scholarly journals On the hypothesis of dioicous – monoicous species pairs in the Mniaceae (Bryophyta); morphology, sexual condition and distiribution

2019 ◽  
Vol 68 (1-2) ◽  
pp. 67-81
Author(s):  
Timo Koponen
Keyword(s):  
North America ◽  
Chromosome Number ◽  
Cell Size ◽  
Cross Sections ◽  
Morphological Characters ◽  
Limited Range ◽  
Diploid Chromosome Number ◽  
Leaf Cell ◽  
Species Pairs ◽  
Forested Areas

Abstract Some early observations seemed to show that, in the Mniaceae, the doubling of the chromo-some set affects a change from dioicous to monoicous condition, larger size of the gametophyte including larger leaf cell size, and to a wider range of the monoicous counterpart. The Mniaceae taxa are divided into four groups based on their sexual condition and morphology. 1. Dioicous – monoicous counterparts which can be distinguished by morphological characters, 2. Dioicous – monoicous taxa which have no morphological, deviating characters, 3. Monoicous species mostly with diploid chromosome number for which no dioicous counterpart is known, and 4. The taxa in Mniaceae with only dioicous plants. Most of the monoicous species of the Mniaceae have wide ranges, but a few of them are endemics in geographically isolated areas. The dioicous species have either a wide holarctic range or a limited range in the forested areas of temperate and meridional North America, Europe and SE Asia, or in subtropical Asia. Some of the monoicous species are evidently autodiploids and a few of them are allopolyploids from cross-sections of two species. Quite recently, several new possible dioicous – monoicous relationships have been discovered.

scholarly journals Morphological, anatomical and karyological investigations of the Turkish endemic species Lathyrus woronowii Bornm. (Fabaceae)

2017 ◽  
Vol 76 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Fatma Güneş ◽  
Çiler Meriç
Keyword(s):  
Chromosome Number ◽  
Cross Sections ◽  
Endemic Species ◽  
Diploid Chromosome Number ◽  
Dam Construction ◽  
Annual Species ◽  
International Union ◽  
First Time ◽  
Iucn Criteria ◽  
General Appearance

AbstractLathyrus woronowiiBornm., an endemic species of Turkey, is threatened with extinction due to dam construction. It exists only in the Çoruh valley, Artvin. This annual species is in the critically endangered (CR) category according to the International Union of Conservation of Nature (IUCN) criteria. Its morphology, anatomy and karyology are studied here for the first time. A detailed description is given and the general appearance of the species has been drawn; cross sections from the stem and leaf have been taken and examined; and the diploid chromosome number (2n = 14) has been reported and illustrated for the first time.

STUDIES ON SOLIDAGO L.: IV. THE CHROMOSOME NUMBERS OF CERTAIN TAXA OF THE GENUS SOLIDAGO

1959 ◽  
Vol 37 (2) ◽  
pp. 209-228 ◽  
Author(s):  
Jean R. Beaudry ◽  
Denise L. Chabot
Keyword(s):  
North America ◽  
Chromosome Number ◽  
Geographical Distribution ◽  
Chromosome Numbers ◽  
Morphological Characters ◽  
Basic Number ◽  
Western North America

The authors report the chromosome numbers of 25 taxa of the genus Solidago which had not yet been studied from this standpoint, and review the literature. The chromosome numbers of 42 taxa have now been published. The basic number of the genus is nine. Thirty-three taxa are diploid (2n = 18), five are tetraploid (2n = 36), three are aggregate taxa containing both diploid and tetraploid cytodemes, and one is hexaploid (2n = 54). Polyploidy has thus contributed to the evolution of the genus Solidago but it seems that most of the species have differentiated gradually. S. decemflora DC. of western North America differs from S. nemoralis Ait. of the same continent by morphological characters, its geographical distribution, and its chromosome number, the first taxon being tetraploid and the second diploid; the two are thus good species and not only varieties of the same species. The S. rigida of authors is an aggregate made up of two entities which are distinguished not only by their morphology and geographical distribution but also by their chromosome numbers; the eastern one (S. rigida L.) is tetraploid, whereas the western one (S. parvirigida Beaudry) is diploid. The bog and marsh goldenrods, S. Purshii and S. uliginosa, also possess different chromosome numbers, the first being diploid and the second tetraploid.

