萘乙酸对干旱胁迫下毛白杨幼苗生长及光合能力的影响

Effects of spraying naphthylacetic acid on the growth and photosynthetic ability of Populus tomentosa seedlings under drought stress

该文探索了植物生长调节剂萘乙酸对干旱胁迫下毛白杨苗木光合生理特性的影响。试验以1a生毛白杨扦插苗为试材,设置无干旱胁迫对照(S1)、干旱胁迫对照(S2)、干旱+20mg/L萘乙酸(S3)、干旱+50mg/L萘乙酸(S4)、干旱+80mg/L萘乙酸(S5)共5个处理。结果表明:(1)毛白杨植株幼苗受干旱胁迫后,会显著降低其叶片叶绿素含量、净光合速率和气孔导度,而蔗糖含量、蔗糖磷酸合成酶(SPS)和蔗糖合成酶(SS)活性会显著升高,其株高生长受到显著抑制。(2)喷施萘乙酸能一定程度上提高干旱胁迫下毛白杨叶片叶绿素含量、净光合速率和气孔导度,蔗糖含量有所降低,SPS和SS活性提高。(3)萘乙酸浓度不同对干旱胁迫的响应存在差异,除蔗糖含量外均呈现出随着浓度的升高先上升后下降的趋势,蔗糖含量呈现出逐渐升高的趋势,喷施50mg/L萘乙酸对缓解毛白杨幼苗干旱胁迫效果最显著。

This article explores the effect of plant growth regulator naphthylacetic acid on the photosynthetic physiological characteristics of Populus tomentosa seedlings under drought stress.The experiment used one-year old Populus tomentosa cuttings as the test material,and set up 5 treatments including no drought stress control(S1),drought stress control(S2),drought+20mg/L naphthoic acid(S3),drought+50mg/L naphthoic acid(S4),and drought+80mg/L naphthoic acid(S5).The results showed that:(1)After drought stress,the seedlings of Populus tomentosa significantly decreased their chlorophyll content,net photosynthetic rate,and stomatal conductance,while sucrose content,sucrose phosphate synthase(SPS),and sucrose synthase(SS)activities significantly increased,and their plant height growth was significantly inhibited.(2)Spraying naphthylacetic acid can to some extent increase the chlorophyll content,net photosynthetic rate,and stomatal conductance of Populus tomentosa leaves under drought stress, while sucrose content decreases and SPS and SS activities increase.(3) There are differences in the response of different concentrations of naphthylacetic acid to drought stress, except for sucrose content, which shows a trend of first increasing and then decreasing with the increase of concentration. The sucrose content shows a gradually increasing trend, and spraying 50mg/L naphthylacetic acid has the most significant effect on alleviating drought stress in Populus tomentosa seedlings.