Search results for "haploid"

In vitro anther culture of sweet orange (Citrus sinensis L. Osbeck) genotypes and of a C. clementina × C. sinensis 'Hamlin' hybrid

2014

Citrus, and particularly sweet oranges, are very recalcitrant to anther culture. In this paper it was evaluated for the first time the response of 27 genotypes of Citrus sinensis and of one hybrid C. clementina × C. sinensis, to in vitro anther culture. Ten genotypes of sweet oranges showed embryogenic callus induction, mostly blood sweet oranges genotypes, such as Tarocco, Moro and Sanguinelli. In vitro microspore developmental switches from the gamethophytic to the sporophytic pathway were shown by DAPI staining in microspores of these responsive genotypes, after 10 months in culture. However, microsatellite marker analyses showed that these calli were heterozygous. The flow-cytometric an…

Human germ cell differentiation from fetal- and adult-derived induced pluripotent stem cells

2010

Historically, our understanding of molecular genetic aspects of human germ cell development has been limited, at least in part due to inaccessibility of early stages of human development to experimentation. However, the derivation of pluripotent stem cells may provide the necessary human genetic system to study germ cell development. In this study, we compared the potential of human induced pluripotent stem cells (iPSCs), derived from adult and fetal somatic cells to form primordial and meiotic germ cells, relative to human embryonic stem cells. We found that ∼5% of human iPSCs differentiated to primordial germ cells (PGCs) following induction with bone morphogenetic proteins. Furthermore, …

Near-Haploidy in a Malignant Sacrococcygeal Teratoma

1999

Cytogenetic analysis of a malignant sacrococcygeal teratoma in an adult patient revealed near-haploid (77%), near-diploid (19%), and polyploid (4%) cells. The near-haploid cells had a karyotype of 25,XX,der(5)t(5;7)(p15;p13),+7,der(9)t(6;9)(p21;q34),r(17)(p13q25) . In the near-diploid and polyploid cells identical copies of the structural chromosomal changes were found. Although some of the anomalies observed appear unique to this case, a common breakpoint in chromosome 6 was previously reported as specific in a subgroup of extragonadal germ cell tumors of adults.

Advancement on isolated microspore culture in Citrus clementina Hort. ex Tan., cvs. Monreal Rosso and Nules.

2013

Gametic embryogenesis through isolated microspore culture in mandarin (Citrus reticulata Blanco), Mandarino Tardivo Di Ciaculli: effect of meta-Topol…

2016

Haploid technology, allowing the single-step development of complete homozygous genotypes from heterozygous plants through gametic embryogenesis, has already an enormous impact on breeding programs of many important crops. Microspore embryogenesis can be carried out through in vitro culture of anther or isolated microspore. Experiments have been carried out via isolated microspore culture in Citrus reticulata (Blanco), Mandarino Tardivo di Ciaculli, investigating the influence of two culture media, of two plant growth regulator types and of two temperature treatments applied before the culture or just after the culture. After ten months of culture, for all the media tested, different struct…

Use of irradiated pollen to induce Parthenogenesis and haploid production in fruit crops.

2012

Preliminary Results on the Effect of Magnetic Fields on Anther Culture and Pollen Germination of Citrus clementina Hort. ex Tan.

2003

Exposure to electromagnetic fields seems to modify the biological behaviour of seeds, roots, pollen grains and buds of several plants. This procedure has been also suggested as a tool to improve the utilization of plant species (Firetto et al., 2000, 2001, Petruszewski S., 1996). Since the first haploid embryogenic calli production and plantlet regeneration by anther culture of C. clementina Hort. ex Tan. 'Nules' was reported (Germany et al., 1994), several studies have been carried out to improve both the frequency of microspore embryogenesis and the percentage of plantlet regeneration. To enlarge the number of respondent genotypes and to improve the induction rate (the frequency of pollen…

Tècniques d'anàlisi genètica: Tema 2

2014

El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València Tema 2 de 8, que componen l'assignatura. En aquest tema es presenta l'nàlisi genètica clàssica aplicada a organismes haploides

Androgenesis and doubled-haploid production in food legumes

2011

International audience

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…