Academic literature on the topic 'Cattle Germplasm resources Cryopreservation'
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Journal articles on the topic "Cattle Germplasm resources Cryopreservation"
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Kim, S. W., C. Y. Choe, D. K. Kim, A. R. Choi, and H. H. Seong. "35 EFFECTS OF THAWING TEMPERATURE OF FROZEN SEMEN ON VIABILITY OF REFROZEN AND THAWED CHICKSO (KOREAN BRINDLE CATTLE) AND KOREAN ALBINO CATTLE SPERMATOZOA." Reproduction, Fertility and Development 28, no. 2 (2016): 147. http://dx.doi.org/10.1071/rdv28n2ab35.
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Germplasm cryopreservation from a desired species with agricultural and genetic importance would protect them from the risk for extinction. Semen freezing from Korean native cattle would be a good approach for protecting genetic resources due to their limited numbers. It has been known that sperm could resist cryo-damages by freeze-thaw cycles. Thus, we performed 2 refreezing experiments with different initial thawing temperatures using frozen Korean native cattle semen. A total of 5 Hanwoo, Korean Albino, and brindle cattle were used as semen donors. After thawing by using 5°C/2 min or 37°C/40 s with cooling rates, the semen was diluted with the same volume of cryo-media in the first thawing temperature and refrozen. Sperm motilities were determined and compared between animals and groups after rethawing. The mean sperm concentration and motility was 45 × 106 mL–1 (range 2.3 to 89 × 106 mL–1) and 40% (range 13 to 55%). Mean values of motility and viability of sperm that underwent second preservation were significantly higher in 5°C than in 37°C (P < 0.01). However, the activity of viable sperm thawed at 5°C was significantly decreased before refreezing. It is estimated that refreezing of frozen semen from rare Korean native cattle is possible with resistant properties of survived spermatozoa. The higher motility and viability of refrozen semen could be obtained with 5°C thawing procedure for reuse of frozen semen.
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Arcos, Martha Liliana, Faisury Ossa, and Tito Efraín Díaz. "Criopreservación de aislados nativos de la bacteria ruminal Fibrobacter succinogenes." Corpoica Ciencia y Tecnología Agropecuaria 5, no. 1 (October 31, 2004): 60. http://dx.doi.org/10.21930/rcta.vol5_num1_art:26.
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<p>En el presente trabajo se estandarizó una técnica de criopreservación en nitrógeno líquido, usando como crioprotector dimetil sulfóxido al 5%, para la preservación de aislados nativos bacterianos de <em>Fibrobacter succinogenes</em>. El respectivo protocolo de criopreservación se evaluó determinando la viabilidad bacteriana por el transcurso de un año. La escala de MacFarland, ampliamente conocida en la estimación de poblaciones bacterianas aerobias, fue validada como técnica de estimación de bacterias anaerobias, usando la técnica de conteo bacteriano por <em>roll-tube </em>(R2 = 0.95). Se utilizaron dos aislados nativos, C7 y C9, de <em>Fibrobacter succinogenes</em>, obtenidos del rumen de bovinos en pastoreo de <em>Brachiaria decumbens</em>, en los Llanos Orientales de Colombia. Quince días después de la exposición de los cultivos al proceso de criopreservación, se apreció una reducción en el número de bacterias viables con relación a la población inicial de cada uno de los aislados (C7 = 9.25 x 108 UFCml-1 vs. 6.15 x 108 UFCml-1 y C9 = 12.51 x 108 UFCml-1 vs. 9.26 x 108 UFCml-1). Sin embargo, no se presentaron diferencias en la población de bacterias viables en los muestreos posteriores (C7 = 6.13 – 6.16 x 108; C9 = 9.26 – 9.35 x 108 UFCml-1). Esta técnica permite mantener la viabilidad bacteriana y puede considerarse como un procedimiento eficiente y de fácil aplicación para la preservación de bacterias ruminales. Además, constituye una herramienta fundamental para el establecimiento de bancos de germoplasma de microorganismos anaerobios ruminales en Colombia. El uso conjunto de las técnicas de criopreservación y la escala de MacFarland, posee ventajas sobre los métodos de preservación y estimación de poblaciones por cultivos activos, por su confiabilidad, eficiencia y bajo costo.</p><p> </p><p><strong>Cryopreservation of native isolates </strong><strong>of ruminal bacteria <em>Fibrobacter </em></strong><strong><em>succinogenes</em></strong><strong>.</strong></p><p>In this study, the technique of cryopreservation in liquid nitrogen to preserve native isolates of the fibrolytic bacteria <em>Fibrobacter succinogenes </em>was standardized. The technique efficiency was evaluated by establishing the bacterium viability during one year. The Mac-Farland scale, widely used to estimate aerobic bacterial populations, was validated by the roll tube technique (R2=0.95). Two native <em>F. succinogenes </em>strains, C7 and C9, were used. These strains were obtained from cattle fed on <em>Brachiaria decumbens </em>in the eastern lowlands of Colombia. Fifteen days after the initiation of the cryopreservation process, a reduction in the number of viable bacteria (CFU ml-1) was registered (C7 from 9.25 x 108 to 6.15 x 108 and C9 from 12.51 x 108 to. 9.26 x 108). However, the bacterial populations did not present differences in subsequent samplings (C7=6.13 – 6.16X108, C9=9.26 – 9.35X108 CFU ml-1, range over a year). Results indicated that the standardized cryopreservation technique is an effective and easy procedure to preserve ruminal bacteria, which would be a very useful tool to create a germplasm bank of Colombian ruminal anaerobic microorganisms. The cryopreservation technique, and the MacFarland scale have an advantage over other methods of preserving bacteria and methods of estimating populations of bacteria by active cultures. The procedures used in this research are reliable and economical techniques using minimal storage spaces and laboratory resources.</p>
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Yang, Huiping, and Terrence R. Tiersch. "Concepts, History, Principles, and Application of Germplasm Cryopreservation Technology." EDIS 2020, no. 5 (October 12, 2020): 10. http://dx.doi.org/10.32473/edis-fa223-2020.
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Germplasm are living genetic resources that can serve as bearers of heredity, and include germ cells and their precursors, plant seeds and pollen, animal sperm, oocytes, embryos, and larvae. Cryopreservation refers to the preservation of biological materials at extremely low temperatures, typically using solid carbon dioxide at -80°C or liquid nitrogen at -196°C for freezing, and cryogenic storage in perpetuity. Germplasm cryopreservation is an important technology applied for medical treatment, maintenance of biological diversity, preservation of valuable genetic resources, assistance of breeding programs, and conservation of imperiled species. This extension publication is intended to introduce the basic concepts, history, principles, and applications of germplasm cryopreservation technology.