A contribution to the taxonomy of the Oxytropis campestris complex in northwestern North America

1980 ◽  
Vol 58 (16) ◽  
pp. 1820-1831 ◽  
Author(s):  
Wayne J. Elisens ◽  
John G. Packer
Keyword(s):  
North America ◽  
Chromosome Number ◽  
Cell Size ◽  
Guard Cell ◽  
Chromosome Numbers ◽  
Species Status ◽  
Polyploid Series ◽  
Continental Divide ◽  
Northwestern North America

The Oxytropis campestris complex in northwestern North America is a polyploid series comprising at least seven morphologically and geographically distinct taxa. In light of the data of the present study, the authors propose that five taxa be reelevated to species status: O. cusickii Greenm., O. monticola Gray, O. columbiana St. John. O. jordalii Porsild, O. varions (Rydb.) K. Schum.; and that two taxa be recombined as subspecies: O. monticola Gray ssp. dispar (A. Nels.) Elisens & Packer and O. jordalii Porsild ssp. davisii (Welsh) Elisens & Packer.Three different chromosome numbers are present in the complex and represent the tetraploid (2n = 32), hexaploid (2n = 48), and dodecaploid (2n = 96) condition. Three species have uniform chromosome numbers (O. cusickii, 2n = 48; O. jordalii, 2n = 32; and O. columbiana, 2n = 48), two taxa, O. varians and O. monticola ssp. monticola, exhibit two different chromosome numbers. No attempt to subdivide O. varians was undertaken as; with the exception of guard cell size, no differences were observed between hexaploid and dodecaploid representatives. At least two distinct entities appear to be present in O. monticola ssp. monticola, for, while morphologically, cytologically (2n = 32), and ecologically uniform east of the continental divide, it is quite variable in appearance and has a different chromosome number (2n = 48) west of the divide.

Comparative Analysis of Genetic and Morphological Variation within the Platanthera hyperborea Complex (Orchidaceae)

2020 ◽  
Vol 45 (4) ◽  
pp. 767-778
Author(s):  
Eranga Wettewa ◽  
Nick Bailey ◽  
Lisa E. Wallace
Keyword(s):  
North America ◽  
Diploid Species ◽  
Morphological Characters ◽  
Evolutionary Patterns ◽  
Founding Population ◽  
Multiple Origins ◽  
Geographic Structure ◽  
Species Complexes ◽  
Nuclear Its ◽  
Cryptic Taxa

Abstract—Species complexes present considerable problems for a working taxonomy due to the presence of intraspecific variation, hybridization, polyploidy, and phenotypic plasticity. Understanding evolutionary patterns using molecular markers can allow for a more thorough assessment of evolutionary lineages than traditional morphological markers. In this study, we evaluated genetic diversity and phylogenetic patterns among taxa of the Platanthera hyperborea (Orchidaceae) complex, which includes diploid (Platanthera aquilonis) and polyploid (Platanthera hyperborea, P. huronensis, and P. convallariifolia) taxa spanning North America, Greenland, Iceland, and Asia. We found that three floral morphological characters overlap among the polyploid taxa, but the diploid species has smaller flowers. DNA sequence variation in a plastid (rpL16 intron) and a nuclear (ITS) marker indicated that at least three diploid species have contributed to the genomes of the polyploid taxa, suggesting all are of allopolyploid origin. Platanthera convallariifolia is most like P. dilatata and P. stricta, whereas P. huronensis and P. hyperborea appear to have originated from crosses of P. dilatata and P. aquilonis. Platanthera huronensis, which is found across North America, has multiple origins and reciprocal maternal parentage from the diploid species. By contrast, P. hyperborea, restricted to Greenland and Iceland, appears to have originated from a small founding population of hybrids in which P. dilatata was the maternal parent. Geographic structure was found among polyploid forms in North America. The area of Manitoba, Canada appears to be a contact zone among geographically diverse forms from eastern and western North America. Given the geographic and genetic variation found, we recommend continued recognition of four green-flowered species within this complex, but caution that there may be additional cryptic taxa within North America.

