Obligatory amphimixis and variation in chromosome number within and among South American populations of Nacobbus aberrans (Thorne, 1935) Thorne & Allen, 1944 (Nematoda: Pratylenchidae)

Nematology ◽  
2005 ◽  
Vol 7 (5) ◽  
pp. 783-787 ◽  
Author(s):  
Géraldine Anthoine ◽  
Didier Mugniéry
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Experimental Approach ◽  
Taxonomic Status ◽  
Reproductive Mode ◽  
South American ◽  
Complementary Information ◽  
Haploid Chromosome Number ◽  
Nacobbus Aberrans

AbstractThere are conflicting opinions concerning the reproductive mode and the taxonomic status of Nacobbus aberrans, so we have addressed these issues by an experimental approach based on the inoculation of immature and vermiform females in in vitro conditions. Complementary information on chromosome number was provided. Five South American populations of Nacobbus aberrans were tested. No population was observed to be able to reproduce by parthenogenesis in in vitro conditions. The basic haploid chromosome number seems to be seven, at least for four of the five populations studied. However, all populations had individuals with haploid chromosome numbers ranging from five to eight, six to eight being the most frequent number, regardless of the 'race' group or the native country. The variation in the chromosome number suggests that N. aberrans may be considered as a set of different karyological genetic entities.

scholarly journals Peculiarities of chromosomal variability in cultured tissues of Deschampsia antarctica Desv. plants with different chromosome numbers

2016 ◽  
Vol 14 (1) ◽  
pp. 36-43 ◽  
Author(s):  
V. A. Kunakh ◽  
D. O. Navrotska ◽  
M. O. Twardovska ◽  
I. O. Andreev
Keyword(s):  
Tissue Culture ◽  
Chromosome Number ◽  
Chromosome Numbers ◽  
Diploid Chromosome Number ◽  
Deschampsia Antarctica ◽  
Donor Plant ◽  
Modal Class ◽  
Chromosomal Variability ◽  
Diploid Cells

Aim. To clarify the details of chromosome variation in calli derived from D. antarctica plants in the initial passages of the culture in vitro. Methods. Induction of callus from root explants of plants, which were grown from seeds, and consequent subcultivation of tissue culture. Cytogenetic analysis of squashed slides stained by acetic-orcein and counting the number of chromosomes in mitotic metaphase plates. Results. There were analyzed the cultured tissues derived from D. antarctica plants with different chromosome numbers: diploid plants (2n=26), mixoploid plant with B-chromosomes (2n=26+1-3B), and mixoploid plant with near-triploid modal class (2n=36, 38). Analysis of callus tissues of all plants at 2-4 passages revealed mixoploidy, presence of polyploid and aneuploid cells. The modal class in all studied calli was composed of diploid and aneuploid cells with near-diploid chromosome number. The cytogenetic structure of cell population of cultured tissues was found to vary with characteristics of the karyotype of donor plant. The largest range of variation in the number of chromosomes (from 18 to 63 chromosomes) was found in tissue culture of diploid plant (2n=26) from the Galindez Island, and the highest frequencies of polyploid (47 %) and aneuploid cells were in the culture of mixoploid plant with near-triploid modal class from the Big Yalour Island. Conclusions. In different D. antarctica cultured tissues at the early stages of the culture, the modal class was composed of diploid cells and cells with near-diploid chromosome number irrespective of karyotype of donor plant (diploid, mixoploid poliploid).Key words: Deschampsia antarctica Desv., plant tissue culture, chromosomal variability in vitro, mixoploidy.

Gender dependent and independent morphological dimorphism in sexual and apomictic Antennaria monocephala sensu lato

1991 ◽  
Vol 69 (7) ◽  
pp. 1433-1448 ◽  
Author(s):  
J. G. Chmielewski ◽  
C. C. Chinnappa
Keyword(s):  
Chromosome Number ◽  
Key Words ◽  
Reproductive Biology ◽  
Chromosome Numbers ◽  
Evolutionary History ◽  
Multivariate Analyses ◽  
Reproductive Mode ◽  
Polyploid Complex ◽  
Adaxial Surface ◽  
History Of

Taxa included in the Antennaria monocephala DC. polyploid complex were previously circumscribed at the specific, subspecific, or varietal levels without concensus. The purpose of this phenetic study was to construct a taxonomy that not only reflects the presumed evolutionary history of the complex but also presents a taxonomy that is both functional and informative, regardless of an individual's gender or more importantly, the reproductive mode of the population. The rank of subspecies (A. monocephala ssp. monocephala and A. monocephala ssp. angustata (Green) Hultén) was accepted as the most appropriate level of gender independent circumscription that satisfied the purpose of the phenetic study. These subspecies differ with respect to tomentum, chromosome number, reproductive biology, and (in part) provenance. The former taxon, A. monocephala ssp. monocephala, is a sexual diploid (2n = 28); the latter taxon, A. monocephala ssp. augustata, is an apomictic polyploid, with chromosome numbers ranging from tetraploid (2n = 56) to octoploid (2n = 112). In A. monocephala ssp. monocephala the adaxial surface of the basal and cauline leaves is glabrous-strigose, as is the stem. In A. monocephala ssp. angustata the adaxial surface of both basal and cauline leaves is floccose-tomentose, as is the surface of the stem. Key words: Antennaria monocephala polyploid complex, multivariate analyses.

