Institut für Züchtungsforschung an Obst
The Rosaceae family includes cherries as a valuable stone fruit commodity for fresh markets and manufacturing (Quero-Garcia et al., 2019). Cherry cultivation faces multiple challenges that include increased pest invaders Drosophila suzukii and Rhagoletis cerasi and plant diseases including brown rot (Monilinia laxa) and cherry leaf spot (Blumeriella jaapii) together with severe weather events such as hailstorms and late frosts (Quero-Garcia et al., 2019). Cherry leaf spot (CLS) which results from the fungus Blumeriella jaapii is particularly damaging sweet cherry (Prunus avium) and sour cherry (Prunus cerasus) together with other Prunus varieties in fundamental areas for cherry cultivation worldwide (Proffer et al., 2013). Prunus fruticosa and other wild species of the Prunus genus serve as important genetic resources for breeding programs (Stegmeir et al., 2014). P. fruticosa, is a shrub native from middle Europe to Western Siberia and Western China (Hrotkoet al., 2020). This self-incompatible, tetraploid species (2n = 4x = 32) is a key ancestor of the cultivated sour cherry (P. cerasus), developed from natural hybridizatio n between sweet cherry (Prunus avium) and P. fruticosa (Mackova et al., 2017). This research investigates the molecular mechanisms of CLS resistance in Prunus species, focusing on the wild relative P. fruticosa. It combines genetic mapping and transcriptomic approaches to identify resistance genes and pathways. The study will: 1) refine the P. fruticosa genetic map using SSR markers; 2) validate and fine-map previously identified CLS resistance QTLs; 3) identify differentially expressed genes (DEGs) and pathways associated with CLS resistance via transcriptomic analysis; 4) construct lncRNA-mRNA regulatory networks; 5) develop molecular markers for marker-assisted selection; and 6) inform the conservation and utilization of Prunus genetic resources. The study uses existing Prunus populations, including 'Schattenmorelle' x 'Pc 2' and 'Schattenmorelle' x P. maackii, and will involve phenotyping for CLS resistance, DNA/RNA extraction, genotyping, linkage map construction, QTL analysis, transcriptome sequencing, and qRT-PCR validation.
Alexander von Humboldt-Stiftung
