14C-sucrose transport to young leaves, root tips and nodules in control and treated plants of the two lines occurred even after 1h of its application on fully expanded source leaves. Generally, no differ- ences between sink organs or treatments were observed (Figure 1). Interestingly, in the absence of salt, specific radioactivity in nodules increased significantly and reached a maximum after 3h and then declined after 24h; this was not the case for young leaves and root tips, in which specific radio- activity remained unchanged and increased only after 24 h. The two lines displayed the same trend.
The increase in specific radioactivity observed in control nodules was not recorded in treated nodules. In fact, no change in specific radioactivity was observed even after 24h of 14C-sucrose application on fully expanded source leaves in TNC 1.8; it increased slightly in TNC 11.9 but remained sig- nificantly lower than that in control nodules. Under stress conditions, young leaves and root tips had the same specific radioactivity as in control plants. It increased only after 24 h, but values were inferior to control values in root tips of the two lines and young leaves of TNC 11.9. The specific radioactivity in young leaves of TNC 1.8 was not affected by salt.