Identification of fungi inhabiting underground plant parts of soybean [Glycine max (L.) Merrill] in two developmental stages

Abstract

Soybean [Glycine max (L.) Merrill] plants are potential hosts for different pathogens. Soil-borne diseases, caused by pathogenic fungi, are considered to be the main reason for the loss of soybean yields worldwide. The aim of the research was to isolate fungi inhabiting underground parts of soybean in order to identify potential pathogens present in south-east Poland. Research material comprised of seven soybean cultivars grown in field in 2017-2019. Samples collected in three subsequent vegetative seasons constituted soybean plants with disease symptoms on cotyledons, stems and roots. Fragments of the infected plant tissues were subjected to mycological analysis. A total of 1692 pure fungal isolates were obtained from the sampled plants and almost 80% of these isolates were assigned to Fusarium genus. Among Fusarium spp. isolates, the most frequently detected species was F. oxysporum (71.3%). Other detected Fusarium species included: F. graminearum, F. culmorum, F. avenaceum, F. poae, F. solani (syn. Neocosmospora solani), F. sporotrichioides and F. fujikuroi. Other fungi accounted for approx. 19% of the obtained isolates and their main representatives were: Alternaria alternata, Trichoderma sp., Rhizoctonia solani, Mucor sp., Cladosporium sp. and Rhizopus sp. Comparison of these results with published data from other regions of Poland shows differences in prevalence of different species of soil-borne fungi.