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NUKARI, A., M. UOSUKAINEN, and V.-M. ROKKA. "Cryopreservation techniques and their application in vegetatively propagated crop plants in Finland." Agricultural and Food Science 18, no. 2 (December 4, 2008): 117. http://dx.doi.org/10.2137/145960609789267506.
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Cryopreservation protocols have been introduced as techniques for germplasm preservation of vegetatively propagated horticultural and staple food crops. In Finland, cryopreservation has been studied since 1990s, beginning with cryopreservation of forest tree breeding material and since 2004 on cryopreservation of genetic resources of horticultural plants and potato. Priority was given to cryopreservation of raspberry (Rubus ideaus L.), strawberry (Fragaria x ananassa Duch.) and potato (Solanum tuberosum L.) and the possibility to use cryotherapy in eradication of raspberry bushy dwarf virus (RBDV) from in vitro cultures were studied on raspberry. Modified droplet vitrification cryopreservation protocols were designed for raspberry and strawberry and cryotherapy combined with thermotherapy was proven to be a successful application to eliminate RBDV from infected raspberries. Cryotherapy method can be applied for a large scale elimination of viruses from plant germplasm and from candidate nuclear stock in a certified plant production scheme. Routine use of cryotechniques in germplasm preservation of vegetatively propagated horticultural plants was started. Besides for long term germplasm preservation, cryopreservation techniques can be applied also for maintenance of mother stocks in certified plant production schemes and in commercial plant production. Cryopreservation of potato shoot tips needs additional detailed research to obtain sufficient recovery and regrowth rates.;
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Liu, Yicun, Tianqi Huang, Shunquan Lin, and Yuanyuan Jiang. "Programmed Cooling and Vitrification Method Applied to the Germplasm Preservation of Eriobotrya Plants." HortScience 58, no. 2 (February 2023): 164–69. http://dx.doi.org/10.21273/hortsci16816-22.
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Long-term cryopreservation of germplasm is of great importance to maintaining genetic resources. A cryopreservation technology system has not yet been established for Eriobotrya, an important fruit tree in the Rosaceae. In this study, Eriobotrya plants were used as test materials for the following purposes: to study different types of vitrification solution, compare different methods involving programmed cooling vitrification and rapid freezing vitrification; and evaluate the effects of vitrification solution loading time, low-temperature acclimation culture, dark culture, and cryoprotectant use in preculture medium for ultra-low-temperature preservation of Eriobotrya germplasm resources. Plant vitrification solution 1 had the best comprehensive effect on different vitrification solution tests. The programmed cooling and vitrification method yielded a certain survival rate with different vitrification solutions and materials, but the survival rate under the rapid freezing method was 0%. The longer the vitrification solution was loaded, the higher the survival rate. The most suitable time for dark culture of Eriobotrya plants after cryopreservation was 20 days. The preculture medium supplemented with 5% dimethyl sulfoxide resulted in significantly higher preservation than the control medium, and the optimal sucrose concentration was 0.3 mol⋅L−1. A stable, high-survival, and novel cryopreservation procedure for loquat plants was established. The operating procedures are described in a procedural and standardized manner. These findings provide a theoretical basis for research of the cryopreservation of germplasm resources of Eriobotrya plants.
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Shands, Henry L. "The U.S. National Plant Germplasm System." Canadian Journal of Plant Science 75, no. 1 (January 1, 1995): 9–15. http://dx.doi.org/10.4141/cjps95-004.
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The United States Department of Agriculture's (USDA) Agricultural Research Service (ARS) manages the National Plant Germplasm System (NPGS). The USDA's National Genetic Resources Program was created in 1990, using the NPGS as the model by which other life forms would also be preserved and utilized. While the NPGS is a broadly defined system, ARS has a specific role of acquiring, characterizing, preserving, documenting, and distributing germplasm to scientist users for research and breeding. The NPGS provides genetic resources to users at no cost but with a request to return data to incorporate in the Germplasm Resources Information Network (GRIN) database. The database is available as hard copy, diskette through PC-GRIN, and, for some crops, a CD-ROM disk. Service to users is the primary objective. The NPGS and 40 crop advisory committees exchange technical information on the most important conservation issues. Recent research advances at the National Seed Storage Laboratory provide guidance for storage management of orthodox and desiccation-sensitive seed and vegetative germplasm. Cryopreservation may receive more attention and play a more important role for the vegetative germplasm because improved seed management under conventional refrigerated storage is now possible. Key words: Germplasm, databases, cryopreservation
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Bettoni, Jean Carlos, Zvjezdana Marković, Wenlu Bi, Gayle M. Volk, Toshikazu Matsumoto, and Qiao-Chun Wang. "Grapevine Shoot Tip Cryopreservation and Cryotherapy: Secure Storage of Disease-Free Plants." Plants 10, no. 10 (October 15, 2021): 2190. http://dx.doi.org/10.3390/plants10102190.
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Grapevine (Vitis spp.) is one of the most economically important temperate fruit crops. Grapevine breeding programs require access to high-quality Vitis cultivars and wild species, which may be maintained within genebanks. Shoot tip cryopreservation is a valuable technique for the safe, long-term conservation of Vitis genetic resources that complements traditional field and in vitro germplasm collections. Vitis is highly susceptible to virus infections. Virus-free plants are required as propagation material for clonally propagated germplasm, and also for the global exchange of grapevine genetic resources. Shoot tip cryotherapy, a method based on cryopreservation, has proven to be effective in eradicating viruses from infected plants, including grapevine. This comprehensive review outlines/documents the advances in Vitis shoot tip cryopreservation and cryotherapy that have resulted in healthy plants with high regrowth levels across diverse Vitis species.
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Purdy, P. H., C. S. Wilson, S. F. Spiller, and H. D. Blackburn. "Biobanking genetic resources: challenges and implementation at the USDA National Animal Germplasm Program." Reproduction, Fertility and Development 28, no. 8 (2016): 1072. http://dx.doi.org/10.1071/rd15399.
