scholarly journals Ex situ conservation of genetic resources of field elm (Ulmus minor Mill) and European white elm (Ulmus laevis Pall)

Genetika ◽  
2004 ◽  
Vol 36 (3) ◽  
pp. 221-227
Author(s):  
Jelena Aleksic ◽  
Sasa Orlovic

Principles of the conservation of genetic resources of elms (Ulmus spp) do not differ fundamentally from the general principles accepted for the conservation of genetic resources of other common Noble Hardwoods. Efficient conservation can best be achieved through appropriate combination of in situ and ex situ methods, which have distinct advantages. Besides that, ex situ conservation is employed when emergency measures are needed for rare endangered populations and when populations are too small to be managed in situ (e.g. risks of genetic drift and inbreeding). The aim of our research is ex situ conservation of genetic resources of field elm {Ulmus minor Mill) and European white elm (Ulmus laevis Pall) through establishment of field genebanks. Sampling was conducted in one population of field elm and one population of white elm. Plant material (buds) from 8 trees of field elm and 10 trees of white elm was used for in vitro production of clones. Obtained clones will be used for establishment of field genebanks on the experimental estate of the Institute of Lowland Forestry and Environment.

Author(s):  
Roland Bourdeix ◽  
Steve Adkins ◽  
Vincent Johnson ◽  
Lalith Perera ◽  
Sisunandar

Author(s):  
Jane Muthoni ◽  
Hussein Shimelis ◽  
Rob Melis

Plant genetic resources (PGRs) play an important role in agriculture, environment protection, cultural property and trade; they need to be conserved. There are two fundamental approaches for the conservation of PGRs: in situ and ex situ. In situ conservation is the conservation of ecosystems and natural habitats and the maintenance and recovery of viable populations of species in their natural surroundings. Ex situ preservation is the storage of seeds or plant materials under artificial conditions to maintain their long term viability and availability for use. Genebanks employ seed storage, field collections of living plants and in vitro storage (tissue culture or cryopreservation) for ex situ preservation of PGR. Storage of orthodox seeds, which are tolerant to low moisture content and low temperatures at appropriate temperature and humidity, is the most convenient ex situ conservation method. Plants that produce recalcitrant seeds or non-viable seeds are conserved in field genebanks as well as in-vitro in slow growth media for short-to-medium term and cryopreservation in liquid nitrogen at -1960C for long-term periods. Cryopreservation is very expensive and needs trained personnel; this could explain why this method is rarely used for conservation of plant genetic resources in most developing countries. Potato tubers are bulky and highly perishable; the crop is generally conserved as clones either in field genebanks (with annual replanting), in-vitro conservation in slow growth media for short-to-medium term and cryopreservation for long term. Field genebanks are expensive to maintain and the crop is exposed to many dangers; hence, cryopreservation is the only feasible method for long term conservation. However, given the high cost of cryopreservation, long-term conservation of potato genetic resources is poorly developed in most resource-poor countries leading to high rates of genetic erosion. This paper looks into the various methods that that can be applied to conserve potato genetic resources and the status of conservation of potatoes in major genebanks and some countries.


2021 ◽  
Vol 5 (10) ◽  
pp. 2490-2504
Author(s):  
Raymond Liang ◽  
Vijay Menon ◽  
Jiajing Qiu ◽  
Tasleem Arif ◽  
Santosh Renuse ◽  
...  

