Search results for " Ploidy"

Prognostic significance of tumor ploidy and histomorphological parameters in adenocarcinoma of Barrett's esophagus.

1999

<i>Background:</i> Despite recent advances in surgical and multidisciplinary treatment, the prognosis for patients with adenocarcinoma of Barrett’s esophagus remains poor. The low prognostic accuracy of even surgical pathologic TNM staging suggests that additonal parameters are necessary in determining the prognosis. <i>Method:</i> In a retrospective analysis of 50 patients who underwent transhiatal or transthoracic esophageal resection due to adenocarcinoma of Barrett’s esophagus, a quantitative DNA analysis using image cytometry was performed in addition to the TNM classification and usual morphological criteria. At the time of DNA analysis the histomorphological p…

Chromosome numbers and DNA ploidy levels of selected species ofHieracium s.str. (Asteraceae)

2007

Chromosome numbers and /or ploidy levels are reported for 44 species and subspecies ofHieracium s.str. from the following European countries: Andorra, Austria, Bulgaria, Czech Republic, France, Italy, Montenegro, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland and Ukraine. The chromosome numbers/DNA ploidy levels ofH. bocconei (2n ∼ 4x),H. bupleuroides subsp.leviceps (2n = 27),H. caesioides subsp.caesioides (2n = 27),H. basifolium (H. caesium agg., 2n = 36),H. plumbeum (H. caesium agg., 2n = 36),H. glaucum subsp.nipholepium (2n= 27),H.gouanii (2n = 18),H. gymnocerinthe (2n = 27),H. ramondii (2n = 27),H. recoderi (2n = 18),H. stelligerum (2n = 18), andH. tomentosum (2n = 18, 2n ∼ 2x, …

USE OF IN VITRO TISSUE CULTURE IN PROPAGATION AND GENETIC IMPROVEMENT OF FRUIT TREES

2020

La coltura in vitro, applicata alla propagazione e miglioramento genetico della biodiversità vegetale, può rappresentare uno strumento efficace per affrontare i problemi attuali come i cambiamenti climatici, le nuove esigenze dei consumatori e indirettamente lo sviluppo delle aree rurali. Inoltre, può assumere un ruolo strategico nel miglioramento genetico e nella propagazione delle cultivar al fine di ottenere genotipi resistenti, con frutti migliori dal punto di vista organolettico e piante capaci di adattarsi ai cambiamenti climatici. Il miglioramento genetico attraverso i metodi convenzionale è limitato da molti fattori infatti, gli alberi da frutto sono caratterizzati da un lungo perio…

Karyological observations on Isoetes duriei Bory (Lycophyta, Isoetaceae) in Sicily

2001

Somatic embryogenesis through in vitro anther culture ofCitrus sinensisL. Osbeck ‘Moro’

2019

In many crops, anther culture is the most used method to induce gametic embryogenesis, aimed to regenerate homozygous plants. However, also somatic embryogenesis can be obtained by this method, when somatic tissue is involved in regeneration process. Many factors can affect this procedure, such as genotype, pre-treatments applied to floral buds, pollen developmental stage, donor plant states, culture media composition and growth culture conditions. Anthers of Citrus sinensis L. Osbeck, cv. Moro, were collected at the vacuolate stage, and after a chilling (4°C) pre-treatment of 7 days, were placed on the same medium, evaluating different temperature stresses applied after the placing in cult…

Ploidy manipulation for genetic improvement in some Mediterranean fruit crops

2017

Plant breeding is focused on selection of new genotypes with improved traits. Conventional methods based on hybridization and those based on biotechnology (somatic hybridization, genetic transformation, ploidy manipulation, etc.) are used to create novel genetic variations. Biotechnology provides powerful tools for plant breeding, for instance, haploid technology allows achievement of homozygous lines from heterozygous parents in one step, which reduces significantly the time required by conventional methods. Concerning woody species, characterized by self-incompatibility, long juvenile period and high degree of heterozygosity, this technique is the only way to get homozygous lines. Haploid…

An updated catalogue of chromosome numbers in the genus Isoetes L. (Isoetaceae, Lycopodiophyta)

2010

Somatic embryogenesis and flow cytometric assessment of nuclear genetic stability for Sansevieria spp.: an approach for in vitro regeneration of orna…

2023

Sansevieria Thunb. species are traditionally known as succulent ornamental plants worldwide. They are also cultivated for medicinal, fodder, soil conservation and fiber uses, and for their capacity to reduce environmental pollution. Sansevieria sexual propagation is limited by the lack of viable seeds, and reproduction is largely made via vegetative propagation by suckers or cuttings. For these reasons, genetic improvement by conventional breeding is limited. To overcome this problem and to address the increasing demand from customers for novel Sansevieria varieties, many commercial companies regularly use in vitro propagation, as is the case in the breeding process of several ornamental pl…

TP53 mutations and S-phase fraction but not DNA-ploidy are independent prognostic indicators in laryngeal squamous cell carcinoma

2005

To prospectively evaluate the prognostic significance of TP53, H-, K-, and N-Ras mutations, DNA-ploidy and S-phase fraction (SPF) in patients affected by locally advanced laryngeal squamous cell carcinoma (LSCC). Eight-one patients (median follow-up was 71 months) who underwent resective surgery for primary operable locally advanced LSCC were analyzed. Tumor DNA was screened for mutational analysis by PCR/SSCP and sequencing. DNA-ploidy and SPF were performed by flow cytometric analyses. Thirty-six patients (44%) had, at least, a mutation in the TP53 gene. Of them, 22% (8/36) had double mutations and 3% (1/36) had triple mutations. In total, 46 TP53 mutations were observed. The majority (41…