This document discusses germplasm and its conservation. It begins by defining germplasm as a collection of genetic resources for an organism, such as a seed bank or gene bank, that contains the genetic information for a species. Germplasm conservation is important to preserve genetic diversity and provide plant breeders resources to develop new crop varieties. Methods of conservation include in situ conservation of plants in their natural habitat and ex situ conservation of seeds, tissues, cells or DNA stored outside the natural habitat. Cryopreservation in liquid nitrogen at -196°C is an effective long-term storage method that stops cellular metabolism. The document outlines the cryopreservation process and applications for conserving plant species and genetic variations.
Somaclonal Variation in Plant tissue culture - Variation in somaclones (somatic cells of plants)
Somaclonal variation # Basis of somaclonal variation # General feature of Somaclonal variations # Types and causes of somaclonal variation # Isolation procedure of somaclones via without in-vitro method and with in-vitro method with their limitations and advantages # Detection of isolated somaclonal variation # Application (with examples respectively related to crop improvement) # Advantages and disadvantages of somaclonal variations.
https://www.youtube.com/watch?v=IZwrkgADM3I
Also watch, Gametoclonal variation slides to understand, how to changes occur in gametoclones of plants.
https://www.slideshare.net/SharmasClasses/gametoclonal-variation
A process where an embryo is derived from a single somatic cell or group of somatic cells. Somatic embryos (SEs) are formed from plant cells that are not normally involved in embryo formation.
Embryos formed by somatic embryogenesis are called Embryoids.
The process was discovered for the first time in Daucas carota L. (carrot) by Steward (1958), Reinert (1959).
Somaclonal Variation in Plant tissue culture - Variation in somaclones (somatic cells of plants)
Somaclonal variation # Basis of somaclonal variation # General feature of Somaclonal variations # Types and causes of somaclonal variation # Isolation procedure of somaclones via without in-vitro method and with in-vitro method with their limitations and advantages # Detection of isolated somaclonal variation # Application (with examples respectively related to crop improvement) # Advantages and disadvantages of somaclonal variations.
https://www.youtube.com/watch?v=IZwrkgADM3I
Also watch, Gametoclonal variation slides to understand, how to changes occur in gametoclones of plants.
https://www.slideshare.net/SharmasClasses/gametoclonal-variation
A process where an embryo is derived from a single somatic cell or group of somatic cells. Somatic embryos (SEs) are formed from plant cells that are not normally involved in embryo formation.
Embryos formed by somatic embryogenesis are called Embryoids.
The process was discovered for the first time in Daucas carota L. (carrot) by Steward (1958), Reinert (1959).
The presentation gives overview of production of secondary metabolites using callus culture as well as tissue culture techniques. Various batch and continuous culturing process are described on the basis of secondary metabolite to be synthesised.
The isolation, culture and fusion of protoplasts is a fascinating field in plant research. Protoplast isolation and their cultures provide millions of single cells (comparable to microbial cells) for a variety of studies.
WHAT IS ARTIFICIAL SEED..?
Artificial seed can be defined as artificial encapsulation of somatic embryos, shoot bud or aggregates of cell of any tissues which has the ability to form a plant in in-vitro or ex-vivo condition.
Artificial seed have also been often referred to as synthetic seed.
HISTORY
Artificial seeds were first introduced in 1970’s as a novel analogue to the plant seeds.
The production of artificial seeds is useful for plants which do not produce viable seeds. It represents a method to propagate these plants.
Artificial seeds are small sized and these provides further advantages in storage, handling and shipping.
The term, “EMBLING” is used for the plants originated from synthetic seed.
• The use of synthetic varieties for commercial cultivation was first suggested in Maize (Hays & Garber, 1919).
HYBRIDIZATION & HAPLOID PRODUCTION
Introduction
WIDE HYBRIDIZATION
INTER-SPECIFIC HYBRIDIZATION
Barriers to distant hybridization
Techniques to overcome barriers
Haploids and Doubled Haploids in Plant
Production of haploids and doubled haploids
a) Induction of maternal haploids
Wide hybridization
3. In vitro induction of maternal haploids – gynogenesis
Induction of paternal haploids – Androgenesis
Production of Homozygous Diploid Plants
Application of Haploids in Plant Breeding
Importance and Implications of Anther and Pollen Culture
Germplasm Conservation in situ, ex situ and on-farm and BiodiversityKK CHANDEL
The variability among living organisms from all sources including terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of ecosystems
The presentation gives overview of production of secondary metabolites using callus culture as well as tissue culture techniques. Various batch and continuous culturing process are described on the basis of secondary metabolite to be synthesised.
