The cytogeography of Aster pilosus var. pilosus in southern Ontario revisited (Compositae: Astereae)

1989 ◽  
Vol 67 (12) ◽  
pp. 3517-3519 ◽  
Author(s):  
J. G. Chmielewski ◽  
J. C. Semple
Keyword(s):  
Chromosome Numbers ◽  
Island Region ◽  
Southern Ontario ◽  
Aster Pilosus

Chromosome numbers were determined for 228 individuals (215 populations) of Aster pilosus var. pilosus from a wider area of southern Ontario than previously reported. Tetraploids occurred throughout the known distribution of the variety in southern Ontario, and the majority were found on clay plains and bedrock outcrops. Hexaploids were by and large restricted in distribution to glacial moraine and till and sand deposits in the "Ontario Island" region, where tetraploids were infrequent, and in parts of the southern Niagara Peninsula, where tetraploids were more common. Two pentaploids were encountered.

MEIOSIS AND POLYPLOIDY IN ONTARIO SPECIES OF CRATAEGUS IN RELATION TO THEIR SYSTEMATICS

1979 ◽  
Vol 21 (2) ◽  
pp. 231-241 ◽  
Author(s):  
M. Muniyamma ◽  
J. B. Phipps
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Pollen Sterility ◽  
Southern Ontario ◽  
Agamic Complex ◽  
Species Complexes ◽  
Extensive Documentation ◽  
Meiotic Irregularities ◽  
The Common ◽  
Taxonomic Studies

Chromosome number determinations of 68 accessions of about 20 species in 11 series of Crataegus (hawthorn), Rosaceae, occurring in southern Ontario are presented. This is the first extensive documentation of chromosome numbers in North American Crataegus since Longley's (1924) account which was based on sectioned material. Our results, taken in the context of our cytological work proving the presence of apomixis in the genus, and taxonomic studies, clearly establish that in Ontario Crataegus is part of an extensive agamic complex consisting of diploids (2n = 34), polyploids (3x and 4x) and some aneuploids. Cytological observations of the triploids (2n = 51) and tetraploids (2n = 68) that have indicated the occurrence of meiotic irregularities and various degrees of pollen sterility in some of the polyploid taxa studied, underline the significance of apomixis in Crataegus evolution. One of the common Ontario species, C. punctata, is shown to be a probable sexual diploid and further cytological work should now be concentrated on particular species complexes.

Carex lacustris × C. trichocarpa (Cyperaceae), a new natural hybrid

1989 ◽  
Vol 67 (3) ◽  
pp. 790-795 ◽  
Author(s):  
P. M. Catling ◽  
A. A. Reznicek ◽  
K. Denford
Keyword(s):  
New York ◽  
Chromosome Numbers ◽  
New York State ◽  
Morphological Characters ◽  
Natural Hybrid ◽  
Southern Ontario ◽  
York State ◽  
Natural Hybrids ◽  
Marker Compounds ◽  
Carex Lacustris

The new natural hybrid Carex lacustris × C. trichocarpa is described from material found in southern Ontario and New York State. The plants are sterile with incompletely developed stamens and distorted pollen that failed to stain with lactophenol. The parentage is confirmed through intermediacy in distinctive morphological characters. The new hybrid possesses unique features of each parent including the red apices of the inner sheath bands of C. trichocarpa and the long ligules of C. lacustris. The flavonoid spectrum of the hybrid was found to be consistent with the proposed parentage. Luteolin glycosides were found only in C. lacustris, whereas tricin glycosides were restricted to C. trichocarpa. Although the hybrid had marker compounds from both putative parents, complementation was incomplete. The occurrence of this hybrid suggests that sedges with quite different chromosome numbers can and do form natural hybrids.

The cytogeography of Aster pilosus (Compositae): Ontario and the adjacent United States

1978 ◽  
Vol 56 (10) ◽  
pp. 1274-1279 ◽  
Author(s):  
John C. Semple
Keyword(s):  
United States ◽  
Ploidy Level ◽  
Lake Ontario ◽  
The United States ◽  
Southern Ontario ◽  
First Report ◽  
Close Proximity ◽  
The University ◽  
Coarse Gravel ◽  
Aster Pilosus

The chromosome numbers of individuals from 48 sites in southern Ontario and 12 sites in the eastern U.S.A. were determined. Twenty-one populations in Ontario of Aster pilosus var. pringlei were found to be hexaploid with 2n = 48 (first report for taxon). Sixteen populations of Aster pilosus var. pilosus were tetraploid 2n = 32 (first report for this ploidy level) and 11 populations were hexaploid 2n = 48. In southwestern Ontario, hexaploids of var. pilosus were found concentrated in one region on glacial sand, till soils, and coarse gravel fill, while tetraploids were only found on finer textured silt plains and limestone outcropping. In Ontario, the two varieties are nearly allopatric, only growing in close proximity on Presqu'ile Point on Lake Ontario. Both tetraploid and hexaploid plants of var. pilosus were found in the United States. The hexaploids were common near the Great Lakes but rare further south. Aster pilosus var. demotus was treated as a synonym of var. pilosus, since nearly glabrous plants produced pilose shoots when transplanted to the greenhouse at the University of Waterloo.

New chromosome numbers inAlchemillaL.(Rosaceae)from Turkey

1997 ◽  
Vol 27 (1-2) ◽  
pp. 191-194 ◽  
Author(s):  
Sema Hayirlioğlu-Ayaz ◽  
Osman Beyazoğlu
Keyword(s):  
Chromosome Numbers

ON CHROMOSOME NUMBERS IN THE GRASS FAMILY (POACEAE) IN RUSSIA, WITH SPECIAL ATTENTION TO THE FAR EAST

2020 ◽  
Vol 68 ◽  
pp. 29-64
Author(s):  
N.S. Probatova ◽  
Keyword(s):  
Chromosome Numbers ◽  
Russian Far East ◽  
Far East ◽  
Grass Species ◽  
Original Material ◽  
Mountain Regions ◽  
Grass Family ◽  
The Far East ◽  
The World ◽  
The Russian Far East

The paper summarizes information on chromosome numbers (CNs) of the Grass species (Poaceae) in the flora of Russian Federation, obtained on the original material, most part - from the Russian Far East (RFE). In some species the CNs are known in Russia or in the world only from RFE, in some – from one locality or few, or from one subregion of RFE. The grass species in RFE often occur in mountain regions and near seacoasts; some species are endemics, some were studied near the limits of their geographical distribution areas. The diversity of CNs, the special features of the CNs distribution in some grass groups are discussed. The alien species are abundant in RFE, and their CNs are also involved in the study. For karyologically polymorphous species further studies are needed.

Identification and Chromosome Numbers of Some Bromus Species 1

Crop Science ◽  
1961 ◽  
Vol 1 (5) ◽  
pp. 375-375 ◽  
Author(s):  
J. Nath ◽  
E. L. Nielsen
Keyword(s):  
Chromosome Numbers
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