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