Gharti-Chhetri, Gokarna , Olsson, Christer , Bimb, Hari , Olsson, Olof .
Development of a biological control system for rice blast disease (Magnaporthe grisea) in Nepal.
Rice corresponds to 58.8% of the total cereal production in Nepal. Rice blast caused by Magnaporthe grisea (Anamorph: Pyricularia grisea) is the most notorious disease for the loss of rice yield in Nepal.
Lacto-fuchsin staining of moist filter paper grown rice blast samples of leaves, panicles and seeds collected from 16 different rice varieties from different places in the Kathmandu valley identified five different pathogenic fungal species namely M. grisea, Bipolaris oryzae, Fusarium spp., Microdochium oryzae and Alternaria padwikii. Analysis of 13 lines collected from Khumaltar Research Station showed blast spores on leaf, neck or seed.
Twenty-nine bacterial and six yeast strains were isolated from rice fields in Kathmandu Valley. Out of the 29 bacterial strains, nine grew on Pseudomonas isolation agar (PIA). Surprisingly all nine of these were resistant to ampicillin and carbenicillin and five of them in addition were resistant to both kanamycin and tetracycline. Other four strains were moderately sensitive to kanamycin and/or tetracycline. Out of the 20 strains not growing on PIA, all were sensitive and moderately sensitive to kanamycin and/or tetracycline.
The GFP and luxAB marker genes were transferred from the E. coli Sm10gfp2X strain to the two most kanamycin sensitive PIA grown Nepalese bacteria, denoted NB25 and NB28, by conjugation. Conditions to bio-colonize the GFP labeled bacteria on chosen Nepalese rice varieties and tests to see whether such bacteria will hinder M. grisea spread will now be performed. Initially we will test various ways to propagate, preserve and pre-treat the bacteria for a maximal colonization, optimize seed inoculation conditions and regimes for application. Also these tests will be performed in the green house but later in the field.
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1 - Göteborg University, Department of Cell and Molecular Biology, Box 462, Göteborg, SE-405 30, Sweden
2 - Göteborg University, Department of Cell and Molecular Biology
3 - Nepal Agriculture Research Council, Biotechnology Unit/Ag-Botany Division
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM