scholarly journals Physical localization of 45S rDNA in Cymbopogon and the analysis of differential distribution of rDNA in homologous chromosomes of Cymbopogon winterianus

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0257115
Author(s):  
Shivangi Thakur ◽  
Upendra Kumar ◽  
Rashmi Malik ◽  
Darshana Bisht ◽  
Priyanka Balyan ◽  
...  

Cymbopogon, commonly known as lemon grass, is one of the most important aromatic grasses having therapeutic and medicinal values. FISH signals on somatic chromosome spreads off Cymbopogon species indicated the localization of 45S rDNA on the terminal region of short arms of a chromosome pair. A considerable interspecific variation in the intensity of 45S rDNA hybridization signals was observed in the cultivars of Cymbopogon winterianus and Cymbopogon flexuosus. Furthermore, in all the varieties of C. winterianus namely Bio-13, Manjari and Medini, a differential distribution of 45S rDNA was observed in a heterologous pair of chromosomes 1. The development of C. winterianus var. Manjari through gamma radiation may be responsible for breakage of fragile rDNA site from one of the chromosomes of this heterologous chromosome pair. While, in other two varieties of C. winterianus (Bio-13 and Medini), this variability may be because of evolutionary speciation due to natural cross among two species of Cymbopogon which was fixed through clonal propagation. However, in both the situations these changes were fixed by vegetative method of propagation which is general mode of reproduction in the case of C. winterianus.

2021 ◽  
Author(s):  
Shivangi Thakur ◽  
Upendra Kumar ◽  
Rashmi Malik ◽  
Darshana Bisht ◽  
Priyanka Balyan ◽  
...  

AbstractCymbopogon, commonly known as lemon grass, is one of the most important aromatic grasses having therapeutic and medicinal values. FISH signals on somatic chromosome spreads off Cymbopogon species indicated the localization of 45S rDNA on the terminal region of short arms of a chromosome pair. A considerable interspecific variation in the intensity of 45S rDNA hybridization signals was observed in the cultivars of Cymbopogon winterianus and Cymbopogon flexuosus. Furthermore, in all the varieties of Cymbopogon winterianus namely Bio-13, Manjari and Medini, a differential distribution of 45S rDNA was observed in a heterologous pair of chromosome 1. The development of Cymbopogon winterianus var. Manjari through gamma radiation may be responsible for breakage of fragile rDNA site from one of the chromosomes of this heterologous chromosome pair. While, in other two varieties of Cymbopogon winterianus (Bio-13 and Medini), this variability may be because of evolutionary speciation due to natural cross among two species of Cymbopogon which was fixed through clonal propagation. However, in both the situations these changes were fixed by vegetative method of propagation which is general mode of reproduction in the case of Cymbopogon winterianus.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5316 ◽  
Author(s):  
Naiara Pereira Araújo ◽  
Cayo Augusto Rocha Dias ◽  
Rodolfo Stumpp ◽  
Marta Svartman

Trinomys Thomas (1921) is a terrestrial genus of spiny rats endemic to the Brazilian areas of Atlantic Forest and the transitional areas of Cerrado and Caatinga. Although most species have been already karyotyped, the available cytogenetic information is mostly restricted to diploid and fundamental numbers. We analyzed the chromosomes of two Trinomys species: Trinomys moojeni (2n = 56, FN = 106) and Trinomys setosus setosus (2n = 56, FN = 106 and 2n = 56, FN = 108). Our analyses included GTG- and CBG-banding, silver-staining of the nucleolar organizer regions, and chromosome mapping of telomeres and 45S rDNA by fluorescent in situ hybridization (FISH). Comparative GTG- and CBG-banding suggested that the interspecific variation may be due to rearrangements such as pericentric inversions, centromere repositioning, and heterochromatin variation. We report two new karyotypes for T. s. setosus and describe for the first time the banding patterns of the two Trinomys species.


Genetics ◽  
1983 ◽  
Vol 104 (4) ◽  
pp. 677-684
Author(s):  
J L Santos ◽  
J Orellana ◽  
R Giraldez

ABSTRACT Meiotic pairing preferences between identical and homologous but not identical chromosomes were analyzed in spontaneous tetraploid/diploid chimeras of three male grasshoppers (Eyprepocnemis plorans) whose chromosome pair 11 were heterozygous for C-banding pattern and in four induced tetraploid/diploid chimaeral rye plants (Secale cereale) heterozygous for telomeric heterochromatin C-bands in chromosomes 1R and 2R. In the grasshoppers, a preference for identical over homologous pairing was observed, whereas in rye both a preference for homologous rather than identical pairing and random pairing between the four chromosomes of the set was found. From the results in rye, it can be deduced that pairing preferences do not depend exclusively on the similarities between chromosomes involved. It is suggested that genotypic or cryptic structural differences between the homologous chromosomes of each pair analyzed might be responsible for the pairing preferences found. This hypothesis can also explain the results obtained in grasshoppers, although the possibility of premeiotic association cannot be excluded in this material.