The isolation, culture and fusion of protoplasts is a fascinating field in plant research. Protoplast isolation and their cultures provide millions of single cells (comparable to microbial cells) for a variety of studies.
WHAT IS ARTIFICIAL SEED..?
Artificial seed can be defined as artificial encapsulation of somatic embryos, shoot bud or aggregates of cell of any tissues which has the ability to form a plant in in-vitro or ex-vivo condition.
Artificial seed have also been often referred to as synthetic seed.
HISTORY
Artificial seeds were first introduced in 1970’s as a novel analogue to the plant seeds.
The production of artificial seeds is useful for plants which do not produce viable seeds. It represents a method to propagate these plants.
Artificial seeds are small sized and these provides further advantages in storage, handling and shipping.
The term, “EMBLING” is used for the plants originated from synthetic seed.
• The use of synthetic varieties for commercial cultivation was first suggested in Maize (Hays & Garber, 1919).
HYBRIDIZATION & HAPLOID PRODUCTION
Introduction
WIDE HYBRIDIZATION
INTER-SPECIFIC HYBRIDIZATION
Barriers to distant hybridization
Techniques to overcome barriers
Haploids and Doubled Haploids in Plant
Production of haploids and doubled haploids
a) Induction of maternal haploids
Wide hybridization
3. In vitro induction of maternal haploids – gynogenesis
Induction of paternal haploids – Androgenesis
Production of Homozygous Diploid Plants
Application of Haploids in Plant Breeding
Importance and Implications of Anther and Pollen Culture
Germplasm Conservation in situ, ex situ and on-farm and BiodiversityKK CHANDEL
The variability among living organisms from all sources including terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of ecosystems
Dr. Ehsan Dulloo discusses conservation strategies to respond to the global loss of plant genetic resources at the 29th International Horticulture Congress, including ex situ conservation, in situ conservation, cryopreservation, seed banks and the importance of crop wild relatives.
http://www.bioversityinternational.org/research-portfolio/conservation-of-crop-diversity/
Plant tissue culture,its methods, advantages,disadvantages and applications.Komal Jalan
Plant tissue culture is the most widely used technique for growing very large number of plant using a very small part of the main plant(explant). Tissue culturing is very common for many popular and demanding crops.Few of them discussed here are Potato,Papaya,Pinepple,Banana,Gerbera,Sunflower,Orchids
Germplasm Conservation || Presented by Mamoona GhaffarMamoona Ghaffar
Germplasm Conservation || Presented by Mamoona Ghaffar
it's all about germplasm conservation, features, types & approaches, & limitations of germplasm storage
Feel free to ask about your queries.
A gene bank is a managed collection of genetic resources. Gene banks are necessary whenever the genetic resources fundamental to farming and harvesting animals and plants are threatened. While modern genetic techniques make it possible to bank any plant or animal tissue that contains DNA, most gene banks are collections either of whole organisms, their reproductive cells or early life stages. The technologies used for aquatic gene banking are as applicable to industry (broodstock collections, prospecting for new genetic material) as they are for traditional conservation. Gene banks are a type of biorepository which preserve genetic material.
Genetic material of plants which is of value as a resource for present and future generations of people is referred to as plant genetic resources.
The whole library of different alleles of a species or sum total of genes in a species is known as gene pool, also called germplasm, genetic stock and genetic resources.
The term gene pool was coined by Dobzhansky in 1951.
The term germplasm was first used by Weismann in 1883.
This ppt gives you the information under the broad topic "willife conservation and management". It includes the brief knowledge about 'cover construction' along with it here also discussed about
'genetic diversity' and it's preservation. Also I added a few slides about strategies to restore the degraded biodiversity.
Until two decades ago the genetic resources were getting depleted owing to the
It was imperative therefore that many of the elite, economically important and endangered species are preserved to make them available when needed.
The conventional methods of storage failed to prevent losses caused due to various reasons.
A new methodology had to be devised for long term preservation of material.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
2. INTRODUCTION
A germ is a collection of genetic resources for an
organism.For plants,the germplasm may be stored
as a seed collection(even a large seed bank) or for
trees in a nursery.Animal as well as plant genetics
may be stored in a gene bank or cryobank.
Germplasm is a living tissues from which new
plants can be grown.It can be a seed or another
plant part-a leaf,a piece of stem,pollen or even just
a few cells that can be turned into the whole plant.
It contains the information for a species genetic
make up,a valuable natural resources of plant
diversity.
3. GERMPLASM IN AGRICULTURAL
PURPOSE…..
Agricultural benefits from uniformity among crop
plants within a variety,which ensures consistent
yield and make management easier.
However,genetic uniformity leaves crops especially
vulnerable and to new pests and stresses.
