Physiological Analysis Of Salt-tolerant Honeysuckle （Lonicera Japonica L.） And Its Amelioration Funtions Inaddition To Exogenous K₂SiO₃·nH₂O

The mature stem foliar bud and blade were used as the explants of Honeysuckle（Lonicera japonica L.）,and the combining medium schemes inducing callus,differentiation and rooting,etc.were designed with different concentration of NAA IBA 6-BA KT based on the MS culture medium,using the mixed level orthogonal experiment design,therefore the system of tissue culture and rapid propagation of honeysuckle was established.A technical system of tissue culture and rapid propagation of Honeysuckle（Lonicera japonica L.）involves the optimum medium of every experiment step and the operating rules（the choice of explants,the induction of callus,the differentiation of tufted bud and the taking root）.With the completely randomized experiment design,the sand culture experiment in the green house was conducted to study the growth and physiological response of salt stress with different salt concentration（0,50,100 Mm NaCl）on the two seedling stages（Tissue culture seedlings and one-year-old seedlings）of Honeysuckle（Lonicera japonica L.）.The analyse parameters included the aspects of the growth,photosynthetic pigements,osmotic adjustment substances,antioxidase and total flavonoids the aims are to reveal.Discuses the mechanism of salt tolerance of Honeysuckle（Lonicera japonica L.）and to compare the ability of the salt tolerance of the seedling stages.Based on physiological responses of Honeysuckle（Lonicera japonica L.）to NaCl stress,alleviative effect of exogenous K₂SiO₃·nH₂O to NaCl stress were also studied.The function of exogenous silicon in salt stress possibly lied in the differences in the growth,photosynthetic characteristics,leaf ultra-structure,ion distribution,osmotic adjustment substances,antioxidase and secondary metabolite.The main results were described as follows:1.The callus development was influenced by ex-plant’s types,and hormone concentrations of media.The callus induction and plant regeneration of foliar bud were significantly higher than the mature stem and blades’,which can induce callus with compact constitution.The culture medium with different plant growth regulators combination had great effect on the inducing rate,and the best medium for callus induction was MS+6-BA 0.05mg/L+NAA 1.0mg/L.MS with low concentration of auxin and cytokinin adapted to induce the differentiation of tufted bud by the callus of Honeysuckle is MS+NAA 0.03mg/L+IBA 1.00mg/L.The MS,MS+NAA 0.03mg/L+IBA 1.00mg/L,which induces the differentiation of roots can significantly improve the inducing rate of roots,make the tufted roots more compact and improve the propagative rate.2.Comepared to control,different levels of NaCl concentration decreased the biomass of both tissue culture seedlings and one-year-old seedlings.The low salt level had no obvious inhibition of both 2 seedling stages of honeysuckle on photosynthetic pigment content,but medium and high salt levels significantly inhibited the synthetiseing and accumulation of photosynthetic pigments.A proline content of two seedling stages increasing with NaCl concentration increased.Under the same treatment,a higher relative proline rate was found in tissue culture seedlings compared to one-year-old seedlings.Generally with the increase of salt concentration,the soluble protein content decreased,and it was lower than the respective control in the end of stress.Under the same treatment,a low relative soluble protein rate was found in tissue culture seedlings compared to one-year-old seedlings.To a certain extent,MDA content decreased remarkably with NaCl levels increased means Honeysuckle is tolerant of salt stress.At lower salt lelvels,SOD and POD activities of both two seedling stages were unchanged as compared to control,and SOD、POD and CAT activities of tissue culture seedlings were higher than that of one-year-old seedlings.The secondary metabolite of flavonoids content in tissue culture seedlings was significantly higher than the control,but unchanged in one-year-old seedlings.Therefore,the tissue culture seedlings were more sensitive to salt stress than one-year-old seedlings.3.Under salt stress,the plant of Honeysuckle（Lonicera japonica L.）changed their own adaptive strategy by improving morphological,physiological and biochemical processing to adjust salt environment,and it directly resulted in biomass reduction.The change trend in biomass were in line with the change levels of photosynthesis,osmotic adjustment substances,antioxidant system and secondary metabolites,which influenced by the salt stress.4.Generally,the exogenous silicon could significantly improve and effectively maintain biomass.Under salt stress,silicon alleviated salt stress not only through improving the structure of physical barrier,but participating in metabolic and physiological processing.The exogenous K₂SiO₃·nH₂O application could improve ion distribution and maintain higher photosynthesis.Silicon could make injury of cytoplasmic organoids of mesophyll tissue improve,showed as adherent chloroplast thylakoid lamellae arrangement,a slight expansion of the phenomenon,nucleus and mitochondria were largely intact,which helped to maintain the integrity of the chloroplast ultrastructure and make it possible for plants to perform normal physiological function.Optimal concentration of K₂SiO₃·nH₂O addition could promote the content of proline to protecte plant of Honeysuckle（Lonicera japonica L.）from oxidative stress,lipid peroxidation and cell injury.Also,it can keep the soluble protein and soluble sugar content to regulate physiological metabolism.Silicon enhanced the antioxidant enzyme system in different degree to prevent excessive oxidation.