Anatomical Studies On The Primary Vascular System Of Seedling Of Ginkgo Biloba L.

Anatomical development of primary vasculature at seedling stage in Ginkgo biloba L.was investigated by series-section and light microscopy techniques. A diarch or triarchsiphonostele with exarch primary xylem was found at lower cotyledonary node zone (CNZ).Subsequently, the primary vascular system extended from lower CNZ acropetally intoepicotyl and cotyledons and basipetally into hypocotyl and root, showing endarch eustele anddiarch or triarch exarch radiostele respectively, to form an entire vascular system.In addition,two-trace and unilacunar cotyledonary node in Ginkgo seedling was observed.It was suggested that the Ginkgo CNZ can be termed" Ginkgo Type" for its uniquefeatures differing from the other five CNZ types advanced by Gu Angen.