• Sexual CycleSexual Cycle
– new plants arise from the fusion of parental gametesnew plants arise from the fusion of paren...
Angiosperm Life Cycle
Natural Cloning
stolon
rhizome
corm
tuber bulb
KalanchoeKalanchoe
Vegetatively – propagated
crops
Alternative Propagation Method: Tissue culture
In an effort to increase productivity, alternative
propagation methods have...
Vegetative propagation of importance to agriculture,
horticulture and forestry since it provides:
1.For the production of ...
The term “tissue culture”
is an inclusive name for both
organ and cell culture.
Plant tissue culture
 the growing of isol...
Totipotency of Plant CellsTotipotency of Plant Cells
Plant cells possess profound ability to showPlant cells possess profo...
PTCPTC
• Demonstration of totipotency of plant cellsDemonstration of totipotency of plant cells
– Ability of the different...
 Genomic equivalenceGenomic equivalence
 Different kinds of somatic cells inDifferent kinds of somatic cells in
organism...
DNA
Primary RNA
transcript
protein
inactive mRNA
Inactive protein
mRNA degradation
control
Translational control
by riboso...
Tissue cultureTissue culture
• Technique for maintaining plant tissuesTechnique for maintaining plant tissues
indefinitely...
 For rapid vegetative propagation of plants
 For production and extraction of valuable
secondary metabolites rather than...
PTCPTC
*For conservation of biodiversity and genetic resources*For conservation of biodiversity and genetic resources
*For...
• Micropropagation- large scale cloning of plantMicropropagation- large scale cloning of plant
speciesspecies
– Meristem c...
• Crop improvementCrop improvement
– Salt toleranceSalt tolerance
– Insect resistanceInsect resistance
– Herbicide resista...
Two major underlying principles
1. The necessity to isolate the
plant part from the intact plants
2. The need to provide t...
Explant and Explant Sources
Pieces of whole plants, small organ itself or pieces of
tissue from stems, leaves, ovules, see...
PTCPTC
Sterilization
Biggest preoccupation of a plant tissue culturist is how
to prevent contamination of the culture. Pre...
PTCPTC
Duration of surface sterilization is important:
Too long: plant tissue will be damaged
Too short: will not destroy ...
PTCPTC
Cultural Factors
Sterile operations are conducted within a
laminar flow cabinet. With a laminar flow
cabinet air ta...
Cultural Factors
Explants are put into a sterilized nutrient medium.
It is absolutely necessary to maintain a sterile
envi...
PTCPTC
Culture medium
• The components of a plant tissue culture mediumThe components of a plant tissue culture medium
inc...
Plant growth regulators
The growth regulator requirements for most callus cultures
are some combinations of auxins and cyt...
Classes of plant growth substances:
1. Auxins.
2. Cytokinins
3. Gibberellins
4. Ethylene
5. Abscissic acid
6. Brassinoster...
Auxin/cytokinin interactionAuxin/cytokinin interaction
auxin
high
low
cytokinin
high
low
Root formation from
shoot
Adventi...
Fern spore germination in a
plant tissue culture system
Lilian B. Ungson, Ph.D
Professorial Lecturer
Institute of Biology
...
Fern Life Cycle
Platycerium
Asplenium musifoliumAsplenium musifolium
Adiantum sp.
(Maiden Hair Fern)
Adiantum
Cyathea contaminans
(Tree Fern)
Cyathea contaminans
(Tree Fern)
Cyathea contaminans
(Tree Fern)
Christella
Christella
Fern for experimental studies
• Ease of culture of using gametophytes
at different stages of development
•Spores and gamet...
Spore culture in a plant tissue culture system
Raghavan in 1993 said that fern haplophase is not considered
as a tissue cu...
•Cells dedifferentiate in
tissue culture and can give
rise to the diverse cell types,
thus it possess all the genes
necess...
The fern gametophyte stages
has its origin in a single cell like
the carrot cell culture.
Comparisons made
between molecul...
Each sorus has a
•central axis to which
the sporangia are
attached;
• Indusium-covering
underneath the
sporangia,
• Annulu...