BioResources ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 103-120
Author(s):  
Harjeet Kaur ◽  
Dharm Dutt ◽  
C. H. Tyagi

Sofia (Cymbopogon martini), and lemon (Cymbopogon flexuosus) grasses, are exclusively cultivated for extraction of important lemongrass and palma rosa oils. Lignocellulosic residue (LCR) of sofia and lemon grasses left after steam distillation can successfully be used for the production of chemical grade pulp. Steam distillation mitigates the problem of mass transfer, and facilitates the faster penetration of cooking liquor by leaching out a part of extraneous components. Sofia grass produces a pulp yield of 43.7% of kappa number 20 at an active alkali dose of 14% (as Na2O), maximum cooking temperature of 160 oC and cooking time 90 min. Likewise, lemon grass produces a pulp yield of 41.4% of kappa number 12.5 under the same conditions except temperature (150 oC) by a soda pulping process. Addition of 0.1% AQ at optimum cooking conditions reduces kappa number by 26 and 8% for sofia and lemon grasses with insignificant increase in pulp yield i.e. 0.2 and 0.4% for sofia and lemon grasses, respectively. The mechanical strength properties of lemon grass soda-AQ pulp are better than sofia grass. Bauer-McNett fiber classification further validates that +20 fractions are more (62.63%) in lemon grass than in sofia grass (42.72%).


2019 ◽  
Vol 11 (2) ◽  
pp. 263-266 ◽  
Author(s):  
Anju Bhatnagar

The essential oils of Cymbopogon flexuosus (lemon grass) of the family Poaceae collected from different altitudes of the Uttarakhand region of Himalaya were subjected to detailed GC/MS analysis in order to determine the variation of concentration in their constituents. The GC/MS analysis led to the identification of 29 constituents forming 90.62 to 93.58% of their total oil content. The major constituents were citral, geraniol, citronellol,citranellal, linalool, borneol, ?-myrcene limonene, ?-caryophyllene, camphene, ?-cadinene, ? terpineol, neryl acetate and heptenone. Plants collected from 450 m altitude afforded citral (74.58 %) [a isomeric mixture of geranial and nearl] as a major constituents whereas only a less percentage of citral (64.21%, 68.29%) was found in the plants collected from two other altitudes i.e 250m and 1000m respectively. The geraniol, cam-phene and neryl acetate were obtained in a high concentration form the plants collected at 250 m altitude but in the plant from two other altitudes, it was found only in less proportion. Similarly, ?-cadinene, ?-terpineol and camphene were the major constituents of plants at 1000m altitude but in other plants it was detected in very low concentration. Since, the concentration of plant constituents affected by altitude and season, medicinalproperties of such plants and their use in biological application would vary accordingly.


2015 ◽  
Vol 10 (3) ◽  
pp. 951-956 ◽  
Author(s):  
Aradhana Basu ◽  
Swati Panda ◽  
Nabin Dhal

The rare earth elements are a set of seventeen chemical elements which involve the lanthanide series from Lanthanum (La), Tolutetium (Lu), Scandium (Sc), and Yttrium (Y) in the periodic table. Even if Rare Earth Elements are used widely in industry and agriculture in China as well as India for a long time, there has been increasing interest in the application of REEs to plants in recent years. In this paper, we discussed the effect of REE on growth and physiological activities of the plant. By compilation and investigation of these data, we found that REEs have promoting impact at certain concentration. An increase in Chlorophyll, enzymes and protein content further indicated the stimulating effect of La on physiological activities of the selected plants. Depending on the results of this preliminary investigation we can say that a new REE hyperaccumulator, Cymbopogon flexuosus (Lemon grass), was discovered which could accumulate Lanthanum is 20.725 mg g-1 and 25.625 mg g-1 dry mass in root and shoot part respectively under natural growth conditions. Advanced research should be invested regarding the impacts of REEs on yields of cultivated plants.


1990 ◽  
Vol 17 (3) ◽  
pp. 239 ◽  
Author(s):  
LH Ji ◽  
P Langridge

Bread wheat is an allohexaploid with three pairs of homoeologous chromosomes. This means that each chromosome pair is present in three related but not truly homologous chromosomes. In order to maintain the integrity of the three chromosome sets, pairing must be very tightly controlled at meiosis to allow homologous but not homoeologous chromosomes to pair and recombine. Several genes (termed Ph genes) are known to be involved in controlling chromosome pairing in wheat, but the strongest effect has been associated with a gene on the long arm of chromosome 5B, Phl. The manipulation of this gene can be used to induce recombination between chromosomes that will not normally pair at meiosis. This has application in the introduction of new genetic information into wheat. Elucidation of the mechanism of action of the Ph genes has centred around genetic and cytogenetic studies with little attempt to investigate the molecular biology or biochemistry of these genes. Isolation of genes in meiosis in yeast and genes associated with the aerly stages of meiosis in lily have provided a potential entry point into the identification of the analogous genes in wheat.


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