Analyses of virulence of European isolates of clubroot (<em>Plasmodiophora brassicae</em> Wor.) and mapping of resistance genes in rapeseed (<em>Brassica napus</em> L.)
DOI:
https://doi.org/10.5073/dissjki.2017.009Abstract
Clubroot caused by the obligate biotrophic protist Plasmodiophora brassicae is a serious soilborne disease of cruciferous crops including oilseed rape (Brassica napus L.). Physiological specialisation of pathogen populations causes differences in pathogenicity, rendering breeding for resistance difficult. Therefore, it is important to get more detailed information on the virulence of P. brassicae in Europe. Samples of infected plants were collected all over the main European oilseed rape growing regions and forty-eight isolates were characterised under greenhouse conditions by artificial inoculation on the European Clubroot Differential (ECD) series and the differential set of Somé et al. (1996) followed by optical rating of disease symptoms. In total, 33 different ECD triplet codes were detected of which classifications ‘16/14/31’, ‘16/31/31’ and ‘17/31/31’ were most common. Based on results obtained on the differentials of Somé et al. (1996) P1 is the prevalent pathotype on oilseed rape fields in the maritime region of Northern Europe whereas P3 was most frequently detected in the continental part of Europe. As breeding for resistance is the most powerful tool to control clubroot, broadening of the genetic basis of resistance in oilseed rape is needed. Therefore, clubroot resistances derived from two rutabaga (Brassica napus var. napobrassica) varieties, i.e., ‘Invitation’ and ‘Wilhelmsburger’, were genetically mapped in doubled haploid (DH) populations of crosses to the susceptible oilseed rape (Brassica napus L.) cultivar ‘Ladoga’. The DH populations were analysed for resistance against two P. brassicae isolates showing different virulence patterns in the greenhouse. The segregation ratios indicated the effectiveness of one, two and three resistance genes, respectively, conferring resistance in these DH populations depending on the P. brassicae isolate used. Studies on F1 plants give hint to dominant resistance genes in both donor lines located on chromosomes A03, A05 and A08.
Downloads
Published
Issue
Section
License
Once a dissertation has been published, the copyright remains at the author. Herby, the author remains the right to further distribute and exploit the work.
License
The dissertations of the book series "Dissertationen aus dem Julius Kühn-Institut" are licensed under a Creative Commons Attribution 4.0 International license.
You are free to:
- Share — copy and redistribute the material in any medium or format
- Adapt — remix, transform, and build upon the material for any purpose, even commercially
Under the following terms:
-
Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.