Previous View
APSnet Home
Plant Disease Home

Disease Note.

First Report of Balansia on Andropogon bicornis and Panicum cam-pestre in the Savannas of Colombia. H. Koga, National Grassland Research Institute, Nishinasuno, Tochigi 329-27, Japan. S. Kelemu and M. S. Sanchez, Centro Internacional de Agricultura Tropical, AA. 6713, Cali, Colombia. Plant Dis. 79:1074. Accepted for publication 31 July 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-1074A.

The savannas of the eastern plains of Colombia cover an area of approximately 5.5 million hectares. There are at least 153 documented plant species, which belong to 93 genera and 34 families. Andropogon bicornis L. and Panicum campestre Nees are among the predominant native plant species in the Colombian savanna ecosystem. Dark brown to black asco-mata on abaxial surfaces of unrolling leaves of A. bicornis were observed during a survey conducted in November, 1994, in Carimagua, Colombia, (latitude: 0437'N; longitude: 7126'E; altitude: 150 to 175 m; mean annual rainfall: 2,100 mm; mean annual temperature: 26C). Perithecia were ovoid (130 to 330 ? 90 to 140 μm) and ostioles were short necked. Filamentous asci (90 lo 200 ? 2 to 6 μm) contained ascospores that were approximately the same length as the ascus. Gray to black circlets of as-comata were observed on P. campestre stems just below the nodes. The morphology of perithecia, asci, and ascospores of the fungus on P. campestre were similar to those on A. bicornis, with perithecia size of 180 to 330 ? 120 to 140 μm, and asci of 90 to 180 ? 3 to 6 μm. Using Diehl's classification, the fungus on P. campestre was identified as Balansia henningsiana (A. Moller) Diehl, and that on A. bicornis was identified as B. subnodosa Atk. in Chardon. Scanning electron microscopy of transverse sections of infected tissues of both plants showed that the hyphae of these fungi developed in Ihe intercellular spaces of host leaf blades. These results suggest that the two Balansia species are endophytic. This is the first report of Balansia on A. bicornis and P. campestre in the savannas of Colombia. Voucher specimens have been deposited at CIAT, Colombia, and NGRI, Japan.