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Francisqueti AM, Marin RR, Hengling MM, Hosomi ST, Pritchard HW, Custódio CC, Machado-Neto NB. Orchid seeds are not always short lived in a conventional seed bank! ANNALS OF BOTANY 2024; 133:941-952. [PMID: 38365444 DOI: 10.1093/aob/mcae021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 02/09/2024] [Indexed: 02/18/2024]
Abstract
BACKGROUND AND AIMS Orchid seeds are reputed to be short lived in dry, cold storage conditions, potentially limiting the use of conventional seed banks for long-term ex situ conservation. This work explores whether Cattleya seeds are long lived or not during conventional storage (predried to ~12 % relative humidity, then stored at -18 °C). METHODS We explored the possible interaction of factors influencing seed lifespan in eight species of the genus Cattleya using physiological (germination and vigour), biochemical (gas chromatography), biophysical (differential scanning calorimetry) and morphometric methods. Seeds were desiccated to ~3 % moisture content and stored at -18 °C for more than a decade, and seed quality was measured via three in vitro germination techniques. Tetrazolium staining was also used to monitor seed viability during storage. The morphometric and germination data were subjected to ANOVA and cluster analysis, and seed lifespan was subjected to probit analysis. KEY RESULTS Seeds of all Cattleya species were found to be desiccation tolerant, with predicted storage lifespans (P50y) of ~30 years for six species and much longer for two species. Cluster analysis showed that the three species with the longest-lived seeds had smaller (9-11 %) airspaces around the embryo. The post-storage germination method impacted the quality assessment; seeds equilibrated at room temperature for 24 h or in 10 % sucrose solution had improved germination, particularly for the seeds with the smallest embryos. Chromatography revealed that the seeds of all eight species were rich in linoleic acid, and differential scanning calorimetry identified a peak that might be auxiliary to selecting long-lived seeds. CONCLUSIONS These findings show that not all orchids produce seeds that are short lived, and our trait analyses might help to strengthen prediction of seed longevity in diverse orchid species.
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Affiliation(s)
- Ana Maria Francisqueti
- Unoeste Campus II, Agronomy College, Building 2, room 201, Rodovia Raposo Tavares, km 572. Limoeiro, Presidente Prudente SP, 19067-175, Brazil
| | - Rafael Rubio Marin
- Unoeste Campus II, Agronomy College, Building 2, room 201, Rodovia Raposo Tavares, km 572. Limoeiro, Presidente Prudente SP, 19067-175, Brazil
| | - Mariane Marangoni Hengling
- Unoeste Campus II, Agronomy College, Building 2, room 201, Rodovia Raposo Tavares, km 572. Limoeiro, Presidente Prudente SP, 19067-175, Brazil
| | - Silvério Takao Hosomi
- Unoeste Campus II, Agronomy College, Building 2, room 201, Rodovia Raposo Tavares, km 572. Limoeiro, Presidente Prudente SP, 19067-175, Brazil
| | - Hugh W Pritchard
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, PR China
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, West Sussex RH17 6TN, UK
| | - Ceci Castilho Custódio
- Unoeste Campus II, Agronomy College, Building 2, room 201, Rodovia Raposo Tavares, km 572. Limoeiro, Presidente Prudente SP, 19067-175, Brazil
| | - Nelson Barbosa Machado-Neto
- Unoeste Campus II, Agronomy College, Building 2, room 201, Rodovia Raposo Tavares, km 572. Limoeiro, Presidente Prudente SP, 19067-175, Brazil
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Popova E, Kulichenko I, Kim HH. Critical Role of Regrowth Conditions in Post-Cryopreservation of In Vitro Plant Germplasm. BIOLOGY 2023; 12:biology12040542. [PMID: 37106743 PMCID: PMC10135868 DOI: 10.3390/biology12040542] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/26/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023]
Abstract
Cryopreservation is an effective option for the long-term conservation of plant genetic resources, including vegetatively propagated crops and ornamental plants, elite tree genotypes, threatened plant species with non-orthodox seeds or limited seed availability, as well as cell and root cultures useful for biotechnology. With increasing success, an arsenal of cryopreservation methods has been developed and applied to many species and material types. However, severe damage to plant material accumulating during the multi-step cryopreservation procedure often causes reduced survival and low regrowth, even when the optimized protocol is applied. The conditions at the recovery stage play a vital role in supporting material regrowth after cryopreservation and, when optimized, may shift the life-and-death balance toward a positive outcome. In this contribution, we provide an overview of the five main strategies available at the recovery stage to improve post-cryopreservation survival of in vitro plant materials and their further proliferation and development. In particular, we discuss the modification of the recovery medium composition (iron- and ammonium-free), exogenous additives to cope with oxidative stress and absorb toxic chemicals, and the modulation of medium osmotic potential. Special attention is paid to plant growth regulators used at various steps of the recovery process to induce the desired morphological response in cryopreserved tissues. Given studies on electron transport and energy provision in rewarmed materials, we discuss the effects of light-and-dark conditions and light quality. We hope that this summary provides a helpful guideline and a set of references for choosing the recovery conditions for plant species that have not been cryopreserved. We also propose that step-wise recovery may be most effective for materials sensitive to cryopreservation-induced osmotic and chemical stresses.
