scholarly journals Challenges and Prospects for the Conservation of Crop Genetic Resources in Field Genebanks, in In Vitro Collections and/or in Liquid Nitrogen

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1634 ◽  
Author(s):  
Bart Panis ◽  
Manuela Nagel ◽  
Ines Van den houwe

The conservation of crop genetic resources, including their wild relatives, is of utmost importance for the future of mankind. Most crops produce orthodox seeds and can, therefore, be stored in seed genebanks. However, this is not an option for crops and species that produce recalcitrant (non-storable) seeds such as cacao, coffee and avocado, for crops that do not produce seeds at all; therefore, they are inevitably vegetatively propagated such as bananas, or crops that are predominantly clonally propagated as their seeds are not true to type, such as potato, cassava and many fruit trees. Field, in vitro and cryopreserved collections provide an alternative in such cases. In this paper, an overview is given on how to manage and setup a field, in vitro and cryopreserved collections, as well as advantages and associated problems taking into account the practical, financial and safety issues in the long-term. In addition, the need for identification of unique accessions and elimination of duplicates is discussed. The different conservation methods are illustrated with practical examples and experiences from national and international genebanks. Finally, the importance of establishing safe and long-term conservation methods and associated backup possibilities is highlighted in the frame of the global COVID-19 pandemic.

2005 ◽  
Vol 41 (4) ◽  
pp. 475-489 ◽  
Author(s):  
VINCENT LEBOT ◽  
ANTON IVANCIC ◽  
KUTTOLAMADATHIL ABRAHAM

This paper addresses the preservation and use of minor root crop genetic resources, mostly aroids and yams. Conservation is fraught with difficulty: ex situ collections are expensive to maintain and methods for on-farm conservation have not been studied. Conventional breeding strategies present serious limitations when applied to these species. Furthermore, the evaluation and distribution of improved material are as problematical as its conservation. The similarities shared by these species regarding their domestication, breeding constraints and improvement strategies as well as farmers' needs, are briefly reviewed. Based on these biological constraints, we propose a practical alternative to current conservation and breeding strategies. This approach focuses on the geographical distribution of allelic diversity rather than localized ex situ and/or in situ preservation of genotypes. The practical steps are described and discussed. First, a core sample representing the useful diversity of the species is assembled from accessions selected for their diverse and distant geographic origins, wide genetic distances, quality, agronomic performances and functional sexuality. Second, the geographical distribution of this core sample, in vitro via a transit centre, allows the direct use of selected genotypes by farmers or for breeding purposes. Third, the distribution of genes is realized in the form of clones resulting from segregating progenies and, fourth, farmers select clones with local adaptation.


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.


2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Youwei Wang ◽  
Zhi-bo Han ◽  
Yong-ping Song ◽  
Zhong Chao Han

Mesenchymal stem cells (MSCs) hold great promise as therapeutic agents in regenerative medicine and autoimmune diseases, based on their differentiation abilities and immunosuppressive properties. However, the therapeutic applications raise a series of questions about the safety of culture-expanded MSCs for human use. This paper summarized recent findings about safety issues of MSCs, in particular their genetic stability in long-termin vitroexpansion, their cryopreservation, banking, and the role of serum in the preparation of MSCs.


1995 ◽  
Vol 62 (4) ◽  
pp. 568-571
Author(s):  
F. Lugnani

Physiopathological bases of cryosurgical damage are described: hypothermia, freezing, thawing are all disruptive moments causing necrosis. Last-generation cryosurgical apparatus allows the use of liquid nitrogen circulating through thin probes that are inserted percutaneously under u.s. guidance. Also thermosensors are used to monitor the procedure placing them in selected spots. 404 patients were treated in 3 different but homogeneous groups. Results of control biopsies were available at 3 months for 298 (15 pos.) and for 141 at 12 months (13 pos.). Cryoablation appears to be an interesting procedure, but its complexity requires accurate training with a steep “learning curve”; only long-term follow-up will test in the future its real efficacy.


