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| Author(s): |
Mariana de Souza e Silva
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2006-02-02 |
| Examining board members: |
Ivan Paulo Bedendo;
Jose Otavio Machado Menten;
Alfredo Seiiti Urashima
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| Advisor: | Ivan Paulo Bedendo |
| Abstract | |
Leaf scald, caused by Xanthomonas albilineans, is an important disease of sugarcane, That can interfere on the yield and longevity of infected plants. The disease intensity is variable, especially according to climate factors and cultivated varieties, and the damage quantification is very difficult through observation of plants in the field. Resistant varieties has been efficient to disease control, but the pathogen diversity can promote the breakdow of resistance. In commercial fields located in São Paulo State has been observed that the same sugarcane variety is resistant to leaf scald in a region, but susceptible in another one. This kind of behavior has suggested the occurrence of strains of X. albilineans that can be responsible for the breakdow of resistance of the cultivated varieties. It would be relevant to determinate pothogen variability in São Paulo State, because that information would be useful to indicate varieties for different regions and to guide breeding programs to obtain resistant varieties. Based upon the above points, the objective of the present study was to investigate the genetic diversity of bacterial isolates collected in commercial areas, using molecular techniques as PCR, rep-PCR, RFLP, and pathogenicity assays. The results showed that all isolates from plants exhibiting typical leaf scald symptoms belonged to species X. albilineans. It was also possible to determinate the occurrence of genetic diversity and pathogenic variability among the isolates sampled in the distinct regions. Thus, the results obtained in the present study can contribute to new investigations to confirm the association of the breakdow of resistance with the variability of the pathogen. (AU) | |
| FAPESP's process: | 03/06126-4 - Biochemical, molecular and pathogenic characterization of isolates of Xanthomonas albilineans (Ashby) Dowson, agent responsible for sugarcane leaf scald |
| Grantee: | Mariana de Souza e Silva |
| Support Opportunities: | Scholarships in Brazil - Master |