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There is adequate infrastructure in the US to identify and acquire germplasm from the major beef and dairy cattle and swine breeds. However, when we venture outside these species, the same tasks become more difficult because of a lack of breed associations, databases that include genotypic and phenotypic data and low numbers of animals. Furthermore, acquisition of germplasm from non-cattle and non-swine species can be difficult because these animals are often not located near the National Animal Germplasm Program, which makes collection and preservation of the samples in a timely manner that much more complicated. This problem is compounded because not all preservation protocols are optimised for field collection conditions or for all types of germplasm. Since 1999, the USDA National Animal Germplasm Program has worked to overcome these obstacles by developing policies, procedures and techniques in order to create a germplasm repository for all agricultural species (wild and domesticated) in the US. Herein, we describe these activities and illustrate them via a case study on how our efforts collecting Navajo-Churro sheep have created a secure backup of germplasm and how we specifically overcome these issues as they relate to rare and minor breeds of agricultural species.
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Silversides, F. G., Y. Song, R. Renema, B. R. Rathgeber, and H. L. Classen. "Cryopreservation of germplasm from chickens kept in Canadian research institutions." Canadian Journal of Animal Science 88, no. 4 (December 1, 2008): 577–80. http://dx.doi.org/10.4141/cjas08030.
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Twenty-three genetically distinct lines of chickens are maintained as living populations by Agriculture and Agri-Food Canada and Canada’s eight Faculties of Agriculture. Historically, cryogenic storage of avian genetic material has been difficult, but we have developed techniques of gonadal transplantation to allow recuperation of stored genetic material into living birds. Gonads from 1660 day-old chicks or late-term embryos (810 females and 850 males) from 18 chicken populations from four Canadian institutions were harvested and cryopreserved using dimethylsulfoxide as a cryoprotectant. Future efforts will be directed to completing the collection of the populations kept in Canadian publicly-funded institutions that conduct agricultural research. Key words: Chicken, genetic resources, cryopreservation, gonads
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Wang, Min-Rui, Wenlu Bi, Mukund R. Shukla, Li Ren, Zhibo Hamborg, Dag-Ragnar Blystad, Praveen K. Saxena, and Qiao-Chun Wang. "Epigenetic and Genetic Integrity, Metabolic Stability, and Field Performance of Cryopreserved Plants." Plants 10, no. 9 (September 13, 2021): 1889. http://dx.doi.org/10.3390/plants10091889.
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Cryopreservation is considered an ideal strategy for the long-term preservation of plant genetic resources. Significant progress was achieved over the past several decades, resulting in the successful cryopreservation of the genetic resources of diverse plant species. Cryopreservation procedures often employ in vitro culture techniques and require the precise control of several steps, such as the excision of explants, preculture, osmo- and cryoprotection, dehydration, freeze-thaw cycle, unloading, and post-culture for the recovery of plants. These processes create a stressful environment and cause reactive oxygen species (ROS)-induced oxidative stress, which is detrimental to the growth and regeneration of tissues and plants from cryopreserved tissues. ROS-induced oxidative stresses were documented to induce (epi)genetic and somatic variations. Therefore, the development of true-to-type regenerants of the source germplasm is of primary concern in the application of plant cryopreservation technology. The present article provides a comprehensive assessment of epigenetic and genetic integrity, metabolic stability, and field performance of cryopreserved plants developed in the past decade. Potential areas and the directions of future research in plant cryopreservation are also proposed.
Dissertations / Theses on the topic "Cattle Germplasm resources Cryopreservation"
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Salinas-Flores, Liliana, and n/a. "Understanding and improving the cryopreservation of pacific oyster (Crassostrea gigas) oocytes via the use of two approaches : modification of an existing cryopreservation protocol and manipulation of the lipis fraction of the oocytes." University of Otago. Department of Food Science, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080305.143446.
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Cryopreservation of gametes is a valuable tool for the fast-growing aquaculture industry in New Zealand. In the present study, research was aimed to improve the cryopreservation of Pacific oyster (Crassostrea gigas) oocytes. For this, two main approaches were used: the modification of an existing published (standard) cryopreservation protocol for oyster oocytes and the modification of the oocytes themselves prior to cryopreservation. The objectives in the chapters of this thesis were: (a) determination of the cryobiological characteristics of oyster oocytes; (b) assessment and reduction of intracellular ice formation (IIF) in oocytes; and (c) modification of the lipid fraction (cholesterol and fatty acids) of oocytes prior to cryopreservation.
Knowledge of the membrane permeability parameters in response to concentrations of water and ethylene glycol (EG), the influence of temperature upon these parameters, and the osmotic tolerance limits of oyster oocytes were used to develop computer models that simulated the cellular volume changes that oocytes underwent during EG addition and removal. The models predicted that when one part of EG was added in one step to one part of oocyte suspension and equilibrated for 20 min at 20 �C, similar volume changes in oocytes would be obtained, compared to a more complicated multi-step addition method. This method of addition resulted in similar post-thaw fertilization rates to those obtained by using the multi-step addition method, thus reducing oocyte handling.
Cryomicroscopy was used to assess the effect of cooling rates and EG concentration on the temperature at which oocytes underwent IIF. It was found that IIF occurred at higher subzero temperatures when fast cooling rates were used (30 and 5 �C min⁻�) and at EG concentrations ranged between 0 and 15%. At a relatively slower cooling rate of 0.3 �C min⁻� and with 10% EG, which are the conditions employed in the standard cryopreservation protocol, no IIF occurred.
The steps of the standard protocol that were more likely to cause oocyte damage were identified by evaluating the fertilization rate of oocytes at each step. Results showed that oocytes were most damaged by cooling them to -35 �C and followed by plunging them in liquid nitrogen. Contrary to what had been observed under the cryomicroscope, transmission electron microscopy (TEM) analysis revealed that all oocytes cryopreserved by the standard protocol contained cytoplasmic ice. In addition, it was also observed that oocytes were at two developmental stages when frozen (prophase and metaphase I). These observations prompted the development of alternative cooling programmes aimed to reduce intracellular ice. The effect of cooling rate, plunge temperature and time held at the plunge temperature were thus evaluated, based on post-thaw fertilization rate of oocytes. Overall, neither the cooling rate nor the holding time had an effect on oocyte fertility. However, the plunge temperature had an effect, where oocytes plunged at -60 �C had lower post-thaw fertilization rates than oocytes plunged at -35 �C. Through the slowing of the cooling rate, lengthening of the holding time and lowering of the plunge temperature, it was possible to reduce the amount of ice in the cytoplasm. However, the reduction of intracellular ice did not improve the post-thaw fertilization rate of the oocytes; on the contrary, post-thaw fertilization decreased notoriously. From these results, it can be suggested that oyster oocytes are more likely to be damaged by exposure to high intra and extracellular solute concentration than IIF during cryopreservation.
