Seed-Borne Fungi Associated with Diverse Rice Varieties Cultivated in the Western North Region of Ghana

Abstract

Rice is a major staple in the Ghanaian diet. However, its production is constrained by fungal diseases. A survey was conducted in 2018 in three selected districts in the Western North Region of Ghana using a structured questionnaire and face-to-face interaction with 230 farmers to assess their knowledge, perceptions of seed-borne fungal diseases, and management practices. Additionally, fungi associated with farmer’s seeds were isolated and identified through the Agar and Blotter tests. Findings indicate that 72.7% of the farmers in the selected districts relied on their saved seeds for planting. Thirteen fungal genera were associated with the rice seed samples collected from the three districts. The Juaboso district had the majority (13) of seed-borne fungi. The seed samples were categorized into various forms of discolouration, and significant differences ( P < 0.05 ) existed among the seed samples for this parameter. The AGRA rice, a farmer-saved seed from Juaboso, had the highest level of seed discolouration (41.96%). Fungi identified to be associated with the dark brown/brown discolouration of rice seeds were Bipolaris spp., Fusarium spp., Macrophomina phaseolina and Aspergillus spp. The only fungus associated with the yellow/pale yellow colour was Bipolaris spp. The fungi Bipolaris spp., Curvularia spp., and Botryodiplodia spp. were associated with the dark spot discolouration. Alternaria spp., and Aspergillus spp. were observed on the greyish white seed discolouration sample. Fungi are associated with rice cultivation and vary according to district and rice variety. A complex of pathogenic and saprophytic fungi therefore infects rice grains both in field and storage conditions.

Mycoflora associated with stored rice from storage facilities in Makassar and Maros, Indonesia

“…Rhizoctonia solani can survive for extended periods in the soil, and infected plant debris or soil particles can adhere to the surface of seeds, potentially leading to transmission during planting or germination (Singh et al 2019). Bipolaris oryzae is a seedborne pathogen known as the causal agent of brown spots in rice; it is a hemibiotrophic parasite that can infect and remain dormant in the seeds, and the dormant inoculum will be reactive during seed germination (Sunder et al 2014;Ackaah et al 2023;Thuy et al 2023). So far, there is no report of mycotoxin produced by these pathogens or any other risk related to human health.…”

“…(Ali et al 2018); A. flavus, Fusarium proliferatum (Phan et al 2021); A. flavus, A. parasiticus (Qi et al 2022); Bipolaris spp., Fusarium spp., Macrophomina phaseolina, Aspergillus spp., Curvularia spp., Botryodiplodia spp. (Ackaah et al 2023); A. niger, Talaromyces pinophilus (Laut et al 2023); and Alternaria alternata, F. moniliforme, Rhizopus nigricans, Helminthosporium oryzae, Pyricularia grisea (Kumar et al 2023).…”

Metagenomic Sequencing to Analyze Composition and Function of Top-Gray Chalky Grain Microorganisms from Hybrid Rice Seeds

“…Some factors, including warm weather, moist circumstances during rice heading and filling periods, and the relatively higher glume dehiscence rate in hybrid rice seeds, usually lead to a higher chalkiness rate in seed grains and make seeds more susceptible to infection, resulting in poor seed quality [2][3][4]16]. It had been previously reported that the rice seed-infecting pathogens were fungal microorganisms that could invade hulls and kernels, causing seed quality reduction and seedling diseases [17,18]. In our experiment, bacteria could be cultivated on the beef medium, but they could not grow on the rice flour medium, which was similar to endosperm ingredients.…”

Potential of LAMP assay as a tool for ecological monitoring and on-site detection of Bipolaris oryzae in rice

“…These infections have been shown to signi cantly reduce the quality of rice seeds [8,9]. Depending on the agroecology, disease severity and crop sensitivity, seedborne infections in rice cause yield losses of 50-80 per cent [10,11]. These pathogens promote seed discoloration, seed rot, impaired seed germination and seedling vigour and impede the plant throughout its early development stage.…”