title: A high-throughput method for genotyping S-RNase alleles in apple.
abstract: We present a new efficient screening tool for detection of S-alleles in apple. The protocol using general and multiplexed primers for PCR reaction and fragment detection on an automatized capillary DNA sequencer exposed a higher number of alleles than any previous studies. Analysis of alleles is made on basis of three individual fragment sizes making the allele interpretation highly accurate. The method was employed to genotype 432Malusaccessions and exposed 25 different S-alleles in a selection ofMalus domesticacultivars of mainly Danish origin (402 accessions) as well as a selection of otherMalusspecies (30 accessions). The allele S3 (28 %) was the most common among the Danish cultivars followed by S1 and S7 (both 27 %). The alleles S36 and S40 not previously reported fromM.domesticawere found in 6 and 17 cultivars, respectively. Complete allelic composition was found in 91 % of the 369 diploid accessions and in 86 % of the 63 triploids concerned. We further identified a relatively high frequency of S33 and S34, which has not been considered by most previous studies. The protocol presented here is easy to adopt and saves both time and work effort compared to previous methods. The robustness is illustrated by the great accuracy and a high number of S-alleles presented.
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 3rd Floor, 1871 Frederiksberg C, Denmark.
authors.forename: Bjarne
authors.initials: B
authors.lastname: Larsen
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 3rd Floor, 1871 Frederiksberg C, Denmark.
authors.forename: Marian
authors.initials: M
authors.lastname: Ørgaard
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 3rd Floor, 1871 Frederiksberg C, Denmark.
authors.forename: Torben Bo
authors.initials: TB
authors.lastname: Toldam-Andersen
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 3rd Floor, 1871 Frederiksberg C, Denmark.
authors.forename: Carsten
authors.initials: C
authors.lastname: Pedersen
keywords: Apple; Breeding; Compatibility; Fragment analysis; Malus domestica; S-RNase alleles