In an effort to modify the lipid content of oyster oocytes prior to cryopreservation and thus, making them more resistant during cryopreservation, oocytes were incubated in solutions that would add or remove cholesterol or in solutions rich in long chain fatty acids (EPA or DHA). Oocytes incubated in cholesterol-rich solutions showed a positive uptake of fluorescently labelled cholesterol and this effect was dose dependent. Nevertheless, this uptake did not improve the post-thaw fertilization rate nor did it increase the total cholesterol content of the oocytes. When oocytes were incubated in non-conjugated or conjugated EPA or DHA, no increase in the proportion of these fatty acids was identified in the fatty acid profiles of whole oocytes and no improvement of the post-thaw fertilization rate was recorded.
Given that there was no uptake of fatty acids from the incubation media by the oocytes, a different approach was taken. This involved the supplementation of lipid-rich diets to the oyster broodstock during gametogenesis (cold-conditioning) and vitellogenesis (warm-conditioning). Despite results showing that lipid content and, indeed, fatty acid profile was altered through the diet, the results also showed that fresh oocytes from broodstock fed during cold-conditioning did not show any improvement in their fertilization rates, nor did they benefit from a lipid-rich diet during warm-conditioning. On the other hand, cryopreserved oocytes did have higher post-thaw fertilisation rates when broodstock were fed during cold-conditioning and, although no effect was found from feeding broodstock with either of the lipid-rich diets during warm-conditioning, trends indicated that a diet consisting of fresh microalgae or the commercial supplement Algamac would yield the highest post-thaw fertilization rates.
This thesis has furthered the understanding of some of the factors that determine cryosurvival in oyster oocytes and has demonstrated that both physical and biological issues must be taken into consideration for cryopreservation. Specifically, the results in this thesis helped to modify an empirically developed cryopreservation protocol for Pacific oyster oocytes. In addition, the results also showed strong evidence of the survival of oyster oocytes to intracellular ice and highlighted the importance of supplying the broodstock with lipid-rich food during the periods of gamete formation and maturation in order to obtain oocytes that are more amenable to cryopreservation. These benefits could be of significant practical importance and may be extended for the development or refinement of cryopreservation protocols for other shellfish species of commercial importance to the aquaculture industry of New Zealand.
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Souch, Graham Robert. "Long-term conservation of Allium germplasm resources : the cryopreservation of A. sativum using an encapsulation/dehydration approach." Thesis, University of Derby, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433865.
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Chang, Yunsheng. "Evaluation of immunological techniques for host fish identification, and cryopreservation of embryos for conserving rare freshwater mussels." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-12052009-020208/.
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Bailekae, Masenya Matshidiso. "Development of cryopreservation strategies for improved reproductive competence in South Africa pig genotypes." Thesis, [Bloemfontein?] : Central University of Technology, Free State, 2012. http://hdl.handle.net/11462/145.
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Thesis (M. Tech. Agriculture) -- Central University of Technology, Free state, 2012Frozen-thawed boar sperm has the potential to impact the future of the swine industry. The objectives of the study were to characterise semen of Kolbroek and Large White boars, find a suitable holding temperature and extender, determine the effect of breed and pregnancy rate following artificial insemination by frozen-thawed boar semen. A total of eight boars and 33 sows were used in this study. The 120 ejaculates were collected from each individual Kolbroek and Large White boars with the gloved-hand technique. Macroscopic and microscopic sperm characteristics were recorded. The bodyweight of Kolbroek (154.7 kg) was significantly lower compared to Large White (189.9 kg) boar. However, no significant differences were observed in Kolbroek and Large White boar semen volume (140 and 170 ml), sperm concentration (0.727 and 0.761 x 109 sperm/ml), and total sperm motility (95 and 91%). A positive correlation existed between bodyweight and semen volume of Kolbroek (r= 0.22) and Large White (r= 0.26). Conversely, the bodyweight of Large White was positively correlated to sperm concentration of Large White (r= 0.37) but negatively correlated to Kolbroek (r= -0.66). Storage time and temperature did not affect Large White boar sperm motility rate. However, Kolbroek sperm total motility rate (61.0%) was affected at 25°C after 24 hours. The highest total sperm motility rate was observed for semen diluted with Tris-based extender (74.1%) in Kolbroek boars at 48 hours of storage. Large White boar semen diluted with BTS (62.9%), Kobidil+ (69.3%) and Tris (65.1%) showed significantly higher sperm motility rate at 48 hours of storage, compared to Citrate (27.6%) extender. Cryopreservation significantly reduced sperm motility rate for Kolbroek (30.2%) and Large White (24.0%) boars. However, a high pregnancy rate was recorded in both sows of inseminated with raw diluted (100% vs. 81.3%) and frozen-thawed (50% vs. 50%) semen of Kolbroek and Large White boars. In conclusion, the bodyweight of Kolbroek and Large White boar was positively correlated with ejaculated semen volume. Kolbroek and Large White boar sperm stored at 18°C for 24 hours maintained the acceptable sperm motility rate. Kolbroek boar semen diluted with Tris-based extender maintained high sperm motility rate. Cryopreservation significantly reduced sperm motility rate regardless of breed; however, pregnancy rate from frozen-thawed semen was high for Kolbroek (50%) and Large White (50%) even though the frozen-thawed fertility was low.
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Essack, Lubaina. "Towards development of a cryopreservation protocol for germplasm of Podocarpus henkelii." Thesis, 2012. http://hdl.handle.net/10413/8545.
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The trees belonging to the genus Podocarpus, of which only four species are native to South Africa, are renowned for their superior quality timber. Prior to 1880, Podocarpus henkelii, together with P. falcatus and P. latifolius, played a significant role in the development of the country as they were heavily utilised as timber trees for the building of dwellings, furniture and other necessary items. Due to this over-exploitation in the timber trade, all the Podocarpus species in South Africa have been afforded a ‘Protected’ status on the IUCN red data list of species that are either threatened or in danger of extinction. However, despite the obvious need to conserve the threatened genetic diversity of these species, few attempts (aside from in vitro micropropagation) have been made to explore ex situ Podocarpus germplasm conservation in the long-term. Consequently, the primary aim of this study was to establish a protocol for the long-term conservation of germplasm of Podocarpus henkelii Stapf ex Dallim. Jacks.
