%0 Journal Article %T Polyethylene glycol and chilling overcome Somatic embryogenesis obstacle in Pyrus communis %A Ameri, Atefe %A Davarynejad, Gholam Hossein %A Moshtaghi, Nasrin %A Tehranifar, Ali %J Scientia Horticulturae %@ 0304-4238 %D 2018