Assessment of <i>Fusarium avenaceum</i> inoculation methods for consistent development of pea root rot under greenhouse conditions

<i>Fusarium avenaceum</i> (<i>Fave</i>) is the most dominant pathogen of the pea root rot complex in the Canadian prairies. Its increasing prevalence and broad host range present significant challenges, underscoring the urgent need for research to develop effective management strategies including breeding for resistance. A critical aspect of efficient pathogen studies and screening pea lines for resistance under controlled conditions is selecting an appropriate inoculation method. In previous experiments, we observed that classical <i>Fave</i> inoculation methods such as seed inoculation either lacked uniform infection or killed plants before emergence. Therefore, we tested different <i>Fave</i> conidia inoculation methods to assess disease development in various pea lines after <i>Fave</i> exposure and refined these methods to develop an optimized indoor screening protocol for <i>Fave</i>. Among the tested methods, soil inoculation with <i>Fave</i> conidia resulted in the most consistent and uniform disease symptoms across repeated experiments. This method could be most effective for germplasm screening for partial resistance. A modified seed inoculation method also resulted in moderate disease levels, making it the most effective for testing the virulence of different isolates of <i>Fave</i> on the same genotype. Root soaking resulted in uniform but low disease severity and can be used for studying host–pathogen interactions where observation during the infection process is important.