THE MATURE EMBRYO OF GINKGO BILOBA L: IN VITRO CULTURE AND ITS CYTOHISTOLOGICAL STUDIES Cytohistological Studies on the Callus Genesis and Meristematic Nodule Formation of Paeonia×lemoinei ‘Golden era’ Cytohistological Study on Morphogenesis of the Adventitious Bud in the in Vitro Culture of Micro-Cross Sectioned Leaf Midveins from Hybrid Populus Cytological Observation on Culture of Embryo in Vitro of Tripterygium hypoglaucum Cytohistological Study on Somatic Embryogenesis in Asparagus officinalis L.