Identification of fungi associated with soybeans and effective seed disinfection treatments

Abstract

Sprouts can be a vehicle for the transmission of several pathogens capable of causing human illness, and the potential source of contamination is seed used for sprouting. The limited information about seed‐borne pathogens as well as their incidence on soybean seeds for soybean sprout industry led the objectives of this study that were to identify seed‐borne pathogens on commercial sprout soybean seeds and to evaluate different decontamination treatments on disinfection effectiveness and sprout quality. Seeds of “MFS‐561,” a sprout soybean cultivar, from three production regions were used in this study. The internal transcribed spacer (ITS1 and ITS2) DNA sequences of the isolated fungi from MFS‐561 seeds were used for species identification. Seven disinfection treatments were evaluated on their effectiveness on reducing fungal incidence and impact on sprout characteristics. Out of 55 fungal isolates obtained from the soybean seeds, seven species and six genera were identified. The most frequent genera across regions were Alternaria, Diaphorte, and Fusarium. The treatment of soaking seeds in 2% calcium hypochlorite for 10 min and 5% acetic acid for 2 min before sprouting were promising seed disinfection treatments as they significantly reduced fungi incidence without any negative effects on sprout quality.

Diversity of the Seedborne Fungi and Pathogenicity of Fusarium Species Associated with Intercropped Soybean

“…In this study, we identified 13 genera of the seedborne fungi and found Fusarium as the highest isolated genus (55.00%, 82/148), which was followed by Colletotrichum , Alternaria , Diaporthe/Phomopsis and nine other genera with less isolation frequency. Except for Colletotrichum , our results are nearly consistent with previous studies [ 34 , 35 ], but Escamilla et al [ 34 ] identified seven species in six fungal genera from the commercial sprout soybean seeds in the United States and among them the most frequent genera were Alternaria , Diaphorte and Fusarium . However, Wei et al [ 36 ] found that the genus Penicillium was the dominant population of seedborne fungi in different soybean cultivars in several soybean-producing regions of China, which were followed by Fusarium and Aspergillus.…”

Seed-borne pathogenic fungi on some soybean varieties

“…Attack of plant pathogens is one of the reasons for low soybean productivity and 55 fungal species has been isolated from soybean seeds. The most frequent genera were Alternaria, Diaphorte, and Fusarium (Escamilla et al 2019). Certified seeds do not guarantee to be free from seed-borne pathogens (Bishaw et al 2013).…”

“…Seed-borne pathogens are agents that are found internally or externally in seeds and have the potential to cause diseases in plants (Gupta et al 2017;Pedraza et al 2018). Several pathogenic fungi like Rhizopus, Alternaria, Culvularia, Diaporthe, Mucor, Corynespora, Cercospora, Colletotrichum, Phoma, Pythium, Fusarium, Aspergillus, and Cladosporium have been isolated from soybean seeds (Saylendra and Fatmawaty 2010;Kinnikar et al 2015;Escamilla et al 2019).…”

The effect of presowing treatment of seeds of winter rapeseed (Brassica napus L.) and winter brown mustard (Brassica juncea L.) with modern fungicides on their sowing qualities and biometric characteristics of seedlings

“…During the entire growth season, rapeseed and mustard plants, as well as other oil crops, for example, sunflower, soybean, black mustard, false flax, are affected by various diseases: fusarium, verticillium wilt, Alternaria blight and others [5][6][7][8][9]. The infestation of seeds with pathogens can lead to a rapid decrease in their sowing qualities, in the first place, germination.…”

“…The results of research carried out on different oil crops show that an effective way of disinfecting seeds from infection and obtaining healthy seedlings is the presowing treatment of seeds with fungicidal disinfectants [5][6][7][10][11][12]. In modern agricultural production, disinfectants of different kinds are used: chemical and biological, which are characterized by different mechanisms of action and allow preserving the potential of plant productivity.…”