Annulus=thick-walled
plate or transverse
band or ring that extend
around the
circumference
of the sporangium
Function in
s...
Spore patch
Platycerium coronarium
Spores inside the sporangiumSpores inside the sporangium
Internal condition of the spore
• Freshly released spores are immature
• Need to complete series of cytological
and bioche...
Cytological changes during maturation of spore Onoclea
a. Beginning of vacuolation.
during spore enlargement
b. Nucleus at...
SPORE- represents the beginning of the haploid or
gametophytic phase
Nucleus with dehydrated
chromatin
Dormant spore
Stora...
Chloroplast movement and
origin of polarity in germinating
spores
a. Unpolarized spore
showing uniform
distribution of
chl...
Germination of spores
nucleus
Cell wall
formation delimiting
rhizoid initial
rhizoid initial Elongated rhizoid
Protonema
i...
An asymmetric cell division is the cytological hallmark of
germination of fern spores
The development potential of the spo...
Section of germinated spore of Polypodium vulgare
Protonema initial
Rhizoid initial
The basal wall of
the rhizoid is in
co...
Germinated spore of Blechnum spicant to show
relationship between rhizoid and protonema initial
Protonema initial
Rhizoid ...
Whole mounts of germinating spores of Onoclea sensibilis
A. Asymmetric division delimiting the rhizoid.
B. Elongation of t...
Rhizoid initial growth is tip growth
Similar to pollen tube
 it is a cell that grows by apical extension like pollen tube...
A. Tip domain- rich in Golgi vesicles
B. Sub-apical domain- with metabolically active organelles:
mitochondria, dictyosome...
Rhizoid
Protonemal initial
Ungerminated spore
Rhizoid initial
Filamentous protonema
Spore Germination
Gives rise
to green ...
Rhizoid initial
Nucleus is confined to the
base of a newly-cut
rhizoid initial
Surrounded by a chloro-
plasts, mitochond...
Protonemal initial
Progenitor of the prothallus
Distinctive feature is abundant
chloroplasts
 Cytoplasm is filled with ...
Formation of protonema
A
B
C
A. early stage,
form
almost identical
cells
B. Division in
both cells to form
filaments
C. In...
A B
Rhizoid initiation in the
presence of actinomycin D
Rhizoid initiation
Basal medium without
actinomycin D
Normal germi...
Stored mRNA
In seeds and fungal spores, there is stored template
mRNA carry codes for the first proteins of germination
...
Start of Planar
Morphology
Prothallial Development
Filamentous growth: Protonemal initial
formed by division of transverse...
Gametophytes of Asplenium showing longitudinal
division of the terminal cells
Formation of the planar
gametophyte due to ...
Planar growth in producing a prothallus
a. Filamentous protonema, b. ist longitudinal div of terminal cell
c. Formation of...
Prothallus development- how heart-shape is attained
 At first apical cell appears as a small indentation at tip of
spatul...
Germination of fern
spores and development
of gametophyte
Rhizoid develops from basal
cell
Prothallial cell may divide
t...
Assuming a heart-shaped structure – Prothallus
(Fern Gametophyte)
Prothallial Development
Mature ProthallusMature Prothallus
Sex organs on gametophytes
 When antheridial development precede archegonia,
antheridia are confined to ventral surface b...
Sex organs on gametophytes
Development of antheridium (A,B) and archegonium (C-H)
Primary
spermatogenous
or
androgonial cells
divide several
times to...
Mature antheridium with
sperms forming in
spermatogenous cells
Mature sperm – large,
coiled and ciliated
A. Archegonial initial divided into
inner and outer cell and outer cell
divided anticl to form 2 neck cells
B. Formation o...
Day 7
Rhizoid and protonema
Day 9
Rhizoid and protonema
Day 14 Young prothallus
Day 49
Sporophyte on gametophyte
Day 42
Development of
antheridia
Fern culture Day 65
Sporophytes on drying gametophyte
Sporophytes on gametophytes
Areas for further investigation .
1. Response of spores to light quality and chemicals has many
similarities with behaviou...
