摘要
[Objective]The paper was to study the physiological mechanism of Oncidium hybridum‘Gower Ramsey’infected by Erwinia carotovora pv.carotovora.[Method]O.hybridum‘Gower Ramsey’was inoculated with E.carotovora by needle-punching method.The leaves inoculated with sterile water were used as control,and samples were collected at 12,24,36 and 48 h post inoculations to determine the physiological indexes,respectively.[Result]The contents of MDA,flavonoid,lignin,soluble protein and the activities of POD,SOD,CAT,PPO and PAL in O.hybridum leaves first increased then decreased.At 12 h post inoculation,the activities of SOD and CAT increased significantly by 40.49%and 37.77%(P<0.01,the same below),respectively;the contents of flavonoid increased significantly by 21.56%(P<0.05,the same below);and the activities of PAL,POD and PPO increased significantly by 42.29%,81.8%and 37.98%,respectively.The contents of MDA and lignin increased significantly by 57.98%and 58.72%at 24 h,respectively;the content of soluble protein increased by 87.71%at 24 h,and 61.28%at 36 h,while the content of Pro increased at 24 h(P>0.05,the same below),and increased significantly by 23.66%at 36 h;the content of soluble sugar content had no significant difference compared with the control.Additionally,the chlorophyll a and carotenoid contents tended to decrease dramatically,while chlorophyll b increased significantly by 95.33%at 24 h,then decreased.The initial fluorescence parameter of Fm/Fv and Y(II)decreased significantly by 47.14%and 54.61%,respectively,while the Y(NO)increased significantly by 33.61%,compared with the control.[Conclusion]The contents of Pro,MDA,lignin,soluble protein and the activities of POD,SOD,CAT,PPO and PAL in O.hybridum leaves are closely related to the infection of E.carotovora,which provide new clues for revealing the infection mechanism of E.carotovora in O.hybridum.
基金
Young and Middle-aged Teacher Educational Research Project of Fujian Province(KLA19009A)&Major Agricultural Science and Technology Project of Fujian Province(2015NZ0002-1)&Science and Technology Innovation Fund of Fujian Agriculture and Forestry University(KF2015108).