Characterization of the Reproductive Mode in Guayule In Vitro

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 483a-483
Author(s):  
Roy N. Keys ◽  
Dennis T. Ray ◽  
David A. Dierig
Keyword(s):  
Field Experiments ◽  
Reproductive Mode ◽  
Dichlorophenoxyacetic Acid ◽  
Initial Field ◽  
Breeding Lines ◽  
Reproductive Modes ◽  
Desert Southwest ◽  
2,4 Dichlorophenoxyacetic Acid

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

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 A long reads-based de-novo assembly of the genome of the Arlee homozygous line reveals chromosomal rearrangements in rainbow trout

2021 ◽  
Author(s):  
Guangtu Gao ◽  
Susana Magadan ◽  
Geoffrey C Waldbieser ◽  
Ramey C Youngblood ◽  
Paul A Wheeler ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Chromosome Number ◽  
Genome Assembly ◽  
De Novo Assembly ◽  
De Novo ◽  
Sequence Data ◽  
Structural Variations ◽  
High Coverage ◽  
Haploid Chromosome Number ◽  
Long Reads

Abstract Currently, there is still a need to improve the contiguity of the rainbow trout reference genome and to use multiple genetic backgrounds that will represent the genetic diversity of this species. The Arlee doubled haploid line was originated from a domesticated hatchery strain that was originally collected from the northern California coast. The Canu pipeline was used to generate the Arlee line genome de-novo assembly from high coverage PacBio long-reads sequence data. The assembly was further improved with Bionano optical maps and Hi-C proximity ligation sequence data to generate 32 major scaffolds corresponding to the karyotype of the Arlee line (2 N = 64). It is composed of 938 scaffolds with N50 of 39.16 Mb and a total length of 2.33 Gb, of which ∼95% was in 32 chromosome sequences with only 438 gaps between contigs and scaffolds. In rainbow trout the haploid chromosome number can vary from 29 to 32. In the Arlee karyotype the haploid chromosome number is 32 because chromosomes Omy04, 14 and 25 are divided into six acrocentric chromosomes. Additional structural variations that were identified in the Arlee genome included the major inversions on chromosomes Omy05 and Omy20 and additional 15 smaller inversions that will require further validation. This is also the first rainbow trout genome assembly that includes a scaffold with the sex-determination gene (sdY) in the chromosome Y sequence. The utility of this genome assembly is demonstrated through the improved annotation of the duplicated genome loci that harbor the IGH genes on chromosomes Omy12 and Omy13.

Period of harvest, sprouting ability of cuttings, and in vitro plant regeneration in Fraxinus excelsior

1994 ◽  
Vol 72 (2) ◽  
pp. 261-267 ◽  
Author(s):  
Conceição Eneida Silveira ◽  
Alain Cottignies
Keyword(s):  
Chromosome Number ◽  
In Vitro Culture ◽  
Adventitious Roots ◽  
Woody Plant ◽  
Fraxinus Excelsior ◽  
Stem Cuttings ◽  
Natural Conditions ◽  
Apical Bud ◽  
Woody Plant Medium

Propagation by stem cuttings and in vitro culture of apical bud explants were studied on Fraxinus excelsior L. Stem cuttings from 4- to 7-year-old trees growing under natural conditions sprouted only when cuttings were taken from dormant material. Only 6% of those that had sprouted developed roots by the 7th month of culture. Similarly, only apical bud explants harvested during the dormant period sprouted in vitro. Up to 87% of these sprouts developed two to four branching adventitious roots after 5 months of culture. During the initial phase of in vitro culture, the Quoirin and Lepoivre medium and the woody plant medium favoured sprout lengthening. During the phase of multiplication, up to three sprouts per explant developed with the woody plant medium in the presence of a combination of high 6-benzylaminopurine (3.0–4.0 mg∙L−1) and low indole-3-butyric acid (0.01–0.03 mg∙L−1) concentrations. Rooting was obtained in a medium without any growth regulators. Microscopic analysis showed a direct connection between the vascular elements of adventitious roots and stem of plantlet. Chromosome number in root apices of ash plantlets and ash trees grown under natural conditions was 2n = 46. Key words: chromosome number, Fraxinus excelsior L., in vitro plants, micropropagation, stem cuttings.

