Effects of Boron Nutrition on ^45Ca Retranslocation and Distribution in Rape(Brassica napus L.)Cultivars

摘要

Using tracer techniques with the radioisotope 45Ca, the effects of boron supply from soil andnutrient solution on the retranslocation of 45 Ca from leaves to other parts of rape plants were studied. Resultsindicated that only a small portion of foliar-applied 45Ca could be retranslocated to other parts of the rapeplant. There was no pronounced effect of boron level in the soil on 45 Ca retranslocation. Increasing boron con-centrations in the nutrient solution significantly reduced 45 Ca radioactivity in root and stem, but increased 45 Cauptake and 45 Ca translocation to the upper leaves of rape plants. It was suggested that 45 Ca absorbed by newlydeveloped roots was easily distributed to upper leaves of rape plants. Boron may alter distribution of calciumvia its effect on root development or growth of newly developed roots.