Chromosome number and plant morphology in some ecotypes of Poa pratensis L.

Euphytica ◽  
1972 ◽  
Vol 21 (2) ◽  
pp. 171-180 ◽  
Author(s):  
G. J. Speckmann ◽  
G. E. Van Dijk
Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 159-163 ◽  
Author(s):  
A. Mariani ◽  
E. Falistocco

Karyological and morphological studies of Medicago murex with 2n = 16 and 2n = 14 chromosomes were undertaken. Analysis of the somatic chromosomes, using both conventional staining techniques and C-banding, showed that the 2n = 14 karyotype derived from the 2n = 16 karyotype. Plant morphology of the two types differs in relation to the characters of the leaves, florets, and pods. Attempts to obtain hybrids between the two types were completely unsuccessful. From these results it appears that the two M. murex types are not as closely related as has been usually considered and that they should be regarded as two different species.Key words: Medicago murex, chromosome number, C-banding.


CYTOLOGIA ◽  
2010 ◽  
Vol 75 (4) ◽  
pp. 443-449 ◽  
Author(s):  
Raghavan Ramakrishnan Nair ◽  
Karur Nallappagounder Shiva ◽  
Srambikkal Anchu ◽  
Thondiath John Zachariah

1937 ◽  
Vol 15c (6) ◽  
pp. 281-297 ◽  
Author(s):  
J. M. Armstrong

The somatic chromosome numbers of 20 species of Poa were determined. The basic chromosome number for the genus was found to be seven. The species arranged themselves in a polyploid series from diploid to dodecaploid, tetraploids and hexaploids being the most numerous. Three aneuploid species possessed chromosome numbers suggestive of a nonaploid origin. Polymorphism was found to be present in P. compressa L., P. palustris L. and P. nemoralis L. All species examined conformed to the long chromosome type common to the subfamily, Pooideae. The spindle fibre attachment for the chromosomes in the various species ideograms was found to be regularly median or submedian.The chromosome variability and the mode of seed production were examined in Poa pratensis L., using selected, uniform strains, indigenous plants and plants grown from commercial seed. The somatic chromosome number was found to range from 50 to 87 ± 1, 10 of the 19 plants examined possessing aneuploid numbers. The selected strains possessed the same chromosome number for both plants examined, while in the other material the number was variable. A study of meiosis in the P.M.C. showed the selected strains to vary from regular behavior to an irregularity of 3.9 unpaired univalents per cell. All strains possessed large percentages of morphologically good pollen which germinated actively on the stigmas. Reduction was observed in the E.M.C. of the selected strains and a study of the course of embryological development showed no irregularities which might lead to aposporous reproduction. A high frequency of polyembryony was observed which was correlated to the degree of irregularity at meiosis. A theory is advanced to explain how constant aneuploid numbers may be maintained in sexually reproduced strains.


Bothalia ◽  
1977 ◽  
Vol 12 (2) ◽  
pp. 215-221 ◽  
Author(s):  
T. B. Vorster

Cytogenetic studies were undertaken in the  Eragrostis curvula Complex. Three plants were studied at each of 16 collecting points. The overall morphology and embryo sac development of all plants were evaluated, while the chromosome number and microsporogenesis of some of the plants were also studied. The collecting points were chosen so ^s to represent a variable environment extending from the bushveld to the highveld regions of the Transvaal. It was found that the embryo sac development of the plants from the bush\eld and the highveld were, for all practical purposes, obligate diplosporic apomicts, whereas the transition area contained obligate as well as facultative diplosporic apomicts. The same pattern also held as far as the plant morphology, chromosome number and microsporogenesis were concerned.


Taxon ◽  
1977 ◽  
Vol 26 (5-6) ◽  
pp. 557-565 ◽  
Author(s):  
Áskell Löve
Keyword(s):  

Taxon ◽  
1970 ◽  
Vol 19 (1) ◽  
pp. 102-113 ◽  
Author(s):  
Áskell Löve
Keyword(s):  

Taxon ◽  
1977 ◽  
Vol 26 (2-3) ◽  
pp. 257-274 ◽  
Author(s):  
Áskell Löve
Keyword(s):  

2020 ◽  
Vol 62 (1-2) ◽  
pp. 7-21
Author(s):  
M. Dudáš ◽  
P. Eliáš jun. ◽  
D. R. Letz ◽  
Z. Bártová ◽  
V. Kolarčik

The distribution of Sonchus palustris in Slovakia was studied using herbarium specimens and literary sources. The herbarium studies, supplemented with targeted field search in the years 2015–2018, revealed 61 new localities and confirmed many other older locations. The species has been recorded in 19 phytogeographical districts and sub-districts of Slovakia. Most of the records are concentrated in the Podunajská nížina lowland in SW Slovakia and in the Ipel'sko-rimavská brázda region in southern Slovakia. Our results showed that the species is relatively common in different types of wetlands and its re-evaluation in the recent version of the Slovak red list is not needed. Chromosome number data for two new populations in eastern Slovakia (both 2n = 18) were counted. The distribution map is given.


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