Exploitation of a marker dense linkage map of potato for positional cloning of a wart disease resistance gene

Abstract

A marker-saturated linkage map of potato was used to genetically map a locus involved in the resistance against wart disease Synchytrium endobioticum race 1. The locus mapped on the long arm of chromosome 4 and is named Sen1-4 in contrast to a Sen1 locus on chromosome 11. The AFLP markers from the Sen1-4 interval enabled the isolation of BAC clones from an 11 genome equivalent BAC library. This was achieved via fingerprinting of BAC pools with the AFLP primer pairs that resemble the genetic marker loci. With non-selective AFLP primers, fingerprints of individual BAC clones were generated to analyse the overlap between BAC clones using FPC. This resulted in a complete contig and a minimal tiling path of 14 BAC clones enclosing the Sen1-4 locus. The BAC contig has a genetic length of $6 cM and a physical length of $1 Mb. Our results demonstrate that map-based cloning of Sen1-4 can be pursued on the basis of a strategy of marker saturation alone. Genetic resolution achieved by screening large numbers of offspring for recombination events may not be required. Together with the construction of the BAC contig, a physical map with the position of the markers is accomplished in one step. This provides proof of concept for the utility of the marker saturation that is offered by the ultra dense AFLP map of potato for gene cloning.

Construction of a 10,000-Marker Ultradense Genetic Recombination Map of Potato: Providing a Framework for Accelerated Gene Isolation and a Genomewide Physical Map

“…In view of the average insert size of a BAC library and the estimated genome size of 840 Mb (Tempelaaret al 1985;Bennett et al 1997), the current number of marker loci should be sufficient for gene-cloning efforts via BAC landing, since the average distance between markers is estimated to be 84 kb. Proof of concept was recently obtained by the cloning of the late blight resistance gene R3a (Huang et al 2004(Huang et al , 2005 and the construction of a BAC contig comprising the wart disease resistance gene Sen1-4 (Brugmans et al 2006). Both studies demonstrated that marker spacing was in accordance with the expected physical distance.…”

Marker-assisted combination of major genes for pathogen resistance in potato

“…Whether the different wart resistance genes are linked could not be assessed due to the small number of plants in each family. A second, independent locus Sen1-4 has been identified on potato chromosome IV (Brugmans et al 2005), which may be responsible for the wart resistance alleles originating from Ry126 and Ry62. Sen1 and Ry adg are both located in the same 'hot spot' for pathogen resistance on the distal end of the long arm of potato chromosome XI, which is syntenic with the N locus in tobacco for resistance to tobacco mosaic virus (Gebhardt and Valkonen 2001).…”

Potato resistance to quarantine diseases

“…Устойчивость к патотипу 1 возбудителя рака картофеля детерминируется доминантными аллелями генов Sen1 (синоним Sen1XI) (Hehl et al, 1999) и Sen14 (Brugmans et al, 2006). Ген Sen14 картирован на длинном плече хромосомы IV на расстоянии 5 сМ от центромера (Brugmans et al, 2006).…”

“…Устойчивость к патотипу 1 возбудителя рака картофеля детерминируется доминантными аллелями генов Sen1 (синоним Sen1XI) (Hehl et al, 1999) и Sen14 (Brugmans et al, 2006). Ген Sen14 картирован на длинном плече хромосомы IV на расстоянии 5 сМ от центромера (Brugmans et al, 2006). Ген Sen1 локализован на дисталь ном конце длинного плеча хромосомы XI в мегакластере последовательностей, кодирующих белки с NBSLRR доменами, в том числе Rгены и QTLs, детерминирующие устойчивость к Yвирусу картофеля, вирусу аукуба моза ики картофеля, вирусу скручивания листьев картофеля и G. pallida (Obidiegwu et al, 2014).…”