Study on the Relationship between the Content of Vitamin C and Resistance of Paulownia spp. to Witches′ Broom

During 1990～1992,the content of VC and the activity of VC oxidase (VCO)in different varieties of Paulownia spp.were tested.It shows that the VC content and the activity of VCO are obviously different in leaves of the resistant and susceptible varieties.In those varieties which show resistance to witches′ broom,its VC content is higher,and the activity of VCO is lower,on the contrary for the susceptible varieties,the VC content is lower and the activity of VCO is higher.Besides,significant difference can also be seen between healthy and diseased plants of the same varities,the VC content is higher and the activity of VCO is lower in the healthy plant than those in the diseased plant.It is snggested that VC plays an important role in the resistance to witches′ Broom of Paulownia spp.