References
 Raghavan, V. 1989. Developmental Biology of Fern
Gametophytes. Cambridge University Press, Cambridge.
 Ragha...
Bio 130 tissue culture --intro lecture  dev strategies part i tissue cultue 2013-2014
Bio 130 tissue culture --intro lecture  dev strategies part i tissue cultue 2013-2014
Bio 130 tissue culture --intro lecture  dev strategies part i tissue cultue 2013-2014
Bio 130 tissue culture --intro lecture  dev strategies part i tissue cultue 2013-2014
Bio 130 tissue culture --intro lecture  dev strategies part i tissue cultue 2013-2014
Upcoming SlideShare
Loading in...5
×

Bio 130 tissue culture --intro lecture dev strategies part i tissue cultue 2013-2014

800

Published on

Published in: Technology, Self Improvement
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
800
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
46
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide
  • From seeds they do not breed true
  • From seeds they do not breed true
  • ne
  • Tulate plate
  • Transcript of "Bio 130 tissue culture --intro lecture dev strategies part i tissue cultue 2013-2014"

    1. 1. • Sexual CycleSexual Cycle – new plants arise from the fusion of parental gametesnew plants arise from the fusion of parental gametes – development from seedsdevelopment from seeds – plants propagated by seeds are not clonesplants propagated by seeds are not clones – resultant plant has unique genetic make-up; differentresultant plant has unique genetic make-up; different from either parent and other offspringfrom either parent and other offspring • Asexual or Vegetative CycleAsexual or Vegetative Cycle – genes copied exactly at each mitotic divisiongenes copied exactly at each mitotic division – genetic make-up of resultant plant identical to that ofgenetic make-up of resultant plant identical to that of the parent and other offspringthe parent and other offspring – Common, allowing them to survive habitatsCommon, allowing them to survive habitats – Independent of pollinating vectorsIndependent of pollinating vectors
    2. 2. Angiosperm Life Cycle
    3. 3. Natural Cloning stolon rhizome corm tuber bulb
    4. 4. KalanchoeKalanchoe
    5. 5. Vegetatively – propagated crops
    6. 6. Alternative Propagation Method: Tissue culture In an effort to increase productivity, alternative propagation methods have been developed. Plant PropagationPlant Propagation
    7. 7. Vegetative propagation of importance to agriculture, horticulture and forestry since it provides: 1.For the production of uniform material for crop planting, 2.For the multiplication of good quality or superior trees, ornamentals, vegetables etc. Plant PropagationPlant Propagation
    8. 8. The term “tissue culture” is an inclusive name for both organ and cell culture. Plant tissue culture  the growing of isolated plant parts aseptically, on appropriate media and a whole new plant can be produced. Utilizes growth of small pieces of tissue or small organs in sterile or aseptic conditions “in vitro” techniques ((literally means “in a glass” PTCPTC
    9. 9. Totipotency of Plant CellsTotipotency of Plant Cells Plant cells possess profound ability to showPlant cells possess profound ability to show their full genetic potential and follow atheir full genetic potential and follow a developmental pathway similar to that of thedevelopmental pathway similar to that of the zygote resulting in the formation of a newzygote resulting in the formation of a new plant.plant.