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Affiliation(s)
- Elena Popova
- K.A. Timiryazev Institute of Plant Physiology of Russian Academy of Sciences, Botanicheskaya 35, Moscow 127276, Russia
| | - Irina Kulichenko
- K.A. Timiryazev Institute of Plant Physiology of Russian Academy of Sciences, Botanicheskaya 35, Moscow 127276, Russia
| | - Haeng-Hoon Kim
- Department of Agricultural Life Science, Sunchon National University, Suncheon 57922, Republic of Korea
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Entensa Y, González-Morales A, Linares C, Vázquez JG, Martínez-Montero ME, Zevallos-Bravo BE, Hajari E, Höfer M, Villalobos-Olivera A, Lorenzo JC. Cryopreservation of Seeds of the Highly Valued Tropical Timber Species Swietenia Mahagoni . CRYOLETTERS 2022. [DOI: 10.54680/fr22610110412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: Swietenia mahagoni wood is one of the most valuable in world trade and, as a result, natural populations have been decimated due to unsustainable harvesting. The decline in natural population levels is being exacerbated by climate change. In order to ensure
the preservation of valuable genotypes, there is an urgent need to develop strategies to conserve the genetic diversity present within this species. At present, cryopreservation is the most viable option for the long-term storage of plant germplasm, particularly for long-lived species which
are challenging to maintain in the field. OBJECTIVE:To cryopreserve intact seeds of S. mahagoni, with the dual goal of retaining the biosynthetic capacity of plants, which is critical since this species is highly valued for medicinal purposes. MATERIALS AND METHODS: Seeds
at a moisture content of 6% were immersed in liquid nitrogen (LN) before warming and recovery. Plantlet establishment and growth were assessed over a period of 70 days and anthraquinone synthesis was determined in roots, stems and leaves. RESULTS: The results showed an initial lag in
the germination rate of cryopreserved seeds compared with control seeds; however, this difference disappeared over time. The lag in seedling emergence observed in cryostored seeds was also evident in the plant characteristics measured following 30 days of culture when all plant parameters
measured were significantly higher in plants produced from control than cryostored seeds. However, after 70 days of growth, these differences were no longer apparent. Anthraquinone levels were also initially lower (at 30 days) in plants regenerated from cryopreserved seeds than those from
control seeds, however, this difference was substantially reduced by 70 days thereby indicating the ability of these plants to accumulate secondary metabolites, albeit at a reduced rate, during the early stages of development. CONCLUSION: In S. mahagoni, the delay in anthraquinone
production in plants regenerated from cryostored seeds during the early stages of development may have occurred as a consequence of the preferential allocation of resources towards the initiation of recovery processes in response to the stresses imposed by cryopreservation. Once the stresses
were overcome and plant growth resumed, resources could be directed to secondary processes such as anthraquinone synthesis.
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Affiliation(s)
- Ysmel Entensa
- Laboratory for Plant Breeding and Conservation of Genetic Resources, Bioplant Centre, University of Ciego de Ávila, Ciego de Ávila, 69450, Cuba
| | - Abel González-Morales
- Laboratory for Plant Breeding and Conservation of Genetic Resources, Bioplant Centre, University of Ciego de Ávila, Ciego de Ávila, 69450, Cuba
| | - Claudia Linares
- Laboratory for Plant Breeding and Conservation of Genetic Resources, Bioplant Centre, University of Ciego de Ávila, Ciego de Ávila, 69450, Cuba
| | - José Gerardo Vázquez
- Laboratory for Plant Breeding and Conservation of Genetic Resources, Bioplant Centre, University of Ciego de Ávila, Ciego de Ávila, 69450, Cuba
| | - Marcos Edel Martínez-Montero
- Laboratory for Plant Breeding and Conservation of Genetic Resources, Bioplant Centre, University of Ciego de Ávila, Ciego de Ávila, 69450, Cuba
| | | | - Elliosha Hajari
- Plant Improvement; Agricultural Research Council-Tropical and Subtropical Crops; Private Bag X11208, Nelspruit, 1200, South Africa
| | - Monika Höfer
- Julius Kühn Institute, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden, Germany
| | - Ariel Villalobos-Olivera
- Laboratory for Plant Breeding and Conservation of Genetic Resources, Bioplant Centre, University of Ciego de Ávila, Ciego de Ávila, 69450, Cuba
| | - José Carlos Lorenzo
- Laboratory for Plant Breeding and Conservation of Genetic Resources, Bioplant Centre, University of Ciego de Ávila, Ciego de Ávila, 69450, Cuba
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Pence VC, Bruns EB. The Tip of the Iceberg: Cryopreservation Needs for Meeting the Challenge of Exceptional Plant Conservation. PLANTS 2022; 11:plants11121528. [PMID: 35736677 PMCID: PMC9227111 DOI: 10.3390/plants11121528] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 11/28/2022]
Abstract
Cryopreservation is increasingly important as a conservation tool, particularly for threatened exceptional species. The goal of this study was to investigate the current knowledge of plant cryopreservation through a search of the literature in Web of Science and align that with the 775 species currently identified on the Working List of Exceptional Plants. While there is a good foundation in plant cryopreservation research, particularly with economically important species, there are significant gaps in research on families that contain the largest numbers of currently known exceptional species, including the Dipterocarpaceae, Rhizophoraceae, and Pittosporaceae. Even families well represented in both in the literature and on the List of Exceptional Plants had much less overlap at the level of genus. Tropical trees, a significant portion of exceptional species, were not as well represented in the literature as herbaceous species. Over 70% of all articles dealt with in vitro cryopreservation, with much less emphasis on other methods (seed, embryo, dormant bud, and pollen) that will be more cost-effective for species where they can be applied. While the research on plant cryopreservation to date provides a strong foundation and is being utilized effectively for conserving the diversity of a number of economically important species, this study revealed significant gaps that can help prioritize future research to more effectively conserve the diversity of threatened exceptional species.
