Genotype-specific responses to the effects of commercial Trichoderma formulations in lentil (Lens culinaris ssp. culinaris) in the presence and absence of the oomycete pathogen Aphanomyces euteiches

ABSTRACT

Members of the endophytic fungal genus Trichoderma have been established as plant-beneficial microbes and are most successful commercial biologicals in the form of bio-fertilisers, biocontrol agents, and growth stimulators. We report the variable interactions among different lentil genotypes and Trichoderma strains in both the presence and absence of biotic stress (root-rot pathogen Aphanomyces euteiches). Two commercial Trichoderma formulations, namely RootShield^® (RS) and RootShield^® Plus (RSP) based on T. harzianum T22 and T. virens G41, respectively, were evaluated for control of Aphanomyces root rot and plant growth promotion in 23 wild and cultivated lentil genotypes. No significant disease control was recorded with either formulation in any lentil genotype. Significant genotype-specific plant growth promotion was observed in terms of root and shoot development and leaf parameters in a genotype-specific manner. Genotypes of Lens culinaris and Lens tomentosus, both in the primary lentil gene pool, demonstrated the maximum response. The overall effect of Trichoderma treatment was markedly higher under biotically stressed conditions in comparison to unstressed conditions. In many cases, negative responses were recorded, particularly in the absence of root-rot disease. L. tomentosus PI 572390 exhibited positive responses for most of the tested parameters. Our findings clearly indicate that, in the case of lentil, plant genotype plays a major role in interactions among the tested Trichoderma strains and the plant. Moreover, the influence of Trichoderma was greater and more favourable under conditions of biotic stress vs. the absence of stress.

KEYWORDS:

• Lentil genotypes
• biotic stress
• biocontrol
• plant growth promotion

Acknowledgements

BioWorks Inc. is gratefully acknowledged for providing RootShield^® and RootShield^® Plus. Assistance received from Dr. Sabine Banniza, University of Saskatchewan, Canada, towards data analysis is sincerely acknowledged. We also thank the Crop Development Centre (CDC) pulse research group, University of Saskatchewan, Canada for technical support, and Dr. Sheridan L. Woo, University of Naples, Italy for her valuable inputs.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Natural Sciences and Engineering Research Council of Canada [grant number IRCPG 395994-09] and Saskatchewan Pulse Crop Development Board [grant number BRE 1202].