scholarly journals Improvement Of Orchid Vanda Hybrid (Vanda limbata Blume X Vanda tricolor Lindl. var. suavis) By Colchicines Treatment In Vitro

2016 ◽  
Vol 10 (11) ◽  
pp. 83 ◽  
Author(s):  
Mustika Tuwo ◽  
Ari Indrianto
Keyword(s):  
Chromosome Number ◽  
Morphological Characters ◽  
Effective Concentration ◽  
Cytological Analysis ◽  
Stomatal Index ◽  
Duration Of Treatment ◽  
Stomatal Size ◽  
Soaking Time ◽  
Anatomical Characters

The purpose of this research was to evaluate the growth phase of orchid Vanda hybrid (Vanda limbata Blume X Vanda tricolor Lindl. var. suavis) response with colchicines treatment, to determine precise effective concentration of colchicines and duration of treatment to induce polyploidy. This research used variation of colchicines concentration which were 0.01%; 0.05%; 0.1%; 0.5%; 1% and 0% and incubation for 6 hours; 12 hours; 18 hours; 24 hours; and  4 days. Treatment was done in aseptic condition using protocorm aged 7 week after sowing. After treatments, plants were planted on Vacint and Went (VW) medium supplemented with of 150 ml/l coconut water. After four months, they were subcultured in medium VW + 150 ml/l + 150g/l banana extract. The results showed that the orchid Vanda hybrid was intolerant to colchicine concentration of 0.1; 0.5 and 1% by death protocorm was more than 50%. Concentration of 0,5% with 6 hours soaking time is the most effective to induced tetraploid in orchid Vanda hybrid. Morphological characters of tetraploid plantlets had lower average number and length of roots, the number, length, and width of the leaves than those of control. Anatomical characters of the tetraploid plantlets revealed the highest stomatal size and had smaller of stomatal index than controls. This evident indicated a negative correlation between stomatal index and ploidy level. Cytological analysis with flow cytometry revealed that tetraploid plantlets (2n=4x=76) stained with DAPI showed the chromosome number more than those of control (2n=2x=38).Key words      : polyploidization, colchicine, vanda orchid, chromosome number

scholarly journals One more Microtus species with asynaptic sex chromosomes

2018 ◽  
Vol 70 (3) ◽  
pp. 443-447
Author(s):  
Jelena Blagojevic ◽  
Marija Rajicic ◽  
Vladimir Jovanovic ◽  
Tanja Adnadjevic ◽  
Ivana Budinski ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Sex Chromosomes ◽  
Diploid Chromosome Number ◽  
First Finding ◽  
Chromosomal Polymorphisms ◽  
Southeastern Serbia

Arvicoline voles are known as a karyotypically extremely polymorphic group in which the genus Microtus leads with the highest rate of karyotype change. A member of this genus, the European pine vole Microtus subterraneus (de Selys-Longchamps, 1836), is widely distributed in Europe and parts of Asia. There are two cytotypes differing in diploid chromosome number, 2n=54 and 52, each showing different chromosomal polymorphisms. At two localities in southeastern Serbia, Mt. Jastrebac and Vlasina, we found the 2n=52 cytotype. Meiotic preparations from males revealed the presence of asynaptic sex chromosomes. Although asynaptic sex chromosomes are frequent in Microtus, this is the first finding for M. subterraneus. From summarized data it appears that two-thirds of the studied species, mainly from Microtus and Terricola subgenera, possess asynaptic sex chromosomes.

scholarly journals Big and beautiful: the Megaxyela species (Hymenoptera, Xyelidae) of East Asia and North America

