Effects of boron-calcium nutrition on suspension-cell of rape cultivars with different boron efficiency

Effects of boron calcium nutrition on B, Ca, Mg concentration together with growth of suspension cell of two rape (Brassica napus L.) cultivars were studied. The results showed that, elevation of boron concentration in culture medium promoted growth of cells, but the effects of changing calcium supply on growth of cells were associated with rape cultivar and boron level. The boron inefficient cultivar Bakow was more sensitive to boron deficiency and more adaptable to higher boron supply than boron efficient cultivar Tezao16. Comparatively higher supply of calcium in culture medium hindered growth of cells,but the optimum level of calcium for cell growth of Tezao16 was higher than Bakow. It implicated that differences between genotypes in response to boron efficiency expressed at cellular level. The difference of necessary amount of boron for plant metabolism proposed to be the main cause which lead to genetic difference of boron efficiency between two rape cultivars. Increasing boron supply in culture medium significantly reduced calcium concentration in cells, while magnesium concentration in cells fluctuated as boron supply increased. There is no pronounced effect of calcium supply on boron concentration in cells. These results implicated a comprehensive relationship among boron, calcium and magnesium in rape cells.