镉对“华硕”苹果生长和矿质元素含量的影响

以二年生盆栽"华硕"/T337苹果为试材,采用整株解剖的方法,研究了25 mg·kg^-1Cd处理对苹果叶片光合参数和叶片解剖结构、叶绿素含量、各组织生物量和矿质元素含量的影响,以期为果园Cd污染修复提供参考依据。结果表明:Cd处理下苹果叶片净光合速率、气孔导度和蒸腾速率分别比对照降低18.0%、40.0%和31.6%,叶片厚度、上表皮厚度、栅栏组织厚度和海绵组织厚度减少,叶片生长量降低。对照植株各组织均未检测到Cd,Cd处理植株各组织Cd含量由高到低依次为根>砧木茎>二年生枝>一年生枝>当年生枝>叶片>果实。Cd处理降低了植株P、K和Mg含量,以及根系Ca含量。Cd抑制了苹果植株对B、Mn和Zn的吸收,但Cu含量增加。Cd对植株不同组织铁含量的影响不同,表现为二年生枝条Fe含量降低,一年生枝条Fe含量增加。因此,Cd能通过破坏苹果叶片细胞结构抑制光合参数和生长量,还能影响苹果植株对P、K、Mg、B、Mn和Zn的分配。

Effects of Cadmium on Growth and Mineral Element Content in 'Huashuo'Apple

Taking the 2-year-old pot cultured‘Huashuo’/T337 apple trees as experimental materials,the effects of photosynthetic parameters and anatomical structure of leaves,chlorophyll content,biomass and mineral elements in apple tissues under the 25 mg·kg^-1 cadmium treatment by using the method of whole plant dissection,in order to provide theoretical basis for Cd pollution restoration in orchard.The results showed that the net photosynthetic rate,stomatal conductance,and transpiration rate of apple leaves were reduced by 18.0%,40.0%,and 31.6%,respectively,and leaf thickness,upper epidermis thickness,palisade tissue thickness,and spongy tissue thickness were significantly reduced,leaf biomass was inhibited under Cd treatment.No Cd was detected in each tissue of the control plants,and the order of Cd content in each tissue of Cd treatment was root>rootstock stem>biennial branches>annual branches>branches of the year>leaf>fruit.Cd treatment reduced P,K,and Mg contents in plants,and Ca content in roots.Cd inhibited the absorption of B,Mn and Zn by apple plants,but the Cu content increased.Cd had different effects on the Fe content of different tissues of the plant.The Fe content of biennial shoots decreased and the Fe content of annual branches increased.In summary,Cd can inhibit the photosynthetic parameters and growth of apple leaves by destroying the cell structure,and it can also affect the distribution of P,K,Mg,B,Mn and Zn in apple plants.