Genetic diversity of germplasm gives plant
breeders the sustained ability to develop new high
yielding ,high quality varieties that can resist
constantly evolving pests ,diseases and
environmental stresses.
4. Sexually compatible wild species and landraces –
ancestral varieties of crop species are the key to
genetic diversity,but the amount of land where
plants grow wild continues to shrink and many plant
species are disappearing.
That’s why the plant science community has
developed conservation system to
evaluate ,catalogue and distribute germplasm for
people all over the world to use.
7. ABSTRACT
The ever growing human population demands
increased agricultural productivity if possible through
methods that don’t harm the natural environment.The
genetic improvement of crop species is one answer to
this problem.
However,to successfully do so, a diverse array of
genotypes would be needed. Since continued overuse
and misuse of our natural resources together with
intensive agriculture are causing tremendous amount of
genetic erosion.
It is imperative that crop genetic resources be
conserved.
8. HISTORY ABOUT GERMPLASM
Even since primitive man learned the art of learning and
realised the economic utility of plants,he started saving
selected seeds or vegetative propagules from one
season to next.Conservation was taught and decreed in
part of India and China as far back as(700 B.C).
The concept of physical basis of heredity expressed
by the 19th century Biologist August
Weisamann.According to his theory,germplasm,
which is independent from all other cells of the
body(somatoplasm) is essential element of germ
cells(eggs and sperm) and is the heredity material that
is passed from generation to generation.
9. Weisamann first proposed this theory in 1883,it was
later published in (1892; The Germplasm:A Theory
of Heredity).Bajaj 1995 and Staristky 1997 reported
that some of the valuable gene pools might be lost
unless co-ordinated efforts are made towards the
conservation of genetic stock all over the world.
Realising the danger of genetic resources the
U.N Conferences on Human Environment held in
Stockholm in 1972,recommended conservation of
the habitat that are rich in genetic diversity.
10. WHAT IS GERMPLASM CONSERVATION?
Plant germplasm is the genetic sources material used by
the plant breeders to develop new cultivars.
They may include:
Seeds
Other plant propagules are:
Leaf
Stem
Pollen
Cultured cells
Which can be grown into mature plant?
Germplasm provide the raw material( genes) which the
breeder used to develop commercial crop varieties.
11. NEED FOR CONSERVATION OF GERMPLASM
Loss of genetic diversity among plant species.
Human dependence on plant species for food and
many different uses.E.g. basic food crops,building
materials,oils,lubricants,rubber and other
latexes,resins,waxes,perfumes,dyes fibres and
medicines.
Species extinction aand many other are threatened
and endangered-deforestation.
Great diversity of plants is needed to keep the
various natural ecosystems functioning stably-
interactions between species.
Aesthetic value of natural ecosystems and diversity
of plant species.
13. IN SITU CONSERVATION
In situ conservation is on- site conservation or
conservation of natural resources in a natural
population of plants such as forests genetic
resources in natural population of tree species.
It is the process of protecting an endangered plant
in its natural habitat either by protecting or cleaning
up the habitat itself or by defending the species
from predators.
It is applied to conservation of agriculture
biodiversity in agro ecosystem by
farmers,especially those using unconventional
farming practice.
16. Ex situ conservation means literally,”off-site
conservation “.It is the process of protecting an
endangered species of plants or animal outside of
its natural habitat;for example, by removing part of
the population from a threatened habitat and
placing it in a new location ,which may be a wide
area or within the care of humans.
17. EX SITU CONSERVATION CAN BE CARRIED OUT
BY SEVERAL METHODS
Seed gene bank
In vitro storage
Dna storage
Pollen storage
Field gene bank
Botanical gardens
18. IN VITRO METHOD FOR GERMPLASM CONSERVATION
In vitro method employing shoots, meristems and
embryos are ideally suited for the conservation of
germplasm.The plant with recalcitrant seeds and
genetically engineered can also be preserved by this in
vitro approach.
There are several advantages associated with in vitro
germplasm conservation.
Large quantities of material can be preserved in small
space.
The germplasm preserved can be maintained in an
environment free from pathogens.
It can be protected against the nature’s hazards.
From the germplasm stock large number of plants can
be obtained whenever needed.
19. THERE ARE THREE MAIN APPROACHES FOR THE IN
VITRO CONSERVATION OF GERMPLASM
CROPRESERVATION
COLD STORAGE
LOW –PRESSURE AND LOW OXYGEN -
STORAGE
21. CRYOPRESERVATION
Cryopreservation (Greek,krayos-frost)literally mean
in the frozen state.The principle involved in
cryopreservation to bring the plant cells and tissue
cultures to a zero metabolism or non-dividing state
by reducing the temperature in the presences of
cryopreservation.
CRYOPRESERVATION broadly means the storage
of germplasm at very low temperature.
