Embryo culture involves growing immature or mature embryos in vitro with the goal of producing a viable plant. There are several types of embryo culture, including mature embryo culture, immature embryo culture (also called embryo rescue), and culture of adventive or abortive embryos. Embryo culture is used for overcoming embryo abortion in wide crosses, preventing embryo abortion in some fruits, overcoming seed dormancy, shortening breeding cycles, and studying embryonic growth and development. Specialized culture media and sterile techniques are required depending on the embryo developmental stage.

1. Organ Culture

20. Importance
Production of virus free germplasm

21. EMBRYO CULTURE
Embryo culture is the culturing of embryos excised from the ovaries at
earlier stages of their development. This technique helps to overcome
problems associated with embryo development. Embryos are prevented
from development by different factors like incompatibility with the
female tissue, absence of endosperm etc. Hybrids produced by wide
crosses usually fail to develop inside the ovaries of the mother plants. In
such cases, the embryos can be rescued (the technique is called embryo
rescue) and grown in culture media so as to produce viable progeny.

22. Embryo Culture
• Isolation & growth of an immature or mature
embryo in vitro, with the goal of obtaining a
viable plant.
• The first attempt to grow the embryos of
angiosperms was made by Hannig (1904) from
two Crucifers Cochleria & Raphanus.

23. Types of Embryo culture
• Mature Embryo Culture
• Culture of surgically dissected embryo
• Immature Embryo Culture/ Embryo rescue
• Culture of intact seed containing
undifferentiated embryo
• Culture of adventive embryos from
proembryonic seeds
• Culture of inviable or abortive embryo

24. Mature Embryo Culture
• It is the culture of mature embryos derived
from ripe seeds.
• This type of culture is done when embryos
do not survive invivo or become dormant
for long periods of time.
• This culture is done to eliminate the
inhibition of seed germination.

25. • Mature embryo culture: to analyse the
various parameters of embryonic growth and
the metabolic and biochemical aspects of
dormancy and germination

26. • Culture of surgically disected embryos:
- the mature seed embryo can be dissected
surgically into a number of segments
- Such embryo segments are cultured to analyse
the relationship of different parts of the
embryo to its final form in culture

27. Immature Embryo Culture
• It is the culture of immature embryos or
proembryos to rescue the embryos of wide
crosses. Globular and heart shaped-
proembryo stage
• This type of culture is mainly used to
avoid embryo abortion with the purpose
of producing a viable plant.
• To understand the control of
differentiation and the nutritional
requirements

28. • Culture of intact seeds containg
undifferentiated embryo:
• Spherical mass of tissue lacking both radicle
and plumule
• No seed coat, seed coat is reduced to a
membraneous structure

29. • Culture of adventive embryos from
polyembryonic seeds
• Besides the zygotic embryo produced from
egg cell some embryos are produced from
nucellar tissue
• Such additional abortive embryos can be
exploited in culture for clonal propogation

30. • Culture of inviable or abortive embryos:
Inviable or abortive embryos may develop due
to unsuccessful crosses
Possible to raise hybrid plant by culturing the
inviable embryos in vitro

31. Media Requirement
• For Mature embryos-
Basal salt medium with a carbon energy
source.
• For Immature embryos-
Different vitamins, amino acids & growth
regulators are required.

32. Culture-medium factors
• mineral salts – K, Ca, N most important
• carbohydrate and osmotic pressure
- 2% sucrose works well for mature embryos
- 8-12% for immature embryos
- transfer to progressively lower levels as
embryo grows

33. Culture-medium factors
• Amino acids
- reduced N is often helpful
- up to 10 amino acids can be added to
replace N salts, incl. glutamine, alanine,
arginine, aspartic acid, etc.
- requires filter-sterilizing a portion of the
medium

34. Culture-medium factors
• natural plant extracts
- Coconut milk (liquid endosperm of
coconut)
- enhanced growth attributed to undefined
hormonal factors and/or organic
compounds
- others – extracts of dates, bananas, milk,
tomato juice

35. Culture-medium factors
• Plant Growth Regulators
- globular embryos – require low conc. of
auxin and cytokinin
- heart-stage and later – moderate level of
auxin & low level of cytokinin
- GA and ABA regulate "precocious
germination"

36. Embryo Rescue
• In immature embryo culture, wide hybrids
often suffer from early spontaneous abortion
due to several barriers which operate at pre- &
post- fertilization levels.
• Pre- fertilization barriers include all factors
that hinder effective fertilization .
(due to inhibition of pollen tube growth)

37. Embryo Rescue
• Post fertilization barriers retard the
development of the zygote after fertilization
and normal development of the seed.
(due to failure of endosperm)
• This is known as embryo-endosperm
incompatibility where the endosperm produces
toxins that kills the embryo.

38. EMBRYO
CULTURE
OF
MAIZE

39. Procedure
Immature cob is taken from the healthy field
↓
Its Immature seeds (Kernels) were extracted out
↓
Surface sterilize the immature seeds by treating them with
0.1% mercuric chloride solution for 7 minutes
↓
Give three washings with autoclaved distilled water
↓
Dissect out the embryo from the seed under totally aseptic
conditions
↓
Culture the embryos in the jars containing MS media
↓

40. Applications of Embryo Culture
• Prevention of embryo abortion in wide crosses
• Overcoming Seed dormancy
• Shortening of breeding cycle
• Prevention of embryo abortion with early
ripening stone fruits

41. • Helps determining the factors that regulate
the growth of primordial organs of the
seedling plant
• Study the metabolic and biochemical aspects
of dormancy and germination
• Analysis of various parameters of embryonic
growth
• To study the nutritional requirements

42. • Changes in the nutritional requirement of
embryo at different stages
• Effect of aminoacids, vitamins and plant
hormones can be observed on embryo culture

43. Applied applications
• To raise a healthy plant from abortive or non-
viable embryos
• To overcome seed dormancy
• Shortening the breeding cycle
• To overcome self-sterility of seeds
• Seed testing

44. Other applications
• To study evolutionary relationship
• To study the host parasite interaction
• To study mutagenic effect