Detection of fungi and transmission of Alternaria alternata by seeds of Golden Trumpet Tree Handroanthus chrysotrichus (Mart. Ex DC) Mattos.

Abstract

Handroanthus chrysotrichus has high economic, ornamental and medicinal value, being used in landscaping projects and urban trees because of its floristic beauty. This study aimed to identify and quantify fungi associated with Handroanthus chrysotrichus (Mart. ex DC) Mattos seeds, evaluate the effect of aseptic seed germination and incidence of fungi Alternaria alternata and verify that is transmitted from seed to seedling . We evaluated the quality health through the filter paper method and PDA (potato dextrose agar). To test germination boxes we used type “gerbox “ substrate with filter paper at 25°C with 12 hours photoperiod for seven days. The seeds, in sanity, were subdivided, and a subsample submitted to superficial disinfection (with 1 % sodium hypochlorite, 70% alcohol and distilled water) and some were not. In the germination test, we also evaluated the transmission through fungal lesions detected in the seedlings. We identified and quantified fungi: Cladosporium sp.,  Alternaria alternata, Epicoccum sp., Phoma sp., Phomopsis sp., Aspergillus
sp., Fusarium sp., Chaetomium sp. and Rhizoctonia sp. In general, the asepsis provided drastic reduction in the incidence of all fungi that one can interfere that most of the seeds were infesting fungi. The fungi did not interfere directly in the percentage of normal seedlings and aseptic reduced germination proving to be phytotoxic. The Alternaria alternata fungus was detected in all samples and its transmission was detected, causing rot cotyledons and bad root formation.