S-GENOTYPE ASSIGNMENT OF EUROPEAN PEAR CULTIVARS USING S-RNASE SPECIFIC CAPS MARKER

T. Takasaki-Yasuda, Y. Moriya, T. Nakanishi, H. Iwanami, H. Bessho
European pear (Pyrus communis L.) exhibits gametophytic self-incompatibility controlled by a single S-locus with multi alleles but has not been assigned with various pairs of S alleles by cross-incompatibility with pollen parents and between cultivars. The Rosaceae S alleles encode S ribonucleases (S-RNases) as a stylar product. For S-genotyping European pear cultivars, the full-length cDNAs of 17 S-RNases were cloned from stylar RNA using RACE cloning. Comparison of the nucleotide sequences between these cDNAs and 13 putative S-RNase alleles previously amplified by genomic PCR revealed that 12 corresponded to the putative Sa-, Sb-, Sc-, Sd-, Se- (Sj-), Sh-, Si-, Sk-, Sl-, Sm-, Sn- and Sp-RNase alleles and the other five corresponded to new S-RNase alleles (designated as Sg-, Sq-, Sr-, Ss- and St-RNase alleles). S-RNase specific PCR methods have been developed for genotyping Rosaceae fruit trees. Genomic PCR, with a set of primers ‘FTQQYQ’ and 'EP-anti-IIWPNV2' designed from the cDNA sequences, was used to amplify 17 S-RNase alleles; 1906 bp (Sg), 1642 bp (St), 1414 bp (Sl), ca. 1.3 kb (Sk and Sq), 998 bp (Se), 440 bp (Sb) and ca. 350 bp (Sa, Sc, Sd, Sh, Si, Sm, Sn, Sp, Sr and Ss). Among them, S-RNase alleles of similar size were discriminated by digestion with 11 restriction endonucleases. The PCR amplification of 17 S-RNase alleles following digestion with the restriction endonucleases provided a CAPS marker system for rapid S-genotyping of European pear cultivars harboring 17 S alleles. Using the CAPS analysis, the pairs of 17 S alleles were found in 104 cultivars, which were classified into 49 S-genotypes. Among these, 22 genotypes were shared by two or more cultivars, which were cross-incompatible. These results suggested that there were many cross-incompatible combinations among European pear cultivars.
Takasaki-Yasuda, T., Moriya, Y., Nakanishi, T., Iwanami, H. and Bessho, H. (2008). S-GENOTYPE ASSIGNMENT OF EUROPEAN PEAR CULTIVARS USING S-RNASE SPECIFIC CAPS MARKER. Acta Hortic. 800, 391-400
DOI: 10.17660/ActaHortic.2008.800.49
https://doi.org/10.17660/ActaHortic.2008.800.49
European pear, self-incompatibility, S-genotype, S-RNase, CAPS marker
English

Acta Horticulturae