Root growth characteristics of rape cultivars responding to B deficiency

The root growth dynamics of boron?efficient and inefficient rape cultivar were studied under solution culture, soil culture and MS medium culture, respectively. The results showed that the root growth, in particularly the tip elongation, of two rape cultivars was decreased significantly by boron deficiency, but the reduction of the inefficient cultivar was much more than that of the efficient one. Cultured for 5 days in a B?deficient solution, the anatomical structure of root tip of the inefficient cultivar was destroyed seriously, its root cap was disappeared, the root tip was enlarged, and the tip cells disformed and disarranged. The damage of the efficient cultivar by B deficiency was much less, it had a normal root cap, and a slightly enlarged root tip. These suggest that the genotypical difference of rape cultivars to B deficiency was firstly appeared in the root tip formation and enlongation.