Transcriptome Analysis of Abnormal Anther Development in Ponkan (Citrus reticulata)

'Qianyang seedless' (QS) is a widely cultivated Ponkan mandarin cultivar in China, which is a seedless bud sport derived from the seedy Ponkan mandarin. SSR and AFLP analysis suggested that QS shares a very close genetic background with 'Egan NO.1' (EG), a seedy Ponkan mandarin variety. We have previously conducted some exploration into the causes of male sterility (MS) in QS. However, transcriptional changes during the critical stage of anther development with defects are still insufficient, and the process of microspore development that results in unviable pollen remains pending in QS. In this study, we determined the initial stage of abnormal anther development in QS through cytological observations and performed transcriptome sequencing on the anthers of EG and QS at the key stage to identify the essential genes involved in MS of QS.