The seeds of Podocarpus henkelii exhibit recalcitrant behaviour and can therefore not be stored in conventional seed banks. This has necessitated the investigation of alternative methods of germplasm conservation with a focus on cryopreservation which is presently considered the most reliable, efficient and cost-effective means of storing the genetic resources of recalcitrant-seeded species for prolonged periods. The first objective of this study was to investigate the effect of slow (two-step) and ultra-rapid cooling on the post-thaw survival of variously treated P. henkelii embryos. The results of this investigation revealed that the rate of cooling employed had a significant effect on explant viability as none of the precultured, cryoprotected embryos that were slowly cooled survived cryostorage while some of the preconditioned embryos responded to ultra-rapid cooling (i.e. 36% shoot production and 88% callus formation). For ultra-rapid cooling, it was found that flash-drying prior to cooling was a prerequisite for survival as osmotic dehydration alone did not effectively prepare the tissues for the stresses imposed during cryostorage. Furthermore, for those flash drying intervals that yielded positive results, preconditioning explants with 10% glycerol proved the most effective pre-cooling treatment. However, due to the low recovery numbers after ultra-rapid cooling, a third cryopreservation technique i.e. cryogenic vitrification, was investigated.
For cooling by vitrification, data obtained from preliminary experiments showed that precultured explants needed to be initially loaded with 18% sucrose (w/v) + 14% glycerol (v/v) for 20 min and subsequently immersed in Plant Vitrification Solution 3 (PVS3) at 0°C for 10 min prior to cooling. However, relatively low success was achieved for P. henkelii embryos cooled by vitrification as the highest post-cooling survival obtained was only 20% germination, 27% shoot formation and 37% callus formation.
Due to the low post-thaw survival obtained despite the rigorous manipulations employed in the development of the slow cooling, ultra-rapid cooling and vitrification protocols, it was decided that an alternative explant should be investigated for the conservation of P. henkelii germplasm. The explant of choice was adventitious buds induced to form on, and subsequently excised from, mature P. henkelii embryos. The first objective was to develop a suitable protocol for the induction of adventitious buds on P. henkelii embryos. The medium that induced in the highest percentage of embryos (85%) to form adventitious buds consisted of Douglas-fir cotyledon revised (DCR) basal medium supplemented with 30 g L-1 sucrose, 0.05 mg L-1 NAA, 0.5 mg L-1 BA and 6 g L-1 agar. This medium also resulted in the highest average number of buds formed per embryo (i.e. 35 ± 3 buds per embryo). Once the adventitious bud induction medium was developed, it was necessary to optimise the size of adventitious bud clumps to be used as explants for cryopreservation. Three bud clump sizes were investigated: ca 3, 5 and 10 buds per clump. However, none of the bud clumps survived excision from the mother-tissue despite the investigation of three different types of bud-break media. The resultant tissue mortality is suggested to have occurred because the adventitious bud clumps were excised prior to bud break and shoot development which could have exacerbated excision-related cellular and sub-cellular damage.
It was therefore decided that attempts should be made to induce adventitious buds directly on P. henkelii embryos post-cooling, thereby eliminating the possibility of potentially lethal excision-related damage. The protocols that yielded the best results after ultra-rapid cooling and cooling by vitrification were used in this experiment. For ultra-rapid cooling, embryos were first cryoprotected with 5% followed by 10% glycerol for 1 h in each and subsequently flash dried for 30 min prior to immersion in nitrogen slush. For cooling by vitrification, embryos that were first precultured on 0.3
M sucrose for 1 d were loaded with 10% glycerol + 14% sucrose (LS4). The loaded explants were then immersed in ice-cold PVS3 and maintained on ice for 10 min prior to cryostorage. The effect of each pretreatment (either independently or in combination) on adventitious bud production pre-cooling was also investigated. For both protocols the various pretreatments decreased not only the capacity of the embryos to form buds but also the average number of buds formed per embryo (i.e. 7 ± 2 buds per embryo and 14 ± 2 buds per embryo were formed on treated embryos prior to ultra-rapid cooling and cooling by vitrification, respectively). Thus, it was predicted that even if the percentage of cryopreserved embryos forming buds was minimal, the number of possible plantlets that could be regenerated from adventitious buds per cryopreserved explant would compensate for the low recovery of embryos post-cooling. However, none of the embryos that were cryopreserved by either ultra-rapid cooling or by vitrification formed adventitious buds after eight weeks in culture.
The very restricted success achieved in this study despite the investigation of three cryopreservation techniques and two different explants only serves to reinforce the difficulties associated with the conservation of recalcitrant germplasm. The large size and structural complexity of P. henkelii embryos, coupled with their high water content post-shedding, are just some of the characteristics to which their intractability to the manipulations involved in the development of a successful cryopreservation protocol could be attributed. For future investigations, development of adventitious buds produced on cryopreserved root segments (as opposed to entire roots), and/or use of seedling meristems as explants which might be amenable to cryopreservation are suggested as possible avenues for the long-term conservation of P. henkelii genetic diversity.Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.
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Chatiza, Fungayi Primrose. "Characterization of testes and functional evaluation of cryopreserved epididymal spermatozoa from three South African antelope species." Thesis, 2014. http://hdl.handle.net/10210/8791.
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Ph.D. (Zoology)This project involves a detailed study of three South African antelope species, springbok, impala and blesbok. The study investigates the origins of sperm in terms of testicular histology and subsequently the major storage organ, the cauda epididymis. Sperm of these species were characterized in terms of their quality (morphology, motility, vitality characteristics among others and their physiology: when exposed to different media and cryopreservation protocols. Finally sperm fertilization biology of the three species and evaluation of fertilization and developmental success when using homologous and heterologous oocytes (relative comparison) were assessed. Cauda epididymal spermatozoa was recovered post-mortem from the testes of culled springbok (n =38); impala (n =26) and blesbok (n =42) during winter months in South Africa and cryopreserved in a Tris-fructose-citric acid extender (Biladyl) supplemented with 20% egg yolk and 7% glycerol under field conditions. Longevity of sperm was assessed in Tris and Citrate extenders and modified Tyrode lactate in vitro fertilization (IVF) media. Oocytes were collected from the ovaries of domestic cows (n =165), springbok (n = 72) and blesbok (n = 42) and matured in domestic cattle M199 maturation media supplemented with 10% FCS, 10IJg/mi LH, 10IJg/mi FSH and antibiotics. Heterologous (zona intact and zona free) and homologous fertilization was carried using a domestic cattle IVF protocol. Results were analysed using SPSS version 18.0 (Statcon, South Africa). Interspecies comparisons were made using parametric tests: paired t-test for the freezing effect, one-way analysis of variance (ANOVA), Mixed between-within subjects ANOVA for longevity, Non Parametric test for motility characteristics and least squares ANOVA for...