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Affiliation(s)
- Valerie C. Pence
- Center for Conservation and Research of Endangered Wildlife (CREW), Cincinnati Zoo & Botanical Garden, 3400 Vine St., Cincinnati, OH 45220, USA
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
- Correspondence:
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Burkhan H, Rajan KS, Appalasamy S, Poobathy R, Chew BL, Mariappan V, Subramaniam S. Effect of Cryopreservation Method Supported with Biochemical Analyses in the Axillary Bud of Jewel Orchid, Ludisia discolor. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11070879. [PMID: 35406859 PMCID: PMC9002730 DOI: 10.3390/plants11070879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/10/2022] [Accepted: 03/10/2022] [Indexed: 05/04/2023]
Abstract
This study investigated conserving an endangered terrestrial jewel orchid Ludisia discolor, using in vitro grown axillary buds. Excised segments of axillary buds (4-5 mm in length) were precultured on a modified Murashige and Skoog (MS) medium supplemented with 0.2 M sucrose for 24 h and osmoprotected in a loading solution for 20 min. Then, axillary buds were dehydrated in plant vitrification solution 2 (PVS2) for 10 min at 0 °C and incubated in liquid nitrogen for 1 h. Subsequently, axillary buds were rewarmed rapidly by dilution solution and transferred to a growth recovery medium supplemented with 0.05 µM melatonin, which led to an improved survival chance (16.67%) for cryopreserved L. discolor. The osmotic stress and the overproduction of reactive oxygen species (ROS) during cryopreservation stages may result in cryoinjuries and poor survival as increased levels of proline (5.51 µmol/g), catalase (85.64 U/g), peroxidase (565.37 U/g), and ascorbate peroxidase activities (12.19 U/g) were detected after dehydration, preculture, rewarming, and loading stage, respectively. Results obtained from this study indicate that further experimental designs which apply different PVS and exogenous antioxidants are needed for improved survival and regrowth of L. discolor.
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Affiliation(s)
- Hazirah Burkhan
- School of Biological Sciences, Universiti Sains Malaysia (USM), Georgetown 11800, Penang, Malaysia
| | - Kirutika Selva Rajan
- School of Biological Sciences, Universiti Sains Malaysia (USM), Georgetown 11800, Penang, Malaysia
| | - Suganthi Appalasamy
- Department of Natural Resource and Sustainability, Faculty of Earth Science, Universiti Malaysia Kelantan (UMK), Locked Bag No. 100, Jeli 17600, Kelantan, Malaysia
| | - Ranjetta Poobathy
- School of Biological Sciences, Quest International University (QUIP), Ipoh 30250, Perak, Malaysia
| | - Bee Lynn Chew
- School of Biological Sciences, Universiti Sains Malaysia (USM), Georgetown 11800, Penang, Malaysia
| | - Vanitha Mariappan
- Centre of Toxicology and Health Risk Studies (CORE), Faculty of Health Sciences, Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur 50300, Federal Territory of Kuala Lumpur, Malaysia
| | - Sreeramanan Subramaniam
- School of Biological Sciences, Universiti Sains Malaysia (USM), Georgetown 11800, Penang, Malaysia
- National Poison Centre, Universiti Sains Malaysia (USM), Georgetown 11800, Penang, Malaysia
- School of Chemical Engineering Technology, Universiti Malaysia Perlis (UNIMAP), Arau 02600, Perlis, Malaysia
- Centre for Chemical Biology, Universiti Sains Malaysia (USM), Bayan Lepas 11900, Penang, Malaysia
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Kulak V, Longboat S, Brunet ND, Shukla M, Saxena P. In Vitro Technology in Plant Conservation: Relevance to Biocultural Diversity. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11040503. [PMID: 35214833 PMCID: PMC8876341 DOI: 10.3390/plants11040503] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/05/2022] [Accepted: 02/09/2022] [Indexed: 05/27/2023]
Abstract
Plant diversity is critical to the functioning of human societies, and evidence shows that plant conservation success is driven by integrative approaches that include social and biological factors. Plants have a unique capacity to reproduce asexually, and propagation practices can yield large numbers of plantlets. These plantlets can be used in several ways to fulfil conservation goals including the repopulation of regions with declining densities of threatened species that hold cultural meaning. However, the potential of in vitro technologies in the conservation of plants that hold cultural meaning is understudied. In this paper we focus upon the roles of in vitro technologies in the conservation of plants relevant to biocultural environments and provide an overview of potential knowledge gaps at the interface of in vitro and plants used traditionally, including those meaningful to Indigenous Peoples. We conclude that in vitro technologies can be powerful tools in biocultural conservation if they are deployed in a manner respectful of the socio-cultural context in which plants play a role, but that further research is needed in this regard. We suggest several epistemological points to facilitate future research.
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Affiliation(s)
- Verena Kulak
- School of Environmental Design and Rural Development, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.L.); (N.D.B.)
| | - Sheri Longboat
- School of Environmental Design and Rural Development, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.L.); (N.D.B.)
| | - Nicolas D. Brunet
- School of Environmental Design and Rural Development, University of Guelph, Guelph, ON N1G 2W1, Canada; (S.L.); (N.D.B.)
| | - Mukund Shukla
- Plant Agriculture Department, Gosling Research Institute for Plant Preservation, University of Guelph, Guelph, ON N1G 2W1, Canada;
| | - Praveen Saxena
- Plant Agriculture Department, Gosling Research Institute for Plant Preservation, University of Guelph, Guelph, ON N1G 2W1, Canada;
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Pradhan N, Fan X, Martini F, Chen H, Liu H, Gao J, Goodale UM. Seed viability testing for research and conservation of epiphytic and terrestrial orchids. BOTANICAL STUDIES 2022; 63:3. [PMID: 35142915 PMCID: PMC8831675 DOI: 10.1186/s40529-022-00333-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/14/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Seed viability testing is essential in plant conservation and research. Seed viability testing determines the success of ex-situ conservation efforts, such as seed banking but commonly testing protocols of orchids lack consistency and accuracy, therefore, there is a need to select an appropriate and reliable viability test, especially when conducting comparative studies. Here, we evaluated the suitability of three seed viability tests, Evans blue test (EB), Fluorescein diacetate test (FDA) and Tetrazolium test (TTC), with and without sterilization, on seeds of 20 orchid species, which included five epiphytes and fifteen terrestrials, using both fresh seeds and seeds stored at - 18 ºC for 6 to 8 years. RESULTS We found that sterilization and lifeform of seeds affected seed viability across all tests but the storage time was not an influential factor. Sterilization negatively affected seed viability under EB and FDA test conditions but increased the detection of viable seeds in the TTC test in both epiphytic and terrestrial species. The EB test, when administered without sterilization provided the highest viability results. Being non-enzymatic unlike TTC and FDA tests, as expected, the EB test was the most reliable with similar results between sterilized and not sterilized seeds for most epiphytic and terrestrial species as well as when compared between groups. CONCLUSIONS The lifeform of the species and seed sterilization prior to testing are important influential factors in orchid seed viability testing. Since EB test was found to be reliable we recommend the EB test for seed viability assessment in orchids rather than the less reliable but commonly used TTC test, or the FDA test, which require more expensive and sophisticated instrumentation. Since storage time was not an influential factor in orchid seed viability testing, the recommendations of this study can be used for both fresh as well as long-term stored orchid seeds. This is helpful for research and especially for conservation measures such as seed banking. However, due to the species specificity of the bio-physiology of orchids, we call for comprehensive viability test assessment in the hyper diverse orchid family to be extended to a greater number of species to facilitate efficient conservation and research.
