Mineral Absorption and Oxygen Consumption in Grafted and Non-grafted Cucumbers

Mineral absorption and oxygen consumption were investigated in comparison of own-root cucumber (Cucumis sativus L. cv. Tokiwa-hikari No. 3) and grafted cucumber on figleaf gourd (Cucurbita ficifolia Bouche).Mineral concentrations in the nutrient solution at the end of culturing experiments under a vinyl-coverd greenhouse in winter were expressed in percent of those in the solution without plants. NO3-N, P, Ca and Mg concentrations evaluated as the contents of mineral absorbed per unit volume of water absorbed were higher in grafted plants than own-root plants, but with K the reverse was the case. These results coincided with the previous report on xylem sap analysis. In the present experiments, no differences between grafted plants and own-root plants were found in water uptake per unit top weight.Such tendency of mineral absorption as mentioned above was also found except for K at 10°C, 16°C and 20°C in growth chamber. In particular, the P absorbed per unit volume of water absorbed by own-root cucumber plants decreased remarkably at 10°C.The quantity of O2 consumption in roots excised from grafted plants and own-root plants was almost the same at 16°C and 24°C, but it was 1.5 times higher at 12°C in grafted plants than own-root plants. A similar result was also obtained in comparison of roots of young figleaf gourd and young cucumber plants.