Detecção de Magnaporthe oryzae em sementes de arroz por meio da técnica LAMP (amplificação isotérmica de ácidos nucleicos)

• Autor(a) principal: Teixeira, Nara Cristina
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/7949
• topic: Oryza sativa; Sementes; Brusone; Diagnóstico molecular; Oryza sativa; Seeds; Rice blast; Molecular diagnosis; AGRONOMIA::FITOSSANIDADE

Considered the most destructive disease of rice (Oryza sativa), the blast caused by the fungus M. oryzae is of concern worldwide. Because the pathogen staying power in the soil and crop residues for long and indeterminate periods is essential monitoring before the pathogen's entry into new areas, due to the commitment of nearby plantations. The seeds are considered the main ways of spread of disease due to storage, transportation and introduction into harmless areas. The methodology currently recommended by the Ministry of Agriculture for fungi monitoring seed is the "Blotter test", however, the morphological characterization can often be uncertain due to the rapid growth of fungal invasion and the similarity between structures of some pathogens. Morphologically M. oryzae can be indistinguishable from some species, such as the causal agent of rice blast wheat and other grasses therefore the most adequate way for safe diagnosis is the molecular detection. In seeds percentage infestation is often low, which is nevertheless important because the seed of transmission capacity for the seedling, however small conidia concentrations may be insufficient for the molecular detection by techniques potentially used as PCR (Polymerase Chain Reaction). Technically a methodology for molecular amplification isothermal LAMP (Loop- Mediated Isothermal Amplification) simpler recently been developed, which allows to safely identify the target, due to the projection of specific primers based on exclusive regions of the genome of the organism. The technique has advantages as high sensitivity due to the recognition by the initiators of six regions of the target, in addition to specificity, speed and security in the diagnosis. It is important to consider the cost reduction compared with PCR, due to use of constant temperature and straightforward interpretation of results using turbidity generated in positive samples or color change if the addition of dyes, eliminating the use of devices, specialized professionals in handling high standard laboratories. The interpretation the results with the naked eye makes the seed control in environments such as laboratories, warehouses, cooperatives with minimal structure, reflecting positively on the proper targeting of lots, either for planting, consumption or disposal. Therefore, the aim of this study was to survey the main potentially destructive pathogenic fungi found in seeds, and develop a rapid detection kit by LAMP methodology for M. oryzae.