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BREEDING . AGRONOMICS. BIOTECHNOLOGY . Strategically breed plants to create new, more robust seeds that perform better – and longer – in the field. Use precision ag, planting density, plant health protection, and conservation tillage to make acres more productive . - PowerPoint PPT Presentation
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ALL THREE ARE CRITICAL IN DELIVERING YIELD TODAY –
AND TOMORROW
BREEDING
Strategically breed plants to create new,
more robust seeds that perform better –
and longer – in the field.
AGRONOMICS
Use precision ag, planting density, plant health protection, and conservation tillage to
make acres more productive.
BIOTECHNOLOGY
Supplement breeding
advancements by adding special
beneficial genes to the plant.
The Three Pillars of Yield
In Vitro Culture The culture of organized living material
cell under artificial condition in tubes, glasses, dishes
The process of growing organized living materials artificially in the laboratory
The culture and maintenance of organized living materials, in sterile, nutritionally (synthetic media) and environmentally
(controlled) supportive conditions
Organized living material
Homogeneous (tissues)
Heterogeneous
(organs)
TissueHooke (1665) and Leeuwenhoek
(1677) using microscope discovered tissues were made of cells
CellsThe cells of a particular tissue had a
common structure.
Cell Taken to its
simplest form A plasma
membrane… Surrounding
cytoplasm… Containing
hereditary material.
Level of complexity Xavier Bichat (1771-
1802): An organ is composed of different tissues
Several organs can be grouped together as an organ system (e.g. the digestive system)
OrganismOrgan-
systemOrganTissueCell
Level of complexity Purkinje (1835) Observed a fertilised
hen's egg (a single cell) could develop into an embryo (many
specialised cells in a compact mass) C19th botanists showed that plant
tissues consist of many different types of cells.
THE CELL THEORY Schleiden (1838) & Schwann (1839)
“The cell is the basic unit of living tissue”
The cell is an autonomous unit (“a citizen”) grouped together to form an
organism (“the society”).
« Omnis cellula e cellula »Virchow (1858) “all cells come from pre-existing cells”
Cell cultureThe process by which
prokaryotic, eukaryotic or plant cells are grown under controlled
conditions.Cell culture was first successfully undertaken in animal cell by Ross Harrison (1907) and in plant cells
by Haberlandt (1902)
ORGANISMAL THEORYReichert (a morphologist):
An organism has a structured plan
Image Credit Frog embryo fate map
Plasmodesmata
Strasberger (a cytologist):
Cells are connected in an organism sometimes
by cytoplasmic bridges
Acellular organismsSome organisms do
not have cellular compartments
Unicellular organisms
Some organisms only consist of a single cell
But these do usually have the cell components (nucleus, membrane, etc)
Tissue culture
Cells can be cultured away from a body
But this often requires elaborate support systems (technology)
In vitro cultivation of organs, tissues & cells at defined temperature using an incubator & supplemented with a medium containing cell
nutrients & growth factors
Organized living material
1.Animal Cells2.Plant Cells
Plant Tissue Culture
“the aseptic culture of plant protoplasts, cells, tissues or organs under conditions which lead to cell multiplication or regeneration of organs or whole plants “
Plant Tissue Culture
…. each living cell has a complete genetic blueprint and therefore has the potential to develop into an entire plant.
… unlike animal cells, living plant cells can de-differentiate and then re-differentiate to form different cell types
… cells differentiate
… living plant cells can re-differentiate
Totipotency
…Haberlandt .. early 1900’s … proposed concept of totipotency … cells cultured under right conditionsCallus cultured from tree cambium Gautheret et al. (1930).
… cells kept alive but did not develop
Early Plant Cell Culture
Cell enlargement … role of auxins Cell division ... role of cytokinins
- dependent on discovery of “growth regulators”
Early Plant Tissue Culture
Regeneration from tobacco pith .. (Skoog and Miller) … interaction of auxin and cytokinin gives differentiation.
Carrot plants from root cells (Stewart, 1964)
Tobacco plants from single cells(Vasil & Hilderbrandt, 1965)
Requirement Appropriate tissue (some tissues culture better than
others) A suitable growth medium containing energy sources
and inorganic salts to supply cell growth needs. This can be liquid or semisolid
Aseptic (sterile) conditions, as microorganisms grow much more quickly than plant tissue and can over run a culture
Growth regulators, both auxins & cytokinins. Frequent sub-culturing to ensure adequate nutrition
and to avoid the build up of waste metabolites
Course Outline Introduction to in vitro culture
Determining factors in plant tissue culture Micropropagation
Pattern of development Micropropation enterprice