Search results for "Embryogenesis"

Beneficial Effect of Two Culture Systems with Small Groups of Embryos on the Development and Quality of In Vitro-Produced Bovine Embryos

2014

Summary Currently, in vitro-produced embryos derived by ovum pick up (OPU) and in vitro fertilization (IVF) technologies represent approximately one-third of the embryos worldwide in cattle. Nevertheless, the culture of small groups of embryos from an individual egg donor is an issue that OPU-IVF laboratories have to face. In this work, we tested whether the development and quality of the preimplantation embryos in vitro cultured in low numbers (five embryos) could be improved by the addition of epidermal growth factor, insulin, transferrin and selenium (EGF-ITS) or by the WOW system. With this aim, immature oocytes recovered from slaughtered heifers were in vitro matured and in vitro ferti…

Anther culture in Citrus:a powerful tool to recover seedless triploids

2004

Study on anther culture in hazelnut (Corylus avellana L.) .

2013

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…

Micropropagation of juvenile and adultDigitalis obscura and cardenolide content of clonally propagated plants

1991

Cultures ofDigitalis obscura L. were established from axillary buds of mature plants or leaves of seedlings obtained under aseptic conditions. Explants were cultured on Murashige and Skoog medium containing benzyladenine and/or naphthaleneacetic acid. Shoot proliferation from axillary buds was not affected by seasonal fluctuations in the stock plants and increased relative to the cytokinin concentration, but auxin reduced the multiplication rate. Differentiation of somatic embryos and adventitious buds from cultured leaves required naphthaleneacetic acid alone or combined with benzyladenine, respectively. Cardenolide pattern and content of the regenerated plants were determined by high perf…

Molecular specification of cell lines in the embryo of Platynereis (Annelida)

1992

In this study we describe the site and moment of histospecific differentiation in developmental stages of the annelid Platynereis dumerilii by use of biochemical markers. The monoclonal antibody (mab) OI7 and uncloned hybridoma supernatants (pAb's) OI8, OI10, OI46 and OI69 recognize neural antigens that appear asynchronously during development. By an enzymatic test, acetylcholinesterase (AChE) was found specific for nervous tissue as well. The patterns of neural structures labelled by antibodies differ, however, from those revealed by AChE staining. Experimental inhibition of transcription (with actinomycin D) and of translation (using puromycin) demonstrate that the expression of histospec…

GAMETIC AND SOMATIC EMBRYOGENESIS BY ANTHER CULTURE TECHNIQUE IN CITRUS AND IN OTHER MEDITERRANEAN FRUIT TREES

2010

Salt tolerance of Rana temporaria: spawning site selection and survival during embryonic development (Amphibia, Anura)

1999

AbstractSpawning site selection of Rana temporaria is dependent on the salinity of the water. In the nature reserve 'Salzwiesen von Münzenberg' (Germany) the frogs avoided increased conductivity values, Cl- ion concentrations and salinities and selected lower values for spawning. In the laboratory Gosner stages 20/21 to 22/23 were more sensitive to sodium than the earlier G stages 8 to 20/21 (exposition for 72 h) though they were exposed for the shorter time period of 24 h. The 'no observed effect concentration' (NOEC) between G stages 8/9 and 20/21 was 648 ppm (3350 μS, 2.2‰ salinity) for Na+ and 1872 ppm (6500 μS, 4.0‰ salinity) for K+. The NOEC between G stages 20/21 and 22/23 was 1490 p…

Secondary somatic embryogenesis and plant regeneration in myrtle (Myrtus communis L.).

1998

Immature seeds, as well as hypocotyls and cotyledons excised from seedlings of Myrtus communis L., were cultured on media containing half-strength Murashige and Skoog macronutrients (MS/2) with combinations of auxins and cytokinins, in order to study their morphogenetic competence. Somatic embryogenesis was obtained from cotyledons, hypocotyls and 2-month-old immature seeds with 0.1 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D). The percentage of explants showing this primary somatic embryogenesis ranged from 4% for hypocotyls to 12% for 2-month-old immature seeds. In the latter, somatic embryogenesis was also obtained in media containing 2,4-D plus a cytokinin, and with only a cytokinin. Som…

Influence of culture conditions on embryo formation and maturation in auxin-induced embryogenic cultures of Digitalis obscura.

1994

Somatic embryogenesis was induced in hypocotyls of Digitalis obscura using indoleacetic acid or 2,4-dichlorophenoxyacetic acid with different culture and subculture conditions. Indoleacetic acid-induced embryogenic cultures were used to investigate the effects of amino acids, polyamines and growth regulators on embryo differentiation and maturation. Supplementation of the media with amino acids, polyamines or abscisic acid did not influence or had an adverse effect on embryogenic response. Gibberellic acid at 1.4 μM in either culture (30 days) or subculture medium was effective in promoting both differentiation and normal embryo development. The efficiency of somatic embryogenesis was great…