    10. 10. PTCPTC • Demonstration of totipotency of plant cellsDemonstration of totipotency of plant cells – Ability of the differentiated cell to revert to itsAbility of the differentiated cell to revert to its undifferentiated state and form all parts of aundifferentiated state and form all parts of a mature organismmature organism – Similar to the ability of a zygote to generate aSimilar to the ability of a zygote to generate a complete plantcomplete plant
    11. 11.  Genomic equivalenceGenomic equivalence  Different kinds of somatic cells inDifferent kinds of somatic cells in organisms all have the same genesorganisms all have the same genes  Differences between cells in a multicellularDifferences between cells in a multicellular organism come from differences in geneorganism come from differences in gene expressionexpression PTCPTC
    12. 12. DNA Primary RNA transcript protein inactive mRNA Inactive protein mRNA degradation control Translational control by ribosome selection among mRNAs Protein activity control Transcriptional control 1 2 Processing control 3 Transport control mRNA mRNA 6 4 5 Steps at which gene expression can be controlled in eukaryotes NUCLEUS CYTOPLASM
    13. 13. Tissue cultureTissue culture • Technique for maintaining plant tissuesTechnique for maintaining plant tissues indefinitely on an artificial mediumindefinitely on an artificial medium subcultured Callus Callus undifferentiated roots redifferentiation shoots Somatic embryos organogenesis Somatic embryogenesis subcultured
    14. 14.  For rapid vegetative propagation of plants  For production and extraction of valuable secondary metabolites rather than directly from plants grown in the wild APPLICATIONS PTCPTC
    15. 15. PTCPTC *For conservation of biodiversity and genetic resources*For conservation of biodiversity and genetic resources *For elimination of some diseases in plants, particularly*For elimination of some diseases in plants, particularly those caused by virusesthose caused by viruses
    16. 16. • Micropropagation- large scale cloning of plantMicropropagation- large scale cloning of plant speciesspecies – Meristem cultureMeristem culture • Propagation of rare speciesPropagation of rare species • Pathogen - free propagulesPathogen - free propagules – Sometimes exhibits somaclonal variationSometimes exhibits somaclonal variation Uses of biotechnologyUses of biotechnology
    17. 17. • Crop improvementCrop improvement – Salt toleranceSalt tolerance – Insect resistanceInsect resistance – Herbicide resistanceHerbicide resistance • e.g Brassica campestris herbicide resistance intoe.g Brassica campestris herbicide resistance into Brassica napusBrassica napus Uses of biotechnologyUses of biotechnology
    18. 18. Two major underlying principles 1. The necessity to isolate the plant part from the intact plants 2. The need to provide the appropriate environment in which the isolated plant part can express its intrinsic or induced potential through the use of a suitable culture media and their proper culture conditions. Initiating Tissue Culture PTCPTC
    19. 19. Explant and Explant Sources Pieces of whole plants, small organ itself or pieces of tissue from stems, leaves, ovules, seeds, buds, inflorescence. The part of the plant from which explants are obtained depends on : 1. Type of culture to be initiated 2. Purpose of the proposed culture 3. Plant species to be used PTCPTC
    20. 20. PTCPTC Sterilization Biggest preoccupation of a plant tissue culturist is how to prevent contamination of the culture. Presence of microorganisms in cultures results in loss of time, energy and money.
    21. 21. PTCPTC Duration of surface sterilization is important: Too long: plant tissue will be damaged Too short: will not destroy the microorganisms Usually: ca. 20 minutes in 5% calcium hypochlorite and 5-15 minutes in 0.5- 1.0 % sodium hypochlorite
    22. 22. PTCPTC Cultural Factors Sterile operations are conducted within a laminar flow cabinet. With a laminar flow cabinet air taken from outside of the hood is forced through a dust filter and then the filtered air which passed through a high efficiency particulate air (HEPA) filter is blown in a very smooth laminar flow towards the user or out of the workplace. The filters can remove up to 99.97% of dust, pollen, molds, bacteria and other airborne particles as small as 0.3 microns.
