The document discusses the differences between tapetum and integumentary tapetum in plants, highlighting their roles and origins. Tapetum is the innermost layer of the anther, essential for nutrient transfer during microsporogenesis, while integumentary tapetum, also known as endothelium, derives from the innermost layer of the integument and surrounds the embryo sac. Both structures have unique characteristics and may vary in layering and morphology across different plant families.

1. DIFFERENCE BETWEEN TAPETUM AND
INTEGUMENTARY TAPETUM

2. Introduction
• Tapetum is the innermost layer of anther wall
and attains its maximum development at the
tetrad stage of microsporogenesis.
• It completely surrounds the sporogenous
tissue and is of considerable physiological
importance because all the food material to
the sporogenous tissue must pass through it.
• It is composed of a single layer of cells having
dense cytoplasm and prominent nuclei.
• Tapetum is od dual origin in angiosperms.
• Based on its behaviour, tapetum is of two
types: Amoeboid tapetum and Secretory
tapetum.
Tapetum

3. • Plants belonging to the sympetalae with unitegmic ,
tenuinucellate ovules, the nucellus degenerates at an
early stage of ovule development and the innermost
layer of the integument becomes specialized to perform
the nutritive function for the embryo sac. This
specialized tissue, present around the embryo sac is
called endothelium.
• Occurrence of endothelium has been observed in 65
families of dicots.
• Endothelium usually single layered but in Asteraceae it
is multi-layered.
• Interesting feature of the endothelial cells is the
development of adventive embryos.
• In Begoniaceae, Droseraceae and Fabaceae the
persistent nucellar cells form an endothelium like
tissue. Because of its different origin it has been called
false endothelium.
Integumentary tapetum

4. Differences between Tapetum and Integumentary
tapetum
Tapetum
 It is the part of wall layer of
anther(innermost layer of
anther).
 Have dual origin, tapetal
portion toward outside
contributed by parietal layer
and inner portion derived from
connective tissue.
 Completely surround
sporogenous tissue.
Integumentary tapetum
 Part of ovule.
 Derived from innermost layer
of integument.
 Its surround the entire
embryo sac.

6. Tapetum
 Single layered.
 In some species , tapetal cell of
different origin may also differ
morphologically so they re called as
Dimorphic tapetum.
 It is of two types, Amoeboid tapetum
and Secretory tapetum.
 Example- Tradescantia and Alectra
thomsoni.
Integumentary tapetum
 Usually single layered but multi-
layered in Asteraceae.
 Also known as Endothelium and in
Begoniaceae , Droseraceae and
Elatinaceae persistent nucellar cells
form an endothelium like tissue,
because of its different origin has
been called false endothelium.
 No further types
 Example- Glossocardia Bosvallia and
Volutarella ramosa