ppt in plant biotech

2.  Introduction (organogenesis)
 Factor affecting organogenesis
 Advantages of organogenesis
 Application of organogenesis
 Somatic hybridization
 Somatic hybridization technique
 Mechanical
 enzymatic
 Isolation of protoplast
 Advantages of somatic hybridization
 Limitation of hybridization
 Difference between organogenesis and somatic hybridization

3. Introduction
 Organogenesis is a process of differentiation by which plant
organ viz. roots, shoots, bud flower, stem, etc. are formed while
adventitious refers to the development of organ or embryo from
unusual points of origin of an organized explant where a
preformed meristem is lacking.
 This process is much more common than somatic embryogenesis
and has far more potential for mass clonal propagation of plants.
INTRODUCTION

4. FACTORS AFFECTING ORGANOGENESIS-
Physical factor
Chemical factor

5. PHYSICAL FACTOR
 Intensity of light-the blue region of spectrum promotes shoot formation and
red light induce rooting.
 The treatment of blue light followed by treatment of red light also stimulates
the organogenesis phenomenon.
 Temperature-increase in temp. up to 33°c may be associated with rise in the
growth of tobacco callus but for shoot-bud differentiation a lower temp.
18°c may be optimal.
 Electric stimulation- Bagga et.al 1985 suggested the role of phytochrome in
shoot induction.

6. CHEMICAL FACTOR
 Cytokinin or auxin - cytokinin in the medium leads to the
promotion of bud differentiation and development.
 Kinetin is 30,000 times more potent than adenine.
 Phosphate-increase level of the phosphate in the medium is
reported to counteract the inhibitory effect of auxin.
 Casein hydrolysate – casein hydrolysate or tyrosine also induces
kinetin type bud formation even in the presence of higher level of
IAA in the medium.

8. Advantages of organogenesis-
 Cheap.
 Fast process.
 No variables.
 Less space.
 Easily scale.

9. APPLICATION OF ORGANOGENESIS
 Scale up easily.
 Variation is not produce.
 Use as a bioreactor.
 Protoplast culture.
 Gene transfer.

20. SOMATIC HYBRIDIZATION
Development of hybrid plants
through the fusion of somatic
protoplasts of two different plant
species/varieties is called somatic
hybridization.

21. Somatic hybridization technique
1. isolation of protoplast
2. Fusion of the protoplasts of desired species/varieties
3. Identification and Selection of somatic hybrid cells
4. Culture of the hybrid cells
5. Regeneration of hybrid plants

22. SOMATIC HYBRIDIZATION
 The technique of hybrid production through the fusion of isolated somatic protoplast under in vitro
conditions and subsequent development of their product (heterokaryon) to a hybrid plant is known as
somatic hybridization.
 In somatic hybridization the nucleus and cytoplasm of both parents are fused in the hybrid cell.
 Sometimes; nuclear genome of only one parent but cytoplasmic genes (plastome) from both the parents
are present in the fused hybrid, which known as cybrid or cytoplasmic hybrid.
 Somatic hybridization involves the following aspects:
1) Fusion of protoplasts .
2) Selection of hybrid cells .
3) Identification of hybrid plants.

23. Protoplast fusion
 It involves mixing of two different genomes and can be achieved by spontaneous or
induced fusion method.
 Spontaneous fusion : -
I. cell fusion is natural process as is observed in case of egg fertilization.
II. During the course of enzymatic degradation of cell walls, adjoining protoplasts may fuse
to form homokaryocytes (homocaryons).
III. These fused cells may sometimes contain high number of nuclei (2-40).
IV. The frequency of homocaryon formation was found to be high in protoplasts isolated
from dividing cultured cells.

24. Induced fusion method :-
I. Isolated protoplasts can be fused by induction.
II. There are several fusion inducing agents which are
collectively referred to as fusogen.
III. example: sodium nitrate ,high glycol, polyvinyl alcohol,
lysozyme, concavalina, electro fusion dextran and dextran
sulphate , fatty acid and esters.

25. Advantages of somatic hybridization
 Production of novel interspecific and intergenic hybrid.
 Pomato (Hybrid of potato and tomato).
 Production of fertile diploids and polyploids from sexually
sterile haploids, triploids and aneuploids.
 Transfer gene for disease resistance, abiotic stress resistance,
herbicide resistance and many other quality characters.

26. Limitations of Somatic hybridization
 Poor regeneration of hybrid plants.
 Non-viability of fused products.
 Not successful in all plants.
 Production of unfavorable hybrids.
 Lack of an efficient method for selection of hybrids.
 No confirmation of expression of particular trait in
somatic hybrids.

27. Difference between organogenesis and somatic
embryogenesis-
 organogenesis  Somatic embryogenesis
 Production of unipolar structure (
shoot or root primordium ).
 Vascular system connected to parent
tissue.
 Organogenesis is a property of the
somatic tissue.
 Organogenesis is a popular process.
 Production of bipolar structure ( shoot or
root axes).
 Vascular system not connected to parent
tissue.
 Somatic embryogenesis pertains to the
reproductive tissue
 Somatic embryogenesis is a relatively less
popular.