Biological control of strawberry crown rot, root rot and grey mould by the beneficial fungus Aureobasidium pullulans

Mudassir Iqbal,Maha Jamshaid,Johan A Stenberg,Ramesh R Vetukuri,Muhammad Awais Zahid,Erik Andreasson

doi:10.1007/s10526-021-10083-w

Abstract

Utilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers, respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33–48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea. In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-treated with A. pullulans followed by inoculation of the pathogens. Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides.

Highlights

Strawberry (Fragaria 9 ananassa Duch.) is one of the most fungicide-dependent crops, being highly susceptible to many pathogens (Garrido et al 2011)
Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides
P. cactorum and B. cinerea showed significantly reduced growth rates during confrontation with all A. pullulans strains compared with their growth rates when grown alone at a resolution of three and five days post-inoculation (DPI) respectively (Fig. 1)

Summary

Introduction

Strawberry (Fragaria 9 ananassa Duch.) is one of the most fungicide-dependent crops, being highly susceptible to many pathogens (Garrido et al 2011). The hemibiotrophic oomycete Phytophthora cactorum (Lebert and Cohn) Schroeter, is a destructive pathogen that causes crown and root rot disease in strawberry (Ellis et al 1998; Golzar et al 2007; Nellist et al 2019; Porras et al 2007; Stensvand et al 1999). Zoospores are the asexual motile stage and they are chemotactically attracted to roots, where they attach to the surface and penetrate the root epidermis. They start developing haustoria to acquire nutrients from the root for their growth and sporulation (Nellist et al 2019)

Methods

Results

Conclusion