S-genotyping of old apple cultivars from the Carpathian basin: methodological, breeding and evolutionary aspects

Abstract

Apple exhibits self-incompatibility controlled by the multiallelic S-locus. Twenty-three old apple cultivars were S-genotyped using three different approaches (allele-specific polymerase chain reaction (PCR) + cleaved amplified polymorphic sequences (CAPS), consensus PCR + sequencing and consensus PCR+CAPS) to compare the robustness and reliability of these techniques and characterise genotypes from the Carpathian basin that might be useful in resistance breeding. Best results were obtained using the ASPF3 and ASPR3S consensus primer pair that detected 96% of all alleles carried by the 23 cultivars tested. Flow cytometry analysis was also needed to control the completeness of the genotypes as was seen in case of a tetraploid cultivar with only three assigned S-alleles. The genetic disparity between the old Carpathian basin and modern apple cultivars was indicated by differences in allele frequency data (S 9 , S 24 and S 26 ) as well as single nucleotide polymorphisms in S 1 , S 2 , S 7 S 24 and S 26 and indels in S 20 and S 26 alleles. An alignment of partial genomic sequences indicated trans-specific and transgeneric evolution of S-ribonuclease alleles in the Maloideae subfamily (S 26 and S 28 ) and a possibly recent introgression event (S 1 ) between Malus×domestica and Malus sylvestris. These data suggest that the genome of old cultivars from the Carpathian basin was enriched by several Malus taxa and are free from the consequences of modern breeding. These cultivars may contribute to the widening of the genetic basis of cultivated apple and prevent genetic erosion in future commercial cultivars.

A high-throughput method for genotyping S-RNase alleles in apple

“…In 13 % of the cultivars the genotype was constituted exclusively of the three ‘common’ alleles, and at least one of the three alleles was represented in 68 % of the cultivars. Similar to our findings, S3 and S7 were the two most common alleles found by Nybom et al ( 2008 ) and Halasz et al ( 2011 ) studying cultivars from primarily Northern Europe and the Carpathian basin, respectively.…”

“…Among these, we find a high frequency of the most common alleles identified in the Danish cultivar collection. We found a relatively high presence of S4 (8 %) compared to both Broothaerts et al ( 2004 ) and Halasz et al ( 2011 ) who found S4 to be among the absolute rarest alleles. We also found a relatively high frequency of S11 (10 %) among the Danish cultivars compared to the cultivars of mixed international origin considered.…”

“…We were able to identify 25 alleles among 432 accessions. In comparison, Nybom et al ( 2008 ) reported 14 alleles, Broothaerts et al ( 2004 ) 18 alleles, Halasz et al ( 2011 ) 20 alleles and only Kim et al ( 2009 ) reporting 22 alleles recorded alleles above S28. In the most recent revision of S-RNase alleles, Matsumoto ( 2013 ) lists 27 S-haplotypes, with S34 as the highest number.…”

Self-incompatibility alleles in Esatern European and Asian almond (Prunus dulcis) genotypes: a preliminary study

“…Almond is a typically outbreeding species, which has dramatic consequences on the genetic diversity of both wild growing and cultivated accessions (Szikriszt et al, 2011), similarly to other fruit species (Halász et al, 2011;Hegedûs et al, 2011). The S-genotypes have been identifi ed for many USA, Spanish, Italian and French almond cultivars (López et al, 2006).…”

Selection of a Suitable Pollinizer for ‘Summer Fantasia’ Plum

“…These pollinizers should flower with commercial cultivars and have abundant, cross-compatible, and active pollen (Crassweller et al, 1980;Kang et al, 2002). Among temperate fruit trees, the most actively studied pollinizers are those of apple cultivars (Bessho et al, 2009;Broothaerts et al, 2004;Hal asz et al, 2011).…”