[Comparison on surface ultrastructure characteristic and drought resistance of different Trichosanthes kirilowii...

Trichosanthes kirilowii has been widely cultivated as its medicinal use, health care and food value. Drought resistance of seedlings is an important feature in breeding. Seeds of two T. kirilowii strains were used to research the difference of surface ultrastructure characteristic and drought resistance. Scanning electron microscope was used to identify the surface ultrastructure characteristic of seeds and PEG was used to simulate drought stress. The seeds germination rate, MDA content, chlorophyll content and the antioxidant enzymes activity were measured under the drought stress. The results showed that the seed surface colour of KXY-001 was lighter than that of KXY-005. The testa cobwebbing of KXY-001 was more intensive than that of KXY-005. The germination rate of KXY-001 was higher than that of KXY-005 under drought stress. The MDA content was increased and the chlorophyll content was decreased with the increasing of drought degree. The SOD activity of KXY-001 was higher than that of KXY-005, while the activity of POD and CAT was also increased firstly and decreased later. Surface reticulate of seeds and hilar traits can be used as identification points to identify the investigated strains. SOD and POD are activated to resist drought in T. kirilowii seedlings and the drought resistance of KXY-001 is superior than that of KXY-005.