水分状况及硼素营养对油菜苗期根系生长及硼营养效率的影响

采用温室盆栽试验 ,研究了不同土壤水分条件下施硼对油菜苗期根系生长、硼吸收、利用及其移动性的影响。结果表明 ,随土壤含水量、施硼量的下降 ,油菜根长、根体积、根系生长速率、根 /冠比减小 ,根系及地上部干物质积累降低 ,植株地上部硼浓度及含硼量下降。而硼利用效率、硼运移指数则随土壤含水量、施硼量的下降而升高。不同油菜品种的根系形态参数 (包括根长、根体积、根干重、根冠比及根系生长速率 )、硼利用效率及运移指数存在明显差异 ,即在相同条件下 ,V1根系较发达 ,硼利用效率、运移指数均高于V4 。研究认为 ,根系发达程度、硼利用效率及硼移动性大小是不同基因型油菜耐缺硼差异的重要因素。

Effect of B supply on rootgrowth and B nutritional efficiency in oilseed rape at seedling stage as affected by soilmoisture regimes

Pot experiment was conducted in greenhouse to determine theeffects of boron (B) supply on root growth and B uptake, utilization and its mobilization in oilseed rape (Brassica napus L. ) at seedling stage under different soil water contents. The results showed that, with the decrease of soil water content and B application levels, decreases in total root length , root volume, root growth rate and the ratio of root to shoot were observed, both root and shoot dry matter production were inhibited. Fur thermore, B concentration and B content in shoot were decreased. However, B utilization efficiency (BUE) and B mobilization index (BMI) increased as a result of the decreases of soil water content and B application levels. Differences in root morphological parameters (including total root length, root volume, root dry matter ,root to shoot ratio and root growth rate) BUE and BMI in oilseed rape cultivars used in this experiment were obvious, that is ,V1 showed larger root system , higher BUE and BMI than V4 under the same conditions. It is suggested that root morophology, BUE and B mobility in plant were the major factors responsible for the differences in response of different oilseed rape cultivars to B deficiency.