Effects Of Prohexadione-Calcium Combined With 6-BA On Growth,Yield And Quality Of Chrysanthemum Morifolium.Ramat.Cv.Hangju

Chrysanthemum morifolium.Ramat.cv.Hangju(Hangbaiju)originated in Tongxiang,Zhejiang province,as one of the eight medicinal chrysanthemums.In recent years,with production area moving north,Shandong has gradually become the main production area.At present,high cost,low yield and low quality are the main problems in producing hangbaiju in Shandong region.In view of the above problems,this study was conducted in the way of exogenous hormone regulation,and foliar spraying was adopted.Set clear water control(CK1),clear water with removing control(CK2),50 mg/L Prohexadione-Calcium combined with 5 mg/L 6-BA that,s about low concentration Prohexadione-Calcium combined with low concentration of 6-BA(Ca50+6-BA5),50 mg/L Prohexadione-Calcium combined with 10mg/L 6-BA that,s about low concentration Prohexadione-Calcium combined with high concentration of 6-BA(Ca50+6-BA10),100 mg/L Prohexadione-Calcium combined with 5mg/L 6-BA that,s about high concentration Prohexadione-Calcium combined with low concentration of 6-BA(Ca100+6-BA5),100 mg/L Prohexadione-Calcium combined with 10mg/L 6-BA that,s about high concentration Prohexadione-Calcium combined with high concentration of 6-BA(Ca100+6-BA10).The feasibility and optimal treatment combination of exogenous hormone treatment in place of artificial removing were studied to provide theoretical basis for reducing planting cost,increasing yield and improving quality of Hangbaiju in Shandong.The main research results are as follows:At the same concentration of Prohexadione-Calcium,high concentration of 6-BA was beneficial to increase the content of chlorophyll and carotenoid in leaves,while low concentration of 6-BA was beneficial to increase the soluble sugar conten.The Prohexadione-Calcium combined with 6-BA treatment reduced the content of IAA,GA3 and ZA in leaves and increased the content of ABA.The soluble sugar and soluble proteincontents in leaves treated with 100mg/L Prohexadione-Calcium combined with 6-BA were significantly lower than that of treated with 50mg/L Prohexadione-Calcium combined with6-BA at the late growth stage(October to November).In the blooming period of Hangbaiju,the Prohexadione-Calcium combined with 6-BA treatment significantly increased the activity of Capitulum PAL and PPO,and decreased the activity of CHI.The Prohexadione-Calcium combined with 6-BA treatment significantly reduced the accumulation of dry matter and nutrient uptake in the roots and stems of Hangbaiju,and increased the accumulation of dry matter and nutrient uptake in the leaves and flowers.Moreover,the 100mg/L Prohexadione-Calcium combined with 6-BA treatment significantly increased the accumulation of dry matter and nutrient uptake in the leaves and flowers of Hangbaiju was higher than the 100mg/L Prohexadione-Calcium combined with 6-BA treatment.When the concentration of Prohexadione-Calcium was the same,dry matter accumulation and nutrient absorption in leaves and flowers of Hangbaiju were decreased with the increase of 6-BA concentration.The dry matter accumulation and nutrient absorption of leaves and flowers were the highest in Ca100+6-BA5 treatment,followed by Ca100+ 6-BA10 treatment.The Prohexadione-Calcium combined with 6-BA treatment inhibited the plant height and branch length at all levels,and the inhibitory effect was enhanced with the increase of Prohexadione-Calcium concentration.The inhibition degree of the Prohexadione-Calcium combined with 6-BA treatment on the secondary and tertiary branch length was significantly greater than that on the primary branch.The Prohexadione-Calcium combined with 6-BA treatment reduced the branch location of Hangbaiju,and the higher the concentration of Prohexadione-Calcium,the better the inhibition effect.The number of branches at all levels was increased by the Prohexadione-Calcium combined with 6-BA treatment,among which the number of tertiary branches was the most significant.Prohexadione-Calcium was cooperated with 6-BA in increasing stem diameter.Ca50+6-BA10 and Ca100+6-BA5 share the maximum stem.The diameter and fresh weight of simple Capitulum,yield treated with the Prohexadione-Calcium combined with 6-BA was higher than that of the clear wate controland clear water with removing control,and the yield increased by 17.66% to 101.48% and6.29% to 48.98%,respectively.Prohexadione-Calcium and 6-BA have synergistic effect on increasing the yield of Hangbaiju.Ca100+ 6-BA5 treatment has the highest yield,followed by Ca100+ 6-BA10 treatment.The contents of soluble sugar,protein,total amino acid and water extract treated with the Prohexadione-Calcium combined with 6-BA were higher than those in clear water control and clear water with removing control,meanwhile the contents of soluble sugar and protein were higher than those in clear water with removing control,which increased by 0.80% to 14.07%and 1.41% to 9.58%,respectively.The contents of soluble sugar and water extract from Hangbaiju treated with 50mg/L Prohexadione-Calcium combined with 6-BA were significantly higher than those treated with 100mg/L Prohexadione-Calcium combined with6-BA,while the contents of total amino acids were significantly lower than those treated with100mg/L Prohexadione-Calcium combined with 6-BA.Compared with the control group,the contents of flavonoids,chlorogenic acid,3,5-o-dicoffeoyl quininic acid in Hangbaiju treated with Prohexadione-Calcium combined with6-BA decreased to some degree,but they were all higher than the contents of medicinal ingredients stipulated in the 2015 edition of Chinese pharmacopoeia,so the medicinal quality was not decreased.Considering the factors of yield and quality,the present study considered that the best effect was the combination of 100mg/L Prohexadione-Calcium combined with 5mg/L 6-BA.