A Novel Experimental Approach for Three-Dimensional Geometry Assessment of Calcified Human Stenotic Arteries in Vitro

2013 ◽  
Vol 39 (10) ◽  
pp. 1875-1886 ◽  
Author(s):  
Renate W. Boekhoven ◽  
Richard G.P. Lopata ◽  
Marc R. van Sambeek ◽  
Frans N. van de Vosse ◽  
Marcel C.M. Rutten
Keyword(s):  
Experimental Approach ◽  
Three Dimensional ◽  
Stenotic Arteries

Anthelmintic effect of four extracts obtained from Caesalpinia coriaria foliage against the eggs and larvae of Haemonchus contortus

2021 ◽  
Vol 30 (3) ◽  
Author(s):  
Diana Rojas-Morales ◽  
Jaime Cubides-Cárdenas ◽  
Andrea Constanza Montenegro ◽  
Carlos Alberto Martínez ◽  
Ronnal Ortíz-Cuadros ◽  
...  
Keyword(s):  
Medicinal Plant ◽  
Haemonchus Contortus ◽  
Probit Analysis ◽  
South American ◽  
Egg Hatching ◽  
Acetone Water ◽  
Acetone Extracts ◽  
Eggs And Larvae ◽  
Anthelmintic Effect

Abstract To investigate the in vitro anthelmintic efficacy of dividivi (Caesalpinia coriaria), a traditional medicinal plant used in Central America and the northern part of South America, extracts from the foliage of this plant were subjected to the egg hatching test (EHT) and larval exsheathment inhibition test (LEIT), against Haemonchus contortus. Four different extracts were evaluated: acetone-water (AW), methanol-water (MW), acetone-water-dichloromethane (AWD) and methanol-water-dichloromethane (MWD). The concentrations used for the EHT and LEIT tests ranged from 500 to 4000 µg mL-1 and six repetitions per concentration. The effective concentrations (EC50) were calculated using Probit analysis. The EC50 for EHT were 2947.0, 3347.0, 3959.6 and 4538.7 µg mL-1 for MWD, MW, AW and AWD, respectively. The EC50 for LEIT were 2883.4, 5927.4, 9876.3 and 9955.4 µg mL-1 for AWD, AW, MWD and MW, respectively. The methanol extracts were the most effective in inhibiting the hatching of eggs, while the acetone extracts showed efficacy in inhibiting larval exsheathment. This study explains the importance that C. coriaria has as a medicinal plant in Central and South American countries.

scholarly journals In vitro responses in Passiflora species with different chromosome numbers, ploidy levels and nuclear 2C values: revisiting and providing new insights

2018 ◽  
Vol 136 (3) ◽  
pp. 549-560 ◽  
Author(s):  
Cristiana Torres Leite ◽  
Darley Aparecido Tavares Ferreira ◽  
Ariane Tonetto Vieira ◽  
Milene Miranda Praça-Fontes ◽  
Adésio Ferreira ◽  
...  
Keyword(s):  
Chromosome Numbers ◽  
Ploidy Levels

scholarly journals Morphological, Anatomical and Cytological Studies of some Moss Species from Nigeria

2017 ◽  
Vol 9 (3) ◽  
pp. 404-413
Author(s):  
Abolade Oluremi BOLAJI ◽  
Julius Olaoye FALUYI
Keyword(s):  
Chromosome Numbers ◽  
Taxonomic Status ◽  
Knowledge Gaps ◽  
Moss Species ◽  
Anatomical Studies ◽  
First Time

Morphological, anatomical and chromosome studies of Hyophila crenulata C, Mull. Ex Dus, Thuidium gratum (P. Beauv) Jaeg., Barbula lambarenensis P. Vard.. Stereophyllum nitense Mitt. and Bryum coronatum Schwaegr from Nigeria, were carried out with a view to bridging some knowledge gaps that exist in their characterization and providing insightful information that could be useful in elucidating their taxonomic status. The morphological and anatomical studies revealed several gametophytic and sporophytic attributes which have not been previously reported and which were diagnostic for the moss species studied. The chromosome studies revealed the chromosome numbers to be Hyophila crenulata n = 4; Thuidium gratum n = 12 (10 + 2 m); Barbula lambarenensis n = 3; Stereophyllum nitense n = 9; and Bryum coronatum n = 10. The study concluded that the details of the morphological and anatomical descriptions as well as the chromosome numbers being reported for the first time in this study for the moss species studied could be very useful in their identification and taxonomic delimitation.

Sign in / Sign up

Export Citation Format

Share Document