Development of sex-linked markers for gender identification of Actinidia arguta

The fruit of the dioecious plant Actinidia arguta has become a great attraction recently. It has long been difficult to distinguish the genders of hybrid seedlings before flowering, therefore increasing the expenditures of breeding. To produce reliable molecular marker for gender identification, this research utilized whole-genome re-sequencing of 15 males and 15 females from an 8-year-old cross population to develop gender specific markers. P51 and P11 were identified as sex-linked markers after verification. Both of these markers, according to the PCR results, only amplified a single band in male samples. These two markers were tested in 97 hybrids (52 females and 45 males) and 31 wild individuals (13 females and 18 males), with an accuracy of 96.88% and 96.09%, correspondingly. This research also verified the universalities of the two markers in Actinidia chinensis samples, and it could be inferred from the PCR results that neither marker was applicable to A. chinensis samples. The BLAST results of the two markers demonstrated that the two markers were closely aligned with different parts of the Y male-specific region of A. chinensis genome, thus they were likely to be useful for the research on the mechanism of sex determination of A. arguta. The two male-linked makers, P51 and P11, have already been used in sex-identification of A. arguta seedlings.