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Affiliation(s)
- Namrata Pradhan
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi 530004 People’s Republic of China
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi 530004 People’s Republic of China
- Seed Conservation Specialist Group, Species Survival Commission, International Union for Conservation of Nature (IUCN), 281196 Gland, Switzerland
| | - Xuli Fan
- Lab of Ecology and Evolutionary Biology, Chenggong Campus, Yunnan University, University Town, Chenggong New District, Kunming, Yunnan 650504 People’s Republic of China
| | - Francesco Martini
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi 530004 People’s Republic of China
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi 530004 People’s Republic of China
- Present Address: Faculty of Forest and Wood Sciences, Department of Forest Ecology, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Huayang Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093 People’s Republic of China
| | - Hong Liu
- International Center for Tropical Botany, Department of Earth and Environment, Florida International University, 11200 SW 8th Street Miami, Florida, 33199 USA
| | - Jiangyun Gao
- Lab of Ecology and Evolutionary Biology, Chenggong Campus, Yunnan University, University Town, Chenggong New District, Kunming, Yunnan 650504 People’s Republic of China
| | - Uromi Manage Goodale
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi 530004 People’s Republic of China
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning, Guangxi 530004 People’s Republic of China
- Seed Conservation Specialist Group, Species Survival Commission, International Union for Conservation of Nature (IUCN), 281196 Gland, Switzerland
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8
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Advances in Breeding, Bioprospecting, and In Vitro Culture of Laelia Orchid Species. HORTICULTURAE 2022. [DOI: 10.3390/horticulturae8020103] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Orchids (Orchidaceae) are plants that are highly appreciated by their beautiful flowers worldwide. Moreover, they represent a source of metabolites with applications in medicine and biotechnology. Within the Orchidaceae family, the Laelia genus is a group of orchid species from the Neotropics and is probably one of the most representative genera of America. Laelia orchids are cultivated by their splendid flowers and are widely used in orchid breeding. Here, we revise the use of the Laelia genus in orchid breeding and metabolite bioprospecting. We also analyze the use of plant tissue culture (PTC) as an alternative to conventional propagation and as a strategy for the recovery of those Laelia species threatened with extinction. We summarize and discuss the recent advances in the application of different PTC techniques for mass multiplication based on asymbiotic germination, organogenesis, protocorm-like bodies development, and somatic embryogenesis, and the advances of in vitro conservation by cryoconservation and the use of slow-growth promoting hormones. Finally, we suggest future directions and venues in research for Laelia species.
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Das MC, Devi SD, Kumaria S, Reed BM. Looking for a way forward for the cryopreservation of orchid diversity. Cryobiology 2021; 102:1-14. [PMID: 34081925 DOI: 10.1016/j.cryobiol.2021.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 05/20/2021] [Accepted: 05/23/2021] [Indexed: 10/21/2022]
Abstract
The family Orchidaceae, with over 25,000 species, includes five subfamilies and nearly 700 genera. Loss of plants in the wild has resulted from clearing of forests and excessive collection for various purposes. Moreover, the requirement of symbiotic association during seed germination under natural conditions adds a certain level of difficulty in retaining the orchid resources in the wild. Cryopreservation is an important arena in conservation science due to its potential of storing genetic resources without altering the genetic makeup. Cryopreserved orchids are a very small percentage of the species, and are also not representative of most genera. Finding effective protocols for the various explant types is of prime importance in conserving orchid diversity. Seed is the most commonly stored and directly useful explant, and direct plunging in liquid nitrogen or PVS2 vitrification appear to be suitable for most tested species. The myriad of other species should be screened as they become available, with special emphasis on seed maturity and moisture content. Studies of protocorms and protocorm-like bodies mostly employ desiccation, PVS2 vitrification or encapsulation-dehydration. Pollinia are generally stored successfully following desiccation or slow cooling. There are too few examples of shoot tip cryopreservation to make a determination, however vitrification techniques are likely the most useful for a range of genera. A systematic and coordinated effort is needed to screen all available species in as many taxa as possible, initially with seed, protocorms and pollinia. It is a charge to the orchid research community to organize this effort and fill in the required data for the large number of untested taxa. In addition, providing stored samples to established orchid cryo collections would greatly increase preservation of these endangered treasures.
