文心兰响应软腐病菌胁迫的生理生化分析

Physiological and Biochemical Analysis of Oncidium in Response to Stress of Soft Rot Pathogen

通过细菌性软腐病菌液针刺接种文心兰‘小樱桃’假鳞茎,分别在0、8、16、24、32 h时取假鳞茎上第一片叶,测定其叶绿素荧光特性[最大光合效率Fv/Fm、实际光合效率Y(Ⅱ)、调节性能量耗散的量子产额Y(NPQ)、非调节性能量耗散的量子产额Y(NO)],超氧化物歧化酶(SOD),过氧化物酶(POD),过氧化氢酶(CAT),多酚氧化酶(PPO)的酶活性,丙二醛(MDA),木质素及可溶性糖含量的变化。结果表明,随着侵染时间的延长,Fv/Fm、Y(Ⅱ)、Y(NPQ)逐渐下降,Y(NO)逐渐升高,光合系统受损;PPO活性及木质素含量逐渐下降;SOD、POD活性逐渐升高;CAT活性与可溶性糖含量先上升后下降;MDA含量在0~24 h逐渐下降,24 h后趋于平缓。探明文心兰感染软腐病后其抗性机制,建立抗性鉴定的生理方法。

The pseudobulb of Sherry Baby,Oncidium was infected by bacterial soft rot bacteria infection.The first leaf on the pseudobulb was sampled 0,8,16,24,32 h,after infection to determine the chlorophyll fluorescence properties[Fv/Fm,Y(Ⅱ),Y(NPQ),Y(NO)],superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),polyphenol oxidase(PPO)activity,malondialdehyde(MDA),lignin,and the change of soluble sugar content.The results showed that with the extension of infection time,Fv/Fm,Y(Ⅱ),Y(NPQ)gradually decline,Y(NO)increased,and the photosynthetic system was damaged.PPO activity and lignin content decreased gradually;SOD and POD activity increased gradually;CAT activity and soluble sugar content first increased and then decreased;MDA content decreased gradually from 0 to 24 h and then leveled off after 24 h.The study would heip to explore the resistance mechanism and establish the physiological method of resistance identification.