Over solid carbon dioxide(at 79°C)
Low temperature deep freezer(at -80°C)
In liquid nitrogen( at -196°C)
22. Among these,the most commonly used
cryopreservation is by employing liquid nitrogen.At
the temperature of liquid nitrogen(at -196°C),the
cell stay in a completely inactive state and thus can
be conserved for longer period.Infact
cryopreservation has been successfully applied for
germplasm conservation.Plant species e.g
rice,wheat,peanut,sugarcane,coconut.
23. MECHANISM OF CRYOPRESERVATION
The technique of freeze preservation is based on
the transfer of water present in the cells from a
liquid to solid state.Due to the presence of salts and
organic molecules in the cells,the cell water
requires much more lower temperature to
freeze(even up to -68°C) compared to the freezing
point of pure water(around 0°C).When stored at low
temperature,the metabolic processes and biological
deteriorations in the cells/tissues almost come to
standstill.
24.
25. TECHNIQUE OF CRYOPRESERVATION
The cryopreservation of plant cell culture followed
the regeneration of plants broadly involves the
following stages.
Development of sterile tissue culture.
Addition of cryoprotectant and pretreatment.
Freezing
Storage
Thawing
Reculture
Measurement of survival/viability
Plant regeneration
26. 1.DEVELOPMENT OF STERILE TISSUE
CULTURE
The selection of plant species and the tissue with
particular references to the morphological and
physiological characters largely influences the ability of
the explants to survive in cryopreservation.Any tissue
from a plant can be used for cryopreservation
e.g.meristems,embryos,endosperm,ovules,seeds,
culture plants.
2.ADDITION OF CRYOPROTECTANT
Cryoprotectant are the compound that can prevent the
damage caused to cells by freezing or thawing.There
are several cryoprotectant which include:
(DMSO,GLYCEROL,ETHYLENE,PROPYLENE,
SUCROSE,MANNOSE,GLUCOSE…..)
28. 3.FREEZING
The sensitivity of the cells to low temperature is visible
and largely depends on the plant species.Four different
types of freezing are used.
Slow freezing method
Rapid freezing method
Stepwise freezing method
Dry freezing method
4.STORAGE
Maintenance of the frozen cultures at the specific
temperature is as important as freezing.In general,the
frozen cells/tissues are kept for storage at temperature
in the range of -72 to-196°C.Storage is ideally done in
liquid nitrogen refrigerator at 150°C in the vapour
phase,or at -196°C in the liquid phase.
30. The ultimate objective of storage is to stop all the
cellular metabolic activities and maintain their
viability .For long term storage temperatue at -
196°C in liquid nitrogen is ideal.
5.THAWING
Thawing is usually carried out by plunging the
frozen sample in ampoules into the warm water
(temp 35-45°C)bath with vigorous swirling.By this
approach,rapid thawing(at the rate of 500-
750°Cmin-1)occurs,and this protects the cell from
the damaging effects ice crystal formation.
31. As the thawing occurs (ice completely melts) the
ampoules are quickly transferred to a water bath at
temperature 20-25°C.This transfer is necessary
since the cells get damaged if left for long in
warm(35-45°C) water bath.
6.RECULTURE
In general thawed germplasm is washed several
times to remove cryoprotectant.The material is then
cultured in a fresh media.
32. 7.PLANT REGENERATION
The ultimate purpose of cryopreservation of
germplasm is to regenerate the desired plant.For
appropriate plant growth and regeneration,the
cryopreserved cell/tissue have to be carefully
nursed and grown.Addition of certain growth
promoting substances ,besides maintenance of
appropriate environmental conditionis often
necessary for successful plant regeneration.
33. APPLICATION OF GERMPLASM
CONSERVATION
Plant materials(cell/tissue) of several species can be
cryopreserved and maintained for severals years ,and
used as and when needed.
Cryopreservation is an ideal method for long term
conservation of cell culture which produces secondary
metabolites e.g. medicines.
Disease (pathogen) free plant material can be frozen
and propagated whenever required.
Recalcitrant seeds can be maintained for long.
Conservationof somaclonal and gametoclonal variation
in culture.
Plant material from endangered species can be
conserved.
Cryopreservation is a good method for the selection of
cold resistant mutant cell lines which could develop into
frost resistant plant.
34. LIMITATION OF GERMPLASM
The expensive equipment needed to provide
controlled and varible rates of cooling/warming
temperatures can however be a limitation in the
application of in vitro technology for large scale
germplasm conservation.
Formation of ice crystal inside the cell should be
prevented as they cause injury to the cell.
Sometimes certain solutes from the cell leak out
during freezing.
Cryoprotectant also effect the viability of cells.