| D.officinale is a traditional Chinese herbal medicine,which is known as the "soft gold" of the botanical world.In recent years,the wild resources of D.officinale declined sharply and was on the verge of extinction.Industrialized production of D.officinale is the main source of the current market.The physiological&morphological characteristics,and chemical constituents of 3 varieties of D.offcinale were studied in this paper.One of variety was collected in Huangshan area as the main test material,and other two control varieties from Wenzhou,Zhejiang province and Liu'an,Anhui Province,which marked Huangshan variety,Wenzhou variety and Liu'an variety,respectly.Quality difference of Huangshan variety was compared with other two varieties,which could provide a theoretical basis for the protection,development and utilization of Dendrobium germplasm resources in Huangshan area.Meanwhile,the rapid propagation system of Huangshan variety was optimized,which provided practical experience for the large-scale production of Dendrobium.The main results were as follows:1.The morphological indexes of 3 varieties of D.officinale were measured,and the results showed that there were obvious differences in stems length,number of stem nodes and number of leaves in 3 varieties of D.officinale,and the stems length,stems section number and leaves number of Huangshan variety were higher than those of the other two varieties.There were also differences in water contents in 3 varieties of D.officinale and the water content of Huangshan variety was the lowest,71.3%,which was significantly lower than that of Wenzhou variety and Liu'an varieties2.The chemical constituents of 3 D.officinale were analyzed.It was found that the content of polysaccharide and the content of dendrobium were significantly higher than that of Wenzhou variety.Content of polysaccharide and dendrobium for Huangshan variety was 35.41%and 0.037%,respectly.3.The roots,stems and leaves of D.officinale from three different areas were analyzed by infrared spectroscopy.The peaks of the spectra of the roots,stems and leaves of D.officinale were nearly similar.The chemical substances were roughly the same.All of them contained sugars,lipids,flavonoids,aromatic,protein and so on.However,there are significant differences in the following areas of 1150cm-1,1150?950 cm-1 range for the attribution of sugar.The stems of Huangshan variety in this spectra range appeared two characteristic peaks,which were 1076?1028 cm-1 respectively,There was only a characteristic absorption peak in this range for leaves of Huangshan variety,which was 1079 cm-1.It indicates that the sugar contents of leaves were lower than that of stems for Huangshan variety.Below 950 cm-1 spectra,there were several absorption peak in stems of Huangshan variety.Those absorption peakd were the sugar ring skeleton vibration absorption characteristic peak.But there were lesser characteristic peaks in the leaves and roots for Huangshan variety.There were significant differences of the chemical constituents and chemical contents for Huangshan variety,comparing with Wenzhou and Liu'an variety.The polysaccharide content of Huangshan stems was the highest through the infrared spectra detecting,which was consistent with the results of the above "2".4.The physiological indexes such as cell membrane permeability,leaves SOD activity,free proline content and Malondialdehyde contents were measured by low temperature stress treatment for 3 varieties of D.officinale.Based on the analysis and evaluation of the physiological indexes,the results showed that there were obvious differences between the cold resistance ability of for 3 varietiesof D.officinale.The order of their cold resistance was:Huangshan variety>Wenzhou variety>Liu'an variety.5.The effects of bud proliferation differentiation and rooting for Huangshan variety were studied by adding different concentrations of hormones on stems segment induction culture medium.The results showed that the stems segment induction rate of D.oofficinale was the highest,reaching 88.9%,while the medium was 1/2MS+NAA 0.3mg/L+6-BA 1 mg/L,Meanwhile,the induced buds in this culture medium grew very well.When the culture medium was 1/2MS+NAA1.Omg/L+6-BA 0.2mg/L+KT 0.2mg/L+activated carbon 0.5mg/L+5%potato juice,the proliferation coefficient was highest,which reached 8.3.Test-tube seedlings grow well,too.This culture medium was helpful for the proliferation of D.officinale.According to the root length,number of roots,robustness and other aspects of each treatment,the best culture medium for Huangshan variety was selected,which was MS+10%banana juice + 0.5mg activated carbon+0.5mg NAA/L at the stage of rooting.Based on the analysis of morphology,chemical composition,infrared spectroscopy,cold resistance and other indexes of 3 varieties of D.officinale coming from different areas,the biological characteristics and chemical constituents of Huangshan variety were better than those of other two varieties of D.officinale.It appeared great prospects of development and utilization.The rapid propagation system of D.officinale was optimized,which provided a theoretical basis for the cultivation,development and utilization of D.officinale... |
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