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Naidoo, Cassandra. "Oxidative status and stress associated with cryopreservation of germplasm of recalcitrant-seeded species." Thesis, 2012. http://hdl.handle.net/10413/9744.
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Genetic diversity of cultivated species and their wild relatives, as well as of wild species encompasses plant genetic resources or germplasm, the ex situ preservation of which embodies a critical aspect of biological conservation. While seed storage affords an efficient ex situ conservation method, recalcitrant seeds are intolerant of desiccation and cannot be stored conventionally in seed banks. Seeds of the three indigenous tree species investigated in this study, viz. Trichilia emetica, T. dregeana and Protorhus longifolia are recalcitrant, with the species considered to be endangered. Cryopreservation, which involves storage at ultra-low temperatures of selected tissue(s) from which plants are subsequently able to be generated, is currently the only method available for long-term ex situ conservation of recalcitrant-seeded species and affords significant potential for the future. Many protocols that have been applied for the cryopreservation of the germplasm of recalcitrant zygotic embryonic axes excised from seeds of tropical/sub-tropical species have resulted in survival post-cryo which has been recorded only as root development or callus formation, with shoot formation seldom occurring. Successful cryostorage of genetic resources cannot be achieved until post-cryopreservation recovery facilitates normal seedling development, i.e. the formation of both a fully functional root and a shoot.
Cryopreservation requires the utilisation of the smallest explant possible (greatest surface area to volume ratio), the most suitable for recalcitrant seeds in general being the zygotic embryonic axis. Based on preliminary studies it was demonstrated that shoot production by axes is inhibited in association with a burst of reactive oxygen species (ROS), produced in response to wounding upon excision of the axis from the cotyledons, when these are attached close to the shoot apical meristem. It was postulated that a combination of the oxidative burst at the site of excision coupled with inadequate antioxidant machinery within the recalcitrant axis tissue, precludes shoot production. It was further considered highly probable that each subsequent stressful manipulation throughout the cryopreservation process would be accompanied by a surge of uncontrolled oxidative activity within the tissue, in response to the stress. Therefore, the primary aim of the study was to investigate the underlying causes of failure of shoot production after procedures associated with cryopreservation and to focus on ways to ameliorate the consequences of unbalanced oxidative metabolism. Additionally, studies were carried out to optimise each step of the cryopreservation procedure, viz. cryoprotection, dehydration, rehydration and cooling, and subsequent recovery, in conjunction with assessment of oxidative responses, ultimately to
achieve successful cryopreservation of the embryonic axes of these species. The experimental work conducted to achieve this aim assessed changes in various biomarkers of injury, those selected for this study being three ROS, viz. superoxide, the hydroxyl radical and hydrogen peroxide, after axes were exposed to various pre-treatments, cryopreservation and recovery.
Concomitantly, the elicited responses of endogenous antioxidant systems accompanying these steps were assessed. Changes in the levels of ROS and antioxidant activity were determined using various biochemical assays, and these parametres, together with assessment of shoot development, were investigated after each step of the cryopreservation process. The effect of stress on oxidative metabolism was tested after exposure to pre-treatments with and without the provision of various antioxidants, viz. DMSO, ascorbic acid and cathodic water, so as to determine the efficacy of selected ROS scavengers and, in general, to develop the best protocol for cryopreservation of embryonic axes of the three species. Significant results, in terms of shoot development and regulated ROS generation, were obtained after three major processes of the cryopreservation procedure. The production of roots and shoots by excised axes of T. emetica, T. dregeana and P. longifolia after excision (75%, 80% and 75%, respectively), and by 40% of excised axes of T. dregeana after each of the two further stages, cryoprotection and desiccation, were major achievements towards cryopreservation of the recalcitrant germplasm. The modulation of ROS by ascorbic acid and cathodic protection significantly improved survival of axes of both Trichilia species. In its entirety, the present study made significant advancements towards cryopreservation of recalcitrant germplasm and also towards understanding oxidative events associated with cryogenic processing and exposure to cryogenic conditions.
This study concludes that unregulated metabolism is one of the underlying causes of failure of recalcitrant germplasm represented by zygotic axes, to survive cryopreservation. The application of antioxidants and cathodic protection during cryopreservation facilitated survival that has been previously unattainable. The outcomes of this study provide an informative platform for further optimising cryopreservation procedures for the germplasm of the species investigated, and extending the work to other recalcitrant-seeded species, especially those of tropical/sub-tropical provenances.Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.
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Ngobese, Nomali Ziphorah. "Effects of some of the procedural steps of cyropreservation on cryo-recalcitrant zygotic embryos of three amaryllid species producing desiccation-sensitive seeds." Thesis, 2013. http://hdl.handle.net/10413/11223.
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Cryopreservation is the most promising method for the long-term conservation of germplasm of plants producing desiccation-sensitive seeds. While such seeds are generally termed recalcitrant in the context of conventional storage practices, the term ‘cryo-recalcitrant’ is used for germplasm which is not readily amenable to cryopreservation. Cryo procedures usually involve a sequential combination of steps which must be optimised to limit the stresses experienced by specimens, thus promoting their survival.
The present contribution reports on the effects of some of the steps involved in cryopreservation on the survival of the embryos of the amaryllids, Ammocharis coranica, Brunsvigia grandiflora and Haemanthus albiflos, with the ultimate aim of developing a protocol(s) for the successful cryopreservation of the germplasm of these species. The main foci of the investigations were the effects of rapid (flash) drying, the use of the cryoprotectant additives, glycerol (5 & 10%) and DMSO (0.1 & 0.25%), and employment of different cooling rates on the zygotic embryos of the selected species, which are known to be recalcitrant as well as being cryo-recalcitrant. Furthermore, this study reports on attempts at improving the rapidity of dehydration during flash drying by applying a vacuum, and also of providing cathodic protection (via highly reducing cathodic water and/or direct exposure to a static {negatively-charged} cathodic field during flash drying) to the explants at various stages in the protocol. These techniques were employed in attempts to ameliorate the adverse effects of reactive oxygen species associated with stresses imposed by the procedures during the cryopreservation process.
