【摘要】 以切花菊品种‘神马’为材料,研究了高温胁迫下外源Ca2+对菊花光合系统及活性氧清除酶系统的影响,探讨了Ca2+可能的作用机制.结果表明:高温胁迫下外源Ca2+抑制了净光合速率(Pn)与实际量子效率(ΦPSⅡ)的大幅度降低,24h后,二者分别比对照高出31.11%与21.88%,而初始荧光(Fo)比对照降低了13.19%;Ca2+明显激活了高温胁迫下叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性,活性氧得到及时清除,24h后,膜脂过氧化产物丙二醛(MDA)的积累量与相对电导率(REC)分别比对照降低29.20%与35.81%,缓解了短期高温胁迫对菊花光合系统的破坏.更多还原

【Abstract】 Taking cut flower chrysanthemum ’Jinba’ as test material,the effects of exogenous Ca2+ on its photosynthetic system and antioxidant enzyme activities under high temperature stress were investigated,with the possible action mechanisms of Ca2+ discussed.The results showed that under high temperature stress,Ca2+ addition greatly inhibited the net photosynthesis rate(Pn)and quantum yield of PSⅡ electron transport(ΦPSⅡ).After 24 h treatment,the Pn and ΦPSⅡ were increased by 31.11% and 21.88%,respectively,and the initial fluorescence(Fo)decreased by 13.19%,compare with the control.Ca2+ addition also greatly enhanced the activities of SOD,POD and CAT,and thus,the active oxygen was scavenged timely.After 24 h treatment,the MDA accumulation and REC were 29.20% and 35.81% lower than the control,respectively.In conclusion,Ca2+ addition could efficiently protect chrysanthemum leaves from the damage in photosynthetic apparatus under short-term high temperature stress.更多还原