不同磷水平对向日葵幼苗根系生长及保护酶活性的影响

Effects of different levels of phosphorus on sunflower seedling root growth and protective enzyme activity

以产量高,且抗性强的‘WWW-178’和‘诚牌223’食用型向日葵品种为材料,利用盆栽试验,用Hoagland’s基本营养液(CK)和60%磷浓度的Hoagland’s基本营养液处理,研究了低磷胁迫对向日葵根系生长状况和保护性酶活性的影响.结果表明:根长变化最为显著(P<0.05),随胁迫时间的延长2个品种根长度均低于对照,而幼苗的地下干质量和根冠比与对照相比达到差异显著水平(P<0.05).不同磷水平下,‘WWW-178’幼苗叶片的超氧化歧化酶(SOD)活性和过氧化氢酶(CAT)活性无显著性变化,过氧化物酶(POD)活性提高,与对照相比差异显著(P<0.05);‘诚牌223’幼苗叶片在低磷胁迫40d后SOD和CAT活性显著降低,POD活性显著提高.敏感型品种的酶活性在胁迫下会有所下降,所以在60%的磷水平环境下,‘WWW-178’向日葵品种较‘诚牌223’向日葵品种具有较强的抗低磷胁迫能力,因此在低磷土壤中更适合种‘WWW-178’向日葵品种种植.

This experiment employed high yield and strong resistance variety ＇WWW-178＇ and edible variety Chengpai 233 sunflowers as materials and studied the influences of low phosphorus stress on sun- flower root growth and activities of protective enzymes. All test sunflowers were grown in pots by using Hoagland basic nutrient solution as control and 60% phosphorus concentration Hoagland solution as treat-ment. The results showed that root length was more sensitive to phosphorus concentration. The root length of two varieties was significantly lower than control during treatment time continued, but the dry weight of foot end and root-shoot ratio were significantly higher than control. The activities of superoxide dismutase （SOD） and catalase （CAT） of ＇WWW-178＇ seedling leaves had no significantly change under different concentration phosphorus,while the activity of peroxidase （POD） significantly increased. The activities of SOD and CAT obviously decreased in ＇Chengpai 223＇ seedling leaves under low phosphorus stress after 40 days, but the activity of POD increased. The enzymes activity of sensitive variety decreased under low phos- phorus stress, ＇WWW-178 ＇ has stronger resistance than ＇ Chengpai 223 ＇ under 60% ph0sphorust. It is suggested that ~WWW-178 ＇ sunflower is suitable cultivated in acid soils with low phosphorus content.