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Affiliation(s)
- Meera Chettri Das
- Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong, 793022, Meghalaya, India.
| | - Seram Devika Devi
- Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong, 793022, Meghalaya, India
| | - Suman Kumaria
- Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong, 793022, Meghalaya, India
| | - Barbara M Reed
- USDA National Clonal Germplasm Repository Corvallis, OR, USA
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Influence of scarification method on seed germination of the terrestrial orchid Anacamptis laxiflora (Lam.). EUROBIOTECH JOURNAL 2021. [DOI: 10.2478/ebtj-2021-0004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
A critical step during in vitro sexual propagation of terrestrial orchids is the treatment of the microscopic seeds with a disinfecting solution that kills bacteria and fungi attached to the seeds. This treatment is necessary to prevent infection of the culture vessels. At the same time, the treatment serves to scarify the seeds, a process that disrupts seed dormancy and initiates germination. The literature is inconclusive with respect to the proper combination of disinfecting solution strength and treatment duration. Both factors should be adapted to each species to guarantee minimal infection rate without damaging the embryo. This research aims to compare three disinfection/scarification methods for seeds of Anacamptis laxiflora (Lam.): (i) soaking in 0.5% NaClO, (ii) soaking in 0.5% NaClO, then centrifugation, and (iii) presoaking the seeds in sucrose solution, then soaking in 0.5% NaClO. The seeds were soaked in the disinfecting solution for 5 to 85 min. Following scarification, the seeds were sown in modified Malmgren nutrient medium. Infected and germinated vessels were counted at 41 and 189 d after sowing. We found that the longer the chemical treatment, the lower the infection rate, and the higher the germination rate. There was no significant difference in germination rate between the NaClO and the NaClO-plus-centrifugation method; in fact, the slight savings in disinfection time effected by centrifugation were more than offset by the added complexity of the method. Moreover, we found that centrifugation significantly delays germination. The sucrose presoak-plus-NaClO method was superior to plain NaClO, as the sucrose stimulates the germination of microbial spores on the surface of the seeds, making them easier to kill. Perhaps seeds with thicker testa as well as whole immature capsules could benefit even more from the pretreatment in sucrose solution.
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Pereira STS, Vendrame WA, Pivetta KFL, Sorgato JC, Faria RTD. Efficiency of cryoprotectors for cryopreservation of two orchid species from Americas. RODRIGUÉSIA 2021. [DOI: 10.1590/2175-7860202172123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract The objective of this study was to evaluate the efficiency of cryoprotective solution (PVS2) combined with phloroglucinol for the cryopreservation of seeds of two orchid species, Encyclia cordigera and Epidendrum ciliare. Seeds of Encyclia cordigera had 91.03% initial viability and 91.99% germination. The treatment of the seeds with PVS2 at 0 °C with 1% phloroglucinol for 60 min returned 93.79% viability and 91.01% germination after recovery from LN, consequently resulting in faster development of protocorms. For Epidendrum ciliare, seed viability was 85.65% and germination was 85.90%. Seed exposure to the PVS2 at 0 °C with 1% phloroglucinol for 180 min showed viability of 39.23% and germination of 37.88%. Despite lower germination, 78.90% of the protocorms reached stage P3 of development, when evaluated 45 days after sowing, not significantly different from the control 1, and showed normal development. These results indicate that PVS2 cryoprotective solution is efficient when combined with phloroglucinol for the cryopreservation and successful recovery of seeds of Encyclia cordigera and Epidendrum ciliare. The present study also indicates that response to cryopreservation and success of recovery after cold storage is species-specific and requires adjustments in exposure time to PVS2 at 0 °C prior to immersion in LN.
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Custodio CC, Machado-Neto NB, Singer RB, Pritchard HW, Seaton PT, Marks TR. Storage of orchid pollinia with varying lipid thermal fingerprints. PROTOPLASMA 2020; 257:1401-1413. [PMID: 32506243 DOI: 10.1007/s00709-020-01514-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
Orchid pollinia have the potential to make a valuable contribution to current techniques of germplasm storage and assisted reproduction, yet information regarding their preservation and their ability to remain viable over time is currently limited. Dactylorhiza fuchsii and Disa uniflora were used as models for investigating potential techniques for storing orchid pollinia. Initially, freshly harvested pollinia of Dact. fuchsii were incubated at 25 °C and 100% RH (relative humidity) for up to 7 days and germinated in vitro. For pollinia from both species, moisture sorption isotherms were constructed and thermal fingerprints generated using differential scanning calorimetry (DSC). Pollinia were stored at three temperatures (5, - 18 and - 196 °C) after equilibration at four different RHs (5, 33, 50 and 75%) and germinated. The isotherms and DSC results varied between species. Compared with D. uniflora, pollinia of Dact. fuchsii consistently equilibrated at higher moisture content (MC) for each RH, had less detectable lipids by DSC and had shorter lifespans, remaining viable after 3-4 months only at - 20 and - 196 °C and at low RH (5 and 33%). Both species' pollinia stored well at - 20 °C and - 196 °C, although there was some evidence of a small loss of viability under cryopreservation. In conclusion, pollen of these two species can be stored successfully for at least 3-4 months, and to maximize the pre-storage quality, it is recommended that fresh pollen is collected from flowers just prior to anthesis.
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Affiliation(s)
- Ceci Castilho Custodio
- Agronomy College, UNOESTE, Rodovia Raposo Tavares, km 572, Presidente Prudente, São Paulo, 19067-175, Brazil
| | - Nelson B Machado-Neto
- Agronomy College, UNOESTE, Rodovia Raposo Tavares, km 572, Presidente Prudente, São Paulo, 19067-175, Brazil.
| | - Rodrigo B Singer
- Departamento Botânica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Hugh W Pritchard
- Department of Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
| | - Philip T Seaton
- Department of Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
| | - Timothy R Marks
- Department of Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
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Khor SP, Yeow LC, Poobathy R, Zakaria R, Chew BL, Subramaniam S. Droplet-vitrification of Aranda Broga Blue orchid: Role of ascorbic acid on the antioxidant system and genetic fidelity assessments via RAPD and SCoT markers. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2020; 26:e00448. [PMID: 32368510 PMCID: PMC7184254 DOI: 10.1016/j.btre.2020.e00448] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/22/2020] [Accepted: 03/28/2020] [Indexed: 11/07/2022]
Abstract
A droplet-vitrification cryopreservation protocol has been successfully developed for Aranda Broga Blue orchid hybrid using protocorm-like bodies (PLBs). However, maximum growth regeneration percentage was recorded at 5% only based on previous report. Thus, to improve growth recovery of cryopreserved PLBs, cryopreservation stages were supplemented with ascorbic acid, tested at 50, 100 and 150 mg/L. However, results demonstrated that exogenous ascorbic acid was not favorable in regeneration of cryopreserved explants (maximum value of 1.67 % with 50 mg/L ascorbic acid supplementation). Total soluble protein and various antioxidant enzyme activities such as catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) were evaluated after each cryopreservation stages in conjunction with the application of exogenous ascorbic acid. Addition of antioxidant must be carefully evaluated and its application may not guarantee successful growth recovery. RAPD and SCoT molecular analysis confirmed the genetic stability of regenerated cryopreserved PLBs as no polymorphism was detected compared to control PLBs culture.
