Strawberry (Fragaria spp.) is a member of the Rosoideae subfamily in the family Rosaceae. The self-incompatibility (SI) of some diploid species is a key agronomic trait that acts as a basic pollination barrier; however, the genetic mechanism underlying SI control in strawberry remains unclear. Two candidate S-RNases (Sa- and Sb-RNase) identified in the transcriptome of the styles of the self-incompatible Fragaria viridis 42 were confirmed to be SI determinants at the S locus following genotype identification and intraspecific hybridization using selfing progenies. Whole-genome collinearity and RNase T2 family analysis revealed that only an S locus exists in Fragaria; however, none of the compatible species contained S-RNase. Although the results of interspecific hybridization experiments showed that F. viridis (SI) styles could accept pollen from F. mandshurica (self-compatible), the reciprocal cross was incompatible. Sa and Sb-RNase contain large introns, and their noncoding sequences (promotors and introns) can be transcribed into long noncoding RNAs (lncRNAs). Overall, the genus Fragaria exhibits S-RNase-based gametophytic SI, and S-RNase loss occurs at the S locus of compatible germplasms. In addition, a type of SI-independent unilateral incompatibility exists between compatible and incompatible Fragaria species. Furthermore, the large introns and neighboring lncRNAs in S-RNase in Fragaria could offer clues about S-RNase expression strategies.

中文翻译：

---

S-RNase等位基因的分子特征作为绿色草莓自交不亲和的决定因素

草莓 （草莓spp.) 是蔷薇科蔷薇亚科的成员。一些二倍体物种的自交不亲和性（SI）是作为基本授粉屏障的关键农艺性状；然而，草莓SI控制的遗传机制仍不清楚。两名候选人S-RNase小号 (小号一种- 和小号b-RNase）在转录组中鉴定出自不相容的风格绿色草莓在基因型鉴定和使用自交后代的种内杂交后，42 个被证实是 S 基因座的 SI 决定簇。全基因组共线性和 RNase T2 家族分析表明，只有小号位点存在于草莓; 然而，没有一个相容的物种包含S-RNase. 虽然种间杂交实验的结果表明，F. viridis(SI) 样式可以接受来自的花粉F. mandshurica（自相容），互易交叉是不相容的。小号一种和小号b-RNase含有大的内含子，它们的非编码序列（启动子和内含子）可以转录成长的非编码RNA（lncRNA）。总的来说，该属草莓展品小号-基于RNase的配子体SI，和S-RNase损失发生在小号相容种质的位点。此外，兼容和不兼容之间存在一种与SI无关的单边不兼容。草莓物种。此外，大内含子和相邻的 lncRNAS-RNase在草莓可以提供关于S-RNase表达策略。