硫脲对花生苗期的毒理效应研究

通过盆栽试验，研究了硝化抑制剂硫脲对花生的生物量、叶片金属离子含量、叶绿素含量、超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性和丙二醛（MDA）含量的影响。结果表明，在低浓度硫脲范围内，其对花生的生长有明显的促进作用，叶片叶绿素含量较高，3种酶的活性随硫脲浓度的增加而升高，体内MDA含量随硫脲浓度的增加而降低；但当硫脲浓度达到5．0mmol·kg^-1。土时，对植株和根系的生长产生了明显的抑制作用，叶片叶绿素含量明显降低，3种酶的活性明显降低，体内MDA的含量显著增加，表明此时硫脲对花生产生了明显的胁迫和毒害作用。

Phytotoxicity by Thiourea Application in the Seedling of Peanuts

The effects of thiourea on the biomass, content of metal ions and chlorophyll level were studied in the leaves of peanut. Effects of thiourea on anti-oxidative system（SOD, POD, and CAT ）and content of MDA in the leaves of peanuts were also investigated. Results showed that thiourea had great impact on the growth of peanuts; it could stimulate the growth of seedlings when the concentration less than 2.5 mmol·kg^-1 soil, under this level, the content of chlorophyll in peanuts maintained at a similar level, while the activities of SOD, POD, CAT increased with the increasing concentration of thiourea and the content of MDA decreased. However, when thiourea concentration was up to 5.0 mmol·kg^-1soil, the phytotoxic symptom was found. The growth of seedlings was inhibited and the content of chlorophyll in peanuts decreased to 1.11 mg·kg^-1FW compared to control. Simultaneously, the activities of SOD, POD, CAT and the content of MDA increased dramatically, which indicated that when thiourea arrived 5.0 mmol·kg^-1soil it could induce environmental stress in the seedlings.