Induced Systemic Resistance Against Nematodes by Plant Growth-Promoting Microbes in Potatoes

Biofertilizers consist of plant growth-promoting microorganisms that establish symbiotic relationships with plant roots and stems. These beneficial microbes play a crucial role in enhancing plant defenses against various threats including insects, nematodes, and microbial pathogens. The purpose of this study was to investigate the effectiveness of two fungal biofertilizers (an endophytic strain of Beauveria bassiana (BA) and a mixture of arbuscular mycorrhizal (AM) fungi), specifically their ability to induce systemic resistance against plant- parasitic nematodes (PPNs) in potatoes (Solanum tuberosum cv. Masquerade) under controlled greenhouse conditions. The study utilized soil collected from Colorado State University’s San Luis Valley (SLV) Research Center where potato tubers exhibited severe symptoms of corky ringspot disease caused by tobacco rattle virus (TRV), which is transmitted by PPNs. Potato tubers were planted in both control soil and SLV soil with and without biofertilizer inoculation. After 12 weeks (approximately three months) of growth, the researchers assessed plant growth parameters and nematode presence. Surprisingly, the SLV soil negatively impacted all measured plant growth parameters. Additionally, the endophytic strain of B. bassiana adversely affected tuber numbers in control soils. These findings highlighted the need for further investigation into the potential use of B. bassiana and AM fungi as biocontrol agents.