    23. 23. Cultural Factors Explants are put into a sterilized nutrient medium. It is absolutely necessary to maintain a sterile environment during the culture of plant tissues. PTCPTC
    24. 24. PTCPTC Culture medium • The components of a plant tissue culture mediumThe components of a plant tissue culture medium include:include: – Macronutrients- provide C,N,P,K, Ca, Mg and SMacronutrients- provide C,N,P,K, Ca, Mg and S – Micronutrients in trace amounts- Mn, Cu, Zn,Micronutrients in trace amounts- Mn, Cu, Zn, Mo, CoMo, Co – Iron supplementIron supplement – VitaminsVitamins – Carbon sourceCarbon source – Plant growth regulatorsPlant growth regulators
    25. 25. Plant growth regulators The growth regulator requirements for most callus cultures are some combinations of auxins and cytokinins. They are organic substances which are active at very low concentrations (10-5 to 10-9 M), can elicit profound cellular changes influencing plant development. PTCPTC
    26. 26. Classes of plant growth substances: 1. Auxins. 2. Cytokinins 3. Gibberellins 4. Ethylene 5. Abscissic acid 6. Brassinosteroids Auxins and cytokinins are the most important for regulating growth and morphogenesis in plant tissue culture PTCPTC
    27. 27. Auxin/cytokinin interactionAuxin/cytokinin interaction auxin high low cytokinin high low Root formation from shoot Adventitious root formation from callus Callus induction in dicotyledons Adventitious shoot formation Axillary shoot proliferation
    28. 28. Fern spore germination in a plant tissue culture system Lilian B. Ungson, Ph.D Professorial Lecturer Institute of Biology U. P. Diliman, Quezon City
    29. 29. Fern Life Cycle
    30. 30. Platycerium
    31. 31. Asplenium musifoliumAsplenium musifolium
    32. 32. Adiantum sp. (Maiden Hair Fern) Adiantum
    33. 33. Cyathea contaminans (Tree Fern)
    34. 34. Cyathea contaminans (Tree Fern)
    35. 35. Cyathea contaminans (Tree Fern)
    36. 36. Christella
    37. 37. Christella
    38. 38. Fern for experimental studies • Ease of culture of using gametophytes at different stages of development •Spores and gametophytes are small, can be cultured in petri dishes •Large populations can produce data which can be subjected to statistical analysis •Advantages derived from the intrinsic features of fern life cycle • Single-celled nature of the spore • Spore germinates to form cells destined for different fates • Growth of gametophytes as a single layer of cells for study of cell division patterns • Growth of the filamentous structure • Formation of sex organs in response to hormonal signals
    39. 39. Spore culture in a plant tissue culture system Raghavan in 1993 said that fern haplophase is not considered as a tissue culture system in the accepted sense of the terminology (Raghavan 1993): plant tissue culture is a collection of techniques used to grow explants on formulated media for induction of growth, differentiation, and regeneration of organs or whole organisms.
    40. 40. •Cells dedifferentiate in tissue culture and can give rise to the diverse cell types, thus it possess all the genes necessary to make any kind of plant cell. Carrot cell culture
    41. 41. The fern gametophyte stages has its origin in a single cell like the carrot cell culture. Comparisons made between molecular changes associated with differentiation of the carrot cell and germi- nation of the fern spore and form changes in the fern gametophyte are germane (Raghavan 1993). Germination of pollen and germination of fern spores both involve activation of growth and induction of metabolic activities in dormant systems
    42. 42. Each sorus has a •central axis to which the sporangia are attached; • Indusium-covering underneath the sporangia, • Annulus –thick-walled ring of cells around each sporangium .The annulus is hygroscopic Fern leaf with sorus indusiumAnnuluS
    43. 43. Annulus=thick-walled plate or transverse band or ring that extend around the circumference of the sporangium Function in spore release
    44. 44. Spore patch
    45. 45. Platycerium coronarium
    46. 46. Spores inside the sporangiumSpores inside the sporangium
    47. 47. Internal condition of the spore • Freshly released spores are immature • Need to complete series of cytological and biochemical changes for maturation and germination • Cytological changes ensure formation and orderly rearrangement of organelles • Maturation is due to the endogenous synthesis of a variety of molecules.
