铁营养对水培芥菜和生菜生长及根系一些酶类特性的影响

本研究通过调节水培营养液中铁深度分别为０，２．８，５．６，８．４，１１．２和１４．０ｍｇＦｅ／Ｌ的６个水平种植生菜和芥菜，比较这两种蔬菜在不同的铁浓度下生长及其对植物铁含量以及根系过氧化氢酶和过氧化物酶活性的影响。结果表明，生菜和芥菜分别在２．８和５．６ｍｇＦｅ／Ｌ时产量最高。在此最适水平以下，随铁深度的增高，产量随铁浓度的增高，产量随着提高；但铁深度超过辽个水平，生菜表现出毒症状，产量降低，芥菜

THE EFFECTS OF Fe ON THE GROWTH AND THE ACTlVITIES OF SOME ENZYMES IN THE ROOTS OF LETTUCE AND MUSTARD IN HYDROPONIC CULTURE

This study reported the effects of Fe in the nutrient solutions with various levels,0,2.8,5.6,8.4,11.2 and 14.4 mgFe/L on the growth,yield,Fe content in plants andthe activities of catalase and peroxidase in the roots of lettuce and mustard ina hydroponic system. The results showed that the yields of the two crops werethe highest when Fe concentration were 2.8 and 5.6 mgFe/L,respectively.The yieldsof both crops decreased if Fe increased further.Moreover,when the Fe levelswere above 2.8 and 5.6 mgFe/L for lettuce and mustard,respectively,lettuceshowed severe Fe toxic symtoms,but mustard only showed reduce yield.Belowthe optimum Fe level,the vegetable(mustard) with higher Fe content in the shootthan in the root was sensitive to Fe deficiency,but could tolerate Fe toxicity.The vegetable(lettuce)with higher Fe content in the root than in the shoot wassensitive to Fe toxicity but unlikely to show Fe deficient symtoms. Under the sameFe level at which plants did not show severe Fe toxic symptom,the vegetable(mustard)with higher activities o f peroxidase and catalase in the root seemed toshow poor tolerence to low Fe, but could tolerate high Fe. Lettuce with loweractivities of both two enzymes in the root could tolerence to low Fe and likelyshow Fe toxic symptoms. The activities of the two enzymes,however,did notdecrease with Fe toxicity.