The genus Pyrus is characterized by an S-RNase-based gametophytic self-incompatibility (GSI) system, a mechanism that promotes outbreeding and prevents self-fertilization. While the S-genotype of the most widely known pear cultivars was already described, little is known on the S-allele variability within local accessions. The study was conducted on 86 accessions encompassing most of the local Sicilian varieties selected for their traits of agronomic interest and complemented with some accessions of related wild species (P. pyrifolia Nakai, P. amygdaliformis Vill.) and some national and international cultivars used as references. The employment of consensus and specific primers enabled the detection of 24 S-alleles combined in 48 S-genotypes. Results shed light on the distribution of the S-alleles among accessions, with wild species and international cultivars characterized by a high diversity and local accessions showing a more heterogeneous distribution of the S-alleles, likely reflecting a more complex history of hybridization. The S-allele distribution was largely in agreement with the genetic structure of the studied collection. In particular, the “wild” genetic background was often characterized by the same S-alleles detected in P. pyrifolia and P. amygdaliformis. The analysis of the S-allele distribution provided novel insight into the contribution of the wild and international cultivars to the genetic background of the local Sicilian or national accessions. Furthermore, these results provide information that can be readily employed by breeders for the set-up of novel mating schemes.

中文翻译：

---

意大利梨种质栽培和野生种中破译S-RNase等位基因模式

梨属植物的特征是基于S -RNase的配子体自交不亲和（GSI）系统，该系统可促进近交繁殖并防止自我受精。虽然小号最广为人知的梨品种-基因型已经描述的，很少有人在已知š本地种质内-allele变化。这项研究是针对86个种质进行的，这些种质涵盖了大多数因其农艺学特征而选择的西西里地方品种，并辅以一些相关野生种的种质（P. pyrifolia Nakai，P。amygdaliformis村）和一些国内和国际品种作为参考。的共识和特异性引物就业启用24的检测小号-alleles合并于48小号-genotypes。结果揭示了S-等位基因在种质间的分布，野生物种和国际品种的特点是多样性高，本地种质显示S-等位基因的异质性更高，这可能反映了更复杂的杂交历史。在小号-allele分布基本符合研究的收集的遗传结构一致。特别地，“野生”遗传背景常常特征在于相同小号在-alleles检测P. pyrifolia和P. amygdaliformis。S等位基因分布的分析为野生和国际品种对当地西西里人或国家登录的遗传背景的贡献提供了新的见解。此外，这些结果提供了育种者可以容易地用于建立新型交配方案的信息。