Photosynthetic rates of Ilex crenata thunb. 'helleri' during propagation

Abstract

A series of experiments was conducted to determine the effect of light, auxin, carbohydrate levels, mineral nutrients and rooting on the net photosynthetic (Pn) rate of unrooted Ilex crenata Thunb. 'Helleri' cuttings. Optimal photosynthetic activity occurred at PAR levels of about 600 micro-Einsteins m⁻² sec⁻¹. The emergence of roots increased the Pn rate. High plant carbohydrate levels were correlated to lower Pn rates while higher Pn rates were correlated to lower CHO levels. These relationships may be indicative of source-sink interactions on the Pn rate of Helleri holly cuttings. An exogenous basal application of indolebutyric acid (IBA) contributed to an increase in cutting Pn, as was the case with the addition of mineral nutrients.