Effect of salinity on chlorophyll contents, proline accumulation and antioxidant enzyme activities of plantlets in vitro in potato
离体条件下盐胁迫对马铃薯试管苗叶绿素含量,脯氨酸累积和抗氧化酶活性的影响

Responses of plantlets of two potato cultivars to NaCl stress at 0-80 mmol concentration were investigated under in vitro conditions in terms of shoot growth,chlorophyll,proline and malondialdehyde(MDA) contents,and antioxidant enzyme activities.With the increase of NaCl concentrations and the time of exposure ,the shoot length decreased significantly for two cultivars tested.Compared to cultivar Zhihuabai,Jingshi-2,plantlets were more inhibited in terms of shoot,fresh weight,root length and number of roots.After 3 weeks of salt stress,the content of chlorophyll a,chlorophyll b and total chlorophyll,and carotenoid of shoot in plantlets were reduced significantly at higher NaCl concentrations(40-80 mmol).Salinity applied from 20 to 80 mmol progressively increased proline and MDA levels in shoot of both cultivars.The amount and rate of accumulations of MDA and proline were higher in cultivar Jingshi-2 than Zihuabai, suggesting a higher degree of lipid peroxidation in Jingshi-2 due to salt stress,low salinity level(20 mmol) led to a significant increase in superoxide dismutase(SOD) and peroxidase(POD) activities but high concentration made them decreased in both cultivars.Zihuabai exhibited higher activities of SOD and POD in NaCl treated plantlets,and more tolerant to salt stress than Jingshi-2 under in vitro conditions,suggesting its possible utilization in the selection of salinity tolerant genotypes in the field conditions.