Changes in sugar content in shoot cuttings of Gardenia in relation to supplemental lighting during rooting

Terminal cuttings of gardenia (Gardenia jasminoides Ellis) were placed for rooting in a low pressure fog system with or without supplemental lighting (35 W/m(2)). In 0, 5, 10, and 15 days after planting, a basal portion of the cuttings (0.5 cm long) was taken for measuring the reducing, nonreducing and total sugars. Also, in 0, 5, 10, 15, 20 and 25 days after planting, measurements of the percentage of rooting, the number and the length of roots were taken. Reducing, nonreducing and total sugars in the rooting region of gardenia cuttings were increased rapidly in the first 5 days and this increase was higher with the application of supplemental lighting. The reducing sugar content continued to increase until the 10th day of rooting but with lower rate in both light regimes. The nonreducing and total sugars under supplemental lighting were decreased from the 5th to the 15th day of rooting, while under natural light the reduction of the sugar content started from the 10th to the 15th day. The emergence of the adventitious roots on the cuttings was noticed on the 8th and 10th day after planting under supplemental and natural light, respectively. Although, the application of supplemental lighting did not influence the percentage of rooting of gardenia cuttings, however, it affected the number and the length of the roots. Under supplemental lighting the cuttings formed more and longer roots as compared to those under natural light.