Cytotaxonomic studies in five species of Rutidosis (Asteraceae) endemic to south-eastern Queensland

2002 ◽  
Vol 50 (2) ◽  
pp. 237 ◽  
Author(s):  
Goro Kokubugata ◽  
Ailsa E. Holland

Somatic chromosomes of five species of Rutidosis endemic to south-eastern Queensland were analysed by the aceto-orcein staining method. The five species were classified into two major groups by their basic chromosome number and asymmetry of chromosome length. Rutidosis glandulosa and R. murchisonii exhibited a basic chromosome number of x = 11 and a gradual change in chromosome length. Rutidosis crispata, R. lanata and R. leucantha exhibited a basic chromosome number of x = 12 and the karyotype was bimodal with respect to chromosome length. On the basis of chromosome evidence, we hypothesise that (1) R. glandulosa and R. murchisonii are closely related, (2) R. crispata and R. leucantha are closely related and (3) R. lanata is most likely to be derived from R. crispata by a hexaploidisation. The present results support Holland’s (1994, 1999) taxonomic treatment of the five species.

2019 ◽  
Vol 54 (4) ◽  
pp. 283-288
Author(s):  
MS Rahman

In the present study, karyomorphological features of Enhydra fluctuans Lour. were investigated. Orcein-staining was used for the authentic chromosomal characterization and identification. In E. fluctuans ‘Simple Chromocenter Type’ of interphase nuclei was observed with many small heterochromatin blocks after orcein staining. Prophase chromosomes showed ‘Gradient Type’ with orcein staining. This species was found to possess 2n=10x=110 with basic chromosome number x=11 and this is probably the first report for this species. The centromeric formula of this species was ‘38m+70sm+2ac’. The above features indicated that E. fluctuans is an advance polyploid with asymmetric karyotype. The total chromatin length (2n) was 295.92 μm. Individual chromosome length ranged from 1.84-4.26 μm. The relative length of each chromosome ranged from 0.006-0.014. The above mentioned data will be useful for karyomorphological characterization of E. fluctuans from Bangladesh. Bangladesh J. Sci. Ind. Res.54(4), 283-288, 2019


Bothalia ◽  
1984 ◽  
Vol 15 (3/4) ◽  
pp. 345-385 ◽  
Author(s):  
J. J. A. Van der Walt

Twenty four species are recognized in this taxonomic treatment of the section Pelargonium which was last revised by Knuth in 1912, Most species occur in the south-western, southern and eastern Cape where they usually grow in rather moist, semi-shaded habitats, A key to the identification o f the species has been compiled, and at least one illustration as well as a distribution map is presented for each species. The section is considered to be the most primitive section of the genus with a basic chromosome number of x = 11.


2021 ◽  
Vol 30 (2) ◽  
pp. 133-140
Author(s):  
Ishrat Jahan Bonna ◽  
Suma Akter ◽  
Syeda Sharmeen Sultana

Three Curcuma L. species were investigated cytogenetically which represent diversed staining pattern of heterochromatins in interphase nuclei and prophase chromosomes with orcein staining. Curcuma longa and C. caesia were found to possess 2n = 3x = 63 somatic chromosomes whereas 2n = 2x = 42 chromosome number in C. zedoaria is reported for the first time from Bangladesh. Total chromosome length recorded in C. longa, C. caesia and C. zedoaria were 145.08 ± 2.85 μm, 164.93 ± 4.29 μm and 97.78 ± 2.41 μm, respectively. This was the first attempt to measure the length of the chromosomes for these species. The experiment confirmed the basic chromosome number x = 21 with triploid (C. longa, C. caesia) and diploid (C. zedoaria) Curcuma plants. Polyploidy could be employed in the evolution and diversification of the genus Curcuma, which is an essential factor to characterize the species of this genus. Dhaka Univ. J. Biol. Sci. 30(2): 133-140, 2021 (July)


PhytoKeys ◽  
2021 ◽  
Vol 187 ◽  
pp. 207-227
Author(s):  
Elizaveta Yu. Mitrenina ◽  
Andrey S. Erst ◽  
Lorenzo Peruzzi ◽  
Mikhail V. Skaptsov ◽  
Hiroshi Ikeda ◽  
...  

Comparative karyomorphological analyses of six out of the eight white-flowered species of Eranthis sect. Shibateranthis have been carried out. All studied specimens of E. byunsanensis, E. lobulata, E. pinnatifida, and E. stellata had a somatic chromosome number 2n = 16 with basic chromosome number x = 8. On the contrary, E. tanhoensis and E. sibirica had a basic chromosome number x = 7. The specimens of E. tanhoensis were diploid with 2n = 14, while the specimens of E. sibirica were polyploid with 2n = 42. Monoploid chromosome sets of the investigated diploid species had 4–5 metacentric chromosomes and 2–4 submetacentric/subtelocentric/acrocentric chromosomes. The highest level of interchromosomal asymmetry, estimated via CVCL, was found in E. byunsanensis and E. pinnatifida. The highest levels of intrachromosomal asymmetry (MCA) and heterogeneity in centromere position (CVCI) were found in E. lobulata and E. byunsanensis, while E. sibirica had the most symmetric karyotype. A multivariate PCoA analysis of basic karyotype parameters (2n, x, THL, CVCL, MCA, and CVCI) highlighted no overlap among species accessions, which was also confirmed by LDA. The average absolute monoploid DNA content (1Cx) of the 23 investigated samples of six Eranthis species varied from 9.26 ± 0.25 pg in E. sibirica to 15.93 ± 0.32 pg in E. stellata. Overall karyological affinity was highlighted between E. lobulata and E. stellata, on one side, and between E. byunsanensis and E. pinnatifida, on the other side. Interestingly, there was no significant correlation between total haploid (monoploid) chromosome length (THL) and 1Cx values in these species.


Author(s):  
Aakriti Bhandari ◽  
Harminder Singh ◽  
Amber Srivastava ◽  
Puneet Kumar ◽  
G. S. Panwar ◽  
...  

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.


1983 ◽  
Vol 8 ◽  
pp. 101-126 ◽  
Author(s):  
G. Vida ◽  
A. Major ◽  
T. Reichstein

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.


Bothalia ◽  
1998 ◽  
Vol 28 (1) ◽  
pp. 83-90 ◽  
Author(s):  
N. C. Visser ◽  
J. J. Spies

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.


Bothalia ◽  
1989 ◽  
Vol 19 (1) ◽  
pp. 125-132 ◽  
Author(s):  
J. J. Spies ◽  
E. J. L. Saayman ◽  
S. P. Voges ◽  
G. Davidse

Cytogenetic studies of 53 specimens of 14 species of the genus  Ehrharta Thunb. confirmed a basic chromosome number of 12 for the genus. Chromosome numbers for 13 species are described for the first time. The highest ploidy level yet observed in the genus (2n = lOx = 120) is reported for E. villosa var.  villosa. B chromosomes were observed in several specimens of four different species.


Bothalia ◽  
1994 ◽  
Vol 24 (2) ◽  
pp. 241-246 ◽  
Author(s):  
J. J. Spies ◽  
T. H. Troskie ◽  
E. Van der Vyver ◽  
S. M. C Van Wyk

Representative specimens of various species of the genera  Andropogon L.,  Cymbopogon Spreng.,  Elionurus Kunth ex Willd.,  Hyparrhenia Foum. and  Hyperthelia Clayton were cytogenetically studied. All specimens had a secondary basic chromosome number of ten. Polyploidy, either as alloploidy or segmental alloploidy. was frequent. The taxa studied represent mature polyploid complexes.  


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