Effect of the MicroalgaChlorella fuscaCHK0059 on Strawberry PGPR and Biological Control of Fusarium Wilt Disease in Non-Pesticide Hydroponic Strawberry Cultivation

Abstract

The purpose of this study was to identify strawberry wilt pathogens and evaluate the efficacy of Chlorella fusca CHK0059 for improving plant growth and suppressing Fusarium wilt. We identified 10 isolates of wilt pathogens of non-pesticide Seolhyang strawberry plant, including Fusarium oxysporum f. sp. fragariae , using morphological and molecular analysis. On the 15 th day after 0.4% CHK0059 treatment, the plant height of the untreated control strawberry plants was significantly greater than that of the CHK0059-treated strawberry plants. After 85 days, both treatments showed a similar tendency regarding the height of the strawberry plants. However, the thickness of strawberry leaves treated with the CHK0059 was found to be 1 mm thicker than that of the untreated control. The flowering percentage of the CHK0059 plants was also 40.2% higher on average than that of the untreated control. The chlorophyll content of strawberry leaves treated with the CHK0059 was also, on average, 6.63% higher than that of the untreated control. After 90 days of the CHK0059 treatment, the incidence of Fusarium wilt in the CHK0059-treated plants had reduced by 9.8% on average compared to the untreated control. The population density of F. oxysporum f. sp. fragariae was also reduced by approximately 86.8% in the CHK0059-treated plants by comparison to the untreated control at 70 days after treatment. The results indicate that the microalga C. fusca CHK0059 is an efficient biological agent for improving strawberry plant growth and suppressing Fusarium wilt disease in organic strawberries.

Effect of Scenedesmus sp. CHK0059 on Strawberry Microbiota Community

“…Genus Scenedesmus is also an evolutionarily important microalga because some of the mitochondrial codons are non-standard, placing it in a different class Chlorophyceae [ 9 ]. Extracts of Scenedesmus obiliquus have been evaluated to increase the seed germination, root development, and cotyledon expansion of certain plants [ 10 ]. As a plant biostimulant, CHK0059 is well documented for its ability to enhance strawberry growth and marketability [ 11 ].…”

Screening of Bacillus subtilis HAAS01 and Its Biocontrol Effect on Fusarium wilt in Sweet Potato

“…At present, sweet potato production mainly relies on chemical pesticides to control the Fusarium wilt of sweet potato. However, the long-term use of chemical pesticides has problems such as resistance of pathogens and environmental pollution, which is not in line with the concept of green agriculture and sustainable development [5].…”

Screening of several microalgae revealed biopesticide properties of Chlorella sorokiniana against the strawberry pathogen Phytophthora cactorum

“…Major water-soluble compounds are polysaccharides, which are considered to enhance plant performance and resilience(Chanda et al 2019). A study showed that the application of living biomass of Chlorella fusca on strawberry plants increased plant health and reduced F. oxysporum wilt, demonstrating a successful application of microalgae as biostimulant and biocontrol agent(Kim et al 2020). With being used as not only biopesticide but also biostimulant enhancing the natural defense…”