2011 ◽  
Vol 23 (1) ◽  
pp. 241
Author(s):  
C. Li ◽  
E. Mizutani ◽  
T. Ono ◽  
T. Wakayama

Mammalian spermatozoa preservation now plays an important role in fertility treatments, generating hybrid animals and protecting endangered and extinct species. To date, the most common method of sperm preservation is freezing in liquid nitrogen (LN2). However, this method requires constant supplementation of LN2 and also presents some safety issues involved in transporting LN2. Here we describe a new sperm preservation method that does not involve freezing. Mouse spermatozoa were cultured in four basic media (HEPES–Chatot-Ziomele-Barister’s medium (HCZB), KSOM, K+-rich nuclear isolation medium (NIM), and PBS) with or without 10% BSA or 15% Ficoll as a cryoprotectant, and preserved in a refrigerator for up to 6 months. These preserved sperm were then injected into fresh oocytes and cultured to the blastocyst stage in vitro or transferred into recipient females to demonstrate their genetic integrity. Oocytes injected with 1-month-preserved spermatozoa in NIM and PBS showed significantly higher blastocyst rates (22.8% and 18.9%) than those in HEPES-CZB and KSOM (1-way ANOVA, P < 0.05). In embryos with 3-month-preserved spermatozoa in NIM or PBS with BSA or Ficoll, 5.3–24.0%; P < 0.05 of embryos, (n = 1056) developed to the blastocyst stage, and the developmental ratio was not decreased even for 6-month preservation (13.6–18.2%; P > 0.05). Surprisingly, 18 pups were obtained using spermatozoa stored in those mediums for 6 months. Moreover, this new method allowed easy production of healthy offspring even after transporting spermatozoa between two countries by aircraft at room temperature without any protection. In conclusion, this method allows for easy long-term preservation of mouse spermatozoa in a simple, modified medium at refrigerator temperature with very low cost and wide application.


2017 ◽  
Vol 66 (1-2) ◽  
pp. 44-50
Author(s):  
Tatjana Vujović ◽  
Đurđina Ružić ◽  
Radosav Cerović

SummaryIn vitro shoot tips of the blackberry cultivar ‘Čačanska Bestrna’ were cryopreserved using the droplet vitrification technique. Upon loading (30 min) in a solution of 1.9 M glycerol and 0.5 M sucrose, the explants were dehydrated for 40 min on ice with the PVS A3 vitrification solution (glycerol 37.5%, dimethyl sulfoxide 15%, ethylene glycol 15% and sucrose 22.5%) and for 40 min at room temperature with the PVS3 solution (glycerol 50% and sucrose 50%). They were subsequently frozen in individual microdroplets of vitrification solution, by direct immersion in liquid nitrogen (LN), and kept therein for 2, 4, 8 and 24 h. The explant rewarming was performed in an unloading solution (0.8 M sucrose) for 30 min at room temperature. The duration of LN exposure did not exert significant effects on the survival and regrowth of explants in both types of vitrification solutions. The survival and regrowth of cryopreserved shoot tips dehydrated with PVS3 solution ranged between 90–95% and 80–90%, respectively. However, dehydration with PVS A3 resulted in a lower survival rate (80–90%) and a considerably lower regrowth rate (55–65%) of explants. Monitoring the shoots regenerated in the in vitro culture revealed their normal capacity for multiplication and rooting in comparison with the controls, which fully confirms the purpose of cryopreservation in the long-term preservation of plant material.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Izulmé Rita Imaculada Santos ◽  
Antonieta Nassif Salomão

Embryonic axes excised from seeds ofGenipa americanaL. desiccated to different water contents were successfully cryopreserved by rapidly plunging seed samples directly into liquid nitrogen. Control and cryopreserved embryonic axes were excised and grown in WPM culture medium for viability assessment. All control embryonic axes (−LN2) excised from fully hydrated seeds (43.89% moisture content) germinated after 21 days of culturein vitro. These high germination percentages persisted even after the water content of the seeds was as low as 6.79%. After freezing in liquid nitrogen high germination percentages, 93%, 96%, and 93%, were observed for embryonic axes excised from seeds dehydrated to 13.26%, 9.57%, and 6.79 moisture content, respectively. The cryopreservation technique described here is recommended for long term conservation ofG. americanagermplasm.


2016 ◽  
Vol 14 (2) ◽  
pp. 49
Author(s):  
Ika Roostika ◽  
Suci Rahayu ◽  
Novianti Sunarlim

