Fine mapping of the Rpi-rzc1 gene conferring broad-spectrum resistance to potato late blight

Abstract

The Rpi-rzc1 gene originates from Solanum ruiz-ceballosii, a wild diploid relative of the cultivated potato. It provides high levels of resistance to late blight both in detached leaflet and in tuber slice tests. Here, we present evidence on the broad-spectrum of this resistance using detached leaflet assays and 509 diverse Polish Phytophthora infestans isolates of which only seven (1.4 %) were virulent on plants with the Rpirzc1 gene. In a previous mapping study genetic distance between the Rpi-rzc1 gene and locus F conferring violet flower colour was 3.4 cM, while on the other side the gene was flanked by marker T1521 located in the distance of 6.1 cM. Adding new RenSeq markers changed the map order and slightly decreased these distances. To further increase the precision of the genetic map we expanded the mapping population with another 240 individuals originating from the same cross. These individuals were assessed for resistance to P. infestans in detached leaflet tests and their flower colours were evaluated. Ten sequence-specific PCR markers were scored in the enlarged mapping population: two were derived directly from the NBS-LRR homologs from the potato genome sequence, two were identified by the Resistance Gene Enrichment Sequencing (RenSeq) approach, and the remaining six from other mapping studies. On the resulting map the Rpi-rzc1 gene is flanked by markers located 0.4 cM from it. Narrowing down the chromosome sector containing the Rpi-rzc1 gene to 1 cM improves the efficiency of marker-assisted selection and will be useful for studies aiming at cloning the gene.

Population Structure of Phytophthora infestans from a Single Location in Poland Over a Long Period of Time in Context of Weather Conditions

“…The virulence of 226 P. infestans isolates was tested using the detached leaflet assay described by Brylińska and Śliwka [ 30 ]. This test was performed on 11 Black’s differentials with the genes R1 – R11 from Solanum demissum (Science and Advice for Scottish Agriculture, Edinburgh, UK) and new resistance sources: the cultivar Bzura with the R2-like gene [ 31 ]; the cultivar Sárpo Mira with the R3a , R3b , R4 , Rpi-Smira2 , and Rpi-Smira1 genes [ 32 , 33 ]; the cultivar Biogold with the Rpi-abpt gene [ 34 ]; the cultivar Toluca with the Rpi-blb2 gene [ 35 ]; and the diploid breeding lines DG 04-IX-21 with the Rpi-phu1 gene [ 36 ], DG 99-10/36 with the Rpi-rzc1 gene [ 37 , 38 ], and DG 99-12/8 with the Rpi-mch1 gene [ 39 ]. A susceptible potato cultivar, Craigs Royal, was used as a control.…”

Marker-assisted pyramiding of potato late blight resistance genes Rpi-rzc1 and Rpi-phu1 on di- and tetraploid levels

“…PCR mixture (20 μL) contained sterile water, 1 μL of each 10 μM primer solution, 2 μL of 2 mM dNTPs, 4 μL of 5× high fidelity buffer and 0.4 U of Phusion DNA Polymerase (Thermo Fisher Scientific, Waltham, MA, US). A touchdown PCR technique was used with initial denaturation for 180 s at 95°C, followed by 7, 8 and 20 cycles of 95°C for 30 s, 67/65/62°C for 20 s and 72°C for 45 s, ending with final elongation of 72°C for 300 s. RenSeq1812 and RenSeq1910 primer sets were used for amplifying, respectively, 520 and 350 bp markers flanking the Rpi-rzc1, each in a distance of 0.4 cM (Brylińska et al 2015). PCR mixture contained 0.4 μL of each 10 μM primer solution, 1 μL of 2 mM dNTPs, 2 μL of 10× PCR buffer and 1 U of Taq Polymerase (Genoplast Chemicals, Rokocin, Poland), filled up with water to 20 μL.…”

Interspecific potato hybrids as donors of durable resistance to pathogens

“…S. stoloniferum (Zoteуeva et al, 2014), S. ruiz-ceballosii -син. S. sparsipilum (Brylińska et al, 2015) и т. д.…”