锰对板栗实生苗生长及生理效应的影响

采用短期培养模拟研究法，在5个Mn2+浓度（0、 0.905、 1.810、 2.715、 3.620 mg/L）处理下，通过测定板栗实生苗木的光合特性、 叶绿素含量、 苗高、 根颚直径、 根系、 生物量与叶片矿质元素等指标，研究了Mn 2+对其生长及生理效应的影响。结果表明， 1）在Mn 2+浓度为0~3.620 mg/L范围内，随Mn2+浓度增大，板栗实生苗净光合速率、 气孔导度、 蒸腾速率、 叶绿素含量、 苗高、 根颚直径、 根重和生物量呈先增加后降低的趋势，其中以Mn 2+浓度1.810和2.715 mg/L处理的效果最好，且两处理间差异不显著（P0.05）; 2）与CK相比，Mn2+增加了苗木对锰的吸收，但抑制了对钙、 铁、 铜的吸收，随Mn2+浓度增大，叶片磷、 硼含量呈先升高后降低趋势，钾含量变化趋势相反; 3）相关分析显示，叶片锰含量与钙、 铁、 铜含量呈显著性负相关（P0.05），与磷、 钾、 硼含量的相关性均不显著（P0.05）。综上，当Mn2+浓度为1.810和2.715 mg/L时均能显著促进板栗苗木的光合及生长; 但Mn2+浓度不宜过高，大于2.715 mg/L则抑制其生长，不利于矿质元素的均衡吸收。

Influence of manganese on growth, physiological effects of chestnut seedlings

 A short term cultivation simulation experiment was carried out to investigate the influence of manganese on growth, physiological effects of chestnut seedlings. The responses of photosynthetic characteristics, chlorophyll content, seedling height, diameter, root, biomass and contents of mineral elements in leaves to different Mn2+ concentrations (0, 0.905, 1.810, 2.715 and 3.620 mg/L) were studied. The results show that in the range of Mn²⁺ 0-2.715 mg/L, the Pn, Gs, Tr, chlorophyll content, seedling height, diameter, root weight and biomass of chestnut seedlings are enhanced significantly (P<0.05) with the increase of the concentration, however when Mn2+ concentration is over 2.715 mg/L, the above indexes are decreased. That is to say, 1.810 and 2.715 mg/L are the most effective treatments with no significant difference between the two treatments (P>0.05). Compared with CK, the Mn²⁺ manganese absorptions are increased under different Mn2+ concentrations, while the absorptions of calcium, iron and copper are restrained. With the increase of the Mn²⁺ concentration, the contents of phosphorus and boron are increased first and then decreased, while the potassium contents are in the opposite variation tendency. The results of correlation analysis show that there are significant negative correlations (P<0.05) between the contents of manganese, and the contents of calcium, iron and copper. A positive correlation between manganese and boron contents, and negative correlations between manganese and phosphorus, potassium contents are also found in the experiment, but not significant (P>0.05). In conclusion, the treatments of 1.810 and 2.715 Mn²⁺ mg/L could promote photosynthesis and growth, and it is unfavorable for the plant growth and for the balanced absorptions of mineral elements when the Mn²⁺ concentration is higher than 2.715 mg/L.