Polyphasic Characterization of Four Aspergillus Species as Potential Biocontrol Agents for White Mold Disease of Bean

Osama O Atallah; Yasser S A Mazrou; Mahmoud M Atia; Yasser Nehela; Abdelrazek S Abdelrhim; Maha M Nader

doi:10.3390/jof8060626

Polyphasic Characterization of Four Aspergillus Species as Potential Biocontrol Agents for White Mold Disease of Bean

J Fungi (Basel). 2022 Jun 12;8(6):626. doi: 10.3390/jof8060626.

Authors

Osama O Atallah¹, Yasser S A Mazrou^{2

3}, Mahmoud M Atia¹, Yasser Nehela⁴, Abdelrazek S Abdelrhim⁵, Maha M Nader⁶

Affiliations

¹ Department of Plant Pathology, Faculty of Agriculture, Zagazig University, Zagazig 44519, Egypt.
² Business Administration Department, Community College, King Khalid University, Guraiger, Abha 62529, Saudi Arabia.
³ Department of Agriculture Economic, Faculty of Agriculture, Tanta University, Tanta 31527, Egypt.
⁴ Department of Agricultural Botany, Faculty of Agriculture, Tanta University, Tanta 31511, Egypt.
⁵ Department of Plant Pathology, Faculty of Agriculture, Minia University, El-Minya 61512, Egypt.
⁶ Agricultural Microbiology Department, Faculty of Agriculture, Zagazig University, Zagazig 44519, Egypt.

Abstract

The genus Aspergillus comprises several species that play pivotal roles in agriculture. Herein, we morphologically and physiologically characterized four genetically distinct Aspergillus spp., namely A. japonicus, A. niger, A. flavus, and A. pseudoelegans, and examined their ability to suppress the white mold disease of bean caused by Sclerotinia sclerotiorum in vitro and under greenhouse conditions. Seriation type of Aspergillus spp. correlates with conidiospores discharge as detected on the Petri glass lid. Members of Nigri section cover their conidial heads with hard shells after prolonged incubation. In addition, sporulation of the tested Aspergillus isolates is temperature sensitive as it becomes inhibited at low temperatures and the colonies become white. Examined Aspergillus spp. were neither infectious to legumes nor aflatoxigenic as confirmed by HPLC except for A. flavus and A. pseudoelegans which, secreted 5 and 1 ppm of aflatoxin B1, respectively. Co-inoculations of Sclerotinia's mycelium or sclerotia with a spore suspension of Aspergillus spp. inhibited their germination on PDA at 18 °C and 28 °C, and halted disease onset on detached common bean and soybean leaves. Similarly, plants treated with A. japonicus and A. niger showed the highest survival rates compared to untreated plants. In conclusion, black Aspergillus spp. are efficient biocides and safe alternatives for the management of plant diseases, particularly in organic farms.

Keywords: Aspergillus spp.; Sclerotinia sclerotiorum; biological control; polyphasic characterization.

Grants and funding

This research was partially supported by the Academy of Scientific Research and Technology (ASRT) [Graduation Projects dedicated to Plant Pathology DEPT., Faculty of Agriculture, Zagazig Univ.]. The authors would like to acknowledge the Deanship of the Scientific Research at King Khalid University for funding the article processing charges (APCs) through the Program of Research Groups under grant number (RGP 2/67/43).