碘离子(I^-)对辣椒和番茄果实品质及抗氧化酶活性的影响

Effects of iodide(I^-) on Capsicum annuum and tomato fruit quality and their antioxidant enzyme activities

用外源碘改善缺碘生态环境并提高作物碘含量,是人体通过自然补碘消除碘缺乏病(IDD)的有效途径。本文以碘离子(I-)为外源碘,对比了吸收I-前后辣椒(Capsicum annuum)和番茄(Lycopersicon esculentum)果实维生素C、可溶性糖和总酸度的水平,系统观察了辣椒在不同生长期各生化参数随I-浓度的变化,分析了I-影响果类蔬菜品质的生化因素。结果表明,0.5 mg·L^(-1) I-处理的番茄果实品质最佳,此时果实维生素C达218.63 mg·kg^(-1)、可溶性糖含量达7.04 mg·kg^(-1)、总有机酸仅为5.4%;0.5~5.0 mg·L^(-1) I-处理的辣椒可以获得维生素C和可溶性糖含量高、总酸度较低的果实。辣椒吸收适量I-(0.5~2.5mg·L^(-1))后,叶片的叶绿素含量增加,过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)的活性增强,分别为对照组(CK)的1.04~3.15、1.47~3.92、1.69~5.01和1.36~2.11倍;丙二醛(MDA)含量降低,为CK的40.3%~95.8%,辣椒果实品质的提高与作物有利的生理生化条件相关联。

It is an effective approach to supply iodine for human body naturally and eliminate the iodine defi-ciency disorders（IDD） by using exogenous iodine to improve the iodine deficiency environment and enhance the iodine content of crops.In this paper,iodide（I-） was used as the exogenous iodine,then,the contents of vitamin C,soluble sugar and total acidity of Capsicum annuum and tomato（Lycopersicon esculentum） fruits before and after absorbing the exogenous I- were compared.The changes in the values of various biochemical parameters under various iodide concentrations in different growth stages of the C.annuum were systematically surveyed.It was analyzed that how the I- affected the fruit quality through biogeochemical factors.The results show that at the treatment of 0.5 mg·L^-1 I-,the tomato fruit quality achieved the best,amounting to 218.63 mg·kg^-1 vitamin C,7.04 mg·kg^-1 soluble sugar,and 5.4% total acidity only.While,as treated by 0.5–5.0 mg·L^-1I-,C.annuum fruits with high vitamin C and soluble sugar contents and low total acidity can be obtained.Furthermore,absorbing proper amount of I-（0.5–2.5 mg·L^-1） could increase chlorophyll（Chl） content,and enhance catalase（CAT）,peroxidase（POD） and superoxide（SOD） activities of C.annuum leaves,being 1.04–3.1,1.47–3.92,1.69–5.01 and 1.36–2.11 times of the untreated control respectively,while,decrease the malondialdehyde（MDA） content to be only 40.3%–95.8% of the untreated control.The improvement of fruit quality was associated with the optimization of biogeochemical factors.