Abstract Mammalian red blood cells (RBCs), which primarily contain hemoglobin, exemplify an elaborate maturation process, with the terminal steps of RBC generation involving extensive cellular remodeling. This encompasses alterations of cellular content through distinct stages of erythroblast maturation that result in the expulsion of the nucleus (enucleation) followed by the loss of mitochondria and all other organelles and a transition to anaerobic glycolysis. Whether there is any link between erythroid removal of the nucleus and the function of any other organelle, including mitochondria, remains unknown. Here we demonstrate that mitochondria are key to nuclear clearance. Using live and confocal microscopy and high-throughput single-cell imaging, we show that before nuclear polarization, mitochondria progressively move toward one side of maturing erythroblasts and aggregate near the nucleus as it extrudes from the cell, a prerequisite for enucleation to proceed. Although we found active mitochondrial respiration is required for nuclear expulsion, levels of mitochondrial activity identify distinct functional subpopulations, because terminally maturing erythroblasts with low relative to high mitochondrial membrane potential are at a later stage of maturation, contain greatly condensed nuclei with reduced open chromatin–associated acetylation histone marks, and exhibit higher enucleation rates. Lastly, to our surprise, we found that late-stage erythroblasts sustain mitochondrial metabolism and subsequent enucleation, primarily through pyruvate but independent of in situ glycolysis. These findings demonstrate the critical but unanticipated functions of mitochondria during the erythroblast enucleation process. They are also relevant to the in vitro production of RBCs as well as to disorders of the erythroid lineage.


2013 ◽  
Vol 41 (1) ◽  
pp. 73 ◽  
Author(s):  
Victoria CRISTEA ◽  
Liliana JARDA ◽  
Irina HOLOBIUC

Within the current context of declining biodiversity, the botanical gardens play an essential role in its conservation. Dianthus callizonus, D. glacialis ssp. gelidus and D. spiculifolius are the species that we seek to preserve in "Alexandru Borza" Botanical Garden of Cluj-Napoca (Romania). Several replicates were collected for each taxon from different populations in order to avoid the genetic uniformity. The material collected from the natural sites, was planted on a rockery, specially designed for this collection in the Botanical Garden. At the time of planting, each individual was sampled for setting up an in vitro collection and further biochemical and molecular analyses. In case of ex situ outdoor conservation of the three Dianthus species, 80.6% of the individuals collected in the field survived during the first year but the percentage decreased drastically after four years. In the case of in situ collected individuals, as well as in the case of in vitro individuals, D. spiculifolius had the best ability to acclimatize in the Botanical Garden, and D. callizonus presented the lowest number of surviving individuals. The ex vitro acclimatization of the plantlets had 80% efficiency at 10ºC, using three different substrates: soil and pearl stone mix 1/1, soil and sand mix 1/1 and pearl stone. All the three species are preserved in vitro, whereas the plantlets are acclimatized outdoors. Ex situ conservation of these species will have a positive impact on the biodiversity conservation.


Author(s):  
Dionis Minev ◽  
Richard Guerra ◽  
Jocelyn Y Kishi ◽  
Cory Smith ◽  
Elisha Krieg ◽  
...  

Abstract There is increasing demand for single-stranded DNA (ssDNA) of lengths >200 nucleotides (nt) in synthetic biology, biological imaging and bionanotechnology. Existing methods to produce high-purity long ssDNA face limitations in scalability, complexity of protocol steps and/or yield. We present a rapid, high-yielding and user-friendly method for in vitro production of high-purity ssDNA with lengths up to at least seven kilobases. Polymerase chain reaction (PCR) with a forward primer bearing a methanol-responsive polymer generates a tagged amplicon that enables selective precipitation of the modified strand under denaturing conditions. We demonstrate that ssDNA is recoverable in ∼40–50 min (time after PCR) with >70% yield with respect to the input PCR amplicon, or up to 70 pmol per 100 μl PCR reaction. We demonstrate that the recovered ssDNA can be used for CRISPR/Cas9 homology directed repair in human cells, DNA-origami folding and fluorescent in-situ hybridization.


