镉污染地区番茄品种的筛选及其抗氧化能力

Screening of tomato cultivars in cadmium-polluted areas and study on their antioxidant capacity

为了筛选可供利用的番茄污染安全品种(Pollution-safe cultivar,PSC),减少镉(Cd)污染地区食品安全隐患,通过土培及水培试验研究了南方地区常见不同番茄(Solanum lycopersicum)品种对Cd的积累差异。首先利用土培试验在2.94 mg/kg Cd胁迫下从25个番茄品种中筛选出高低积累品种,并进一步利用水培试验测定高低积累番茄品种对Cd胁迫的响应情况。土培试验结果表明,在2.94 mg/kg Cd胁迫下,25种番茄株高、总生物量以及产量有显著差异,并且25种番茄果实Cd含量均超过国际食品法典委员会(Codex alimentarius commission,CAC)标准的最高限值(0.05mg/kg)。通过聚类分析,筛选到果实中Cd高积累、中积累、低积累类群分别有7个、4个和14个品种,其中果实Cd含量最高为3.06mg/kgDW,最低为1.47 mg/kg DW,平均为2.21 mg/kg DW。水培试验结果显示,在相同浓度Cd胁迫下,与Cd低积累品种浙粉3053相比,Cd高积累品种钱塘旭日F1其吸收Cd的速度更快、Cd积累量更大、产生氧化应激反应时间更短、对Cd的耐受性也更强。筛选出来的典型Cd高低积累品种,为重金属污染区域农业生产以及开发污染安全品种的分子辅助育种提供参考。种植低Cd积累PSC品种,结合番茄果实Cd含量动态监控,是在中轻度Cd污染地区目前较为可行的方法。

To screen the available tomato pollution-safe cultivar varieties and reduce the potential food safety risks in Cd-polluted areas,the differences of Cd accumulation in different tomato(Solanum lycopersicum)varieties in southern China were studied by soil culture and hydroponic experiments.Firstly,the high and low accumulation varieties were selected from 25 tomato varieties under 2.94 mg/kg Cd stress by soil culture test,and then the responses of high and low accumulation tomato varieties to Cd stress were determined by hydroponic experiments.The results of soil culture test show that under 2.94 mg/kg Cd stress,there were significant differences in plant height,total biomass and yield among 25 tomato cultivars,and the Cd contents of fruits of all 25 tomato cultivars exceeded the highest limit value(0.05 mg/kg)of CAC(Codex alimentarius commission).Through cluster analysis,7,4 and 14 varieties accumulating relatively high,medium,and low concentrations of Cd in the fruits were screened,among which the highest,the lowest,and the average Cd contents in the fruits were 3.06 mg/kg DW,1.47 mg/kg DW,and 2.21 mg/kg DW,respectively.The results of hydroponic experiment show that under the same concentration of Cd stress,Qiantangxuri F1,a high Cd accumulating variety,absorbed Cd faster,accumulated more Cd,used shorter oxidative stress response time and had stronger tolerance to Cd than Zhefen 3053,a low Cd accumulating variety.The typical high and low Cd accumulating varieties can provide a reference for agricultural production in heavy metal polluted areas and the development of molecular-assisted breeding methods of PSC.At present,cultivating low Cd accumulating PSC varieties and dynamic monitoring of Cd contents in tomato fruits are feasible methods in medium and light Cd-polluted areas.