光质交替对LED红蓝光连续光照生菜生理伤害的削减作用机制OA北大核心CSTPCD

In environmentally controlled plant factory,the effects of conventional light(NL,400 μmol/(m2·s),18 h/6 h photoperiod,R/B=4∶1),continuous light(CL,300 μmol/(m2·s),24 h/0 h photoperiod,R/B=4∶1)and spectral alternation continuous light(CL-A,red light with 320 μmol/(m2·s)and 18 h light period,blue light 240 μmol/(m2·s)with6 h light period,respectively)on the growth,yield,DPPH radical scavenging rate,and contents of carbohydrate,reactive oxygen species and MDA of lettuce were investigated via hydroponic culture and diurnal six sampling method(3 times at 6 h interval in the light period and 3 times at 2 h interval in the dark period).The results showed that:The lettuce leaves were damaged and the plant morphology was changed after 12 days treatment.The shoot fresh weight and leaf area of lettuce were the highest and the injury grade was the lowest under CL-A treatment.In NL,CL and CL-A order,the contents of starch and sucrose,the DPPH free radical scavenging rate increased gradually significantly,while the contents of hydrogen peroxide and MDA increased first and then decreased,but the superoxide anions content increased first and then decreased or always increased.In conclusion,light quality alternation alleviates the injury on lettuce caused by continuous red and blue light illumination.This study provides scientific support for the application of alternating light quality and continuous lighting in artificial light plant factories.