Cytogenetic variability of in vitro regenerated Hypericum perforatum L. plants and their seed progenies

Brutovská, R.; Čellárová, Eva; Doležel, Jaroslav

doi:10.1016/s0168-9452(98)00041-7

Cited by 30 publications

(26 citation statements)

References 30 publications

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“…One of the explanations for this phenomenon is the cytological diversity of the cells involved in the organisation of an adventitious bud (Christianson and Warnick 1983). Brutovská et al (1998) noticed the influence of growth regulators such as high concentrations of BA in a medium on the frequency of mixoploidy among the Hypericum perforatum regenerants.…”

Section: Chromosome Number Analysismentioning

confidence: 99%

Chromosome variations in regenerants of Arabidopsis thaliana derived from 2- and 6-week-old callus detected using flow cytometry and FISH analyses

Orzechowska

Stępień

Kamińska

et al. 2012

Plant Cell Tiss Organ Cult

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Shoot organogenesis was induced from 2-and 6-week-old callus derived from the leaves of Arabidopsis thaliana ecotype Columbia (2n = 10). Regenerated plants were evaluated for chromosomal variations by means of flow cytometry and fluorescent in situ hybridization (FISH). Flow cytometric measurements revealed the occurrence of diploid, tetraploid, and octoploid plants among the regenerants of 2-week-old calli, whereas only diploid and tetraploid plants were regenerated from the 6-week-old calli. Chromosome counting showed that plants developed from the 2-week-old calli exhibited mixoploidy and a high frequency of aneuploid cells. These plants were infertile and displayed altered morphology. FISH with 5S and 25S rDNA probes allowed to detect some structural chromosomal rearrangements in regenerated plants. Along with cells which exhibited correct localisation of rDNA loci, also cells bearing chromosomal translocations, deletions or duplications were found. The type of structural aberrations varied between diploid and tetraploid regenerants.

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Section: Chromosome Number Analysismentioning

confidence: 99%

Chromosome variations in regenerants of Arabidopsis thaliana derived from 2- and 6-week-old callus detected using flow cytometry and FISH analyses

Orzechowska

Stępień

Kamińska

et al. 2012

Plant Cell Tiss Organ Cult

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“…Pollination timing has been proposed as a possible influence on the fate of aposporic embryo sacs in H. perforatum (Brutovská et al, 1998). Our observations demonstrate that the egg cell was generally characterised by a strong DAPI stain when compared to the other cells of the embryo sac and the surrounding cells of the nucellus.…”

Section: Cytohistological Investigationsmentioning

confidence: 99%

Genetic diversity and reproductive biology in ecotypes of the facultative apomict Hypericum perforatum L.

et al. 2006

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Apomixis is a mode of asexual reproduction through seed. Progeny produced by apomixis are clonal replicas of a mother plant. The essential feature of apomixis is that embryo sacs and embryos are produced in ovules without meiotic reduction or egg cell fertilisation. Thus, apomixis fixes successful gene combinations and propagates high fitness genotypes across generations. A more profound knowledge of the mechanisms that regulate reproductive events in plants would contribute fundamentally to understanding the evolution and genetic control of apomixis. Molecular markers were used to determine levels of genetic variation within and relationship among ecotypes of the facultative apomict Hypericum perforatum L. (2n ¼ 4x ¼ 32). All ecotypes were polyclonal, being not dominated by a single genotype, and characterised by different levels of differentiation among multilocus genotypes. Flow cytometric analysis of seeds indicated that all ecotypes were facultatively apomictic, with varying degrees of apomixis and sexuality. Seeds set by haploid parthenogenesis and/or by fertilisation of aposporic egg cells were detected in most populations. The occurrence of both dihaploids and hexaploids indicates that apospory and parthenogenesis may be developmentally uncoupled and supports two distinct genetic factors controlling apospory and parthenogenesis in this species. Cyto-embryological analysis showed that meiotic and aposporic processes do initiate within the same ovule: the aposporic initial often appeared evident at the time of megaspore mother cell differentiation. Our observations suggest that the egg cell exists in an active metabolic state before pollination, and that its parthenogenetic activation leading to embryo formation may occur before fertilisation and endosperm initiation.

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“…Structures formed during apomixis can be similar to or can vary significantly in form and position relative to the surmised sexual counterpart (Nogler, 1984;Willemse and van Went, 1984;Koltunow, 1993;Naumova and Willemse, 1995;Koltunow et al, 1998;Araujo et al, 2000). In apomictic Beta (Jassem, 1990), Hieracium (Koltunow et al, 1998), Rosaceae species (Nybom, 1988;Izmailow, 1994), and Hypericum (Brutovska et al, 1998), variation in embryo sac, embryo, and endosperm development is evident among the ovules and seeds of an individual plant.…”

Section: Introductionmentioning

confidence: 99%

Sexual and Apomictic Reproduction in Hieracium subgenus Pilosella Are Closely Interrelated Developmental Pathways

Araujo²,

et al. 2003

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Seed formation in flowering plants requires meiosis of the megaspore mother cell (MMC) inside the ovule, selection of a megaspore that undergoes mitosis to form an embryo sac, and double fertilization to initiate embryo and endosperm formation. During apomixis, or asexual seed formation, in Hieracium ovules, a somatic aposporous initial (AI) cell divides to form a structurally variable aposporous embryo sac and embryo. This entire process, including endosperm development, is fertilization independent. Introduction of reproductive tissue marker genes into sexual and apomictic Hieracium showed that AI cells do not express a MMC marker. Spatial and temporal gene expression patterns of other introduced genes were conserved commencing with the first nuclear division of the AI cell in apomicts and the mitotic initiation of embryo sac formation in sexual plants. Conservation in expression patterns also occurred during embryo and endosperm development, indicating that sexuality and apomixis are interrelated pathways that share regulatory components. The induction of a modified sexual reproduction program in AI cells may enable the manifestation of apomixis in Hieracium .

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Cytogenetic variability of in vitro regenerated Hypericum perforatum L. plants and their seed progenies

Cited by 30 publications

References 30 publications

Chromosome variations in regenerants of Arabidopsis thaliana derived from 2- and 6-week-old callus detected using flow cytometry and FISH analyses

Chromosome variations in regenerants of Arabidopsis thaliana derived from 2- and 6-week-old callus detected using flow cytometry and FISH analyses

Genetic diversity and reproductive biology in ecotypes of the facultative apomict Hypericum perforatum L.

Sexual and Apomictic Reproduction in Hieracium subgenus Pilosella Are Closely Interrelated Developmental Pathways

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