A locus conferring effective late blight resistance in potato cultivar Sárpo Mira maps to chromosome XI

Abstract

Late blight of potato, caused by Phytophthorainfestans, is one of the most economically important diseases worldwide, resulting in substantial yield losses when not adequately controlled by fungicides. Late blight was a contributory factor in The Great Irish Famine, and breeding for resistance to the disease began soon after. Several disease-resistant cultivars have subsequently been obtained, and amongst them Sárpo Mira is currently one of the most effective. The aim of this work was to extend the knowledge about the genetic basis of the late blight resistance in Sárpo Mira and to identify molecular markers linked to the resistance locus which would be useful for marker-assisted selection. A tetraploid mapping population from a Sárpo Mira × Maris Piper cross was phenotyped for foliar late blight resistance using detached leaflet tests. A locus with strong effect on late blight resistance was mapped at the end of chromosome XI in the vicinity of the R3 locus. Sárpo Mira’s genetic map of chromosome XI contained 11 markers. Marker 45/XI exhibited the strongest linkage to the resistance locus and accounted for between 55.8 and 67.9 % of variance in the mean resistance scores noted in the detached leaflet assays. This marker was used in molecular marker-facilitated gene pyramiding. Ten breeding lines containing a late blight resistance locus from cultivar Sárpo Mira and the Rpi-phu1 gene originating from the late blight resistant accession of Solanumphureja were obtained. These lines have extended the spectrum of late blight resistance compared with Sárpo Mira and it is expected that resistance in plants containing this gene pyramid will have enhanced durability.

Diversity of Avr‐vnt1 and AvrSmira1 effector genes in Polish and Norwegian populations of Phytophthora infestans

“…The Rpi‐Smira1 gene has been identified in the cultivar Sárpo Mira, which also contains the R3a , R3b , R4 and Rpi‐Smira2 resistance genes (Rietman et al ., ). The product of Rpi‐Smira1 , which has been mapped to chromosome XI (Tomczyńska et al ., ), recognizes the AvrSmira1 effector (Rietman et al ., ).…”

Breeding of potato resistant to late blight using genetic resources and DNA markers

“…It is well illustrated by an example of the Rpi-phu1 gene which was obtained from CIP in 1970, and although we mapped it in 2006 and sequenced it in 2009, only in 2018 the cultivar 'Gardena' carrying that was registered by Zamarte Potato Breeding Ltd. -Group IHAR. The Rpi-phu1 gene was pyramided with late blight resistance originating from the cultivar 'Sárpo Mira' using MAS for the Rpi-phu1 gene, Rpi-Smira1 (Tomczyńska et al, 2014), and recently also using markers for R8/Rpi-Smira2. To learn more about how Rpi genes function, we performed an expression study in compatible and incompatible interactions between plants with the Rpi-phu1 gene and P. infestans.…”

“…Cultivar Sárpo Mira from Hungarian breeding program, registered in UK in 2002, with at least five genes for late blight resistance: R3a, R3b, R4, Rpi-Smira1 and Rpi-Smira2/ R8 (Tomczyńska et al, 2014).…”

Interspecific potato hybrids as donors of durable resistance to pathogens

“…Расонеспецифичная устойчивость присуща широкому кругу клубненосных видов Solanum и контролируется многочисленными генами, многие из которых пока картированы только как локусы количе-ственных признаков и исследованы значительно слабее, чем расоспецифичные гены (Gebhardt, 2013;Rodewald, Trognitz, 2013;Śliwka, Zimnoch-Guzowska, 2013). При-мером длительной устойчивости к фитофторозу, которую обеспечивает соединение в одном растении (пирамиди-рование) R-генов разной специфичности, служат сорта Sarpo Mira (Rietman et al, 2012;Tomczyńska et al, 2014b), дифференциатор MaR9 (Kim et al, 2012;Yo et al, 2015), а также сложные межвидовые гибриды картофеля, полу-ченные в российских селекцентрах (Рогозина и др., 2013). Эти формы несут 4-7 R-генов (Kim et al, 2012;Rietman et al, 2012;Khavkin et al, 2014) -существенно больше, чем сорта, созданные методами генетической инженерии (Halterman et al, 2016;Haverkort et al, 2016).…”