Basal stem rot caused by Fusarium solani is among the most destructive soil-borne diseases affecting passion fruit (Passiflora spp.). While biological control employing antagonistic microorganisms offers a promising plant protection strategy, reports on antagonists specifically targeting passion fruit basal stem rot remain limited. Here, a screen for F. solani antagonists led to the identification of Bacillus velezensis strain L11-7, whose whole genome was subsequently sequenced. Pot experiments demonstrated that strain L11-7 significantly reduced the severity of stem basal rot, achieving control efficiencies of 92.85%, and exhibited broad antagonistic properties against other plant pathogenic fungi. L11-7 possesses cellulase, glucanase, and protease activities, alongside capabilities for nitrogen and phosphorus production. L11-7 was identified as B. velezensis through morphological analysis, 16S rRNA, gyrB, and rpoB gene sequencing, and whole-genome analysis. Its genome features a single circular 3.97 Mb chromosome harboring 13 s metabolite biosynthetic gene clusters (e.g., fengycin, surfactin, macrolactin H, bacillaene, difficidin) and genes encoding essential cell wall hydrolases. Several genes related to plant growth promotion, including those involved in nitrogen fixation and IAA production, are also present. These results indicate that B. velezensis L11-7 is a prospective biocontrol agent against passion fruit basal stem rot and has plant growth-promoting properties.
Jin et al. (Sun,) studied this question.