The embryos of Ammocharis coranica, Brunsvigia grandiflora and Haemanthus albiflos were initially at water contents (WCs, dry mass basis) of 3.28±0.52, 2.55±0.22, 4.48±0.92 g g-1, respectively, after harvest. These embryos proved to be tolerant to moderately rapid water loss in the short term, with >60% retaining germinability at water contents ≥0.5 g g-1. The results from this study confirmed that dehydration to water contents below 0.5 g g-1 (dry mass basis) compromised survival, and that this effect was exacerbated if the embryos were cryoprotected prior to drying. Interestingly, the rate of water loss in embryos of these species differed, with A. coranica and H. albiflos drying at a (comparably) much slower rate than those of B. grandiflora. Subsequent rapid cooling yielded promising results when compared with slow cooling, as 30% of glycerol cryoprotected, rapidly cooled A. coranica embryos that had been flash-dried to 0.36±0.10 g g-1 generated normal seedlings. It was clear, however, that the effects of these procedures were exacerbated when all the steps of the cryo procedure were applied sequentially. However, the work also showed that these adverse effects may be ameliorated if each step of the cryopreservation protocol is optimised on a species-specific basis, thus promoting the chances of survival after cryopreservation and facilitating subsequent seedling establishment. This was evident in the 30% germination obtained when embryos of A. coranica, which had been cryoprotected with glycerol prior to flash drying before exposure to rapid cooling, while those that had not been cryoprotected or were cryoprotected with DMSO before drying did not survive. The incorporation of cathodic protection during flash drying appeared promising as it promoted the survival of 10% of H. albiflos embryos dehydrated to WCs between 0.37 and 0.26 g g-1 (whereas no survival was achieved without the inclusion of this step), and 70% of A. coranica embryos that were dehydrated to 0.35±0.21. In addition, the reduction of the explant size, from a whole 6 mm embryo to a 3-4 mm excised axis, promoted survival by up to 30% for A. coranica and H. albiflos, even at higher WCs. However, survival in these cases was based on observations of abnormal development, i.e. the development of roots or shoots, or calli. No surviving embryos were obtained from B. grandiflora after cooling, regardless of the preconditioning treatment or rate of cooling, and this was accredited to the greater degree of sensitivity of these embryos to the cryo procedures than those of the other two species. The use of cathodic water to re-hydrate explants after dehydration and of applying a vacuum during flash drying did not result in any observable benefits, and require further investigation for optimisation.
The very limited success towards establishing a cryopreservation protocol for the species investigated in this study reinforces the difficulties associated with the cryopreservation of recalcitrant germplasm, which informs the cryo-recalcitrance of some explants. However, the results obtained have helped to identify a number of intervention points that could be used to minimise the damage incurred during the various procedural steps involved in cryopreservation.Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2013.
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Mynhardt, Neil Philip. "Quality assessment of cryopreserved spermatozoa of the blesbok (Damaliscus pygargus phillipsi), blue wildebeest (Connochaetes taurinus) and African buffalo (Syncerus caffer)." Thesis, 2012. http://hdl.handle.net/10210/6360.
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M.Sc.Climate change, loss of habitat and over-exploitation of natural resources as well as the introduction of invasive alien species through human activities are resulting in an ever increasing risk of extinction of many plant and animal species. There are two major approaches to conserving threatened and endangered species. Firstly the large scale preservation of natural habitat and ecological processes, thereby protecting the species inhabiting the habitat. The second approach involves the ex-situ breeding of rare and endangered species. It is estimated that in the next 200 years approximately 800 mammalian species will require the assistance of breeding programs to ensure long term genetic viability. Biological Resource Banks (BRB) can potentially contribute to this challenge by providing a source of genes that can be used to counter the effects of external selection pressures, genetic drift and inbreeding depression in small or fragmented populations. These banks commonly contain biological materials such as cryopreserved sperm, embryos and cell cultures mainly as genetic and research resources. . Biological resource banks can potentially use these cryopreserved gametes together with assisted reproductive technologies (ART), such as artificial insemination (AI), in vitro fertilisation (IVF), embryo transfer (ET), intracytoplasmic sperm injection (ICSI) and nuclear transfer (NT) to maintain genetic heterogeneity in ex-situ and wild populations. Ascertaining the appropriate protocols for developing the ARTs necessary for non-domestic species is one of the major challenges faced by reproductive physiologists. Typically, there is very little available information about the processing of semen, the effects of diluents, concentration and type of cryoprotectants and freeze-thaw methods for sperm samples of non-domestic species. Procedures proven to be highly effective in humans and laboratory or domestic species, are frequently adopted and modified for use in related wildlife species. It is thus necessary to gain knowledge of the reproductive physiology of wildlife species in order to define effective protocols for the cryopreservation of biomaterials which assists in the conservation of South Africa‘s diverse wildlife species. Sperm quality assessment is a useful tool for assessing the reproductive health of free-ranging populations as well as for selecting individuals for future assisted reproduction programs.
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Vlok, Wynand. "Die testisultrastruktuur van Cyprinidae in Suid-Afrika en Israel met spesiale verwysing na die kriobewaring van Barbus aeneus-sperme." Thesis, 2014. http://hdl.handle.net/10210/11202.
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D.Sc. (Zoology)The spermatogenesis of two freshwater species from South Africa, Barbus marequensis and B. polylepis, and three fresh water species from Israel, B. canis, B. longiceps and Capoeta damascina, was studied. A histological comparison of the process of spermatogenesis was undertaken. The breeding cycle of B. marequensis, B. polylepis, B. canis, B. longiceps and C. damascina was similar to the breeding cycle of B. aeneus and four phases occured within the cycle. The four distinctive phases are post spawning phase, rest phase, pre-spawning phase and the spawning phase (Vlok, 1986) . During the post spawning phase a decline in sperm development is observed and possible lisosomal activity is responsible for the resorption of sperm cells not shed during the spawning phase. The presence of collagen structure provides a distinctive character to the tissue of the testis. The resting phase is characterised by the absence of the lobular structure and the testis is dominated by the collagen tissue. The testis is small and unobtrusive in the abdominal cavities of both species. At the onset of the pre-spawning phase, the testis is filled with spermatogonia. The lobular structure becomes more prominent and the interstitial tissue can be distinguished. Later during the phase, the synchronised development of sperm cells in the cysts of the lobules can be observed, whilst sperm cells in adjacent lobules are in different stages of development. During the spawning phase the testis of all species studied contain mature sperm . cells in the lumens of the lobules.
Books on the topic "Cattle Germplasm resources Cryopreservation"
1
Gottfried, Brem, ed. Ex situ cryoconservation of genomes and genes of endangered cattle breeds by means of modern biotechnological methods. Rome: Food and Agriculture Organization of the United Nations, 1989.
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2
Bajaj, Y. P. S., 1936-, ed. Cryopreservation of plant germplasm I. Berlin: Springer, 1995.
