Institut für Züchtungsforschung an Obst
Pear rust (Gymnosporangium sabinae) is a heteroecious rust fungus that requires both juniper as its primary host and pear trees as its secondary host. On pear leaves, it causes conspicuous red spots on the surface and brown swellings on the lower surface, which can impair the plant's photosynthesis and lead to yield losses. Young trees are particularly vulnerable. In commercial orchards, fungal infestations are typically controlled through the use of fungicides. However, a more sustainable solution lies in identifying resistant or tolerant pear varieties, which could be used in breeding new pear cultivars.Pear genetic resources are being evaluated to identify suitable genetic resources with resistance or tolerance to pear rust. This is being done for the first time using a digital phenotyping method developed in a third-party-funded project (MONIQUA, grant number: 2818712A19).The study will be conducted over the next three years on the pear and wild pear collection of the Julius Kühn Institute (JKI), which includes 130 pear varieties and 541 accessions of 34 Pyrus species. It is planned to survey the pear plots three times a year (June, July, and August) using drones. The images captured will be photogrammetrically processed into orthomosaics. A recognition model will be used to digitally detect symptoms of pear rust and assign them to individual trees. In parallel, a manual assessment will be carried out to compare the results of both methods. The goal is to determine the susceptibility of the evaluated genotypes to pear rust while validating the accuracy of the digital phenotyping method. This approach could significantly reduce the effort needed to evaluate genetic resources and support the development of robust pear varieties for future conventional and organic fruit growing.
Federal Ministry of Agriculture, Food and Regional Identity
