Abstract: In the four successive years from 2009 to 2012，to obtain triploid citrus hybrids，eight elite polyembryonic diploid female parents were crossed respectively with five allotetraploid somatic hybrids and one autotetraploid. A total of 4 442 flowers were pollinated in 15 crosses，from which 1 484 fruits were set，with an average fruit setting rate as 33.4%. As much as 12 578 immature seeds from 1 075 young fruits were cultured in vitro. After shooting and rooting induction，2 832 plants were regenerated，in which 401 and 121 plants proved to be triploids and tetraploids respectively by flow cytometry analysis. Up to 349 triploids and 98 tetraploids survived in the greenhouse after transplantation into greenhouse. The Simple sequence repeat（SSR）markers analysis showed that all of the 89 triploids derived from the cross of W. Murcott × NH were hybrids of both parents.

Key words: citrus, triploid, interploid hybridization, ploidy analysis, SSR marker