274 Effects of Supplemental Calcium on Plant Growth, Ion Accumulation in Roots and Transports to Shoots of Brassica rapa L.
The effects of supplemental Ca on salinity tolerance were tested using a Brassica rapa L. landrace, `Sani', which is salt-sensitive. Plants were grown in a continuous aerated hydroponic system with 0.25-strength Hoagland solutions containing 125 mM NaCl plus 0, 2.5, 5.0 or 10 mM CaCl 2. The effects of Ca treatment were significant in reducing Na accumulation in roots, Na+ transport from roots to shoots and in enhancing K and Ca accumulation and transport. The Ca addition also enhanced the selectivities of both K and Ca over Na of accumulation at roots and of transport to shoots. However, supplemental Ca did not alleviate the growth reduction caused by the NaCl salinity. These results suggest that the growth inhibition of salt-treated B. rapa `Sani' is mainly caused by factors other than Na, K, and Ca contents in plants.