Autotoxicity Of Fritillaria Pallidiflora In Cropping Continous

Fritillaria pallidiflora is deciduous herbal of fritillary,liliaceous,is perennial caudex which has serious succession cropping obstacles, bioassays were used to assess autotoxicity potential of the cause of the succession cropping obstacles of Fritillaria pallidiflora.The conclusions were as follows:The root exudates of Fritillaria pallidiflora seedlings of different ages were collected by using the continous cyclic device. The components and contents of the exudates were identified to examine the differences of root exudates at different ages by Gas chromatography/Mass spectrometry.The results showed that the most contents were the ketone and aldehyde which were 57.90%,74.15%,59.66%,59.32% for one,two,three,four years old Fritillaria pallidiflora seedlings, respectively,while as the urea,benzonic and phenol,alcohol has the least,which less than 0.5%.The root exudates of Fritillaria pallidiflora seedlings at different ages contained similar chemical compounds,which are mainly alkanes,ester,aether,alcohol,acid,phenol, ketone and aldehyde,urea and some benzoic and phenol acids.Germination and early seedling growth bioassays were used to assess aqueous extracts of Fritillaria pallidiflora rhizosphere soil, autotoxicity potential of the different tissues aqueous extracts and root exudates from Fritillaria pallidiflora in this paper.The results indicated that the aqueous extracts had different inhibitory effect on its seed germination while promoted the growth of radical and hypocotyl.The different tissues aqueous extracts from the Fritillaria pallidiflora had different inhibitory effect on its seed germination and early seedling growth.overall,the inhibition potential of Fritillaria pallidiflora on its germination and early seedling growth increased with increased concentration and varied among tissues ranked from the most autotoxicity to the least in the following order:leaves,stems,bulb.Plant roots could secrete exudates which contain root-specific metabolites have critical impacts on the growth of the plant itself. germination percentage,Radical and Hypocotyl length were inhibited by all the compounds of 1,3,5-Triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione,phenols,mixtures of them,both of which are the components of root exudates and the root exudates collected by the continous cyclic device.autotoxicity on its seed germination were increased with increased concentration in a certain range and decreased when beyond the range. The autotoxicity on its early seedling growth increased with increased concentration while can promote the hypocotyl length of Fritillaria pallidiflora in low concentration.The activity changes of POD,CAT,SOD and the content of MDA and chlorophyll were also used to assess autotoxicity potential of root exudates from Fritillaria pallidiflora.The results indicated that the root exudates inhibited the activity of SOD but have not obvious effect on POD and CAT,while have promoted effection on the content of MDA and chlorophyll.