pb, and Zn shared the similar source of origin. A large area of Tiantai County experiencing moderate to a serious level of pollution but most of the toxic elements exhibit low risk to the environment except Cd and Hg. Furthermore, children were more prone to health hazards than adults with following order: As?>?Cr?>?Pb?>?Mn. Overall, As and Pb were prominent for pollution, ecological risk, and human health hazards. 相似文献
249.
An analysis of relevant literature and specimen records was conducted, together with field investigations, to examine the species composition, life form, origin, harmfulness and form of introduction of alien invasive plants in Zhejiang Province, China. A total of 166 alien invasive plant species belonging to 106 genera and 46 families were identified. The most common families represented were Asteraceae, Leguminosae and Gramineae, while the most common places of origin were South America, accounting for 3216% of all species, followed by North America (2563%) and Europe (1959%). Twenty three of the species were considered to cause high levels of damage, 60 medium levels of damage, and 83 low or minimal damage. Based on our records, we removed some invasive species from existing lists and added some new ones. Several suggestions for the management of invasive plants in Zhejiang Province are presented. 相似文献
250.
Hannah M. Wilson David J. Varricchio Frankie D. Jackson Xingsheng Jin 《Historical Biology》2014,26(2):173-182
Lack of stratigraphic context for dinosaur eggs inhibits understanding of dinosaur reproductive biology and the taphonomic processes of egg preservation. Past taphonomic work suggests two features, compression ridges (sharp edge of broken eggshell around egg circumference) and deformation asymmetry (proportion of crushed to rounded sides of the egg), as geopetal structures. We examined these features across a large sample of Spheroolithus eggs from the Cretaceous of Zhejiang, China, to test their utility. On 103 isolated eggs, we determined asymmetry ratios (crushed side egg height divided by rounded side egg height) and observed an average asymmetry ratio of 0.71. Additional observations of in situ eggs demonstrate the stratigraphic downside as more rounded and less fractured, the stratigraphic upside as flatter with heavier fracturing and compression ridges as parallel to original bedding plane. Burial-caused fractures on the upper side of the egg allowed sediment to partially fill, subsequently supporting the bottom portion. Examining these features within 16 clutches allowed differentiation of biotic versus taphonomically altered arrangements. Three common clutch arrangements include planar (minimal egg overlap), offset (extreme overlap) and agglomerate (randomly arranged, closely packed). Analysis of egg strike and dip across clutches favours planar clutches as the principal configuration for Spheroolithus clutches. 相似文献