Types of endosperm

Different types of Endosperm present in Plant life cycles are beautifully described by Rashmi R. Rehman of Gauhati University

1. PRESENTATION ON ‘TYPES OF ENDOSPERM’

GUIDED BY- PRESENTED BY-
DR. NAMITA NATH RASHMI H. RAHMAN
M.SC 2
ND
SEM
DEPT OF BOTANY
ROLL NO 3
GAUHATI UNIVERSITY

3. INTRODUCTION
Endosperm is a nutritive tissue stored in the
seed for the embryo and it is formed by the
fusion of one male gamete with the polar
nuclei.
-Endosperm plays a main role in the diet of
human beings.
-Endosperm is found in all angiosperms except
few families like
Orchidaceae,Podostemonaceae and
Trapaceae.
-The seeds without endosperm: Non-
endospermous seeds or exalbuminous seed.
-The seed containing the endosperm:
Endospermous or albuminous seed.

4. EXAMPLES OF ALBUMINOUS AND
EXALBUMINOUS SEED:
Castor
Pea

5. TYPES OF ENDOSPERM
-Endosperm is classified into 3 types by
Schnarf(1929) on the basis of their mode of
development:
1.Nuclear endosperm
2.Cellular endosperm
3.Helobial endosperm


Fig: A-Nuclear ,B-Helobial C- Cellular
endosperm

6. NUCLEAR ENDOSPERM

In this type of endosperm, the division of the
primary endosperm nucleus and its further
divisions are not followed by wall formation.
Examples. Limnanthes, Oxyspora


Fig: Neuclear endosperm in Limnanthes

 In some plants, the nuclear endosperm
becomes cellular at a later stage.

7.  Ex. Acalypha, Phaseolus.

Fig: A-E; stages in the development of
Neuclear type of endosperm

CELLULARIZATION OF NUCLEAR ENDOSPERM
 The cellularization of nuclear endosperm
shows variations.
 In Acalypha,the endosperm becomes
cellular completely.
In Grevillea, the endosperm is cellular in the
micropylar region and nuclear in the chalazal

8. end. The nuclear chalazal end develops into a
vermiform appendix (Kausik,1941


Fig: Endosperm formation in Acalypha

 In coconut,the endosperm is nuclear type.
Later on it becomes cellular.The PEN
undergoes several free nuclear divisions.
 The endosperm in coconut is partly solid
and partly liquid.

9. Fig: Endosperm formation in Cocos nucifera

CELLULAR ENDOSPERM

 The division of the PEN and its further
divisions are followed by immediate wall
formation and the free nuclear stage is
completely absent.
 It is common in dicots.
 Haustoria are common.

10. Fig: Development of cellular endosperm in
Drimys winteri

Haustoria in Cellular Endosperm
 The haustoria may arise at the
micropylar end or at the chalazal
end or both.
 In Impatiens , micropylar haustorium
is produced.
 In Nemophila both micropylar and
chalazal haustoria are found.

11. Fig: Endosperm in Nemophila


Fig: Micropylar haustorium in Impatiens

12. HELOBIAL ENDOSPERM
 It is intermediate in structure.
 Development is intermediate
between nuclear and cellular types.
It is more common in monocots.
Davis(1966) reported the presence of
helobial endosperm in 14 monocot
families

Fig: Development of helobial type of
endosperm in Eremurus

14. RUMINATE ENDOSPERM

 Endosperm having irregular ridges
and furrows on the surface. E.g
Areca catechu, Myristica

Fig: Ruminate endosperm in Myristica

15. REFERENCE:

1. THE EMBRYOLOGY OF
ANGIOSPERMS, 5
TH
EDITION, S S
BHOJWANI & S P BHATNAGAR
2. DEVELOPMENTAL BOTANY AND
EXPERIMENTAL EMBRYOLOGY,
ANNIE KUMMARESAN
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