国产四种绢藓属植物的核型研究

国产苔藓植物的核型研究,目前尚未见到任何报道。本文对中国产绢藓属4种植物进行了核型研究。观察了配子体有丝分裂中期的染色体和异染色体。4种植物的染色体数目均为11。钝叶绢藓(E．obtusatus),密叶绢藓(E．compressus),东亚绢藓(E．okamurae),的核型公式为K(n)=11＝2V(H)+2J+6(4v+2i)+m(h),陕西绢藓(E.giraldii)为K(n)＝11＝2V(H)+V+2J+5(3v+2i)+m(h)．4种植物的核型均为首次报道。     

Cytological Observation of 4 Chinese Moss Species

In this paper the chromosome countings of 4 moss species are reported for the first time in China. The materials used for investigation were taken from immature capsules. Meiosis in spore mother cells and also mitosis in the case of Plagiomnium cuspidatum were observed, with the result: Didymodon constrictus, n=14, Entodon schensianus, n=10+lm; Plagiomnium cuspidatum, n=6, Cratoncuron jilicinum, n=10. The chromosome numbers ofthe former two species are reported for the first time.     

Cytology of Dicranostigma and Glaucium (Papaveraceae) from China

The cytological studies were performed in 11 populations of Dicranostigma lactucoides, Dleptopodum, and Derectum and one population for Galucium fimbrilligerum. All three species of Dicranostigma possessed chromosome number 2n=2x=12, of which chromosome numbers for Derectum and Dlactucoides are reported here for the first time. Glaucium fimbrilligerum presented the number 2n=2x=10, which is not only new to the genus but also the known lowest number for Glaucium.     

中国水韭属植物的染色体数目及其分类学意义

利用细胞学方法观察统计了中国4种水韭属Isoestes植物的染色体数目。结果发现4个种的染色体基数均为x=11,其中高寒水韭I．hypsophila Hand.-Mazz．为2n=22,为首次报道;台湾水韭 I．taiwanensis DeVol为2n=22;中华水韭I．sinensis Palmer 2n=44为四倍体;而产于云南贵州一带并一直被当作是宽叶水韭I．japonica A．Br．的水韭属植物2n=22,与文献报道的宽叶水韭(2n=66,67,77,87,88,89)完全不同,应重新予以认识和评价。依据本文和其他相关的研究结果,对东亚水韭属植物进行了分类处理。     

A cytological study ofPelargonium sect.Eumorpha (Geraniaceae)

The chromosome numbers of seven species ofPelargonium sect.Eumorpha have been determined from material of known wild origin, and karyotypic comparisons have been made. Within the section there is variation in basic chromosome number (x = 4, 8, 9, 11), variation in chromosome size, and two species have polyploid races. The three species with chromosome numbers based on x = 11 have the smallest chromosomes (1.0–1.5 µm); chromosomes are larger (1.0–3.0 µm) in the other species.P. elongatum has the lowest chromosome number in the genus (2n = 8).P. alchemilloides is exceptional in that it has four cytotypes, 2n = 16, 18, 34 and 36, and the form with 2n = 36 has large chromosomes (2.0–5.0 µm). Evidence from a synthesized hybrid suggests thatP. alchemilloides with 2n = 16 may be of polyploid origin. The three species based on x = 11 appear to be more closely related to species from other sections ofPelargonium that have the same basic chromosome number and small chromosome size, rather than to other species of sect.Eumorpha.     

从细胞学资料看金松属的系统位置

本文比较了金松(属)和杉科其他各属植物的核型,它的染色体数目(2n=20)和基数(x=10)较低,其核型最为对称。细胞学资料支持金松属从杉科分出另立金松科SciadopityaceaeHayata,它的系统位置则很可能比杉科来得原始。这也得到古植物学的支持。     

三种小花蝽核型研究(半翅目:花蝽科)

本文利用姬姆萨染色压片法对花蝽科小花蝽属3个种:荷氏小花蝽Orius horvathi(Reuter),微小花蝽Oriusminutus Linnaeus和东亚小花蝽Orius sauteri(Poppius)的核型做了研究,结果表明3种小花蝽单倍体均具有12条染色体,X-Y性别决定机制,但3种核型行为具特定的差异,其核型特征可用于种间分类。     

