Late blight resistance conferred by Rpi-Smira2/R8 in potato genotypes in vitro depends on the genetic background

Blatnik, Eva (author), Horvat, Marinka (author), Berne, Sabina (author), Humar, Miha (author), Dolničar, Peter (author), Meglič, Vladimir (author)

Potato production worldwide is threatened by late blight, caused by the oomycete Phytophthora infestans (Mont.) de Bary. Highly resistant potato cultivars were developed in breeding programs, using resistance gene pyramiding methods. In Sárpo Mira potatoes, five resistance genes (R3a, R3b, R4, Rpi-Smira1, and Rpi-Smira2/R8) are reported, with the latter gene assumed to be the major contributor. To study the level of late blight resistance conferred by the Rpi-Smira2/R8 gene, potato genotypes with only the Rpi-Smira2/R8 gene were selected from progeny population in which susceptible cultivars were crossed with Sárpo Mira. Ten R8 potato genotypes were obtained using stepwise marker-assisted selection, and agroinfiltration of the avirulence effector gene Avr4. Nine of these R8 genotypes were infected with both Slovenian P. infestans isolates and aggressive foreign isolates. All the progeny R8 genotypes are resistant to the Slovenian P. infestans isolate 02_07, and several show milder late blight symptoms than the corresponding susceptible parent after inoculation with other isolates. When inoculated with foreign P. infestans isolates, the genotype C571 shows intermediate resistance, similar to that of Sárpo Mira. These results suggest that Rpi-Smira2/R8 contributes to late blight resistance, although this resistance is not guaranteed solely by the presence of the R8 in the genome.

• Language: English
• Keywords: potato, potato genotype, potato R8 genotypes, in vitro infection, late blight, resistant cultivars, oomicete, Sárpo Mira
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Publication date: 16.05.2022
• Year: 2022
• Number of pages: 20 str.
• Numbering: vol. 11, iss. 10
• PID: 20.500.12556/RUL-136914
• UDC: 633
• ISSN on article: 2223-7747
• COBISS.SI-ID: 108979459
• Publication date in RUL: 24.05.2022

Record is a part of a journal

• Title: Plants
• Shortened title: Plants
• Publisher: MDPI
• ISSN: 2223-7747
• COBISS.SI-ID: 523345433

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 16.05.2022

Secondary language

• Language: Slovenian
• Keywords: Phytophthora infestans, Solanum tuberosum L., Rpi-Smira2/R8, krompir, krompirjeva plesen, varstvo rastlin, okužba rastlin, oomicete, genotipi krompirja, odporne sorte