Effcts Of Short-days And Ethephon On Flower Formation Of Chrysanthemum And The Physiological And Biochemical Basis

In this paper,three cultivars of chrysanthemum "Chaziyanhong","Jianliuxiangjiu" with purple petalsand"Jinxingdachen" were treated by short-days (10h/d);The three cultivars were sprayed with ETP(0,25,50and75mg/L) in seedling stage, the cultivars of chrysanthemum "Chaziyanhong"and"Jianliuxiangjiu"with purple petals were sprayed with ETP (0,2,10and20mg/L) in seedling stage. The morphologicalindexes involved the date of bud, flower appearing and the length of bud stage.physiological indexes wereinvestigated in seedling stage and florescence.The results showed that:1. Under the treatment of short-days,for the three chrysanthemum cultivars, the dates of bud wereshorter than the control35,48and48days,respectively. And the flower appearing time were shorter thanthe control44,51and46days,respectively. And the length of green bud stage of the chrysanthemumcultivar "Chaziyanhong" was shorter than the control9days. The content of chlorophyll, the dry weight/fresh weight,the soluble sugar content, the soluble protein content and the soluble sugar content/solubleprotein of leaves appeared peak or kept higher value before the green bud and flower appearing.Thesephysiological indexes were lower than the control,the peak were typical and appeared ealier,that might bethe important reason for florescence advanced. During the florescence,the content of chlorophyll, the dryweight/fresh weight,the soluble sugar content and the soluble protein content of leaeves were lower thanthe control.As far as the petals were concerned, the dry weight/fresh weight and the soluble sugar contentof cultivars "Chaziyanhong","Jianliuxiangjiu" were lower than the control. And the content ofanthocyanin,the soluble sugar content, the activities of SOD,POD and CAT were lower than the control ofthe cultivar "Jianliuxiangjiu".2. Under the treatments of ETP at the concentrations of25,50and75mg/L, Excepting the times of budand flower appearing were shortened under the treatment of25mg/L ETP (3days shorter) of the cultivar"Jianliuxiangjiu", the dates of bud and flower appearing of above three cultivars were postponed than thecontrol, the lengthes of green bud stage were shortened and the effects increased with the concentrationincreasing. The content of chlorophyll, the dry weight/fresh weight the soluble sugar content and thesoluble protein content were decreased before the green bud and flower appearing. During the florescence,in the leaves,the content of chlorophyll, the dry weight/fresh weight and the soluble protein content were lowed.And the soluble sugar content,the activities of SOD and the content of MDA were increased of thecultivar "Chaziyanhong".As far as the petals were concerned, the dry weight/fresh weight and thesoluble protein content were increased. The contents of Carotenoids of "Jinxingdachen" weredecreased.The soluble sugar content were decreased ("Jianliuxiangjiu" and25mg/L ETP treatment of"Jinxingdachen") or were increased (25and50mg/L ETP treatment of "Chaziyanhong"). The activities ofSOD were decreased ("Chaziyanhong") or were increased ("Jianliuxiangjiu"). The content of MDA wasincreased of75mg/L ETP treatment of "Chaziyanhong".3. Under the treatments of ETP at the concentrations of2,10and20mg/L, for the cultivar of"chaziyanhong",the times of green bud appearing was extended, and the lengthes of green bud stage wereshortened. The date of flower appearing was2days earlier under the treatments of2mg/L ETP. The datesof flower appearing were3days extended under the treatments of ETP at the concentrations of10mg/Land20mg/L. For the cultivar of "Jianliuxiangjiu",the times of green bud and flower appearing wereshortened, and the effects weakened with the ETP concentration increasing, as well as the lengthes ofgreen bud stage were shortened and the effects increased with the the ETP concentration increasing.Under the treatment of2mg/L ETP.The date of flower appearing was9days earlier than the control.Thecontent of chlorophyll and the dry weight/fresh weight were decreasedg before the green budappearing,and they were increased after the green bud appearing in leaves of "Chaziyanhong".The twoindexes were increased of "Jianliuxiangjiu".The soluble sugar content and the soluble protein contentwere decreased for the two cultivars. During the florescence,in leaves,the content of chlorophyll,thesoluble sugar content and the activities of SOD were decreased,the soluble protein content wasincreased.As far as the petals were concerned,the soluble sugar contents were decreased. The content ofMDA was increased for the cultivar of "Chaziyanhong".