Evaluation of inoculum potential of pathogens in seeds: relation to physiological quality and DNA quantification by qPCR

• Autor(a) principal: Guimarães,Marina de Resende Faria
• Data de Publicação: 2017
• Outros Autores: Siqueira,Carolina da Silva, Machado,José da Cruz, França,Sueny Kelly Santos de, Guimarães,Gabriel Castanheira
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of Seed Science
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-15372017000300224
• topic: seed pathology; fungi; maize; soybean; cotton

Abstract: Given what is already known in regard to seed health and the availability of molecular methods for detection of the pathogens Stenocarpella maydis and Stenocarpella macrospora in maize seeds, Colletotrichum gossypii var. cephalosporioides in cotton seeds, and Corynespora cassiicola in soybean seeds, the aim of this study was to evaluate seed vigor according to different inoculum potentials. The fungus isolates were inoculated on seeds by the technique of water restriction, through which different inoculum potentials are obtained, corresponding to times of seed exposure of 0, 24, 48, and 96 hours for maize and cotton seeds, and 0, 36, 108, and 144 hours for soybean seeds. The seeds were subjected to germination, electrical conductivity, health, and qPCR tests. Results of the blotter test showed that in most pathosystems, there was a higher incidence of the fungi with an increase in inoculum potential. A decrease in germination percentage was observed in all species as inoculum potential increased, as well as further degradation of seed membranes. The qPCR test confirmed that the most damaged seeds in the tests had higher presence of the pathogens.