Karyotypes of eight species of Euphorbia L. (Euphorbiaceae) from China

In this paper, eight species of the genus Euphorbia L. were cytologically studied. The three species of the subgenus Chamaesyce Raf., E. hirta, E. humifusa and E. hypericifolia, had chromosome numbers of 2n = 18, 22 and 32, with their basic chromosome numbers being x = 9, 11 and 8 respectively. The two species of the subgenus Poinsettia (Grah.) House. E. dentata, with 2n=28, a tetraploid, and E. cyathophora, with 2n= 56, a octoploid, had both the basic chromosome number of x= 7. The three species of the subgenus Esula Pers, E. lathyris, E. helioscopia and E. hylonoma, had chromosome number of 2n= 20, 42 and 20, with their basic numbers being x= 10, 7 and 10 respectively. The basic chromosome number of x = 8 is new for E. hypericifolia, in which x = 7 was previously reported. This indicates that this species had both ploidy(2n = 4x = 28, 8x = 56) and dysploidy(x = 7, 8) variations. In E. dentata, there occurred also ploidy variation (2n = 2x, 4x and 8x). A tetraploid cytotype of E. esula was found in China, its diploid cytotype and hexaploid cytotype being previously reported in North America, the Iberian Peninsula and some other European areas. Based on our results and those previously reported, we support the viewpoint that x＝10 may be the original basic chromosome number of Euphorbiaand discuss the role of polyploidy and dysploidy in the speciation and evolution of this genus     

Chromosome banding in three species of <Emphasis Type="Italic">Hypsiboas</Emphasis> (Hylidae,Hylinae), with special reference to a new case of B-chromosome in anuran frogs and to the reduction of the diploid number of 2n = 24 to 2n = 22 in the genus

The chromosomes of hylids Hypsiboas albopunctatus, H. raniceps, and H. crepitans from Brazil were analyzed with standard and differential staining techniques. The former species presented 2n = 22 and 2n = 23 karyotypes, the odd diploid number is due to the presence of an extra element interpreted as B chromosome. Although morphologically very similar to the small-sized chromosomes of the A complement, the B was promptly recognized, even under standard staining, on the basis of some characteristics that are usually attributed to this particular class of chromosomes. The two other species have 2n = 24, which is the chromosome number usually found in the species of Hypsiboas karyotyped so far. This means that 2n = 22 is a deviant diploid number, resulted from a structural rearrangement, altering the chromosome number of 2n = 24 to 2n = 22. Based on new chromosome data, some possibilities were evaluated for the origin of B chromosome in Hypsiboas albopunctatus, as well as the karyotypic evolution in the genus, leading to the reduction in the diploid number of 2n = 24 to 2n = 22.     

A cytotaxonomic study of some Australian species of Drosera L. (Droseraceae)

KONDO, K. & LAVARACK, P. S., 1984. A cytotaxonomic study of some Australian species of Drosera L. (Droseraceae). Karyomorphological comparisons of 15 species of Australian Drosera are presented along with 11 new chromosome counts. In Australia the genus forms an extensive aneuploid series. The species which have chromosome numbers from n =10 to n = 19 show large chromosomes, while those which have chromosome numbers more than 20 show small chromosomes. Drosera paleacca shows the lowest chromosome number in the genus, 2 n = 10, with 10 large chromosomes, indicating a new basic number, x = 5. The non-staining gap between the chromatids of each chromosome is rather wide and their centromeric region is not seen throughout prophase, prometaphase, and metaphase. The C-banding and silver-staining analyses in Drosera petiolaris chromosomes suggest that Drosera chromosomes could have diffuse centromeres and simplified C-segments. Some taxonomic implications are considered, notably the possible removal of Drosera banksii from Drosera section Ergaleium to Drosera section Lasiocephala and the reduction to synonymy of Drosera section Prolifera .     

Chromosome numbers, nuclear DNA content, and polyploidy in Consolea (Cactaceae), an endemic cactus of the Caribbean Islands

Polyploidy, an important mechanism of plant evolution, was investigated in Consolea, an endemic Caribbean opuntioid genus represented by nine subdioecious species with very narrow distributions, including species classified as rare or threatened. Standard chromosome counting and flow cytometric analyses were used to determine chromosome numbers and ploidy of each taxon. Compared to the base number (x = 11), the mitotic and meiotic counts indicated that there are seven hexaploid (2n = 66) and two octoploid species (2n = 88); no diploids were found. Histograms of intact nuclei confirmed that all species are polyploid, with C-DNA values ranging from 4.88-9.50 pg. The variation of DNA content was significantly higher for the octoploids than for the hexaploids. Male and female sexual morphs had similar DNA content, suggesting that there are no sex chromosomes. Cytomixis between cells and microsporocytes with no chromatin were observed. This provides a mechanism whereby gametes with variable chromosome numbers are produced, influencing reproduction and promoting speciation. In conclusion, C-DNA content and chromosome number separated Consolea species into two groups, which may correspond to two phylogenetic lineages or indicate that polyploidization occurred independently, with comparable effects on C-DNA content.     