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Affiliation(s)
- Soo Ping Khor
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800, Gelugor, Penang, Malaysia
| | - Lit Chow Yeow
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800, Gelugor, Penang, Malaysia
| | - Ranjetta Poobathy
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800, Gelugor, Penang, Malaysia
- School of Biological Sciences, Quest International University, 30250, Ipoh, Perak, Malaysia
| | - Rahmad Zakaria
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800, Gelugor, Penang, Malaysia
| | - Bee Lynn Chew
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800, Gelugor, Penang, Malaysia
| | - Sreeramanan Subramaniam
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800, Gelugor, Penang, Malaysia
- Centre for Chemical Biology, Universiti Sains Malaysia, Bayan Lepas, Penang, Malaysia
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James Antony JJ, Zakaria S, Zakaria R, Anak Ujang J, Othman N, Subramaniam S. Biochemical analyses of Dendrobium Sabin Blue PLBs during cryopreservation by vitrification. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2019; 25:1457-1467. [PMID: 31736548 PMCID: PMC6825076 DOI: 10.1007/s12298-019-00703-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 08/05/2019] [Accepted: 08/20/2019] [Indexed: 05/06/2023]
Abstract
Dendrobium Sabin Blue is an important orchid hybrid that has been grown extensively as cut flower, potted plant and is also popular for its deep purplish blue flowers. The most efficient long term conservation method of this hybrid is through cryopreservation. Cryopreservation involving the vitrification method consists of explants exposure to highly concentrated cryoprotective solution followed by freezing rapidly in liquid nitrogen. However, these treatments involved highly concentrated cryoprotectant that could incur toxicity to the explants. Hence, cryopreservation protocol requires biochemical analyses in understanding the damages or injuries occurred during cryopreservation treatments. In this study, biochemical analyses revealed a general reduction in chlorophyll, carotenoid and porphyrin content to 0.40 µg/g F W (thawing stage), 31.50 µg/g F W unloading stage and 2230.41 µg/g F W (thawing stage), respectively in comparison to the control treatments. In addition, increased level in proline content were obtained at different cryopreservation stages with highest level (5.42 µmole/g F W) recorded at the PVS2 dehydration stage. Fluctuated outcomes were obtained in catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POX) enzyme activities in PLBs exposed to different cryopreservation stages. Lowest values recorded for CAT enzyme activity were obtained at the dehydration stage (3.94 U/g). Lowest POX enzyme activities were obtained at the dehydration (122.36 U/g) and growth recovery (106.40 U/g) stages. Additionally, lowest APX enzyme activities values were recorded at the thawing (7.47 U/g) and unloading (7.28 U/g) stages. These have contributed to low regeneration of Dendrobium Sabin Blue protocorm like bodies (PLBs) following cryopreservation. Hence, in the future experimental design, exogenous antioxidant could be included in the cryopreservation procedures to improve the existing protocol.
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Affiliation(s)
- Jessica Jeyanthi James Antony
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800 Georgetown, Penang Malaysia
- Department of Crop Science, Faculty of Agricultural and Food Sciences, Universiti Putra Malaysia, Bintulu Sarawak Campus, Georgetown, Sarawak Malaysia
| | - Suhana Zakaria
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800 Georgetown, Penang Malaysia
| | - Rahmad Zakaria
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800 Georgetown, Penang Malaysia
| | - Jorim Anak Ujang
- Department of Crop Science, Faculty of Agricultural and Food Sciences, Universiti Putra Malaysia, Bintulu Sarawak Campus, Georgetown, Sarawak Malaysia
| | - Nurulhasanah Othman
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Georgetown, Pulau Pinang Malaysia
| | - Sreeramanan Subramaniam
- School of Biological Sciences, Universiti Sains Malaysia (USM), 11800 Georgetown, Penang Malaysia
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Nikishina TV, Kozlova ON, Levitskaya GE, Vysotskaya ON. Study of Dactylorhiza Seeds (D. baltica and D. maculata) from the Orchid Collection of the Cryobank at Timiryazev Institute of Plant Physiology, Russian Academy of Sciences. BIOL BULL+ 2019. [DOI: 10.1134/s1062359019030063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Magrini S, De Vitis M, Torelli D, Santi L, Zucconi L. Seed banking of terrestrial orchids: evaluation of seed quality in Anacamptis following 4-year dry storage. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:544-550. [PMID: 30430713 DOI: 10.1111/plb.12936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
Good-quality dry seeds of some orchids have the potential to survive for decades under conventional seed bank conditions, but further research is needed to fill existing gaps in knowledge regarding seed behaviour under long-term dry storage. The objectives of this study were to evaluate germination ability on two asymbiotic culture media with different nitrogen source; to assess seed desiccation tolerance needed for the storage at sub-zero temperatures; and to study the effects of dry storage at low temperature. Asymbiotic seed germination tests of four Anacamptis species were carried out to evaluate the effects of different culture media, dehydration and dry storage on germination ability. Viability of 4-year-stored seeds was assessed by means of the tetrazolium test. Generalised linear model (GLM) analysis detected significant effects (P < 0.01) of the species, medium and storage time on total germination, while dehydration did not significantly affect it. Except for A. palustris, germination percentage was minimum after 1-month storage and increased with longer storage periods. Tetrazolium viability tests detected high percentages of viable seed (>90%) following 4-year storage in three out of four species. Seeds of the four Anacamptis species proved to be desiccation tolerant and have orthodox storage behaviour. The consequence of these findings is of interest to practical conservation approaches for orchids in seed-banking. The results highlight the importance of multiple assessments of seed quality, both viability and germination, to understand seed storage behaviour.
