327 - 11th Botany Textbook Volume 1

Figure 1.29: V.S. of Agaricus gill
basidiospores monokaryotic
(+) mycelium (+)
basidiospores monokaryotic
(-) mycelium (-)
meiosis
somatogamy
Plasmogamy
basidia with
diploid nucleus
( Karyogamy)
basidiocarp
(2n)
rhizomorph
AGARICUS
secondary
mycelium
dikaryotic cell
Dikaryotisation
Figure Figure 1.36 1.30: Life Life Cycle Cycle of of Agaricus
the haploid primary mycelium.
Thus the life cycle of Agaricus shows
a very short diploid phase, haploid
phase and a prolonged dikaryotic phase
(Figure 1.30).
1.5.9 Mycorrhizae
The symbiotic association between fungal
mycelium and roots of plants is called as
mycorrhizae. In this relationship fungi
absorbs nutrition from the root and in
turn the hyphal network of mycorrhizae
forming fungi helps the plant to absorb
water and mineral nutrients from the soil
(Figure 1.31) Mycorrhizae are classified
into three types
Importance of Mycorrhizae
• Helps to derive nutrition in Monotropa,
a saprophytic angiosperm,
• Improves the availability of minerals
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