二十五种中国角蝉的染色体(英文)

本文记载了中国25种角蝉的染色体,研究表明染色体的数目、大小及其在减数分裂过程中的行为具有种或属一级的分类特征。该科昆虫染色体的数目变异在n＝5到12之间,众数为n＝11,另外,n＝10的类型也较为普遍。绝大多数种类的性别决定机制为XO型,仅个别种类具有新XY性染色体系统。     

中国西部高山8种龙胆属植物的染色体数目

本文报道了我国西部高山上的８种龙胆属植物的染色体数目。其中宽筒龙胆的染色体数目为２ｎ＝４８,提钟龙胆的染色体数目为２ｎ＝２６,小齿龙胆和四数龙胆的染色体数目为２ｎ＝２４,南山龙胆的染色体数目为２ｎ＝１８,上述５种植物的染色体数目为首次报道,其余蓝玉簪龙胆的染色体数目为２ｎ＝２４,线叶龙胆的染色体数目为２ｎ＝４８,钻叶龙胆的染色体数目为２ｎ＝１８。     

Comparative cytological studies of mitotic and male meiotic karyotype of Ascaridia dissimilis (Vigueras, 1931) and Ascaridia galli (Schrank, 1788).

Gametogony and spermatogenesis of A. dissimilis and A. galli were studied. It was found that the chromosome number of A. dissimilis is 2n = 10 for female specimens and 2n = 9 for male ones. The chromosome number of A. galli is also 2n = 10 for female specimens and 2n = 9 for males ones. Comparison of the relative length of chromosomes in the chromosome set, expressed in percentages, shows nearly equal magnitudes for both species. Spermatogenesis processes were studied. It was found that they run a similar course in both species. In the following stages of gametogony and spermatogenesis differences between the two species are not discovered.     

Cyto-evolution of Boronia genomes revealed by fluorescent in situ hybridization with rDNA probes.

The physical location of the 25S-26S rDNA sequences was examined in 11 taxa of nine species of Boronia. In diploid species, two rDNA sites were detected in Boronia clavata (2n = 14), Boronia pinnata 'White' (2n = 22), and Boronia chartacea (2n = 32); four in Boronia megastigma (2n = 14) and Boronia denticulata (2n = 18); six in Boronia pinnata 'Pink' (2n = 22); and eight in Boronia molloyae (2n = 16). Eleven sites were found in Boronia heterophylla 'Red' and 'Near White' (2n = 15), but only two active nucleolar organizer regions (NORs) were observed. In polyploid species, Boronia pilosa (2n = 44) had four rDNA sites, while Boronia coerulescens (2n = 72) had six. Most of the rDNA sequences were terminal, but a few were interstitial. There were also differences in signal intensity indicating that the gene copies between and within rDNA sites might be different. The result suggests that considerable chromosome rearrangements have occurred during Boronia cyto-evolution, leading to variation among Boronia taxa in rDNA copy number, site number, and location. These changes together with dysploid reduction during cyto-evolution have made the Boronia genome considerably diverse in chromosome number, genome organization, and chromosome structure.     

中国蜘蛛抱蛋属的细胞分类学研究Ⅱ

报道了 11种蜘蛛抱蛋属植物的染色体数目和核型。结果如下 :伞柱蜘蛛抱蛋 ** ,2 n=36 =2 0 m+6 sm(2 sat) +10 st,属 2 C型 ;辐花蜘蛛抱蛋 ** ,2 n=38=2 2 m+6 sm(2 sat) +10 st,属 2 C型 ;棒蕊蜘蛛抱蛋 **,2 n =36 =18m +8sm (2 sat) +10 st,属 2 C型 ;柳江蜘蛛抱蛋 **,2 n=38=2 0 m +6 sm(2 sat) +12 st,属 2 C型 ;小花蜘蛛抱蛋 ,2 n=38=16 m +4sm +8st (2 sat) +10 t,属 3C型 ;线叶蜘蛛抱蛋 ** ,2 n=36 =2 0 m(2 sat) +16 st,属 2 C型 ;罗甸蜘蛛抱蛋 ,2 n=38=16 m+6 sm(2 sat) +16 st,属 2 C型 ;四川蜘蛛抱蛋 ,2 n=38=2 4 m +4sm+10 st (2 sat) ,属 2 C型 ;广东蜘蛛抱蛋 ,2 n=36 =18m +2 sm(2 sat) +16 st,属 2 C型 ;洞生蜘蛛抱蛋 **,2 n=36 =18m +2 sm(2 sat) +14st+2 t,属 2 C型 ;大花蜘蛛抱蛋 ,2 n=36 =16 m+6 sm(2 sat) +14st,属 3C型。其中棒蕊蜘蛛抱蛋、柳江蜘蛛抱蛋、线叶蜘蛛抱蛋和洞生蜘蛛抱蛋的染色体数目和核型以及广东蜘蛛抱蛋的核型均为首次报道。     

