Cytotaxonomic studies of Draba species of Canada and Alaska: D. ventosa, D. ruaxes, and D. paysonii

1971 ◽  
Vol 49 (8) ◽  
pp. 1455-1460 ◽  
Author(s):  
Gerald A. Mulligan
Keyword(s):  
North America ◽  
Chromosome Number ◽  
Related Species ◽  
Basic Chromosome Number ◽  
Base Number ◽  
Western North America ◽  
Closely Related Species ◽  
Basic Chromosome ◽  
Hexaploid Species

The cytotaxonomy of three closely related species of Draba, of the mountains of western North America, is discussed and a key is given: D. ventosa A. Gray (2n = 36), D. ruaxes Payson & St. John (2n = ca. 72), and D. paysonii Macbride (2n = 42). Evidence is presented demonstrating that D. ventosa and D. paysonii are triploids reproducing by agamospermy whereas the hexaploid species D. ruaxes is a sexual outcrosser. The former two species produce seed apomictically without any pollen stimulation. Draba ventosa and D. ruaxes have the basic chromosome number x = 12 and D. paysonii has the base number x = 14.

A giant Permian fusulinid from east-central Alaska with comparisons of all giant fusulinids in western North America

1995 ◽  
Vol 69 (5) ◽  
pp. 805-812 ◽  
Author(s):  
Calvin H. Stevens
Keyword(s):  
North America ◽  
Related Species ◽  
The Other ◽  
Lower Permian ◽  
Early Permian ◽  
Western North America ◽  
Closely Related Species ◽  
East Central ◽  
West Texas ◽  
Species Groups

The discovery of a new locality yielding giant Guadalupian (Lower Permian) fusulinids in east-central Alaska extends the range of these forms much farther north than previously known, and into a tectonostratigraphic terrane from which they previously had not been reported. The number of areas from which giant parafusulinids are known in North America is thus raised to eight. Three of these localities are in rocks that previously had been referred to the allochthonous McCloud belt arc, and one, West Texas, is known to have been part of Paleozoic North America. Comparison of species from all areas suggests that there are two closely related species groups: one represented in Texas and Coahuila, and the other represented in Sonora, northern California, northeastern Washington, southern and northern British Columbia, Alaska, and apparently in Texas. These groups may differ because they are of slightly different ages or because interchange between the faunas of Texas–Coahuila area and the other regions was somewhat inhibited during the Early Permian.

A new species of Trigonella sect. Ellipticae (Leguminosae-Papilionoideae) from Iran, including cytogenetic and anatomical notes

Phytotaxa ◽  
2015 ◽  
Vol 202 (1) ◽  
pp. 26 ◽  
Author(s):  
Massoud Ranjbar ◽  
ZAHRA HAJMORADI
Keyword(s):  
New Species ◽  
Chromosome Number ◽  
Related Species ◽  
Somatic Chromosome ◽  
Base Number ◽  
Somatic Chromosome Number ◽  
Chromosome Counts ◽  
Closely Related Species ◽  
A New Species

A new species, Trigonella bakhtiarica, from the Iranian province Chahar Mahal Va Bakhtiari is described, illustrated and compared to its most closely related species, T. aphanoneura. Trigonella bakhtiarica has a longer corolla and differs in the shape, surface and size of its pods, which are taxonomically informative characters in Trigonella sect. Ellipticae. Chromosome counts and meiosis assays show that both species are diploid, and that their euploid plants possess a somatic chromosome number of 2n = 2x = 16, which is consistent with the predicted base number of x = 8.

Cytotaxonomic studies of Draba species in Canada and Alaska: D. oligosperma and D. incerta

1972 ◽  
Vol 50 (8) ◽  
pp. 1763-1766 ◽  
Author(s):  
Gerald A. Mulligan
Keyword(s):  
North America ◽  
Related Species ◽  
Western North America ◽  
Closely Related Species

The cytotaxonomy of two closely related species of Draba, D. oligosperma Hooker (2n = 64) and D. incerta Payson (2n = 112), is discussed and a key is given. Both species are mainly confined to the mountains of western North America, although D. incerta is also disjunct nearly 3000 mi eastward to the tip of Gaspé County in Quebec. Draba oligosperma is an octoploid reproducing mostly by agamospermy and D. incerta is 14-ploid, producing seed by autogamy.

