Effects Of Infection On Growth And Physiology Of Catharanthus Roseus By Cuscuta Japonica

We set up different infection time(0d,15d,30d,45d,60d,90d)and leaf positions(top,middle,bottome leaf position)to investigate the physiological variation of Catharanthus roseus,and detected the respondences and adaptation of Catharanthus roseus was sensitive to infectioned.Cuscuta japcpnica was parasited in Catharanthus roseus seedings in different terms.The experiments were carried out to the influence of Catharanthus roseus in plant height,internode length,top,middle,bottome leaf area,biomass,flower number,bud number diameter of flower,seed number.The result exhibited that these features of the host Catharanthus roseus seedings began to decrease after the host was parasitized.Such decrease was obvious after 30 days,and the parasite hampered the growth and reproduction of the host were inhibited fully after 45 days,and aerial parts depressed it even to die at 60days.After 90 days,the new plant began go in to the new vegetable growth,but generative propagation obvious descent.Vindoline,catharanthine and vinblastine as alkaloids in Catharanthus roseus,these alkaloids dynamic changes under infectioned by Cuscuta japcpnica:The content of Vindoline were represented on top position at first,with the increase of infection time,the content of vindoline is reduce distinguished from top to bottom position.The content of catharanthine has greatly decreased in top,middle and bottom position that with the increase of infection time.Vinblastine contents had a'sharp rise in top position leaves.The result exhibited that vinblastine was biochemistry signal,it was accumulated generous in top position leaves and it can defense parasitic stress. As one osmoregulation regulator,soluble sugars can defence interferential stress by parasitic plant,sucrose contents were more higher in the early days,fructose and glucose contents were higher than control plot in top position leaves.Chlorophyll contents were middle position＞top position＞bottom position,and with the increase of infection time,contents were declined from top posirion to bottom position one by one.In top position leaves,proline contents and so on were increase distinguished in infectioned plant.Cuscuta japcpnica is parasiting on Catharanthus roseu.The results showed that cuscuta not only absorbed nutrition from their host,but also restrained the physiological regulation and function material expression at infection later stage,especially in the aspect of the content of free amino acids,alkaloids,chlorophyll and soluble sugars in the different leaf positions of Catharanthus roseus.Parasitism exerted deep influence on Catharanthus roseus.Catharanthus roseus increased the proline of leaves and regulated the content of free amino acids,alkaloids and soluble sugars to adapt the infection condition in the early days at top leaf position.We discoved that with the increase of infection time,coverage and intensity,Cuscuta japcpnica could control Catharanthus roseus serious,attaining to the restrainingthe growth of Catharanthus roseus,and even made aerial parts come to dead.At the same time,we discoverd that Cuscuta japcpnica was parasited in Catharanthus roseus seedings,is being determined contain a small quantity of chlorophyll,soluble sugars and vinblastine.