【摘要】 对两个耐低温性不同的番茄品系幼苗进行了低温下活性氧含量、保护酶活性和膜酯过氧化作用的比较研究。结果表明 :短时间的低温处理 ,活性氧含量下降 ,保护酶活性上升 ;而长时间的低温会导致活性氧含量上升 ,保护酶活性下降。在低温处理过程中 ,MDA含量、细胞膜透性恒定升高 ,而脂氧合酶 (LOX)活性与低温持续时间的长短无明显关系。 (13± 1)℃ /(7± 1)℃的低温处理未造成细胞膜系和LOX等酶系统活性的破坏和急剧下降。低温环境下 ,耐低温品系 97- 6 6能维持高保护酶活性、低活性氧和MDA含量 ;不耐低温品系97- 72则相反更多还原

【Abstract】 Twotomatoinbredlineswithdifferentlowtemperaturetolerancewereusedinthisexperiment. Thetwolinesweretestedforactiveoxygencontent,protectiveenzymeactivityandlipidperoxidationlevel underexposuretolowtemperature( 1 3± 1 )℃ /( 7± 1 )℃ .Theresultsshowedthatthedecreaseinactive oxygencontentandtheincreaseinprotectiveenzymeactivityduringshortperiodlowtemperaturetreat ment;buttheincreaseinactiveoxygencontentandthedecreaseinprotectiveenzymeactivityduringlongpe riodtreatment.MDAcontentandmembranepermeabilitywereincreasedinthewholeprocessoftolerance . Therewasnosignificantrelationshipbetweentimeoflowtemperaturetreatmentandlipoxidaseactivity . Suchlowtemperatureconditiondidnotdamagethemembranesystemandlipoxidase.Lowtemperature tolerantline 97- 66couldmaintainhigherprotectiveenzymeactivity ,loweractiveoxygencontentandlow erMDAcontentthatlowtemperaturesensitiveline 97- 72 .更多还原