327 - 11th Botany Textbook Volume 1

The sporophyte is not free-living but
attached to the photosynthetic gametophyte
and derives nutrition from it. Sporophyte
is differentiated into foot, seta and capsule.
The foot is bulbous and is embedded in the
gametophyte. It derives nutrition from the
gametophyte and transfers to the sporophyte.
Seta is short and connects foot and capsule.
The capsule consists of single layered jacket
layer and encloses numerous haploid
spores and elaters. The capsule is covered
by protective covering called calyptra. On
maturation the capsule dehisces and spores
are released. Elaters helps in the dispersal
of spores. The spores under favourable
conditions germinate and develop into new
gametophyte. The haploid gametophytic
phase alternates with diploid sporophytic
phase, thus the life cycle of Marchantia shows
alternation of generation (Figure 2.17).
a) L.S. of Antheridiophore
Photosynthetic
region
Antheridium
Antheridiophore
Photosynthetic region
Archegonium
Perichaetium
Figure 2.17
V.S of marchantia sporophyte
Foot
Seta
Capsule
Spores
Elaters
Calyptra
Figure 2.16: Marchantia - V.S. of
Sporophyte
FRAGMENTATION
GEMMAE
ADVENTITIOUS
BRANCHES
(DIOECIOUS)
MALE THALLUS
(n)
FEMALE THALLUS
GERM TUBE
(n)
GERM TUBE
GERMINATION
SPORES
(n)
SPORES TETRAD
(n)
MEIOSIS
Vegetative Reproduction
GAMETOPHYTIC
GENERATION
(n)
MARCHANTIA
ARCHEGONIOPHORE
(n)
ARCHEGONIUM
(n)
EGG
(n)
ANTHERDIOPHORE
(n)
ANTHERIDIUM
(n)
ANTHEROZOID
(n)
FERTILIZATION
Archegoniophore
SPORES MOTHER
CELLS
(2n)
SPOROGONIUM
(2n)
Sexual Reproduction
SPOROPHYTIC
GENERATION
(2n)
OOSPORE
(2n)
b) L.S. of Archegoniophore
Figure 2.15: Marchantia - Sex organs
EMBRYO
(2n)
Figure 2.18 Life cycle of Marchantia
Figure 2.17: Life cycle of Marchantia
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