CORD ◽  
2005 ◽  
Vol 21 (02) ◽  
pp. 34
Author(s):  
Pons Batugal

The International Coconut Genetic Resources Network (COGENT) is a global research network organized by the International Plant Genetic Resources Institute (IPGRI) in 1992 with support from member countries, the Consultative Group on International Agricultural Research (CGIAR), partner institutions, donor agencies, and by regional and international development organizations.                           In the last 12 years, COGENT has been fully operational with 38 member coconut producing countries in five regions (South Asia; Southeast and East Asia; South Pacific; Africa and the Indian Ocean; and Latin America and the Caribbean). It has successfully developed and disseminated to coconut breeders and curators worldwide the International Coconut Genetic Resources Database (CGRD). The CGRD contains characterization data and some pictures of 1,416 accessions which are conserved by national programmes in 28 sites in 23 countries. To further secure conserved germplasm, a COGENT multi-site International Coconut Genebank has been established to conserve 200 important accessions in each region. Coconut varieties with multi-purpose uses are being identified, documented and promoted. The performance of promising 38 high-yielding hybrids are being evaluated in a multilocation  trial involving four African and three Latin America/Caribbean countries to identify suitable varieties and hybrids for resource-poor farmers. Farmers’ varietal preferences in 15 countries are being evaluated. Diversity-linked income-generating activities are being used as a strategy to promote in situ and on-farm conservation and germplasm utilization have been initiated in 15 countries. Protocols for in vitro embryo culture, cryopreservation, morphometric and molecular marker-based methods for locating and characterizing diversity; pest risk assessment and germplasm health management are being developed, tested and upgraded. Strategies and techniques for farmer participatory research, collecting, characterization and ex situ and in situ conservation are being refined.   To strengthen the coconut research capability of COGENT member countries, the COGENT Secretariat and IPGRI have organized 39 country need assessment missions  and conducted 41 workshops and meetings involving 994 coconut researchers to share information and technologies, discuss issues and common problems and opportunities and how to address them; conducted 40 training courses involving 765 participants from 41 countries; supported 274  research and training/capacity building activities  in 30 countries; and led the establishment of the Global Coconut Research for Development Programme (PROCORD). IPGRI and COGENT's current priority involves the further promotion of more effective conservation and use of coconut genetic resources, both regionally and globally.


2007 ◽  
Vol 83 (3) ◽  
pp. 402-407
Author(s):  
J A Loo ◽  
T L Beardmore ◽  
J D Simpson ◽  
D A McPhee

Guidelines were developed by the New Brunswick Forest Gene Conservation Working Group for conserving genetic resources of four native tree species in New Brunswick. Gene conservation guidelines for three of these species aim to maintain sufficient gene pools of known or putatively resistant stock to retain or develop the potential for restoration. Natural populations of American beech (Fagus grandifolia) are known to have genotypes resistant to the beech scale at low frequencies. Gene conservation approaches include in situ and ex situ measures, including resistance breeding. White elm (Ulmus americana) demonstrates a degree of resistance to Dutch elm disease (DED), and will benefit from a mixture of in situ and ex situ conservation measures. Resistance to butternut canker has not yet been demonstrated in populations of butternut (Juglans cinerea), but ex situ conservation of putatively resistant genotypes will be of increasing importance as the frequency of butternut canker escalates. Bur oak (Quercus macrocarpa), threatened by small population size, habitat loss, and ongoing development, requires primarily in situ conservation and restoration efforts. Key words: American beech, bur oak, butternut, disease resistance, ex situ, gene conservation guidelines, genetic resources, in situ, restoration, white elm


2007 ◽  
Vol 35 (5) ◽  
pp. 962-965 ◽  
Author(s):  
M. He ◽  
M.J. Taussig

Cell-free transcription and translation provides an open, controllable environment for production of correctly folded, soluble proteins and allows the rapid generation of proteins from DNA without the need for cloning. Thus it is becoming an increasingly attractive alternative to conventional in vivo expression systems, especially when parallel expression of multiple proteins is required. Through novel design and exploitation, powerful cell-free technologies of ribosome display and protein in situ arrays have been developed for in vitro production and isolation of protein-binding molecules from large libraries. These technologies can be combined for rapid detection of protein interactions.


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