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Journal of Applied and Natural Science 1(1): 76-78 (2009) JANS JANS
JANS JANS
JANS
Black mildews on Goniothalamus species in Agasthyavanam National Park,
Kerala, India
V. B. Hosagoudar
Tropical Botanic Garden and Research Institute, Palode - 695562, Thiruvananthapuram (Kerala), INDIA
E-mail : vbhosagoudar@rediffmail.com
_________________________________________________________________________________________
Abstract : The present study indicated that Goniothalamus rhynchantherus and G. wightii were infected by three black
mildew fungi, namely, Amazonia goniothalami, Irenopsis goniothalami and Trichasterina goniothalami. These fungi
have been described and illustrated in detail.
Keywords: Fungi, Black mildew, Goniothalamus, Endemic, National Park
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INTRODUCTION
Agastyamala, a name after the sage Agastya, located
towards the southern part of the Thiruvananthapuram
district in Kerala state. The hilltop is at an altitude of 1868
m, descends steeply towards the western side. This region
harbours tropical evergreen forest and is known for the
endemic flora of the flowering plants. The genus
Goniothalamus belongs to the family Annonaceae
comprises about 115 species and of which 10 are in India.
Goniothalamus cardiopetalus, G. rhynchantherus, G.
thwaitesii, G. wightii and G. wynaadensis occur in the
Western Ghats region of Peninsular India. Of these,
Goniothalamus rhynchantherus and G. wightii are
endemic to southern Western Ghats and were found
infected with ‘black mildews’ in the present study area.
‘Black mildews’ are the ectophytic fungi cause dense,
black velvet colonies on the surface of the leaves, and on
soft and tender parts of plants. Taxonomically, these fungi
include the members of Meliolaceae, Asterinaceae,
Englerulaceae, Hyphomycetes, etc. However, in the
present study, the black mildews on Goniothalamus
belong to the family Asterinaceae (the genus
Trichasterina) and Meliolaceae (the genera Amazonia and
Irenopsis).
Key to the genera of black mildews on Goniothalamus
species
1. Fruiting body thyriothecia …Trichasterina
1. Fruiting body perithecia …… 2
2. Fruiting body flattened-globose …Amazonia
2. Fruiting body globose with
perithecial setae …Irenopsis
DESCRIPTION OF THE SPECIES
1. Amazonia goniothalami Hosagoudar, Rajkumar, Biju
and Abraham (2001) (Fig. 1).
Colonies predominantly hypophyllous, subdense to
dense, up to 5 mm in diameter, confluent. Hyphae straight,
branching alternate to opposite at acute angles, loosely
to closely reticulate, cells 9-16 x 6-8 µm. Appressoria
alternate, antrorse to closely antrorse, straight, 18-26 µm
long; stalk cells cylindrical to cuneate, 6-8 µm long; head
cells ovate, oblong to cylindrical, entire, 12-15 x 8-12 µm.
Phialides not seen. Perithecia flattened-globose with
radiating cells, up to 160 µm in diameter; ascospores
oblong to ellipsoidal, 4-septate, constricted at the septa,
44-48 x 20-23 µm.
Materials examined: On leaves of Goniothalamus wightii
Hook. f. and Thoms. (Annonaceae), Agasthyamalai,
Kerala, India, Dec. 9, 1999, G. Rajkumar HCIO 43359, TBGT
257.
This is the only species of the genus Amazonia on the
members of the family Annonaceae (Hansford, 1961;
Hosagoudar, 1996; Hosagoudar et al., 1997and Mibey
and Hawksworth, 1997).
This species is known only from the type collection.
2. Irenopsis goniothalami Hosagoudar and Abraham
(1996) (Fig. 2).
Colonies hypophyllous, thin, spreading, up to 10 mm in
diameter, rarely confluent. Hyphae straight to crooked,
branching irregular at acute angles, loosely reticulate, cells
32-34 x 6-8 µm. Appressoria alternate, mostly straight,
rarely curved, antrorse to subantrorse, rarely recurved,
19-20 µm long; stalk cells cylindrical to cuneate 6-10 µm
ISSN : 0974-9411 All Rights Reserved © Applied and Natural Science Foundation www.ansfoundation.org
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Fig. 1. Amazonia goniothalami Hosagoudar, Rajkumar, Biju
and Abraham, a-Appressorium, b-Germinating
ascospores
Fig. 2. Irenopsis goniothalami Hosagoudar and Abraham,
a-Appressorium, b- Phialide, c-Germinating
ascospores, d- Apical portion of the perithecial setae
Fig. 3. Trichasterina goniothalami Hosagoudar and Goos
a- Appressoriate mycelium, b- Thyriothecium,
c- Ascus, d- Ascospores, e- Setae
long; head cells ovate, globose, entire, angular to lobate,
11-15 x 11-16 µm. Phialides mixed with appressoria, alternate
to unilateral, ampulliform, 17-20 x 4-7 µm. Perithecia
scattered, mostly immature, up to 160 µm in diameter.