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Affiliation(s)
- S Magrini
- Tuscia Germplasm Bank, Tuscia University, Viterbo, Italy
| | - M De Vitis
- Tuscia Germplasm Bank, Tuscia University, Viterbo, Italy
| | - D Torelli
- Tuscia Germplasm Bank, Tuscia University, Viterbo, Italy
| | - L Santi
- Department of Agriculture and Forestry Science, Tuscia University, Viterbo, Italy
| | - L Zucconi
- Tuscia Germplasm Bank, Tuscia University, Viterbo, Italy
- Department of Ecological and Biological Sciences, Tuscia University, Viterbo, Italy
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Diengdoh RV, Kumaria S, Das MC. Antioxidants and improved regrowth procedure facilitated cryoconservation of Paphiopedilum insigne Wall. Ex. Lindl. - An Endangered Slipper Orchid. Cryobiology 2019; 87:60-67. [PMID: 30776352 DOI: 10.1016/j.cryobiol.2019.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 02/12/2019] [Accepted: 02/13/2019] [Indexed: 11/16/2022]
Abstract
Orchids and their sustainability are very important issues that need global conservation efforts. Paphiopedilum insigne (an endangered orchid), is one of the most excessively exploited species of orchids and is mentioned in the IUCN Red List and Appendix I of CITES. The prospect for conservation and commercialization of this species would be strengthened with the development of improved cryopreservation techniques. This study reports on successful cryopreservation of protocorms of P.insigne after cryopreservation using vitrification (Vit) and encapsulation-vitrification (E-Vit) techniques. The study compared the addition of four antioxidants to the pretreatment and recovery stages, three growth media, and agitated vs. semisolid culture medium for initial recovery. Recovery after cryopreservation for the control was 27% for Vit and 37% for E-Vit. In both cases agitated culture produced improved recovery by about 10%, but with significantly better recovery with E-Vit. The best recovery (51.2 ± 0.9%) was recorded for 0.5 M sucrose precultured encapsulated protocorms treated for 45 min with PVS2 and recovered in ½ MS (L/S) liquid medium for 10 days under agitation, followed by transfer to semi-solid medium. This recovery was further enhanced (62.7 ± 0.5%) with the incorporation of 30 μM glutathione in both liquid preculture and the liquid and semisolid regrowth medium. This new protocol improved the E-Vit cryopreservation recovery from the initial 37%-63%, providing a suitable technique for storage of this threatened orchid.
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Affiliation(s)
- Reema Vareen Diengdoh
- Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong, 793022, Meghalaya, India
| | - Suman Kumaria
- Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong, 793022, Meghalaya, India
| | - Meera Chettri Das
- Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong, 793022, Meghalaya, India.
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Normah MN, Sulong N, Reed BM. Cryopreservation of shoot tips of recalcitrant and tropical species: Advances and strategies. Cryobiology 2019; 87:1-14. [PMID: 30677412 DOI: 10.1016/j.cryobiol.2019.01.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/19/2019] [Accepted: 01/20/2019] [Indexed: 02/04/2023]
Abstract
There is a pressing need for practical and successful conservation efforts to establish long-term germplasm collections of recalcitrant and tropical species, given the challenge and threat that these plants are facing. Cryopreservation is the only way of conserving some of these species, especially those with temperature or desiccation sensitive (recalcitrant) seeds. This review covers reports on cryopreservation studies of shoot tips (apical and axillary) of tropical and subtropical plants. Since many of these species have recalcitrant seeds, the cryopreservation successes, failures and problems involved with these seeds are also discussed. The methodologies, important factors and steps involved in successful cryopreservation protocols are analyzed. Finally strategies are suggested to develop a successful cryopreservation protocol for new plant species, in particular those with tropical recalcitrant seeds.
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Affiliation(s)
- M N Normah
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia
| | - Norafarain Sulong
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia
| | - Barbara M Reed
- Retired, US Dept. of Agriculture and Department of Horticulture, Oregon State University, Corvallis, OR, 97331, USA.
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Kaur S. Cryopreservation of Orchids - A Review. Recent Pat Biotechnol 2019; 13:114-123. [PMID: 30479222 DOI: 10.2174/1872208313666181127143058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/15/2018] [Accepted: 10/25/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The orchids are one of the beautiful creations of nature which stand apart from any other assemblage of flowering plants. They are highly evolutionary and ecologically significant group of plants that have effectively occupied almost every habitat on the earth. Indiscriminate collections and extermination of their natural habitats have threatened many species of orchids with extinction, resulting in a severe reduction of their genetic resources in nature according to recent patents. It is necessary to adopt sound scientific protocols for the preservation of orchid species. METHOD This cost-effective technique provides large storage time for the conservation of germplasm. Presently, efforts have been made to explore various cryopreservation techniques utilized so far and factors affecting the longevity of the propagules (in vivo and in vitro) while cryopreserving them. The sample to be cryopreserved is freeze-preserved in two ways, a) stepwise at two different subzero temperatures and b) in the rapid method, the samples are placed directly in the liquid nitrogen. RESULTS The orchid seeds and pollen are the most suitable propagules for cryopreservation of orchids due to their minute size and less space requirement. CONCLUSION Among the tissues (such as seeds, pollen, protocorms etc.) seeds are the most reliable. The present article reviews the cryopreservation techniques and factors effecting the cryopreservation, for in vitro conservation of orchid gene pool.
