磷胁迫对樟幼苗根系形态的影响

The Effects of Phosphate Deficiency on Root Development of Cinnamomum camphora(Linn)Presl.Seedlings

磷是植物生长发育所必需的大量营养元素之一,但其土壤中的有效性非常低,因而植物总是处于磷胁迫状态下。磷酸盐缺乏处理导致樟幼苗的总根长度比对照显著增加。根的总表面积和总体积也均随磷酸盐处理浓度的增加而增加。在磷酸盐浓度为2.5～10.0μmol范围内,幼苗根尖数量随磷酸盐浓度的增加而增加,而后则逐渐下降。根系各个连接的平均直径在2.5～20.0μmol范围内逐渐增加,在20.0μmol时达到最大,并与其它磷酸盐缺乏处理(2.5～10.0μmol)之间存在显著差异。根系分叉数量的变化与根尖数量的变化趋势相同,且差异性也相同。总体上,根生物量呈现随磷酸盐供给水平的增加而增加,而地上部分的生物量则在磷酸盐缺乏处理(2.5～10.0μmol)时逐渐增大,而后下降。结果表明:磷缺乏对樟幼苗根系的发育产生很大的影响。

Phosphorus is one of needed macronutrients by plants,but phosphate availability in soil solution is very low all over the world,therefore plants are always under phosphate deficiency.Phosphate deficiency induced significant increase in total root length compared with control.Total surface area and total root volume of a whole root system increased as the phosphate concentrations increased.When phosphate concentrations varied from 2.5 to 10.0 μmol,the number of root tips in a root system increased.When phosphate concentrations were more than 10.0 μmol,the number of root tips decreased.The average diameter of the links in a root system increased in the range from 2.5 to 20.0 μmol of phosphate,reaching the peak at 20.0 μmol.The changes in the numbers of forks were the same as the root tips.In general,root biomass increased as the increase in phosphate concentrations,but shoot biomass increased when phosphate concentrations increased from 2.5 to 10.0 μmol.When phosphate concentrations were more than 10.0 μmol,shoot biomass decreased.The results showed that phosphate deficiency had greatly affects root development of Cinnamomum camphora seedlings.