Plant genotype-dependent biocontrol of wheat diseases

Abstract

Sustainable crop production requires the reduction of chemical pesticides, and the use of beneficial microorganisms such as biological control agents (BCAs) is recommended as a sustainable alternative for disease management. However, the interaction between a host plant and a BCA can influence its biocontrol efficacy, which is currently not well understood. To better understand the role of plant genetic variation in influencing biocontrol efficacy, in this thesis, a winter wheat germplasm of approximately 200 genotypes was explored under controlled conditions for biocontrol efficacy of the BCA Clonostachys rosea during interactions with pathogens – Zymoseptoria tritici causing septoria tritici blotch (STB) and Fusarium graminearum causing fusarium foot rot (FFR). In both pathosystems, significant phenotypic variation was observed for disease susceptibility and C. rosea biocontrol efficacy. However, C. rosea efficacy varied in managing STB (positive effect: 7 genotypes, negative effect: 11 genotypes) and FFR (positive effect: 180 genotypes), suggesting that biocontrol efficacy can be specific not only to plant genotype but also to pathogen and/or plant tissue. Moreover, disease susceptibility and biocontrol efficacy were positively correlated, but distinct marker-trait associations were identified using genome-wide association studies (GWAS). The independent inheritance of disease susceptibility and C. rosea biocontrol efficacy offers the potential for simultaneous selection of these traits in future breeding programs. A few plant defence-related genes were co-localised in GWAS-identified regions for C. rosea biocontrol efficacy. To gain a deeper understanding, two genotypes with varying C. rosea biocontrol efficacy towards STB were used in a transcriptomic study, where differences in gene expression at early hours of inoculation were investigated in direct interaction with Z. tritici, C. rosea and their co-inoculation. The results showed a temporal difference between the genotypes, where the genotype with higher biological control efficacy showed a delayed but strong induction of the immune system by C. rosea. Overall, this thesis contributes towards advancing the knowledge of plants–BCA interaction in affecting biocontrol efficacy, which can aid future disease management and plant breeding efforts.

Keywords

Biological control; Clonostachys rosea; Fusarium graminearum; fusarium foot rot; genome-wide association study; septoria tritici blotch; transcriptomics; wheat; Zymoseptoria tritici

Published in

Acta Universitatis Agriculturae Sueciae
2025, number: 2025:28
Publisher: Swedish University of Agricultural Sciences

SLU Authors

• Chaudhary, Sidhant

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science

Publication identifier

• DOI: https://doi.org/10.54612/a.40imufb8dv
• ISBN: 978-91-8046-463-5
• eISBN: 978-91-8046-513-7

Permanent link to this page (URI)

https://res.slu.se/id/publ/132968