Thought this might interest you plant disease watchers.
peace
misha
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CLAVICEPS AFRICANA, FIRST REPORT - INDIA
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A ProMED-mail post
Date: Jul 18 19:42:43 1999
From: ProMED-mail
Source: EPPO Report-9906, item 99/097
First report of Claviceps africana in India
The ergot of sorghum, _Claviceps africana_, has recently spread to the
Americas and Australia (see EPPO RS 97/031, 97/073, 97/119, 98/114). In
Asia, its presence was so far only reported in Japan, Thailand and Yemen.
In India, another fungus _Claviceps sorghi_ is present and considered as
endemic. The anamorph of _C. sorghi_ (_Sphacelia sorghi_) is
morphologically similar to that of _C. africana_. Five isolates of sorghum
ergot from several locations in southern India had previously been
identified as _C. sorghi_. But recently, further studies have demonstrated
that 2 of them (from Andhra Pradesh and Madhya Pradesh) were in fact _C.
africana_. This finding suggests that the data published in recent years in
India on sorghum ergot disease (thought to be caused only by _C. sorghi_)
may have to be revised, as well as the future strategies to control the
disease. This is the first report of _C. africana_ in India.
Source:
Bogo, A.; Mantle, P.G. (1999) Claviceps africana discovered in India.
Plant Disease, 83(1), p 79.
[_Claviceps sorghi_, first observed in India in 1915, has been considered
the only pathogen that causes sorghum ergot disease in India. The disease
was subsequently observed in Kenya in 1924, spreading to many other
countries in Africa. Characterization of African isolates (size and
morphology of
sclerotia, characteristics of the teleomorph [sexual stage] of the fungus,
and the presence of dihydroergosine which is unique to the African
pathogen, showed that it was a new species, _C. africana_. Unlike _C.
sorghi_ which produces primary conidia, _C. africana_ produces secondary
and tertiary conidia, thus providing a massive inoculative potential for
spread to sorghum and other related species, and pearl millet. Its spread
across large land masses in Africa, Asia, and the Americas is more than
likely associated with its capacity to produce conidia in an iterative
manner. _C. sorghi_ is predominately localized to India, Myanmar, Japan,
Thailand, the Philippines, and possibly Taiwan, whereas _C. africana_ is
present in Africa, the Americas, India, Australia, and perhaps elsewhere.
RAPD analyses of _C. africana_ isolates from Australia, India, Bolivia and
the USA showed that the Australian and Indian isolates are related but
different from those from North and South America.
Recent isolates of the sorghum ergot pathogen in India were found to be
predominantly _C. africana_. In India, _C. sorghi_ is being displaced by
the more aggressive _C. africana_, and it is becoming increasingly
difficult to find sclerotia of _C. sorghi_. Circumstances surrounding the
arrival of _C. africana_ in India are not known, but unwitting importation
of seedlots containing _C. africana_-infected seed and sclerotia is an
obvious possibility.
For comprehensive information about sorghum ergot, see the following
reference:
Bandyopadhyay et al., 1998, Ergot: a new disease that threat to sorghum in
the Americas and Australia. Plant Disease 82:356-367.
Information can also be obtained from a website:
<http://www.sorghumgrowers.com/Research/sorghum.html>. - Mod.DH]
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Michele Gale-Sinex
Communications manager
Center for Integrated Ag Systems, UW-Madison
http://www.wisc.edu
UW voice mail: 608-262-8018
Home office: 415-504-6474 (504-MISH)
Home office fax: Same as above, phone first for enabling
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