    48. 48. Cytological changes during maturation of spore Onoclea a. Beginning of vacuolation. during spore enlargement b. Nucleus at one end of spore c. Spore enlargement accompanied by decrease in cytoplasm d. Enlargement of nucleus prior to dev of proplastids. e. First appearance of proplastids around nucleus f. Continued dev of proplastids g. Mature spore with central nucleus and numerous chloroplasts
    49. 49. SPORE- represents the beginning of the haploid or gametophytic phase Nucleus with dehydrated chromatin Dormant spore Storage granules Storage granules have to be degraded into simple compounds to provide energy and substrates for germination Need for synthesis of nucleic acids Need for biogenesis of organelles e.g. mitochondria for catabolic activity of food reserves and chloroplasts for initiating photosynthesis Histochemical observation: most storage granules disappear within 24 to 36 hours after germination
    50. 50. Chloroplast movement and origin of polarity in germinating spores a. Unpolarized spore showing uniform distribution of chloroplast around nucleus. b. Beginning of polarized move- ment of chloroplasts away from site of presumptive rhizoid initial. c. Spore nucleus in mitosis to form the rhizoid initial d. Formation of the rhizoid initial ( arrow)
    51. 51. Germination of spores nucleus Cell wall formation delimiting rhizoid initial rhizoid initial Elongated rhizoid Protonema initial A B C C rhizoid breaking out of exine
    52. 52. An asymmetric cell division is the cytological hallmark of germination of fern spores The development potential of the spore is parceled out to 2 cells which pursue divergent differentiation pathways. rhizoid initial-- small & lens-shaped, elongates into 1. narrow colorless rhizoid. 2. large cell divides again by a wall perpendicular to the first to form an isodiametric cell called protonema initial with many chloroplasts Appearing tip of the nascent rhizoid initial –first visible sign of germination Spore germination
    53. 53. Section of germinated spore of Polypodium vulgare Protonema initial Rhizoid initial The basal wall of the rhizoid is in contact with the protonema initial and the spore cell Spore cell with a large mass of lipid bodies
    54. 54. Germinated spore of Blechnum spicant to show relationship between rhizoid and protonema initial Protonema initial Rhizoid initial nucleus
    55. 55. Whole mounts of germinating spores of Onoclea sensibilis A. Asymmetric division delimiting the rhizoid. B. Elongation of the rhizoid C.Formation of the protonemal initial Germination of the spore -a process of change from a dormant unicell to a pair of morphologically and functionally different cells A
    56. 56. Rhizoid initial growth is tip growth Similar to pollen tube  it is a cell that grows by apical extension like pollen tubes and root hair  programmed for terminal differentiation,  does not normally divide after it is cut off
    57. 57. A. Tip domain- rich in Golgi vesicles B. Sub-apical domain- with metabolically active organelles: mitochondria, dictyosomes, ER, vesicles C. Nuclear domain: large organelles and male germ unit D. Vacuolar domain. Enlarges as the tube grows. Pollen tube
    58. 58. Rhizoid Protonemal initial Ungerminated spore Rhizoid initial Filamentous protonema Spore Germination Gives rise to green leafy gametophyte Programmed for terminal differentiation
    59. 59. Rhizoid initial Nucleus is confined to the base of a newly-cut rhizoid initial Surrounded by a chloro- plasts, mitochondria, ribo- Somes, Golgi, ER, vesicles, Extensive vacuolation- associated with elongation Chloroplasts degenerate , lose integrity of their thylakoid membrane Escape of starch grains.
    60. 60. Protonemal initial Progenitor of the prothallus Distinctive feature is abundant chloroplasts  Cytoplasm is filled with much lipid bodies, protein granules and chloroplasts. Divides by walls perpendicular to the long axis to produce a filament.
