不同外源硒对番茄的硒生物强化效果

Selenium biofortification effect of different exogenous selenium on tomatoes

【目的】比较土壤中施用不同量硒肥(亚硒酸盐和硒酸盐)对番茄生物量、不同部位硒含量及果实品质的影响,为生产优质的富硒番茄和开发其他富硒蔬菜品种提供参考。【方法】供试番茄品种为金美丽娜,采用盆栽试验,通过在土壤中拌施0.5,1,2和5 mg/kg亚硒酸钠和硒酸钠溶液对番茄进行硒生物强化,以不施用硒肥处理作为对照,测定不同处理成熟番茄的果实生物量、不同部位(果实、茎下部、茎上部、叶下部、叶上部和根)硒含量,以及果实品质参数(有机酸、可溶性糖组成及其含量,维生素C含量等),比较2种硒肥对番茄的硒生物强化效果。【结果】与对照相比,土壤中施用2种外源硒均增加了番茄果实生物量。与对照相比,0.5~5 mg/kg外源硒均显著增加了番茄果实的硒含量(P<0.05),且当土壤中施用硒肥量相同时,硒酸钠处理番茄果实的硒含量极显著高于亚硒酸钠处理(P<0.01)。各施硒处理番茄茎下部、茎上部、叶下部、叶上部和根中硒含量均显著高于对照(P<0.05),且这5个部位的硒含量均随外源施硒量的增加而显著增高(P<0.05)。外源施用硒肥番茄果实中有机酸的组成(草酸、酒石酸、苹果酸、柠檬酸、琥珀酸)几乎没有变化,各处理番茄果实均以苹果酸和柠檬酸为主,但各有机酸组分含量变化较大。与对照相比,外源施0.5~2 mg/kg硒均可显著提高番茄果实中的果糖和葡萄糖含量。与对照相比,土壤中施用0.5~2 mg/kg亚硒酸钠和硒酸钠后,番茄果实总有机酸、总可溶性糖、维生素C含量及糖酸比均显著升高(P<0.05)。【结论】土壤中施入0.5~2 mg/kg硒酸钠既可确保硒富集效果,又能提高果实品质。基于人体健康的考虑,推荐以在土壤中施用0.5 mg/kg硒酸钠的方式进行番茄的硒生物强化。

【Objective】The effects of applying different selenium(Se)fertilizers(selenite and selenate)in soil on tomato biomass,Se content in different parts and fruit quality were compared to provide reference for producing high-quality Se-enriched tomatoes and developing other Se-enriched vegetable varieties.【Method】The cultivar of Jinmeilina was selected for pot experiments with 0.5,1,2 and 5 mg/kg Se(sodium selenite and sodium selenate)in soil,using no fertilizer treatment as the control.The fruit biomass,Se contents in different parts(fruit,stem lower part,stem upper part,leaf lower part,leaf upper part and root)and fruit quality(composition and contents of organic acids and soluble sugars and vitamin C content)of different treatments were measured and Se biofortication effects were compared.【Result】The application of two exogenous Se fertilizers in soil increased the biomass of tomatoes.Compared with the control,0.5-5 mg/kg exogenous Se significantly increased Se content of tomatoes(P<0.05),and selenate treatment was significantly better than selenite treatment(P<0.01).Se contents in the stem lower part,stem upper part,leaf lower part,leaf upper part and root in each treatment were significantly higher than that of the control(P<0.05),and they increased significantly with the increase of Se content(P<0.05).Exogenous application of Se fertilizers had less effect on the composition of organic acids(oxalic acid,tartaric acid,malic acid,citric acid and succinic acid)in tomatoes,malic acid and citric acid were the main organic acids in tomatoes in each treatment,but it changed their contents.Compared with the control,exogenous 0.5-2 mg/kg Se significantly increased contents of fructose and glucose in tomatoes.After applying 0.5-2 mg/kg selenite and selenate in soil,total organic acid,total soluble sugar,vitamin C content and sugar-acid ratio of tomatoes were significantly increased(P<0.05).【Conclusion】Soil application of 0.5-2 mg/kg selenate ensured the accumulation of Se and improved fruit quality of tomatoes.Considering human health,0.5 mg/kg selenate was suggested for Se biofortification of tomatoes.