In order to investigate the effects of different phytohormones combined with chelating agent(EDTA)on the growth and remediation efficiency of grain amaranth under cadmium stress,this experiment was conducted taking grain amaranth with large biomass as material and by pot method to study the effects of different combined treatments on the growth and cadmium accumulation amount of grain amaranth under cad-mium stress.The results showed that,compared with the single Cd2+treatment,the combined treatments of phytohormones and chelating agent alleviated the influence of Cd2+stress to the growth of grain amaranth,in-creased the biomass of each part,enhanced the absorption and enrichment of Cd2+in root and shoot,and fur-ther improved the phytoremediation efficiency.The combined treatments had higher remediation efficiency by root watering.
In order to study the physiological response law and salt tolerance of different species of cut chrysanthemum under salt stress,six cut chrysanthemum varieties were used as materials to study the effects of different concentrations of NaCl on plant growth and physiological and biochemical indexes,and their salt tol-erance was comprehensively evaluated by principal component analysis.The results showed that there were sig-nificant differences among the indexes of different cut chrysanthemum varieties under salt stress.With the in-crease of salt concentration,the chlorophyll content(SPAD)and leaf relative water content(RWC)showed downward trends,the relative conductivity(REC)and malondialdehyde(MDA)content showed upward trends,and the soluble protein(SP)content and superoxide dismutase(POD)and peroxidase(SOD)activi-ties first increased and then decreased.Based on the performance of various indicators of the cut chrysanthe-mum varieties,the salt tolerance of the six varieties was evaluated and sequenced as Seoul＞Princess Heart＞Funi＞Kevin Pink＞Stripe＞Silver Star Purple.The principal component analysis results of the indexes showed that REC,MDA content and SOD activity could summarize most of the information of the seven indexes,and could be used to evaluate the salt tolerance of cut chrysanthemum.
In order to enrich the germplasm bank of Helianthus tuberosus L.and provide a basis for breeding new special varieties and developing H.tuberosus industry in saline-alkali land,in this experiment,thirty four H.tuberosus germplasms were selected to analyze the differences of plant characters,tuber yield and quality characters,and comprehensive evaluation was carried out by principal component analysis.The results showed that there were significant differences in plant traits,tuber yield and quality traits among different germplasms,and the coefficient of variation of main stem branching number and yield were higher,reaching 60.49%and 58.55%,respectively.The coefficient of variation of tuber number,stem number and starch con-tent per plant were also larger,and their values ranged from 33.34%to 44.10%;the coefficient of variation of the other traits was below 30%.The high-yield(＞30 t/hm2)germplasms as S9,S12,S15,S16,S17,S24,S33,S34 and S35,the high-protein germplasms as S11,S13,S23 and S35,the high-soluble sugar germ-plasms as S6,S23 and S24,the high-fiber germplasms as S3,S12,S26,S30 and S34,and the high-starch germplasms as S1,S6,S25 and S33 were preliminarily screened out.The principal component analysis of the 34 H.tuberosus germplasms were conducted based on 9 agronomic traits(including plant traits and yield traits),and 3 principal components were extracted,which could reflect 74.00%of the total information.After comprehensive evaluation,six germplasms suitable for planting in saline soil of Dongying City,Shandong Province were selected,namely X2020-2,HZ,TJ,L2-1,X2020-1 and N2019-4.Among them,the main stem height and node height of HZ were the lowest,the secondary stem and main stem were thicker,and the yield was significantly higher than the other germplasmes,reaching 85.75 t/hm2.The results of this study could provide germplasm re-sources for breeding high-yield,good quality and special functional H.tuberosus varieties.
Continuous cropping seriously affects the growth of plants,resulting in decreased yield and quality of peanut.In addition,long-term continuous cropping also leads to soil acidification and loss of ex-changeable calcium in soil,resulting in hindered development of peanut pod.Supplementing exogenous calci-um could significantly improve pod and seed yields.In order to investigate the synergistic effect of arbuscular mycorrhizal fungi and exogenous calcium on the growth and development of continuous cropping peanut,Hua-yu 22 was used as the test material to study the effects of Funneliformis mosseae synergizing with exogenous cal-cium on the plant traits,dry matter accumulation,mineral element content,yield and quality of continuous cropping peanut.The results showed that the synergistic effect of F.mosseae and exogenous calcium could sig-nificantly increase the plant height and branch number of continuous cropping peanut,promote the accumula-tion of dry matter and the absorption of mineral elements,and thus improve the yield and quality of peanut.In conclusion,the combination of F.mosseae and exogenous calcium could improve the yield and quality of con-tinuous cropping peanut,which could provide practical and theoretical bases for increasing the yield of contin-uous cropping peanut.
In order to determine whether exogenous salicylic acid(SA)can alleviate alkali(Na2 CO3)stress in plants,the Petunia hybrida variety Dream was used as material,and the effects of foliar spraying SA(0.75 mmol·L-1)on seedling growth,protective enzymes activities and chlorophyll fluorescence parameters under Na2 CO3(100 mmol·L-1)stress were studied.The results showed that compared with the control(CK),the plant height,leaf number,plant fresh and dry weights,total root length,total root surface area,root vol-ume,fine root(diameter at 0～2 mm)length and surface area of P.hybrida seedlings decreased significantly after treated with Na2 CO3,while the POD and CAT activities increased significantly,and the TRo/RC and PI-abs decreased significantly.Compared to not spraying SA,foliar spraying SA under Na2 CO3 stress increased the plant height,leaf number,fresh and dry weights of aboveground part,total root length,total root surface area,fine root length and surface area,POD activity,ABS/RC,TRo/RC and PIabs of P.hybrida seedlings.In conclusion,Na2 CO3 stress significantly inhibited the growth of P.hybrida seedlings,and foliar spraying SA could alleviate the inhibitory effect to a certain extent by promoting the growth of fine roots,improving the ac-tivities of protective enzymes and photosynthetic performance of PSⅡ.