New chromosome counts in neotropical Albizia, Havardia and Pithecellobium, and a new combination for Albizia (Leguminosae-Mimosoideae-Ingeae)

RICO ARCE, M. DE L., 1992. New chromosome counts in neotropical Albizia, Havardia and Pithecellobium , and a new combination for Albizia (Leguminosae-Mimosoideae-Ingeae). New chromosome records are given for 11 species and one hybrid in the genera Albizia, Havardia and Pithecellobium , some of which are illustrated. All have the diploid chromosome number 2n = 26, which is widespread in Ingeae with the exception of Calliandra ( 2n = 16 and 22). Additionally, a new combination for the genus Albizia is formalized.     

Cytotaxonomy of Commelinaceae: chromosome numbers of some African and Asiatic species

Chromosome counts are reported for 32 taxa (31 species and 1 subspecies) belonging to 10 genera of Commelinaceae from seven African and Asiatic countries. Counts for 13 species and 1 subspecies are recorded for the first time. Published chromosome numbers for Anhicopsis and Polyspatha are confirmed. It is suggested that Pdisota, Pollia and Stanfieldidla each has a single basic number (x = 20, 16 and 11, respectively). The known cytological diversity in Floscopa is extended. The third continental African species of Coleolrype is found to have the same chromosome number (2n = 36) as the other two. The preponderance of the basic number x = 15 in Commelina is supported. The uncommon basic number x = 13 is reported in four taxa of Cyanotis together with karyotypic differences. The basic number x = 6 is found in a second species of Murdannia . Karyotypic data in addition to chromosome numbers are presented for 24 of the 32 taxa investigated. Karyotypes are found to be useful in assessing relationships in the family, and evolutionary trends in the karyotype are noted.     

Chromosome evolution in the genus Ophioglossum L.

Cytological observations on eleven species of Ophioglossum revealed low gametic ( n ) chromosome numbers of 30, 34 and 60 in populations of O.eliminatum , contrasting with an earlier report of n = 90 in the same species. The rest of the species is based on n =120.Cytologically studied species of Ophioglossum exhibit a range of chromosome numbers from n = 30 in O.eliminatum to n =720 in O.reticulatum. The weighted highest common factor (HGF) from all the reported chromosome numbers in twelve species was found to be 30. This number is proposed as the palaeobasic chromosome number for the genuS. Reported chromosome numbers which are not multiples of 30 were subjected to sequential analysis, yielding three distinct ultimate base numbers, 4, 5 and 6, which can produce n = 30 in seven different ways. The neobasic number, n= 120, appears to have arisen through various combinations and permutations of these, theoretically 2401 routes; only a relatively few of these routes exist today, suggesting that extreme selection has been exerted against the majority, and further suggesting that Ophioglossum represents an evolutionary dead end through repeated cycles of polyploidy and is possibly at the verge of extinction. The stoichiometric model of evolution, which derives the various chromosome numbers possessed by the twelve species from the basic and ultimate basic chromosome numbers, is used to explain chromosomal evolution in the genus.     

Observations of Chromosomes of Malus Species in China

Somatic chromosome numbers of 37 forms (representing 22 species) of apples in China were counted using wall-degradation and hypotonic method. Among the species investigated 3 categories of chromosome numbers, i.e. 2n=34, 51 and 68 are confirmed. The chromosome numbers of the following species are here first reported: Malus ombrophila 2n= 34, M. prattii 2n=34, M. melliana 2n=34, Zhaojiaohonghua (M. sp.) 2n=34, and M. asiatica var. 2n=68. Polyploids (including infraspecific polyploids) account for 41% of the total number of the species investigated. 51 is a predominant number. It is suggested that ploidy variation is an important pathway in apple evolution in China, and triploid may be considered as a suitable evolution grade. There are rich apple germplasm resources in China. The systematic studies of this genus are obviously essential.