自交不亲和是引起柑橘无核的主要原因之一。已有的研究结果显示，S位点编码的S-RNase和F-box基因在自交不亲和反应中发挥了重要作用。项目申请者课题组已克隆了香水柠檬S-RNase与F-box基因全长，初步探讨了香水柠檬S-RNase基因的不同组织表达模式和授粉后不同时期在柱头上的表达量。本项目在前期研究基础上，进一步开展S-RNase与F-box基因的时空表达模式、蛋白质互作、亚细胞定位和转基因以及S-RNase基因编码蛋白对花粉管的影响等研究，初步探明S-RNase基因和F-box基因在香水柠檬自交不亲和中的作用。项目的实施将从理论上进一步阐释香水柠檬自交不亲和的分子基础，为柠檬及其他柑橘类自交不亲和分子机制的研究提供借鉴。

Seedless citrus can be induced in many ways, self-incompatibility is one of the main ways. It is common received that S-locus genes, S-RNase and F-box, play an important role in self-incompatibility. S-RNase and F-box gene was cloned from 'Xiangshui' lemon. The results of expression analysis showed that S-RNase and F-box was specially expressed in pistils and pollens, respectively. Furthermore, they were up-regulated in self-pollinated stigmas than cross-pollinated ones. In this project, further studies were carried out to identify the function of S-RNase and F-box genes in self-incompatibility of 'Xiangshui' lemon, including expression analysis, subcellular localization, protein interaction, transgene and pollen tube growth with S-RNase protein. The project implementation will provide theoretical basis to clarify the molecular mechanism of self-incompatibility in 'Xiangshui' lemon and other citrus species.