-Identification of two new concepts of plant protection: Sexual-hijacking technique and apple immunity

3.1 Sexual Hijacking Fungi technique (SexHiFun, Patent, VENIN projects funded by SPE INRAE and Pré-maturation INRAE, 2020, 2021)

By investigating the capacity of hybrids between the two formae speciales pyracantha and pomi to infect apple and pyracantha hosts, we observed that none of them could parasitize apple. Therefore, we are exploiting this unexpected finding to develop a new biological control strategy based on sexual hijacking. It consists in a massive introduction of V. inaequalis f. sp. pyracantha (PYR) in apple orchards in autumn in order that they mate with V. inaequalis f.sp. pomi (POMI) to generate nonpathogenic progenies. This strategy analogous to the sterile insect technique should lead to the collapse of the population size of fungal pathogens. Since it is based on endogenous organisms that are specific of the target fungus, it is not toxic for human and environment.

3.2 Apple iMmunIty Against VenturIa InaEqualis (AMIàVIE, Invention disclosure in 2019 funded by Pre-maturation Project INRAE, 2021)

Very recently, we discovered in the team that application of V. inaequalis f.sp. pyracantha strains protects apple against scab infection. As these strains are not pathogenic on apple our strategy is to introduce them repeatedly in orchards in spring when scab epidemics start instead of using fungicides. Combining the two techniques -Sexual Hijacking and Apple Immunity, we should reach to reduce pathogen population size that would be a real alternative to fungicides so expected by for growers.

These two discoveries open a new area of research in the biocontrol of fungi.