Micro Propagation

Micropropagation

Micropropagation • Micropropagation is the production of whole plants from small sections of plant such as a shoot tip, node, meristem, embryo, or even a seed • Plant tissue culture is basically the same thing, except that it implies the use of callus tissue generated from plant cells cultured in-vitro.

Micropropagation • Why does micropropagation work? – Plant cells have the ability to reproduce the whole plant from single cells. This is called totipotency. – Totipotency is the ability of a single cell to express the full genome in the cells to which it gives rise by cell division.

Micropropagation • What part of the plant can be used for micropropagation? – Any part of a plant can be used. – Meristems, shoot and root tips, leaf tissue, anthers, embryos, flowers, all parts of a plant can be used.

Micropropagation • The only limitation is that each plant is propagated differently and not every plant will respond the same way. • Each genus, species and variety may require a different tissue which will obtain the best results.

Tip bud

Leaf

Axillary bud

Internode

Root

Starting material for micropropagation

Micropropagation Methods • Micro cuttings • Small sections of plant tissue are cut from the mother plant • Placed into media • Grown out or subdivided again to produce more plants

Micropropagation Methods • Shoot Tip Culture (less 10 mm) • Meristem culture (0.1-0.5 mm) Surface sterilize, wash& culture. Higher cytokinins to over come apical dominance. Adventitious bud production. sub-culture frequently.

Basic in vitro propagation ...

Micropropagation Stages • The Basics of Micropropagation • The Four stages – Stage one – Explant establishment or initiation – Stage two – Multiplication – Stage three – Rooting – Stage four – Acclimatization or hardening off

Benefits for Micropropagation ... ♣ Rapid multiplication of clones ♣ Difficult species ? ♣ Genetic uniformity ? ♣ Aseptic conditions ♣ Micro- stock plants ♣ Controlled environment

Other applications ... ♣ in vitro micro-grafting ♣ Genetic conservation ♣ Plant improvement ♣ Experimental system

Problems arises during micropropagation and their control • Phenolic secretions: Stress. Phytotoxic causes plant death. Antioxidant solution over night. Activated charcoal. Adenine sulphate.

Endogenous contamination Sterilization (external contamination) Viral, fungal or bacterial growth (endogenous). Check sample on different media (PDA) antibiotics (rifamp,cefotax,tetracyc.)

Vitrification: Swelling/thickening of tissue just like callus Enclosed atmosphere CO2 and ethylene and water vapors. Causes morphological abnormalities. Reduce temperature at bottom.

Rooting and Acclimatization • • • •

Proper rooting Specie to specie Critical growth regulators. NAA,IBA etc. In vitro plants are sensitive to environment. • Maintain the relatively high humidity. • Never transplant the in vitro plants directly to open fields.