Induction of somatic embryogenesis by anther-derived callus culture and plantlet ploidy determination in poplar (Populus × beijingensis)

In vitro regeneration through somatic embryogenesis using anther-derived callus from poplar (P. × beijingensis) has been reported. Calli induced from anther connective tissue were used to create suspension cell. Embryogenic cells were enriched by sieving and centrifugation, then embryogenic cells were shaking cultured in liquid medium lacking NH4 + to incubate round callus (RC). Thick slices of RC induced somatic embryo (SE) when incubated in solid Murashige and Skoog medium supplemented with either N-(2-chloro-4-pyridyl)-N-phenylurea or 6-benzyladenine, both supplemented with 1-naphthaleneacetic acid. Plantlets germinated from SE in the treatment that had induced SE. Loose calluses (LC) cultured on solid medium also contained few SEs. Histological studies revealed various stages of SE development. Ploidy levels of regenerated plantlets were analyzed using flow cytometry and chromosome counting, the result showed 452 diploids and 102 tetraploids from 554 RC-derived plantlets, while all of the 107 LC-derived plantlets were diploid. No chimera was observed among plantlets. These results suggested that SEs originated from a single cell.