Biodiversity of Plant Pathogenic Fungi - Kerala Forest Research ...

the diseased portions of the specimens including leaf spots, leaf blight, leaf blotches, leaf
rust and black mildew disease. Foliage rust infection was prevalent in this type of forests
and accounted for 3.69% of the total foliage infection. Aecidium, Colletotrichum,
Corynespora, Coniella, Crossospora, Curvularia, Fusarium, Glomerella, Guignardia,
Phoma, Phomopsis, etc. are the important foliage pathogens. Stem disease including
heart rot accounts for 2% of the total infection. In the evergreen forests, about 5.48% of
the total diseased host samples from all the forest ecosystems were found infected with
fungal pathogens. In other words, about 34.82% of the total plant host species collected
from different forest ecosystems, harbors pathogenic fungi in the evergreen forests in the
Western Ghats.
Pathogenic fungal species richness indices (Menhinick’s index and Margalef’s index)
were found higher than the wet-evergreen forests, shola forests and dry deciduous forests (Table
6). Simpson’s and Shannon species diversity indices also showed higher values than the wet
evergreen forest, shola forest and dry deciduous forest ecosystems (Table 6). Among the 50
pathogenic fungal species encountered in this forest ecosystem, Colletotrichum
gloeosporioides, Glomerella cingulata, Colletotrichum sp., Phomopsis sp. and
Guignardia sp. were the most common and abundant ones (Table 7).
Table 6: Species richness and diversity indices of plant pathogenic fungi in the evergreen forest
ecosystems
No. of
study
plots
Menhinick’s index (R2) Margalef’s index
(R1)
Simpson’s index Shannon index
(H’)
30 3.7909 9.618165 0.0559238797 3.269729
Table 7: Fungal species abundance in the evergreen forests
Sl. No. Abundant fungal species No. of host plants
affected
% to total
1 Colletotrichum gloeosporioides 24 13.25
2 Glomerella cingulata 19 10.49
3 Phomopsis sp. 18 9.94
4 Guignardia sp. 15 8.28
5 Colletotrichum sp. 15 8.28
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