The Power of <i>Daldinia eschscholtzii</i> MFLUCC 20-0215 Fungal Endophytes Native to Nibung Palm ( <i>Oncosperma</i> sp.) in Stimulating Plant Growth

Utilizing microbial biofertilizers has emerged as a viable alternative to enhance crop productivity in sustainable agriculture. Of the 378 endophytic strains from oil palm (<i>Elaeis guineensis</i>) and nibung palm (<i>Oncosperma</i> sp.), 168 strains exhibited phosphate solubilization indices (PSI: 1.47 to 4.37), and, within those isolates, 48 endophytes displayed indole-3-acetic acid (IAA) production (2.91 to 120.90 μg/ml). Culture filtrates from 14 strains with high PSI and IAA production were selected to assess their ability to increase seed germination of sweet and field corn. Eight of these endophytes significantly enhanced seed germination and seedling growth, particularly <i>Daldinia eschscholtzii</i> MFLUCC20-0215 (<i>P</i> ≤ 0.05). This fungal strain also promotes phosphorus availability, as soluble inorganic phosphate in the soil increased from 0.89 ± 0.14 to 2.74 ± 0.09 ppm after inoculation with this strain for 30 days. The total chlorophyll of corn leaves grown in nutrient-depleted (N.D.) soil inoculated with <i>D. eschscholtzii</i> MFLUCC20-0215 was higher than corn grown in N.D. soil (13.37 ± 2.20 μmol m^-2 compared with 5.10 ± 0.06 μmol m^-2). A microbial biofertilizer prototype was developed and used as inoculants in the soil for cultivating crops including tomato (<i>Solanum lycopersicum</i>), chili (<i>Capsicum frutescens</i>), lettuce (<i>Lactuca sativa</i> L.), red coral lettuce (<i>Lactuca sativa</i> var. <i>crispa</i>), and Chinese kale (<i>Brassica oleracea</i>). Significant differences were evident across all growth indexes of the tested crops when comparing our biofertilizer prototype and synthetic fertilizer to the negative control. Here, we present for the first time that nibung palm is a source of beneficial endophytic fungi in promoting plant growth. Our biofertilizer prototype will contribute to sustainable crop production systems by effectively enhancing crop production while minimizing environmental impacts.