Effects of a fungal-bacterial consortium along with their individual components on the resistance to the English grain aphid on wheat under water deficit

Abstract

Microorganisms can live in the rhizosphere and interact with the roots of plants. Nowadays, they are studied as biological alternatives to chemicals in pest control and to be beneficial for growth promotion. They are also able to mitigate the negative effect of decreasing water availability for the plant. Henceforth, the present study investigates the effects of microorganisms on both plant growth and induced resistance in wheat plants (Triticum aestivum L.) against the grain aphid (Sitobion avenae) under different water availability. The two microorganisms studied were Bacillus subtilis and Trichoderma virens. Their consortium was also studied and compared to non-inoculated plants. The resistance of plants against aphids and their feeding behaviour were studied as well as plant response parameters. Aphid probing behaviour was recorded using electropenetrography. Results reveal reduced aphid resistance on plants inoculated with microorganisms. However, the inoculation of T. virens has a negative impact on the duration of aphid feeding in the phloem. The opposite trend was obtained for the ones feeding on plants inoculated with B. subtilis. The consortium’s effects are nuanced. Water availability influences the results. Microorganisms’ inoculation promote plant growth, namely shoot height. To conclude, the use of microbials is discussed as a tool in crop protection.