Author
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GIGLIOTI, E - CENTRO DE CIENCIAS AGRARI |
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Comstock, Jack |
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Grisham, Michael |
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MATSUOKA, S - CENTRO DE CIENCIAS AGRARI |
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TOKESHI, H - ESALQ/USP |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 4/20/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Staining by transpiration method (STM) and tissue blot immunoassay (TBIA) were used to determine the sugarcane reaction to ratoon stunting disease (RSD). STM stained the functional vascular bundles of the sugarcane stalks but not the non-functional ones (NFVB) while TBIA stained the colonized vascular bundles (CVB) by the RSD bacteria. In Canal Point (FL), a good correlation r=0.92 between NFVB and CVB was obtained, using 9 moderately resistant cultivars. In a second trial using 19 cultivars that had a much wider range of RSD reaction, the correlation between the two methods was just r=0.40. In these cultivars, the pathogen was present in the xylem; however, water uptake was not completely prevented. A third experiment was conducted in Houma (LA) to verify whether this might indicate tolerance to RSD. The correlation between CVB and NFVB was r=0.68, but none of them was correlated with yield damage (reduction in tons per acre). The high correlation between CVB and NFVB to identify resistant or moderately resistant cultivars makes either TBIA or STM suitable to screen sugarcane genotypes for RSD resistance in the early stages of selection. The second one seems to be an alternative tool for development of resistant cultivars by sugarcane breeding programs in developing countries, where labor is less costly and equipment as well as reagents required by TBIA are not easily obtained |