    61. 61. Formation of protonema A B C A. early stage, form almost identical cells B. Division in both cells to form filaments C. Initiation of planar growth in both filaments
    62. 62. A B Rhizoid initiation in the presence of actinomycin D Rhizoid initiation Basal medium without actinomycin D Normal germination
    63. 63. Stored mRNA In seeds and fungal spores, there is stored template mRNA carry codes for the first proteins of germination Hypothesis: fern spores also contain stored mRNA. Believed that sufficient mRNA translatable into proteins is stored in the spore as a holdover from sporogenesis To test hypothesis: use of antibiotic actinomycin D (known to inhibit mRNA synthesis) Ground rule established: if a stage of germination proceeded in the presence of actinomycin D in the medium, the event was probably independent of synthesis of NEW mRNA
    64. 64. Start of Planar Morphology Prothallial Development Filamentous growth: Protonemal initial formed by division of transverse walls Planar morphology: by rapid burst of transverse and longitudinal divisions Rhizoid-programmed for terminal differentiation
    65. 65. Gametophytes of Asplenium showing longitudinal division of the terminal cells Formation of the planar gametophyte due to activity of single terminal cells. Ist div is oblique or longitu- dinal Followed by partition at right angles to the first producing a group of three cells. Center cell (wedge-shaped) functions as the meristematic apical cell
    66. 66. Planar growth in producing a prothallus a. Filamentous protonema, b. ist longitudinal div of terminal cell c. Formation of a wall at right angles to the first division wall d. Spatulate plate is formed by repeated oblique or longitudinal divisions with left-right alternation of cell plate orientation
    67. 67. Prothallus development- how heart-shape is attained  At first apical cell appears as a small indentation at tip of spatulate plate. (d, e)  Later, the two sides extend horizontally assuming a heart- shape form and meristematic cell is lodged in the notch between the two lobes.(e, f, g)  During further expansion of the lobes, the apical cell divides transversely (f,g,)  Division of anterior cell by two or three cell walls parallel to each other (g,H) Meristematic cell Apical cell divides transversely
    68. 68. Germination of fern spores and development of gametophyte Rhizoid develops from basal cell Prothallial cell may divide transversely several times to form a filament Plate of cells is formed by longitudinal divisions Growth becomes active along forward margins of the thallus which results in formation of two wings.
    69. 69. Assuming a heart-shaped structure – Prothallus (Fern Gametophyte) Prothallial Development
    70. 70. Mature ProthallusMature Prothallus
    71. 71. Sex organs on gametophytes  When antheridial development precede archegonia, antheridia are confined to ventral surface behind the apical notch of the prothallus Antheridia may be scattered over the entire prothallial surface or confined to the margins of the prothallus  When both sex organs develop at the same time, there is competition for space , nutrients and other resources. Antheridia are confined to the midrib region in the posterior half and archegonia to the anterior region of the midrib
    72. 72. Sex organs on gametophytes
    73. 73. Development of antheridium (A,B) and archegonium (C-H) Primary spermatogenous or androgonial cells divide several times to form androcytes then transformed into spermatozoids
    74. 74. Mature antheridium with sperms forming in spermatogenous cells Mature sperm – large, coiled and ciliated
    75. 75. A. Archegonial initial divided into inner and outer cell and outer cell divided anticl to form 2 neck cells B. Formation of central cell and basal cell from the inner cell. C. Div of central cell into ventral cell and neck canal cell D. Division of neck canal cell E. Nearly mature archegonium with egg, ventral canal cell and binucleate neck canal cell F. Archegonium with egg ready for fertilization E
    76. 76. Day 7 Rhizoid and protonema
    77. 77. Day 9 Rhizoid and protonema
    78. 78. Day 14 Young prothallus
    79. 79. Day 49 Sporophyte on gametophyte
    80. 80. Day 42 Development of antheridia
    81. 81. Fern culture Day 65 Sporophytes on drying gametophyte
    82. 82. Sporophytes on gametophytes
    83. 83. Areas for further investigation . 1. Response of spores to light quality and chemicals has many similarities with behaviour of seeds. 2. Distinct regulatory processes in fern spore germination may give evidences of additional control mechanisms that are already established during seed germination. 3. To find out the mechanism of development in a dormant system at the cellular level of initiation 4. During the development of spores, they require significant amounts of proteins for storage, and for surviving adverse conditions. What strategy do spores use to produce these required amounts of proteins which are in large quantities. 5. What is the trigger that will turn prothallial cells into archegonia or antheridia
    84. 84. References  Raghavan, V. 1989. Developmental Biology of Fern Gametophytes. Cambridge University Press, Cambridge.  Raghavan, V. Cellular and molecular biology of fern haplophase development. In:Komamine, A., H. Fukuda, U. Sankawa, Y. Komeda and K. Syono. 1993. Cellular and Molecular Biology in Plant Cell Cultures. Journal of Plant Research Special Issue No. 3. The Botanical Society of Japan, Tokyo  Reece, R. , L. Urry, M. Cain, S. Wasserman, P. Minorsky, and R. Jackson. 2011. Campbell Biology.
    1. A particular slide catching your eye?

      Clipping is a handy way to collect important slides you want to go back to later.

    ×