供磷水平对一串红橙香公主生长及根系发育的影响

以典型园林植物一串红橙香公主为供试材料,研究不同磷营养液施用量对植株生长和根系形态的影响,营养液供磷水平依次为0(P₀)、15(P₁) 、30(P₂)、60(P₃)、90(P₄)、120(P₅) mg·L^-1。结果表明,供磷水平在0~120 mg·L^-1范围内,株高、冠幅、地径、叶面积、地上部分干物质质量、地下部分干物质质量、根体积和根平均直径随着磷浓度增加呈现出先升高后降低趋势,均在P₂处理达到最大值。叶绿素a和叶绿素总量均在P₁处理达到最大值,P₁处理叶绿素含量与其他各处理差异显著(P<0.05)。根长随着供磷浓度增加而增加,P₅处理达到最大值。P₀处理生长指标、叶绿素含量和根系各指标均最小,且发育延迟。综上说明供磷水平过低或者过高均不利于植株生长,在15~30 mg·L^-1橙香公主观赏效果最佳,是最适合磷浓度范围。

Effects of phosphorus fertilizing on growth and root morphology of Salvia splendens var. Chengxiang Gongzhu

Salvia splendens var. Chengxiang Gongzhu was supposed as typical garden plant, different phosphorus nutrition solution levels were employed to study their effects on the growth and root morphology of the plants. Six phosphorus concentration levels of 0, 15, 30, 60, 90 and 120 mg·L^-1(named as P₀, P₁, P₂, P₃, P₄, P₅) were applied respectively. The results showed that with the increase of phosphorus application, plant height, crown diameter, ground diameter, leaf area, shoot and root dry weight, total root volume, and root average diameter firstly significantly increased and then dropped, which all reached a maximum in P₂ treatment. Chlorophyll a content and total chlorophyll content reached the highest in P₁ treatment, and showed significant difference compared with other treatments (P<0.05). As the concentration of P increased, total root length reached the maximum in P₅ treatment. The growth index, chlorophyll content and root characteristics in P₀ treatment were all the smallest, indicating the developmental delay. Based on this study, P concentration between 15-30 mg·L^-1 would be most suitable for the Salvia splendens var. Chengxiang Gongzhu.