2017 ◽  
Author(s):  
Stephan M. Blank ◽  
Katja Kramp ◽  
David R. Smith ◽  
Yuri N. Sundikov ◽  
Meicai Wei ◽  
...  
Keyword(s):  
North America ◽  
West Virginia ◽  
South Korea ◽  
East Asia ◽  
Morphological Characters ◽  
Old World ◽  
Eastern Usa ◽  
The Usa ◽  
Coi Sequences ◽  
First Time

Megaxyela Ashmead, 1898 comprises 13 species, four of which are described as new and one is removed from synonymy: Megaxyela euchroma Blank, Shinohara & Wei sp. nov. from China (Zheijang), M. fulvago Blank, Shinohara & Wei sp. nov. from China (Hunan, Jiangsu, Zhejiang), M. inversa Blank & D.R. Smith sp. nov. from the USA (West Virginia), M. langstoni Ross, 1936 sp. rev. from the eastern USA, and M. pulchra Blank, Shinohara & Sundukov sp. nov. from China (Hubei, Jilin, Liaoning, Shaanxi, Tibet), South Korea (Kangwon-do) and Russia (Primorskiy Kray). The male of M. parki Shinohara, 1992 is described for the first time. A lectotype is designated for M. gigantea Mocsáry, 1909. A cladogram, based on COI sequences of seven species, is presented and interpreted in view of selected morphological characters. Records of M. fulvago sp. nov. from Hunan and of M. pulchra sp. nov. from Tibet extend the known distribution of Megaxyela in the Old World 600 kilometers farther south and 2500 kilometers farther west than previous records.

Sources of progesterone during gestation in Barbary sheep (Ammotragus lervia)

1983 ◽  
Vol 98 (2) ◽  
pp. 283-NP ◽  
Author(s):  
A. P. F. Flint ◽  
R. D. Burton ◽  
R. B. Heap
Keyword(s):  
Chromosome Number ◽  
Corpus Luteum ◽  
Late Pregnancy ◽  
Hydroxysteroid Dehydrogenase ◽  
Point Of View ◽  
Diploid Chromosome Number ◽  
Domestic Sheep ◽  
Ammotragus Lervia ◽  
Barbary Sheep ◽  
Venous Plasma

Concentrations of progesterone in arterial and ovarian, uterine and jugular venous plasma were determined in four Barbary sheep at various stages of pregnancy. The results, together with ovarian histology, show that the corpus luteum regresses before term in Barbary sheep, as in most breeds of domestic ewes. Uterine synthesis of progesterone was demonstrated in late pregnancy in two animals in which uterine venous levels of progesterone were increased two- to fourfold above arterial concentrations. The placenta contained 3β-hydroxysteroid dehydrogenase. Barbary sheep (diploid chromosome number, 2N = 58) therefore resemble the domestic sheep (2N = 54) rather than the goat (2N = 60) from the point of view of the source of the progesterone required for maintenance of pregnancy.

An Extraordinarily Low Diploid Chromosome Number in the Reptile Gonatodes taniae (Squamata, Gekkonidae)

1994 ◽  
Vol 85 (4) ◽  
pp. 255-260 ◽  
Author(s):  
M. Schmid ◽  
W. Felchtinger ◽  
I. Nanda ◽  
R. Schakowski ◽  
R. Visbal Garcia ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Diploid Chromosome Number

The Chromosome Numbers and Nuclear Cytology of Some Common British Serpulids

1960 ◽  
Vol s3-101 (56) ◽  
pp. 395-400
Author(s):  
S. DASGUPTA ◽  
A. P. AUSTIN
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Somatic Cells ◽  
Diploid Chromosome Number ◽  
Iron Alum ◽  
Artificial Fertilization ◽  
Nuclear Cytology

The chromosome numbers of Hydroides norvegica, Mercierella enigmatica, and Pomatoceros triqueter were determined from squashes of somatic cells in young embryos obtained by artificial fertilization, and stained with iron-alum/aceto-carmine. All had a diploid count of zn = 26 chromosomes. Mitotic and meiotic divisions in the 5 species of Spirorbis examined, and in Filograna implexa, all revealed a diploid chromosome number of 2n = 20. A diploid chromosome number of 14 is suggested for the ancestral serpulid.

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