抄録
We studied the role of adventitious roots in supplying water to Ipomoea pes-caprae growing on sand dunes at Yagaji, Okinawa, Japan. For this purpose, all of the adventitious roots were dug up and the diurnal changes in stomatal conductance (at 7:00, 12:00 and 17:00) and leaf water potential (at predawn and 12:00) were measured at various distances from the taproot in January and June. Digging up roots had significant influences on stomatal conductance (at 7:00 in January and at 17:00 in June) and water potential (except for predawn water potential in January), though no significant differences could be detected in stomatal conductance and water potential between the control and treated plants in other measurements. Moreover, a close linear relationship between water potential and distance from the taproot could not be detected. These results suggest that the adventitious roots are not so useful for supplying water to the mother plant and the demand of water in leaves attached at every position on the vine was supplied from the taproot.
