Production of <i>Purpureocillium lilacinum</i> and <i>Pochonia chlamydosporia</i> by Submerged Liquid Fermentation and Bioactivity against <i>Tetranychus urticae</i> and <i>Heterodera glycines</i> through Seed Inoculation.

Abstract

<i>Pochonia</i><i>chlamydosporia</i> and <i>Purpureocillium</i><i>lilacinum</i> are fungal bioagents used for the sustainable management of plant parasitic nematodes. However, their production through submerged liquid fermentation and their use in seed treatment have been underexplored. Therefore, our goal was to assess the effect of different liquid media on the growth of 40 isolates of <i>P</i>. <i>lilacinum</i> and two of <i>P</i>. <i>chlamydosporia</i>. The most promising isolates tested were assessed for plant growth promotion and the control of the two-spotted spider mite (<i>Tetranychus urticae</i>) and the soybean cyst nematode (<i>Heterodera glycines</i>). Most isolates produced &gt; 10⁸ blastospores mL^-1 and some isolates produced more than 10⁴ microsclerotia mL^-1. Microsclerotia of selected isolates were used to inoculate common bean (<i>Phaseolus vulgaris</i> L.) seeds in greenhouse trials. All fungal isolates reduced the <i>T. urticae</i> fecundity in inoculated plants through seed treatment, while <i>P. chlamydosporia</i> ESALQ5406 and <i>P. lilacinum</i> ESALQ2593 decreased cyst nematode population. <i>Purpureocillium lilacinum</i> was more frequently detected in soil, whereas <i>P. chlamydosporia</i> colonized all plant parts. <i>Pochonia chlamydosporia</i> ESALQ5406 improved the root development of bean plants. These findings demonstrate the possibility of producing submerged propagules of <i>P. chlamydosporia</i> and <i>P. lilacinum</i> by liquid culture, and greenhouse trials support the applicability of fungal microsclerotia in seed treatment to control <i>P. vulgaris</i> pests.