Induction and cultivation of haploid callus of Loropetalum chinense var. rubrum : Induction and cultivation of haploid callus of Loropetalum chinense var. rubrum

For obtaining the complete genome sequence of Loropetalum chinense var.rubrum,haploid callus was induced and cultivated based on previous data of meiosis and microspore development of Loropetalum chinense var.rubrum 'xiyemeihong'.The outer characteristics of the flower bud corresponding to specific development stages were primarily determined and monocaryotic phase of 'xiyemeihong' was selected for induction of haploid callus.SNGM medium supplemented with 2.5 mg/L NAA,0.5 mg/L 6–Benzyladenine and sucrose concentration 30 g/L turned out to be the optimum callus-induction medium.And B5 medium with supplements the same to the induction medium was the optimum medium for semi-solid-state cultivation of pollen callus and for liquid cultivation of anther callus under the rotation speed of 110 r/min and the temperature of 25 ℃.Flow cytometry showed that the absorption peak of the pollen callus was about half of that of the leave callus(the control).Chromosome counting indicated haploids of pollen callus possessed 12 chromosomes while diploids 24 and haploids were detected in 63.1% of pollen callus cells.