镉胁迫对不同品种烟草生长发育和镉吸收规律的影响

Effect of Cadmium Stress on the Growth and Cadmium Absorption Rules of Different Tobacco Varieties

【目的】探讨不同品种烟草对镉(Cd)胁迫的响应,深入了解Cd对烟草的毒害作用,为烟草Cd污染防控提供理论依据。【方法】以10个烟草品种为试材,在不同浓度外源镉胁迫条件下,采用盆栽法测定各烟草品种农艺性状、生理生化指标及镉含量。【结果】镉胁迫对部分烟草品种作用为低促高抑,其他品种表现为抑制作用,其中‘中烟100’和‘豫烟10号’对镉胁迫较敏感,在高、低镉胁迫下生物量降幅均较高,‘中烟100’分别为29.98%、29.94%,‘豫烟10号’分别为22.16%、28.39%;随着镉浓度的升高,烟草叶片叶绿素含量、净光合速率Pn、气孔导度Gs、蒸腾速率Tr整体呈现降低趋势,SOD活性、POD活性、MDA含量、游离脯氨酸含量整体呈增加趋势。烟草各器官镉含量随着镉浓度的升高而增加,表现为叶>茎>根,整个生育期中,镉含量呈现先增加后降低的趋势,在旺长期达到最高值,其中‘中烟100’、‘豫烟10号’和‘豫烟13’叶片镉含量显著高于其他品种,在3 mg/kg镉浓度下‘豫烟10号’叶部镉含量最高、为60.27 mg/kg,‘云烟87’和‘K326’的镉含量较低、分别为38.88、39.23 mg/kg;在10 mg/kg镉浓度下‘中烟100’和‘豫烟13’叶片镉含量较高、分别为109.3、101.3 mg/kg,‘云烟105’的叶片镉含量显著低于其他品种、为62.75 mg/kg。烟草的富集能力随着生育期的后移表现为先增加后降低的趋势,在旺长期富集系数达到最大值,3 mg/kg镉浓度下以‘豫烟10号’的富集系数最高、为18.6,‘云烟87’和‘K326’的富集系数较低、分别为12.00、12.11;在10 mg/kg镉浓度下‘中烟100’富集系数最高、为9.89,‘云烟105’富集系数最低、为6.13,‘中烟100’富集系数是‘云烟105’的1.61倍。【结论】‘中烟100’、‘豫烟10号’和‘豫烟13’为敏镉型品种,‘云烟87’、‘云烟105’和‘K326’为耐镉型品种。

【Objective】The research was conducted to explore the response of different varieties of tobacco to cadmium(Cd)stress,deeply understand the toxic effect of cadmium on tobacco,and provide a theoretical basis for the prevention and control of tobacco Cd pollution.【Method】With ten tobacco varieties as test materials,the agricultural properties,physiological and biochemical indexes and cadmium content under different concentrations of exogenous cadmium were analyzed by pot method.【Result】Cadmium stress promoted the growth of some tobacco varieties under low concentration and inhibited their growth under high concentration,while it showed inhibition effect on the rest of varieties.Among the tested varieties,Zhongyan 100 and Yuyan 10 were sensitive to cadmium stress,and the biomass reduction rates of Zhongyan 100 under high and low cadmium stress were 29.98%and 29.94%,and those of Yuyan 10 were 22.16%and 28.39%,respectively.With the increase of cadmium concentrations,the chlorophyll content,Pn,Gs and Tr of tobacco leaves showed a decreasing trend;while SOD activity,POD activity,MDA content and free proline content in tobacco leaves showed an increasing trend.Cadmium contents in all organs of tobacco increased with the increase of cadmium concentration,and the rule showed as:leaf>stem>root.In the whole growth period,cadmium content showed a trend of increasing first and then decreasing,and the highest value was obtained in the prosperous stage.The cadmium contents in leaves of Zhongyan 100,Yuyan 10 and Yuyan 13 were significantly higher than those of other varieties.The cadmium content in leaves of Yuyan 10 was highest(60.27 mg/kg)at a cadmium concentration of 3 mg/kg,while cadmium contents of Yunyan 87 and K326 were 38.88 mg/kg and 39.23 mg/kg,relatively low.At a cadmium concentration of 10 mg/kg,the cadmium contents in leaves of Zhongyan 100 and Yuyan 13 were 109.3 mg/kg and 101.3 mg/kg,relatively high.The cadmium content in leaves of Yunyan 105 was significantly lower(62.75 mg/kg)than that of other varieties.The enrichment capacity of tobacco showed a trend of increasing first and then decreasing after the growth period,and the enrichment coefficient reached the maximum value generally in the prosperous stage.The enrichment coefficient of Yuyan 10 was highest(18.6)at the cadmium concentration of 3 mg/kg,while the enrichment coefficients of Yunyan 87 and K326 were lower with values of 12.00 and 12.11;At the cadmium concentration of 10 mg/kg,the enrichment coefficient of Zhongyan 100 was highest with a value of 9.89,and enrichment coefficient of Yunyan 105 was lowest with a value of 6.13.The enrichment coefficient of Zhongyan 100 was 1.61 times that of Yunyan 105.【Conclusion】The varieties Zhongyan 100,Yuyan 10 and Yuyan 13 are sensitive to cadmium,while the varieties Yunyan 8,Yunyan 105 and K326 are resistant to cadmium.