Sorghum Diseases in India

Bacterial Diseases of Sorghum
L.E. Claflin 1 , B.A. Ramundo 2 , J.E. Leach 3 , and M. Qhobela 4
Abstract
Bacterial diseases on sorghum have been diagnosed in all major sorghum-producing areas. Bacterial
stripe (Pseudomonas andropogonis), bacterial streak (Xanthomonas campestris pv
holcicola) and bacterial spot (Pseudomonas syringae) are the principal diseases. This review
summarizes previous research efforts and reports research activities in progress or completed, but
yet unpublished. Various facets of the etiology and epidemiology of the major diseases are discussed,
as are the effects of stage of growth on leaf stripe and leaf blight development. Dotimmunobinding
assay and restriction endonuclease analysis, recently developed techniques for
identifying causal agents, are explained. The bacterial pathogen responsible for a disease of pearl
millet observed in northern Nigeria in 1987 was identified as caused by Pseudomonas avenae.
Introduction
Numerous bacteria have been reported as parasitic
to sorghum (Table 1). Of these, the three
most commonly reported are bacterial stripe,
(Pseudomonas andropogonis), bacterial streak
(Xanthomonas campestris pv holcicola), and bacterial
spot (Pseudomonas syringae pv syringae). Bacterial
diseases have been reported from all
sorghum-producing areas in the world and may
reduce yields where climatic conditions favor
disease development. Reports of research on
these sorghum diseases are limited, with fewer
than 40 literature citations since 1929; most appearing
in state or country reports mentioning
bacterial diseases.
Etiology and epidemiology of bacterial diseases
in sorghum is poorly understood, again
because reports are few and most are primarily
observational in nature. For example, it is often
stated that bacterial diseases are favored by a
warm and moist environment, but there is no
experimental evidence to support such a statement.
Likewise, P. andropogonis and X. campestris
pv holcicola are reported to be seedborne (Noble
and Richardson 1968); however, experimental
data was not presented. P. syringae pv syringae
has been shown to be seedborne (Gaudet and
Kokko 1986).
In this review, previous research is summarized;
data that are being published by our laboratories
are also included. Descriptions of
methods and materials, usually absent in publications
of this nature, are included to assist
those with limited access to scientific literature.
Bacterial Leaf Stripe
Causal organism
P. andropogonis is an aerobic, gram negative,
nonspore-forming rod, measuring 0.5 x 1.5 µm,
with one large, sheathed polar flagellum. A fluo-
1. Professor, Department of Plant Pathology Kansas State University, Manhattam, KS 66506, USA.
2. Research Assistant at the above address.
3. Associate Professor at the above address.
4. Former graduate student at the above address. Present address: Agricultural Research Station, Box 829, Maseru, Lesotho.
Claflin, L.E., Ramundo, B.A., Leach, J.E., and Qhobela, M. 1992. Bacterial diseases of sorghum. Pages 135-151 in Sorghum and
millets diseases: a second world review. (de Milliano, W.A.J., Frederiksen, R.A., and Bengston, G.D., eds). Patancheru, A.P. 502 324,
India: International Crops Research Institute for the Semi-Arid Tropics.
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