Fine mapping of Ren3 reveals two loci mediating hypersensitive response against Erysiphe necator in grapevine

• Published in: Euphytica Vol. 213; no. 3; p. 1
• Main Authors: Zendler, Daniel, Schneider, Pierre, Töpfer, Reinhard, Zyprian, Eva
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-03-2017; Springer; Springer Nature B.V
• Subjects: Airborne microorganisms; Analysis; Berries; Biomedical and Life Sciences; Biotechnology; Cultivars; Genetic markers; Genotype & phenotype; Grapes; Leaves; Life Sciences; Plant diseases; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant resistance; Plant Sciences; Quantitative genetics; Selective breeding; Wine; Wines; Resistance; Genetic mapping; Regent; sp; Powdery mildew
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-017-1857-9

Grapevine (
Vitis vinifera
L.) is economically very important for the production of wine, table grapes and raisins. However, grapevine is threatened by a brought range of pathogens. A destructive disease worldwide is powdery mildew caused by the ascomycete
Erysiphe necator.
In the grapevine cultivar `Regent’ a resistance locus against
E. necator
,
Ren3
, was previously reported. It spans an interval of approximately seven Mb on chromosome 15. We attempted to delimit this interval to facilitate its further molecular analysis. New simple sequence repeat markers targeted to the
Ren3
region were designed. They were applied for fine mapping in the cross populations of ‘Regent’ × ‘Lemberger’ and ‘Regent’ × ‘Cabernet Sauvignon’ that segregate for
E. necator
resistance. Complementarily we scored
E. necator
infection levels of ‘Regent’ × ‘Lemberger’ progeny at different time points over the course of the vegetation period in 2015 and 2016. Subsequent QTL analysis revealed a maximum LOD value that shifted during the season from marker GF15-10 located at 2.2 Mb to marker GF15-53 located at 3.5 Mb and to marker ScORA7* located at 9.4 Mb on chromosome 15 (positions according to the grapevine reference genome of PN40024). To investigate the
Ren3
-encoded resistance mechanism we performed detached leaf infection assays for microscopic studies. These revealed that
Ren3
carrying individuals react with a hypersensitive response. Results of detached leaf assays on recombinants in the
Ren3
locus indicate that not only one, but two distinct genetic regions on chromosome 15 mediate hypersensitive response against
E. necator
.