Changes in Leaf Composition in Parthenocissus tricuspidata Planch. During Growth and Senescence of Short Shoots

During expansion of the pre-formed leaves the content of sodium,potassium, chlorophyll and anthocyanin increased for a time,fell, then increased again at the end of the period of leafgrowth. The final increase in anthocyanin content was relatedto the formation of a red margin around the leaves, which wasaccompanied by a loss of chlorophyll in the margin tissue. Thiswas not related to the fall in total leaf chlorophyll whichoccurred earlier. The temporary loss of sodium and potassium from the leaves wascorrelated with the development of axillary inflorescences andan increased rate of shoot growth. Subsequent recovery of leafsodium and potassium took place as the shoots senesced. Shootsfrom the centre of the vine grew slowly and died back to thesecond node, forming spur shoots, whereas at the vine margin,shoots grew more rapidly and died back less.