Research of seed or soil carried Ustilaginoidea virens as the probable infection sources

The relations between inoculum of Ustilaginoidea virens and the formation of disease were not well described for this plant disease. The disease cycle，which begins with the infection of plant tissues and culminates in new false smut balls also have not been fully characterized. The study mainly demonstrated the suppose both seed and soil carried with pathogen could be the major primary infection sources of false smut in fields. The relationship between different inoculations，included inoculum level，and diseases occurance was elucidated. Results from CLSM observation，visual assessments and detection by polymerase chain reaction indicated that rice seed-or soil-carried U. virens was not be the primary infection sources of rice false smut under the inoculation condition described in the study. Factors affecting U. virens infection should be further studied to obtain direct evidence of the primary infection sources of the pathogen.