NaCl胁迫对黄顶菊生长及生理生化的影响

Effect of NaCl Stress on Growth and Physiological Responses of Flaveria bidentis

为揭示黄顶菊在不同质量分数NaCl胁迫下的生长及生理响应机制,对1 a生盆栽苗进行了不同质量分数NaCl胁迫处理.结果表明：NaCl处理明显抑制了黄顶菊的生长.随着NaCl胁迫时间的延长,相对电导率呈上升趋势,MDA含量呈现先升高后降低再升高的趋势.随着胁迫时间的延长,POD、SOD和CAT3种酶活性均出现先升后降的趋势,6 d时0.4%NaCl处理的活性最高.游离脯氨酸、可溶性糖和可溶性蛋白等3种渗透调节物质也呈先升后降再升的规律.NaCl处理质量分数大于0.4%时,会对植物造成致死性的渗透胁迫.综上所述,当土壤质量分数≥0.4%时不适合黄顶菊生长.

A pot experiment was conducted with 1-year-old Flaveria bidentis to study its NaCl tolerance.The results indicated that NaCl treatment significantly inhibited the growth of Flaveria bidentis.The relative conductivity increased considerably and MDA content increased firstly and then decreased again increased over time.POD,SOD and CAT activities increased in the early days and then decreased with extended NaCl exposure.On the 6th day exposure,the activity was the highest at 0.4% NaCl.Osmoregulation substance such as free proline,soluble sugar and soluble protein had the trend that increased firstly and then decreased again increased over time.NaCl concentration will cause fatal osmotic stress when it is greater than 0.4% for plants.In summary,0.4% and higher soil salinity was not suitable for the growth of Flaveria bidentis.