摘要
【目的】在人工模拟镉污染土壤条件下,讨论了叶面喷施Fe对番茄Cd积累及化学形态的影响,旨在为镉污染土壤上番茄的安全生产提供理论依据。【方法】采用土培试验研究了在重金属Cd（10 mg/kg）污染条件下,叶面喷施不同浓度Fe（0、200和400μmol/L,Fe SO4·7H2O）对2个番茄品种（‘4641’和‘渝粉109’）生长、光合特性、品质及果实Cd形态和Cd积累量的影响。【结果】叶面喷施Fe提高了番茄的根、茎、叶、果实干重及植株总干重,增幅分别为20.4%-48.6%、13.3%-56.0%、16.0%-63.1%、9.8%-16.5%和21.6%-40.3%,随着喷施Fe浓度的增加,番茄各部位干质量及总干质量呈先增加后降低的趋势,比较两个番茄品种,‘4641’耐Cd性更强,而‘渝粉109’对Fe的反应更为敏感;随着喷施Fe浓度的增加,2个番茄品种的叶片净光合速率（Pn）、气孔导度（Gs）和蒸腾速率（Tr）呈先增加后降低趋势,在Fe 200μmol/L时最大,品种‘4641’的Pn、Gs和Tr较对照分别增加了8%、11%和2.9%,而‘渝粉109’较对照分别增加了28.7%、15.5%和18.8%。而喷Fe处理却降低了番茄叶片胞间CO2浓度（Ci）,比较2个供试番茄品种,‘4641’光合作用和蒸腾作用强度均高于‘渝粉109’;喷Fe提高了2种番茄果实的硝酸盐含量以及渝粉‘109’还原糖含量,降低了‘渝粉109’果实氨基酸含量,喷施高浓度Fe（400μmol/L）能提高2种番茄果实Vc含量,与对照相比,‘4641’和‘渝粉109’果实硝酸盐增加的幅度分别为18.1%-22.2%、2.3%-22.0%,Vc较对照分别增加了8.2%和13.2%;番茄果实中Cd的主要存在形态为残渣态,其次为盐酸提取态,去离子水提取态和乙醇提取态所占比例较小,残渣态Cd（FR）和盐酸提取态Cd（FHCl）为活性偏低形态Cd,占Cd提取总量的70.8%,去离子水提取态（FW）和乙醇提取态（FE）为活性较高形态Cd,仅占Cd提取总量的11.8%,有效地抑制了Cd的毒害作用。叶面喷施Fe降低了番茄果实各形态镉含量;番茄中Cd主要积累在叶和茎中,而果实和根的积累量较少;喷Fe降低了番茄叶、根、茎、果实的Cd含量,降低幅度分别为7.1%-21.9%、35.6%-50.4%、13.0%-37.0%和2.8%-8.2%,但喷施高浓度Fe（400μmol/L）相比低Fe（200μmol/L）时的番茄各部位Cd含量有所增加,无论是非否喷施Fe,叶、茎、果实中的Cd积累量以及总Cd积累量总是以‘4641’〉‘渝粉109’,表明在Cd污染土壤上种植‘4641’较‘渝粉109’风险更大。【结论】叶面喷施适量Fe能够促进番茄的光合作用和蒸腾作用,提高了番茄各部位的干重,降低了Cd对番茄的毒害效应,同时减少了番茄各部位Cd含量。
【Objectives】In soils simulated with cadmium（ Cd） pollution,different levels of exogenous Fe were added and their influences on the chemical forms of cadmium（ Cd） and the Cd accumulation in tomato were studied to provide a theoretical base for tomato safe production.【Methods】Pot experiments were carried out to investigate the influence of different iron levels（ 0,200 and 400 μmol / L,Fe SO4·7H2O） on the plant growth,the activities of antioxidant enzymes,the accumulation and chemical forms of cadmium（ Cd） in tomato when exposed to Cd（ 10 mg / kg）. 【Results】The exogenous Fe increased the dry weights of roots,stems,leaves,fruits as well as the total dry matter,which increased by 20. 4%- 48. 6%,13. 3%- 56. 0%,16. 0%- 63. 1%,9. 8%- 16. 5% and 21.6%- 40. 3% respectively. The dry weights of plant parts and whole plant were increased first,and then decreased with increasing of Fe levels. Comparing the two tested tomato cultivars,‘4641 ＇had stronger resistance to Cd,‘Yufen 109＇was more sensitive to Fe. The Pn,Gs and Tr values in tomato leaves of both the cultivars were high with moderate Fe（ 200 μmol / L） application,and low with excess Fe（ 400 μmol / L）; compared to the control,the Pn,Gs and Tr of ‘4641＇were increased by 8%,11% and 2. 9% and these of ‘Yufen 109＇were increased by28. 7%,15. 5% and 18. 8%,while concentration of intercellular carbon dioxide（ Ci） decreased with the application of Fe. Both photosynthesis and transpiration of ‘4641＇were stronger than those of ‘Yufen 109＇. The contents of nitrate in fruits of both the cultivars and sugar in ‘Yufen 109 ＇increased after Fe application,while amino acid in ‘Yufen 109＇decreased compared to the control,and the increase of nitrate 18. 1%- 22. 2% and 2.3%-22. 0%. In addition,high Fe application（ 400 μmol / L） facilitated the biological synthesis of Vc in fruit increased by 8. 2% and 13. 2%. Cadmium was mainly existed in the fractions of residual Cd and hydrochloric acid- extractable Cd in fruits,which were low activity form and accounting for 70. 8% of the total. Deionized water extractable Cd（ FW） and ethanol extractable Cd（ FE） were high activity form with only 11. 8% of the total Cd.Toxic effects of Cd on Tomato were effectively inhibited by spraying Fe. Foliar application of different levels of Fe reduced the concentrations of all Cd forms compared to the control. Cadmium was mostly accumulated in leaves and stems with the concentrations of Cd in the order of leaves toots stem fruits with foliar Fe. Spraying Fe could reduce the concentration of Cd in tomato leaves,roots,stems and fruits with a ranges of 7. 1%-21. 9%,35.6%- 50. 4%,13. 0%- 37. 0% and 2. 8%- 8. 2%,respectively. Cadmium concentrations of all plants parts decreased with foliar Fe application compared to the control,while displayed an upward trend when excessive Fe applied. The Cd accumulation of leaves,stems and fruits and total accumulation of ‘4641＇were higher than those of ‘Yufen 109 ＇. It showed that planting ‘4641 ＇ in Cd contaminated soil had greater risk. 【Conclusions 】Appropriate Fe could promote photosynthesis and transpiration of the tomato leaves and increase the dry weights of each part of the tomato plants. Toxic effects of Cd on tomato plants and the concentration of Cd in each part could be decreased by applying the appropriate concentration of Fe.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2015年第4期1006-1015,共10页
Journal of Plant Nutrition and Fertilizers
基金
现代农业产业技术体系建设专项(Nycy-25)
国家自然科学基金项目(20477032)
国家科技支撑计划项目(2007BAD87B10)资助
关键词
铁镉交互
光合特性
番茄品质
镉累积
镉形态
iron and cadmium interaction
photosynthetic characteristic
tomato quality
Cd accumulation
Cd fraction
