4个品种香石竹(Dianthus caryophyllus)对Cd胁迫的响应及累积转运特征

Response,accumulation and transport characteristics of four carnation varieties(Dianthus caryophyllus)to cadmium stress

镉(Cd)是引起土壤污染的常见重金属元素,对生态环境和人体健康危害极大.在中轻度污染区栽培观赏性植物,可为重金属污染土壤安全利用提供可能路径.选取4个香石竹(Dianthus caryophyllus)品种马斯特、理想、凯丝和卡林波,采用盆栽试验,设置高(50 mg·kg^(−1))、中(30 mg·kg^(−1))、低(10 mg·kg^(−1))3个质量分数Cd胁迫,以不添加Cd为对照(CK,0 mg·kg^(−1)),探讨4个品种香石竹对Cd胁迫的响应及其累积转运特征.结果表明,马斯特在不同质量比Cd胁迫下生物量几乎不受影响.45 d时,仅马斯特高Cd质量分数处理叶绿素含量相对值(SPAD)降低8.60%,其余品种均能维持正常.随栽培时间延长,各品种可溶性蛋白(SP)逐渐增加,过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性减弱,说明移栽早期植株受重金属Cd胁迫影响,但可通过自身抗氧化酶系统清除多余自由基,逐渐产生抗性.马斯特、理想、凯丝和卡林波地下部富集系数在1.56~12.72、4.63~15.74、3.56~7.98、5.40~8.50范围内,地上部富集系数在0.17~0.73、0.22~1.18、0.10~0.85、0.13~0.63范围内,重金属从地下部向地上部转移能力较弱,故可保护其地上部免受毒害.

Cadmium(Cd)is a common heavy metal pollutant that significantly threatens both the environment and human health.Cultivating ornamental plants in areas with light to moderate contamination may offer a practical approach for the safe use of heavy metal-contaminated soils.This study investigates four cultivars of carnation(Dianthus caryophyllus),namely Master,Lixiang,Kaisi,and Kalinbo,through a pot experiment.The plants were exposed to Cd stress at three concentrations,with high at 50 mg·kg^(−1),medium at 30 mg·kg^(−1),and low at 10 mg·kg^(−1).A control group(CK,0 mg·kg^(−1))received no Cd treatment.The purpose was to examine the response of these carnation cultivars to Cd stress,as well as their accumulation and translocation characteristics.The results showed that the biomass of Master remained almost unaffected by Cd stress at any concentration.After 45 days,only the high-concentration treatment for Master resulted in an 8.60%decrease in chlorophyll content(SPAD),while the other cultivars maintained normal levels.Over time,the soluble protein(SP)content in all cultivars gradually increased,while the activities of catalase(CAT),peroxidase(POD),and superoxide dismutase(SOD)decreased.This suggests that although the plants were initially impacted by Cd stress,they gradually developed resistance by using their antioxidant enzyme systems to remove excess free radicals.The enrichment factors in the roots for Master,Lixiang,Kaisi,and Kalinbo ranged from 1.56 to 12.72,4.63 to 15.74,3.56 to 7.98,and 5.40 to 8.50,respectively.In the shoots,the enrichment factors ranged from 0.17 to 0.73,0.22 to 1.18,0.10 to 0.85,and 0.13 to 0.63,respectively.The limited translocation of heavy metals from roots to shoots helped protect the aboveground parts from toxicity.