Indigenous fungi from corn as a potential plant growth promoter and its role in Fusarium verticillioides suppression on corn

Abstract

Indigenous fungi can suppress infection by pathogens and produce secondary metabolites that directly or indirectly affect plant growth. This study aimed to test indigenous fungi collected from corn plants as biological control agents and their effects on the viability and vigor of corn seeds. Purposive sampling method was used for sampling where soil samples taken from the rhizosphere zone, corn stem and leaf tissue from three locations namely Maros-South Sulawesi, Bone-South Sulawesi, Sigi-Central Sulawesi, Indonesia. Rhizospheric fungi were isolated from soil collected at the rhizosphere and rhizoplane using a serial dilution technique, while the endophytic fungi isolated from the leaves and stem tissues using surface sterilization method. The isolated fungi were cultured on a potato dextrose agar (PDA) medium. An antagonism test was performed using the dual culture method on PDA media with F. verticillioides as target pathogen. Pathogenicity test and the effect of fungi on corn seed germination was carried out using the blotter test method. Parameters observed were; necrotic symptoms on seedlings, growth potential, germination, growth rate, growth simultaneity, vigor index, germination rate, and time needed for 50% of the total germination. The effect of the isolated indigenous fungi on corn growth was carried out in-planta using seedling trays. The results of the blotter test and in-planta test were further confirmed by a physiological characteristic test. And assessing the fungi's ability to dissolve potassium, phosphate, and produce protease enzymes. A total of 89 fungal isolates were isolated and collected from various parts of the corn plant. Nineteen of the 89 fungal isolates showed inhibitory activity against F. verticillioides by ! 50% inhibition. The fungal isolates JRP 5 MRS, JRP 9 MRS, JRP 10 MRS, JRP 7 MRS, and JEDF 1B BN were selected based on the tests and showed a consistently positive effect on seed viability and vigor with a value of !90%. The isolates did not cause necrosis in corn, and had the ability to suppress the growth of pathogenic F. verticillioides by ! 50%.

Molecular characterization of indigenous microbes and its potential as a biological control agent of Fusarium stem rot disease (Fusarium verticillioides) on maize

“…The indigenous microbial isolates used in this study included 3 isolates of fungi collected from earlier studies, i.e SEDF 6A MRS, JRP 7 MRS, and JRP 10 MRS ( Mirsam et al., 2021 ), as well as 2 isolates of bacteria (S6 and S9) from the collection of the Laboratory of Research Center for Food Crops, National Research and Innovation Agency. Furthermore, indigenous microbial isolates with single spored were purified and made stock by re-culturing on slant media of potato dextrose agar (PDA) for fungi and slant media of nutrient agar (NA) for bacteria using test tubes, then incubated at 28 °C for 7 days.…”

“…Maize crops are susceptible to a wide range of diseases, particularly those caused by pathogenic fungi. Fusarium stem rot disease, caused by Fusarium verticillioides , has recently attacked several Indonesian maize centers ( Suriani et al., 2018 ; Mirsam et al., 2021 ; Pakki et al., 2021 ). This pathogen is reported to obstruct nutrients transported into plant tissues so that plant growth is inhibited and has a negative impact on filling of the cobs and rotting of the cobs ( Zainuddin et al., 2017 ; Suriani et al., 2018 ).…”

“…The indigenous microbial activity provides benefits for plant growth and development, either directly or indirectly. The direct effect is related to the ability of indigenous microbes to inhibit pathogenic activity by producing various compounds or metabolites such as antibiotics and siderophores as well as various antagonistic mechanisms ( Ambrosini and Passaglia 2017 ; Mirsam et al., 2021 ). Meanwhile, the indirect effect is based on their ability to provide and mobilize or facilitate the absorption of various nutrients in the soil as well as to synthesize and change the concentration of various growth-promoting phytohormones ( Simarmata et al., 2020 ).…”

“…In the agricultural sector, the use of indigenous microbes provides a conversion of low-input systems to high and more sustainable output systems. Several studies have shown that indigenous microbes have the potential to be used in controlling F. verticillioides as well as probiotic agents to induce plant growth in vitro and in planta ( Saharan and Nehra 2011 ; Bhattacharyya and Jha 2012 ; Glick 2012 ; Kumar and Gopal 2015 ; Mirsam et al., 2021 ). Indigenous microbial isolates found in previous studies are still going through colony characterization, morphology, and physiology ( Mirsam et al., 2021 ).…”

“…Several studies have shown that indigenous microbes have the potential to be used in controlling F. verticillioides as well as probiotic agents to induce plant growth in vitro and in planta ( Saharan and Nehra 2011 ; Bhattacharyya and Jha 2012 ; Glick 2012 ; Kumar and Gopal 2015 ; Mirsam et al., 2021 ). Indigenous microbial isolates found in previous studies are still going through colony characterization, morphology, and physiology ( Mirsam et al., 2021 ). Therefore, a fast and accurate characterization method is needed to determine the type of indigenous microbes.…”