Paleontological Evidence Against a Major Geographic Barrier at about the Paleolatitude of Colorado, USA, during the Late Campanian (Late Cretaceous): The Conspicuous Absence of Endemic Subclades of Chasmosaurine Ceratopsid (Horned) Dinosaurs and Its Significance

2018 ◽  
Vol 55 (1) ◽  
pp. 5-18
Author(s):  
Keith Berry
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Related Species ◽  
Western North America ◽  
Closely Related Species ◽  
Geographic Barrier

Several paleontologists have suggested that a major geographic barrier at about the paleolatitude of Colorado either prevented or severely restricted biogeographic exchange between the northern and southern regions of western North America during the Late Campanian. However, the origin and nature of this barrier remains enigmatic. In the present study, this hypothesis is tested by determining whether the diversification of Late Campanian chasmosaurine ceratopsid (horned) dinosaurs was affected by the presence of a barrier or, in other words, whether the biogeographic distribution of closely related species was nonrandom with respect to a line of paleolatitude drawn across Colorado. The results of this test indicate that there could not have been a major geographic barrier, which has implications for paleoclimatic and paleogeographic reconstructions of the Colorado region during its early Laramide history.

scholarly journals Intercontinental distributions of species of Cortinarius, subgenus Phlegmacium, associated with Populus in western North America

Botany ◽  
2015 ◽  
Vol 93 (11) ◽  
pp. 711-721 ◽  
Author(s):  
Cathy L. Cripps ◽  
Kare Liimatainen ◽  
Tuula Niskanen ◽  
Bálint Dima ◽  
Richard F. Bishop ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
Populus Tremuloides ◽  
Related Species ◽  
Its Region ◽  
Deciduous Trees ◽  
Western North America ◽  
Type Specimens ◽  
Closely Related Species ◽  
Salix Spp

Three species of Cortinarius subg. Phlegmacium, Cortinarius argutus Fr. and Cortinarius hedyaromaticus C. Cripps & O.K. Mill. (section Arguti stat. nov.) and Cortinarius talus Fr. (section Multiformes), are compared from western North America and Europe. Phylogenetic analysis of the ITS region shows that C. argutus and C. hedyaromaticus are separate, closely related species with rooting stipes. Cortinarius talus is a pale species with a bulbous stipe and a sweet odor similar to that of C. hedyaromaticus; C. argutus lacks this sweet odor. All three species have intercontinental distributions and are associated with deciduous trees, primarily Populus tremuloides Michx., Populus tremula L., but also Salix spp. This study highlights the importance of the study of type specimens and molecular analysis to stabilize the application of established names.

scholarly journals In vitro propagation and cytological analysis of Sophora mollis Royle: an endangered medicinal shrub

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Aakriti Bhandari ◽  
Harminder Singh ◽  
Amber Srivastava ◽  
Puneet Kumar ◽  
G. S. Panwar ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Average Length ◽  
Germplasm Conservation ◽  
Basic Chromosome Number ◽  
Shoot Tip ◽  
Ex Situ ◽  
Ms Medium ◽  
Basic Chromosome ◽  
Shoot Tip Explants

Abstract Background Sophora mollis Royle (family Fabaceae, subfamily-Papilionaceae) is a multipurpose legume distributed in plains and foothills of the North-West Himalaya to Nepal and is facing high risk of extinction due to habitat loss and exploitation by the local people for its fuel and fodder values. Therefore, the present study was conducted to standardize a micropropagation protocol for Sophora mollis by using shoot tip explants and to study the meiotic chromosome count in the species. Results Multiple shoots were induced in shoot tip explants of Sophora mollis in Murashige and Skoog medium supplemented with different concentrations of cytokinins alone (BAP, TDZ, and Kinetin) and in combination with varying concentrations of NAA. MS medium supplemented with BAP (8.9 μM) was observed to be the optimal medium for multiple shoot induction and maximum 25.32 shoots per explant was obtained with average length of 4.5 ± 0.8 cm. In vitro developed shoots were transferred onto rooting media supplemented with different concentrations of auxin (IAA, IBA, and NAA). Maximum 86% rooting was observed in half-strength MS medium supplemented with 21.20 μM NAA with an average of 21.26 roots per culture. In vitro raised plantlets were adapted to greenhouse for better acclimatization and 60% plants were successfully transferred to the open environment. Based on the chromosome counts available from the literature and the current study, the species tend to show a basic chromosome number of x = 9. Conclusion The micropropagation protocol standardized can be helpful for the ex situ mass multiplication and germplasm conservation of the endangered species. Moreover, the ex situ conservation approach will be helpful in actively bridging the gap between ex situ and in situ approaches through the reintroduction of species in the wild. The cytological studies revealed the basic chromosome number x = 9 of the species.