Perithecial setae 0-6, simple, straight to curved, mostly
prostrate, erect, 2-6-septate, rarely nodu lose in the middle,
bulbous at the base, rarely obtuse to broadly rounded at
the apex, up to 150 µm long, ascospores obovoidal, 4-
septate, constricted at the septa, 32-35 x 14-16 µm.
Materials examined: On leaves of Goniothalamus
rhynchantherus Dunn. (Annonaceae), in the evergreen
forest of Chemunji, Bonaccaud, Thiruvananthapuram,
Kerala, India, March 11, 1997, V.B. Hosagoudar TBGT 200,
ILLS (Illinois).
This is the first report of the genus Irenopsis on the
members of the family Annonaceae (Hansford, 1961 and
Hosagoudar et al., 1997).
This species is known only from the type collection.
3. Trichasterina goniothalami Hosagoudar and Goos
(1996) (Fig.3) .
Colonies amphigenous, dense, velvety, up to 10 mm in
diameter, rarely confluent. Hyphae straight to substraight,
branching irregular at acute angles, loosely to closely
reticulate, cells 18-31 x 5-7 µm. Appressoria unilateral,
alternate and about 5% opposite, seated on a broad
base, unicellular, ovate, cylindrical, mammiform, rarely
truncate, 6-13 x 6-10 µm. Mycelial and thyriothecial
setae numerous, simple, straight, erect, obtuse at the
tip, up to 110 µm long. Thyriothecia scattered, orbicular,
carbonaceous black and opaque, up to 110 µm in
diameter; margin crenate, dehisce stellately at the
centre; asci many, globose to slightly ovate, eight
spored, 31-40 x 27-31 µm; ascospores brown,
conglobate, 1-septate, deeply constricted at the
septum, 31-34 x 12-16 µm, wall smooth.
Materials examined: On leaves of Goniothalamus wighti
Hook.f. & Thoms. (Annonaceae), Chemunji, March 11,
1997, V.B. Hosagoudar HCIO 44076, TBGT 510; April 12,
1999, G. Rajkumar HCIO 43368, TBGT 258; Feb. 8, 1998, G.
Rajkumar HCIO 43367, TBGT 259; April 23, 1998, G.
Rajkumar HCIO 43365, TBGT 260; July 16, 1998, G. Rajkumar
HCIO 43366, TBGT 261.
This species differs from Trichasterina polyalthiae Hansf.
in having alternate appressoria, smaller setae and larger
ascospores (Hansford, 1955).
This species is known only from the present locality.
V.B. Hosagoudar / J. Appl. & Nat. Sci. 1(1): 76-78 (2009)
78
ACKNOWLEDGEMENT
Thanks are due to the Director, Tropical Botanic Garden
and Research Institute, Palode for the facilities.
REFERENCES
Hansford, C.G. (1955). Tropical fungi – V. New species and
revisions. Sydowia 9: 1-88.
Hansford, C.G. (1961). The Meliolineae. A Monograph.
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Hosagoudar, V. B. (1996). Meliolales of India. Botanical Survey
of India, Calcutta, pp. 363.
Hosagoudar, V.B. and Goos, R.D. (1996). Some foliicolous
fungi from southern India. Mycotaxon 59: 149-166.
Hosagoudar, V. B., Abraham, T. K. and Pushpangadan, P. (1997).
The Meliolineae - A Supplement. Tropical Botanic Garden
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Hosagoudar, V.B. and Abraham, T.K. (1996). Two new
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(2001). Amazonia goniothalami sp. nov. and some additional
records of fungi on Goniothalamus wightii from India.
Mycotaxon 77: 431 – 434.
Mibey, R.K. and Hawksworth, D.L. (1997). Meliolaceae and
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V.B. Hosagoudar / J. Appl. & Nat. Sci. 1(1): 76-78 (2009)
