Effect of microwave treatment on the formation of adventitious roots and root vigor from excised cucumber (Cucumis sativus L.) cotyledons

摘要

The stimulating effect of microwave (2450 MHz) on root formation and root vigor of excised cucumber cotyledons is studied in this paper. Excised cucumber cotyledons are subjected to microwave irradiation for 6-16 s at 200 W and 12-32 s at 100 W before culturing to develop adventitious roots. Results show that microwave of 2450 MHz with either 100 W or 200 W significantly stimulated root formation from the excised cotyledon. Comparison of the two power levels indicates that the 200 W irradiation hashigher stimulating effect than the 100 W one on the root formation. Root length and root weight were measured after 7 days of culturing, a 9-60 percent increase in root length, 0-35 percent increase in root weight were observed. TTC assay is used to analyze the dehydrogenase activity in the root. Results showed a 0-113 percent increase in the OD level after microwave treatment. A control experiment by simulating the temperature rise during microwave irradiation is designed to evaluate the heat effect.Results indicate that temperature rise does not significantly affect the root formation, root weight and length, as well as root vigor, suggesting the existence of a special microwave stimulating effect other than temperature rise.