scholarly journals Relations and evolution in Cheilanthes (Sinopteridaceae, Pteridophita) in Macaronesia and Mediterranean area, deduced from genome analysis of their hybrids

1983 ◽  
Vol 8 ◽  
pp. 101-126 ◽  
Author(s):  
G. Vida ◽  
A. Major ◽  
T. Reichstein
Keyword(s):  
Chromosome Number ◽  
Genome Analysis ◽  
Chromosome Doubling ◽  
Diploid Species ◽  
Mediterranean Area ◽  
Basic Chromosome Number ◽  
The Other ◽  
Experimental Conditions ◽  
Natural Group ◽  
Basic Chromosome

Nine species of "Cheilantoid ferns" are known to grow in Macaronesia and the Mediterranean basin. Two of them (lacking a pseudo-indusium and having the basic chromosome number X = 29), both aggregate species which we prefer to retain in Notholaena, are not included in this study. The other seven species (with distinct pseudo-indusium and the basic chromosome number X = 30), which we accept as members of the genus Cheilanthes Sw. sensu stricto, were subjected to detailed genome analysis of their natural and experimentally produced hybrids and shown to represent an aggregate of four very distinct ancestral diploids and three allotetraploids. The latter must have once been formed by chromosome doubling in the three diploid hybrids of C. maderensis Lowe with the other three diploid species. Theoretically three more allotetraploids would be possible but their formation has obviously been prevented by the geographical separation of the three respective diploids. The most widely distributed of the tetraploids, i.e. C. pteridioides (Reich.) C.Chr. has also been resynthesized from its ancestors (still sympatric) under experimental conditions. The intermediate morphology of the allotetraploids (as compared with their diploid ancestors) is obviously the reason why their status and existence has so long escaped recognition in Europe. These seven species form a natural group and, in our opinion, should not be divided into sections.

The Natural Groups of Species in the Genus Ips De Geer (Coleoptera: Scolytidae) in North America

1963 ◽  
Vol 95 (5) ◽  
pp. 508-516 ◽  
Author(s):  
G. R. Hopping
Keyword(s):  
North America ◽  
North American ◽  
Related Species ◽  
North American Species ◽  
Closely Related Species ◽  
The North ◽  
The World ◽  
Group Relationships ◽  
Natural Groups

AbstractThe genus Ips is one of four closely related genera in the tribe Ipini, sub-tribe Ipina (De Geer 1775, Balachowsky 1949, Nunberg 1954, Hopping 1963). There are now 32 species of Ips recognized in North America, with a few more as yet undescribed. This paper defines the groups of closely related species with observations on the group relationships of species from other parts of the world. Work is in progress to define the North American species in each group.

Meiotic chromosome behaviour in Cenchrus ciliaris

Bothalia ◽  
1998 ◽  
Vol 28 (1) ◽  
pp. 83-90 ◽  
Author(s):  
N. C. Visser ◽  
J. J. Spies
Keyword(s):  
Chromosome Number ◽  
Meiotic Chromosome ◽  
Basic Chromosome Number ◽  
Chromosome Behaviour ◽  
Meiotic Abnormalities ◽  
Single Specimen ◽  
Cenchrus Ciliaris ◽  
Basic Chromosome ◽  
Single Genome ◽  
Meiotic Irregularities

A basic chromosome number of x = 9 has been confirmed for Cenchrus ciliaris L. Polyploidy is common and levels vary from tetraploid to hexaploid. Aneuploidv is reported for a single specimen, where two chromosomes of a single genome were lost. Various meiotic irregularities were observed. The highest incidence of meiotic abnormalities was observed in the pentaploid specimens. This was attributed to their uneven polyploid level All specimens varied from segmental alloploid to alloploid.

Sign in / Sign up

Export Citation Format

Share Document