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3
Nauk, V. A. Struktura i funkt͡s︡ii͡a︡ spermiev selʹskokhozi͡a︡ĭstvennykh zhivotnykh pri kriokonservat͡s︡ii. Kishinev: "Shtiint͡s︡a", 1991.
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Nivsarkar, A. E. Animal genetic resources of India: Cattle and buffalo. New Delhi: Directorate of Knowledge Management in Agriculture, Indian Council of Agricultural Research, 2013.
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Furduĭ, F. I. Mezhmolekuli︠a︡rnye vzaimodeĭstvii︠a︡ v kriobiologicheskikh sistemakh. Kishinėu: Akademii︠a︡ nauk Moldovy, Institut fiziologii i sanokreatologii, 2012.
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Roman L. Hruska U.S. Meat Animal Research Center. Germ plasm evaluation program: Progress report, no. 12. [Clay Center, Neb.]: U.S. Dept. of Agriculture, 1990.
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Boronchuk, G. V. Strukturno-funkt︠s︡ionalʹnye i biokhimicheskie izmenenii︠a︡ v biologicheskikh sistemakh pri kriokonservat︠s︡ii. Kishinėu: Akademii︠a︡ nauk Moldovy, Institut fiziologii i sanokreatologii, 2008.
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F, Watson P., and Holt W. V, eds. Cryobanking the genetic resource: Wildlife conservation for the future? London: Taylor & Francis, 2001.
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Bajaj, Y. P. S. Cryopreservation of Plant Germplasm I. Springer, 2010.
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Bajaj, Y. P. S., and L. E. Towill. Cryopreservation of Plant Germplasm II. Springer, 2010.
Find full textBook chapters on the topic "Cattle Germplasm resources Cryopreservation"
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Pursel, V. G., and L. A. Johnson. "Cryopreservation of animal germplasm resources." In Biotic Diversity and Germplasm Preservation, Global Imperatives, 337–53. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-2333-1_17.
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Stushnoff, C., and M. Seufferheld. "Cryopreservation of Apple (Malus Species) Genetic Resources." In Cryopreservation of Plant Germplasm I, 87–101. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-662-03096-7_5.
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Acheampong Amankwaah, Victor, Ruth Naa Ashiokai Prempeh, and Marian Dorcas Quain. "Plant Cryopreservation Importance, Approaches and Future Trends." In Biomedical Engineering. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.108806.
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Plant cryopreservation is useful for long term storage of clonal germplasm and endangered species. Clonally propagated crops which produce recalcitrant seeds cannot be easily conserved using conventional methods. Preservation of plants in vitro is limited to two years and not ideal for germplasm storage for a very long time. The need to conserve plant genetic resources through cryopreservation techniques to mitigate the effects of climate change such as extinction of certain plant species cannot be underestimated. Different cryopreservation methods including dehydration, programmed freezing, vitrification and v cryo-plate are employed in the long-term storage of different plants. These methods are usually based on the principle of the removal of freezable water from tissues by physical or osmotic dehydration followed by ultra-rapid freezing. There have been several advancements in the identification and use of cryoprotective agents, nonetheless, its toxicity remains a challenge. To accelerate plant cryopreservation, there is the need for the development of global expertise. The current practice for the conservation of germplasm in the Biotechnology Laboratory in Ghana is through the use of slow growth media. Moving forward, there is the need to work on developing cryopreservation protocols for preservation of germplasm using liquid nitrogen and cryogenic refrigerators.
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Quazi, Sameer, Tanya Golani, and Arnaud Martino Capuzzo. "Germplasm Conservation." In Endangered Plants. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96184.
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With the increase in risk of extinction of various plants, the trend has been shifted to employment of many biotechnological techniques for preservation of genetic resources of plant and is the area of research which needs to be revolutionized after a specific time period because it allows the production and selection of crop varieties with desirable characteristics during breeding process such as improved fuel, food and health facilities. Having an immense research in conservation of non-threatened species, there is a small collection of knowledge available for conservation of endangered ones. This chapter aims to highlight the various techniques in germplasm conservation of endangered or the species which are at extent of extinction and also the future directions in this field. In developing countries where most of agriculture depends upon food crops, the maintenance of genetic variation is of immense importance. On farm conservation provides the best example of preservation and evolution based on genetic variability which can occur ex-situ and in- situ environment in farms or gene bank. So, it presents the best option for conservation or maintenance of ecosystem and biodiversity which ensures survival of endangered species via germplasm. The most point to consider is that germplasm or genes have to be conserved instead of genotype. In situ conservation involves preservation of plant crops in the field condition in ecosystem where plant is adopted to grow in order to maintain self –sustaining process in natural ecosystem. Similarly ex-situ involve the collections of seed banks of genes collected from plant under natural conditions to produce desirable varieties or from tissue culture in laboratory also referred as in-vitro methodology. In –vitro techniques include cryopreservation which include freezing at much lower temperature than that of freezing point i.e. -196 °C in liquid nitrogen for preserving species which are near to extent of endangerment. Cold storage and storing at lower temperature provides best opportunity for protection against damage caused by rapid freezing. Germplasm exchange has become now a usual practice ensuring exchange of varieties between cultivated and wild types as for example in potatoes specie etc. DNA as well as gene or seed banks provide molecular sources for conservation at biotechnological level. The techniques of introgression and incorporation are basic approaches for germplasm conservation. So there is need to revolutionize and practice germplasm conservation for fulfilling future needs being aimed at conserving endangered or threatened species from conservation hotspots.
Conference papers on the topic "Cattle Germplasm resources Cryopreservation"
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Lei, X. J., Y. P. Wang, and W. H. Jia. "CRYOPRESERVATION AND INNOVATIVE UTILIZATION OF GERMPLASM RESOURCES FOR PANAX GINSENG." In ОТ БИОХИМИИ РАСТЕНИЙ К БИОХИМИИ ЧЕЛОВЕКА. Москва: Федеральное государственное бюджетное научное учреждение "Всероссийский научно-исследовательский институт лекарственных и ароматических растений", 2022. http://dx.doi.org/10.52101/9785870191041_88.
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Granaci, Vera. "New achievement in cryopreservation of genetic resources in cattle." In XIth International Congress of Geneticists and Breeders from the Republic of Moldova. Scientific Association of Geneticists and Breeders of the Republic of Moldova, Institute of Genetics, Physiology and Plant Protection, Moldova State University, 2021. http://dx.doi.org/10.53040/cga11.2021.107.
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