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Affiliation(s)
- Saranjeet Kaur
- Department of Applied Sciences, Chandigarh University, Gharuan, Distt.- Mohali, Punjab, India
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Schofield E, Jones EP, Sarasan V. Cryopreservation without vitrification suitable for large scale cryopreservation of orchid seeds. BOTANICAL STUDIES 2018; 59:13. [PMID: 29744709 PMCID: PMC5943204 DOI: 10.1186/s40529-018-0229-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 05/02/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Orchids are under threat from human activities and climate change, with populations limited to small geographic hotspots. This makes them ideal candidates for ex situ conservation. Orchid seeds are desiccation tolerant, but often have poor longevity in seed banks and cryopreservation of orchid protocorms is complex and expensive. Therefore, simple methods for large-scale storage programs are essential to store orchid seeds of different life forms. Seeds of five species representing epiphytic, lithophytic and terrestrial orchids from the Central Highlands of Madagascar were studied to find a simple and effective system of cryopreservation. The use of a vitrification solution prior to cryopreservation to improve survival was investigated, as well as the use of symbiotic and asymbiotic germination media to maximise germination after cryopreservation. Using the filter paper packet method, dried seeds were stored in vapour phase above liquid nitrogen and recovered after thawing with both symbiotic and asymbiotic media. RESULTS The study revealed that cryoprotection is not essential for the species in this study, which represented a range of lifeforms. Vitrification generally led to a decrease in germination post cryopreservation. The use of a symbiotic germination medium post cryopreservation was found to be successful in the species in which it was tested. However, the use of an asymbiotic medium was successful for all the species in this study. CONCLUSIONS Vitrification was not essential for the species in this study as the orchid seeds were already ultralow temperature and desiccation tolerant. However, further studies using more species are required to validate this approach. This may be an ecophysiological or genetic trait of these species. Therefore, this form of dry seed cryopreservation could form part of ex situ orchid seed conservation using a standard method. The methods developed here will store greater genetic diversity compared to what can be achieved with protocorms and are suitable for both asymbiotic and symbiotic recovery after cryopreservation. This will help reduce the time and cost of ex situ conservation, and help develop universal protocols for large genera, compared to custom protocols required for protocorm cryopreservation.
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Affiliation(s)
- Emily Schofield
- Natural Capital and Plant Health, Royal Botanic Gardens, Kew, Richmond, TW9 3AE UK
| | - Edward P. Jones
- Natural Capital and Plant Health, Royal Botanic Gardens, Kew, Richmond, TW9 3AE UK
| | - Viswambharan Sarasan
- Natural Capital and Plant Health, Royal Botanic Gardens, Kew, Richmond, TW9 3AE UK
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Pritchard H, Nadarajan J, Ballesteros D, Thammasiri K, Prasongsom S, Malik S, Chaudhury R, Kim HH, Lin L, Li WQ, Yang XY, Popova E. Cryobiotechnology of tropical seeds – scale, scope and hope. ACTA HORTICULTURAE 2017:37-48. [DOI: 10.17660/actahortic.2017.1167.6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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Zhao G, Fu J. Microfluidics for cryopreservation. Biotechnol Adv 2017; 35:323-336. [PMID: 28153517 PMCID: PMC6236673 DOI: 10.1016/j.biotechadv.2017.01.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 01/23/2017] [Accepted: 01/25/2017] [Indexed: 11/19/2022]
Abstract
Cryopreservation has utility in clinical and scientific research but implementation is highly complex and includes labor-intensive cell-specific protocols for the addition/removal of cryoprotective agents and freeze-thaw cycles. Microfluidic platforms can revolutionize cryopreservation by providing new tools to manipulate and screen cells at micro/nano scales, which are presently difficult or impossible with conventional bulk approaches. This review describes applications of microfluidic tools in cell manipulation, cryoprotective agent exposure, programmed freezing/thawing, vitrification, and in situ assessment in cryopreservation, and discusses achievements and challenges, providing perspectives for future development.
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Affiliation(s)
- Gang Zhao
- Center for Biomedical Engineering, Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230027, Anhui, PR China.
| | - Jianping Fu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, MI 48109, USA
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Wade EM, Nadarajan J, Yang X, Ballesteros D, Sun W, Pritchard HW. Plant species with extremely small populations (PSESP) in China: A seed and spore biology perspective. PLANT DIVERSITY 2016; 38:209-220. [PMID: 30159468 PMCID: PMC6112217 DOI: 10.1016/j.pld.2016.09.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 09/06/2016] [Accepted: 09/07/2016] [Indexed: 05/08/2023]
Abstract
Approximately one fifth of the world's plants are at risk of extinction. Of these, a significant number exist as populations of few individuals, with limited distribution ranges and under enormous pressure due to habitat destruction. In China, these most-at-risk species are described as 'plant species with extremely small populations' (PSESP). Implementing conservation action for such listed species is urgent. Storing seeds is one of the main means of ex situ conservation for flowering plants. Spore storage could provide a simple and economical method for fern ex situ conservation. Seed and spore germination in nature is a critical step in species regeneration and thus in situ conservation. But what is known about the seed and spore biology (storage and germination) of at-risk species? We have used China's PSESP (the first group listing) as a case study to understand the gaps in knowledge on propagule biology of threatened plant species. We found that whilst germination information is available for 28 species (23% of PSESP), storage characteristics are only known for 8% of PSESP (10 species). Moreover, we estimate that 60% of the listed species may require cryopreservation for long-term storage. We conclude that comparative biology studies are urgently needed on the world's most threatened taxa so that conservation action can progress beyond species listing.
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Affiliation(s)
- Ellie Merrett Wade
- Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
| | - Jayanthi Nadarajan
- Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
| | - Xiangyun Yang
- The Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, PR China
| | - Daniel Ballesteros
- Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
| | - Weibang Sun
- Kunming Botanical Garden, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, PR China
| | - Hugh W. Pritchard
- Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
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