Accumulation and Influencing Factors of Mn Content in the Roots of Avicennia marina
Manganese is an essential element for plants,but excessive Mn can lead to plant death.In this stud-y,nine sample plots were set up in the Guangxi Beihai mangrove wetland reserve,where Avicennia marina was suspected to have Mn poisoning symptoms.The physiological and biochemical indexes of A.marina root system and soil physical and chemical factors were determined.The effects of various factors on the root Mn content and soil Mn21content of A.marina were analyzed by variance analysis,Pearson correlation analysis and stepwise regression analysis,so as to explore the reasons for the growth weakness of A.marina.The re-sults showed that root Mn content and soil Mn2+content was significantly correlated with various root physi-ological and biochemical indexes and soil physicochemical factors.Multiple stepwise regression analysis showed that root activity,fibrous root fresh weight,soil electrical conductivity,soil water content,and the in-teraction between fibrous root fresh weight,soil electrical conductivity and soil water content had significant effects on root Mn content.The significant effects on soil Mn2+content was withered branch rate,soil sand,silt,tidal level,and the interaction term of soil sand and tidal level.The Mn content of the root system in the study area was 74.60-256.05 mg/kg,which was much lower than that of the well-growing A.marina root system in Shenzhen(700 mg/kg).Therefore,the growth and decline of A.marina in this area was not direct-ly caused by excessive Mn.The cause of A.marina withering needs further study.
万方数据
维普
