低温条件下油菜素内酯对黄金香柳生理指标的影响

Effect of Brassinolide on Physiology Indexes of Melaleuca bracteata cv. ‘Revolution Gold'Under Different Low Temperature

以二年生黄金香柳扦插苗为试材,研究了不同浓度油菜素内酯(BR)试剂(CK、0.000 1、0.001、0.01、0.1、1mg·L^(-1))在各低温(5、0、-5、^(-1)0℃)条件下对黄金香柳叶片生理指标的影响。结果表明:随着BR试剂浓度的升高,黄金香柳叶片叶绿素含量、游离脯氨酸含量、可溶性糖含量和超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性均呈现先上升后下降的变化趋势,并显著高于对照(CK);当BR试剂浓度为0.1mg·L^(-1)时达到最大值。丙二醛(MDA)含量呈现先下降后上升的变化趋势,显著低于对照;BR浓度为0.1mg·L^(-1)时达到最低值。POD活性、SOD活性和CAT活性在0~5℃增幅最大。说明油菜素内酯有利于提高黄金香柳在低温条件下的生长能力;0.01~0.10mg·L^(-1)的BR试剂最适合黄金香柳在低温下的生长;当温度在0~5℃时,BR试剂对黄金香柳生长的影响最大。

Using the two-year-old cutting seedlings of Melaleuca bracteata cv.‘Revolution Gold＇as material,effects of different concentration of BR（0（CK）,1,0.1,0.01,0.001,0.000 1mg·L-1）on leaf physiological indexes of Melaleuca bracteatacv.‘Revolution Gold＇at different temperature levels（5,0,-5,-10℃）were studied.The results showed that chlorophyll content,free proline content,soluble sugar content,SOD activity,POD activity,CAT activity firstly increasd and then decreasd with the rising of BR concentration.Also,these indexes were significant higher than CK treatment.These indexes were the highest scores when the concentration of BR was 0.1mg·L-1.Interestingly,MDA content was the contrary change trend,meaning,firstly decreas and then increas.It was the lowest scores when the concentration of BR was 0.1mg·L-1.There were the largest increase of SOD activity,POD activity and CAT activity in the 0-5 ℃interval.It could be summed that BR was conducive to the growth ability of this species.The most suitable concentration of BR for the growth of this species under low temperature was 0.01-0.1mg·L-1.When the temperature was 0-5℃,BR had the highest impact on the growth of this species.