The Effect Of Copper Stress On Cotton Antioxidant Metabolism,Yield And Fiber Quality And Copper Distribution Among Various Parts Of Cotton Plants

Cuprum（Cu）is one of the essential elements for plant growth and development,plants will be stressed by too much copper accumulation.At present,the soil has been increasingly polluted with excessive copper emission,which has caused great harm to crops and launched a powerful impact on human and food safety.This study was divided into two parts.First,Ekangmian 10,A409 and CN01 were applied to a hydroponic culture where seedlings were incubated into Hoagland solution with two copper ion contents（0addition,100μmol/L）.In order to investigate the antioxidant enzymes and antioxidant products changes of cotton seedlings exposed to various Cu stress period,the peroxidase activity,superoxide dismutase activity,catalase activity,malondialdehyde content,soluble protein content of cotton leaves were measured at 3,6,12,24 h after Cu treatment;Secondarily,.Ekangmian 10,A409,CN01 and Lu 301 were employed to a pot experiment where three copper levels（0 mg/kg,200 mg/kg,400 mg/kg）were designed to test the cotton response throughout 2018 to 2019.The effects of Cu stress on cotton biomass yield,economic yield and fiber quality properties have been investigated.In addition,it has also been examined on copper ion accumulation and partition into various parts of cotton plant..The main findings were as follows:1.Compared to the control,the peroxidase activity,superoxide dismutase activity,catalase activity and soluble protein content were elevated significantly in 100μM Cu²⁺treatment.malondialdehyde content in leaves was increased as a result of the enhanced membrane lipid peroxidation occurring in leaf cells.Different genotypes had different response with varying copper stress.In terms of the integrated performance in antioxidation metabolism Ekangmian 10 was more sensitive to copper ion stress compared to A409 and CN01.2.Copper stress at 400 mg/kg level led to decreased fiber length in CN01,and fiber strength in Ekangmian 10,and increased length unity in Lu301 compared to the control and the copper stress at 200 mg/kg level.3.Copper stress inhibited the accumulation of root biomass and had less effect on above-ground biomass.The cotton yield was increased by copper stress of 200mg/kg,but decreased by copper stress of 400 mg/kg.The effect of copper stress on root growth was greater than on above-ground part and yield.4.Copper content of cotton increased with increasing copper concentration.Copper distribution in cotton was different with different copper stress which the distribution with200mg/kg was in order:root>lower stem,leaf>central stem,upper stem>fiber and400mg/kg copper stress in order:lower stem>root>leaf,central stem,upper stem>fiber within,the copper content of fiber least.The translocation and accumulation ability showed the same rule in four genotypes which the translocation factor was greater than 1under different treatment and the overground part had higher copper accumulation,it showed that cotton has better absorption and transport mechanism to copper.Ekangmian10 had higher copper accumulation than other three genotypes.