<p>Pruatjan (Pimpinella pruatjan Molk.) is an Indonesian endangered medicinal plant, so that it is highly protected. Cryopreservation can be applied to this plant for long-term preservation. The aim of this research was to obtain a method of encapsulation-vitrification by optimizing each step in cryopreservation protocol i.e. preculture, loading, dehydration with and without freezing in liquid nitrogen. The best treatment of each step would be applied in the following step. On preculture experiment, in vitro shoots were planted on the Driver and Kuniyaki (DKW) basal media containing 0.3 M sucrose and incubated for 1, 2, 3, 4, and 5 days. After those incubation period, shoot tips were encapsulated with 2.5% Na-alginate and soaking for 15 minutes in 100 ppm CaCl2 solution before planting. On loading experiment, precultured explants were loaded in DKW basal solution containing 2 M glycerol and 0.4 M sucrose for 0, 30, 60, and 90 minutes. On dehydration experiment, preculturead and loaded explants were dehydrated with PVS2 solution PVS2 (DKW + 30% glycerol + 15% DMSO + 15% ethyleneglicol + 0.4 M sucrose) for 0, 30, 60, 90, and 120 minutes. The parts of them were freezed in liquid nitrogen (-196oC). The result showed that cryopreservation through encapsulation-vitrification technique could be applied on pruatjan. The best preculture treatment was 5 days incubation period. The best loading treatment was 30 minutes. The best dehydration treatment was 90 minutes. The successful level of this research was still low (10%) so that it needs optimization method.</p><p> </p><p><strong>Abstrak</strong></p><p>Purwoceng (Pimpinella pruatjan Molk.) adalah tanaman obat langka asli Indonesia yang hampir punah sehingga harus dilindungi. Kriopreservasi dapat diterapkan pada tanaman ini untuk penyimpanan jangka panjang. Tujuan penelitian adalah untuk memperoleh teknik enkapsulasi-vitrifikasi dengan melakukan optimasi dari tiap-tiap tahapan kriopreservasi yang meliputi perlakuan prakultur, loading, dehidrasi sebelum dan setelah pembekuan dalam nitrogen cair. Perlakuan yang terbaik kemudian diterapkan pada tahapan percobaan berikutnya. Pada perlakuan prakultur, tunas in vitro ditanam pada media Driver dan Kuniyaki (DKW) dengan penambahan sukrosa 0,3 M dengan masa inkubasi 1, 2, 3, 4, dan 5 hari. Setelah itu, pucuk yang berukuran 0,5 cm dienkapsulasi dengan Na-alginat 2,5% (yang mengandung media regenerasi) dalam larutan CaCl2 100 ppm selama 15 menit sebelum penanaman kembali. Pada percobaan loading, terlebih dahulu eksplan diprakultur kemudian direndam dalam larutan DKW + gliserol 2 M + sukrosa 0,4 M dengan durasi rendam selama 0, 30, 60, dan 90 menit. Pada percobaan dehidrasi, eksplan diprakultur dan loading terlebih dahulu, kemudian direndam dalam larutan krioprotektan PVS2 (DKW + gliserol 30% + DMSO 15% + etilen glikol 15% + sukrosa 0,4 M ) selama 0, 30, 60, 90, dan 120 menit. Eksplan tersebut sebagian dibekukan dalam nitrogen cair (-196oC) dan sebagian lainnya tidak dibekukan. Hasil penelitian menunjukkan bahwa kriopreservasi secara enkapsulasi-vitrifikasi berpeluang diterapkan pada tanaman purwoceng. Perlakuan prakultur terbaik adalah 5 hari. Perlakuan loading terbaik adalah 30 menit dan perlakuan dehidrasi terbaik 90 menit. Tingkat keberhasilan ini masih rendah (10%) sehingga diperlukan optimasi metode.</p>


Author(s):  
А. О. Ляшенко

Проведено дослідження морфологічних характе-ристик деконсервованих сперматозоїдів бугаїв різнихпорід Банку генетичних ресурсів за умов довготрива-лого зберігання в рідкому азоті. Встановлено вірогід-ну різницю між показниками патологічних і мертвихформ сперміїв бугаїв за різних термінів зберігання.У результаті проведених досліджень (за термінівзберігання 10–45 років) у бугаїв молочних порід спо-стерігались вищі за норму значення патологічнихформ сперматозоїдів у середньому на 2,5 %, окрімсперми української чорно-рябої молочної породи, а успермі бугаїв симентальської та м’ясних порід вищі усередньому на 5 %. The morphological characteristics of frozen bull sperm of different breeds the Bank of genetic resources the long-term storage in liquid nitrogen were studied. A significant difference between the indicators of pathological and dead forms of bull semen with different terms of storage was set. The result studies, by the terms of storage 10-45 years, in bulls of dairy breeds were observed above normal ​​of pathological forms of sperm in an average of 2,5 %, except for sperm Ukrainian Black Pied dairy breed. In semen bulls of Simmental and beef breeds above an average of 5 %.


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