Development of the root system inSpirodela polyrhiza (L.) schleiden (Lemnaceae)

摘要: The root structure in members of the Lemnaceae is important to plant researchers, because changes during cell differentiation can more easily be monitored short roots with determinate growth. Here, structural organization and cellular system was assessed highly reducedSpirodela polyrhiza. While protected by a prophyllous sheath, rapid division occurred apical vascular regions immature roots. Concentric rings endodermis Casparian strips, cortex, epidermis enclosed single strand. cytoplasmic density cortex high at apex, but decreased progressively along root. cap junction, closely attached initiation, later became distinct boundary layer filled fibrillar materials. Chloroplasts were well distributed. Numerous plasmodesmata indicated likely symplastic movement ions metabolites as further into reduced body. A apex extreme vacuolization provided possible explanations for considerable distribution weight These conditions probably enable tip serve pendulum against water motion.