Identification of S-genotypes in Chinese cherry cultivars (Prunus pseudocerasus Lindl.)

Self-incompatibility has been studied extensively at the molecular level in Solanaceae, Rosaceae, and Scrophulariaceae, all of which exhibit gametophytic self-incompatibility. In the present study, we successfully isolated nine S-RNase alleles from cultivars of Chinese cherry by PCR amplification from genomic DNA and stylar cDNA combining with cleaved amplified polymorphic sequence marker. Analysis of amino acid sequences revealed five novel S-alleles, S ₂ , S ₄ , S ₆ , S ₈ , and S ₉ , with respective accession numbers in the NCBI database of EF541168, EF541173, EF541172, FJ628598, and FJ628599. Results showed that “Dongtang” and “Yinzhu” contained six S-alleles (S ₁ , S ₃ , S ₅ , S ₇ , S ₈ , and S ₉ ); “Taishanganying” contained four S-alleles (S ₁ , S ₂ , S ₄ , and S ₆ ); “Daiba”, “Dayingzui”, and “Xiaomizi” contained four S-alleles (S ₁ , S ₂ , S ₅ , and S ₈ ); “Laiyangduanzhi”, “Shuangquanchangba”, and “Daqingye” contained three S-alleles (S ₁ , S ₂ , and S ₈ ). It is interesting that different cultivars collected from the same place hold the same S-genotypes. Moreover, pollination tests and pollen tube growth assays showed that nine cultivars were self-compatible. Chinese cherry presented in this article are naturally polyploidy, which is a very useful material for the study of self-compatibility, and much of this information will be valuable for further work on self-(in)compatibility of fruit tree in Rosaceae.