| Camellia oleifera is a unique woody oil tree species in China.Solving the matters in oil tea production is one of the breakthroughs to solve the grain and oil problems.Chrysanthemum morifolium is a medicinal species of Chrysanthemum,Compositae.Its flower is a dried capitulum,which is a common Chinese medicine in China.Chrysanthemum morifolium is often used as one of the intercropping plants under forest.This thesis divided into three sections.The first section,the allelopathic effects of Chrysanthemum morifolium stem-leaf and rhizosphere soil extracts against seed germination of Setaria viridis and Imperata cylindrica were examined.Weed seeds were placed in petri dishes filled with filter papers and treated with different concentrations of extract and determined the germination index and seedling growth index of each treatment.In the second section,two-year-old ’Huajin’ Camellia oleifera seedlings were treated with Chrysanthemum morifolium flower,stem-leaf mixtrue and rhizosphere soil extracts.After treatment of Camellia oleifera with extracts,The growth indexes,soluble sugar,soluble protein,chlorophyll,proline,catalase,peroxidase,superoxide dismutase,soil microbial C,N and other indexes were measured.In the third section,GC-MS was used to detect the petroleum ether extractives from flower,stem-leaf mixture and rhizosphere soil of Chrysanthemum morifolium.The synthetical effect of allelopathy were used to evaluate the allelopathy of Chrysanthemum morifolium to Setaria viridis and Imperata cylindrica.The allelopathy effects of Chrysanthemum morifolium flower,stem-leaf mixtrue,and rhizosphere soil on Camellia oleifera were evaluated by principal component analysis.Those provided a theoretical basis for interplanting Chrysanthemum morifolium under the young forest of Camellia oleifera can reducing weed density and promoting the growth of Camellia oleifera.(1)Effects of Chrysanthemum morifolium extract on weed growth.The allelopathy of stem-leaf mixture extract of Chrysanthemum morifolium to weeds was stronger than that of rhizosphere soil extract.The synthetical effect of allelopathy of two extracts on weeds was showed as inhibition.The low concentration of rhizosphere soil extract(≤0.02 g·ml-1)promoted the germination of Imperata clindrica seeds,while the high concentration(≥0.06 g·ml-1)inhibited the seed germination.And it has a certain promoting effect on the growth of the seedlings of Imperata cylindrica,and it has an inhibitory effect on the germination of Setaria viridis seeds.Under the condition of stem-leaf mixture extracts(0.02 g·ml-1～0.1 g·ml-1),the germination of two weeds seeds were inhibited by the increase of concentration 0.1 g·ml-1 completely inhibited the germination of Imperata cylindrica seeds.The germination rate of Setaria viridis was 99.15%lower than that of the control.The high fresh weight and dry weight of Imperata cylindrica seedlings were significantly decreased by stem and leaf extract.The higher the concentration of stem and leaf extract,the stronger the inhibition was to Setaria viridis.When the concentration was 0.1 g·ml-1,the plant height of Setaria viridis was lower than that of control,which was about 78.78%.The root length of two weeds was strongly inhibited with the increase of the concentration of stem and leaf extracts,at 0.06g ·ml-1,it was significantly lower than 96.43%and 79.81%of the control.(2)Effects of Chrysanthemum morifolium extract on Camellia oleifera growth.The low concentration of flower extract promoted the growth of Camellia oleifera,while the high concentration inhibited the growth.The results showed that 0.05 g·ml-1 flower extract treatment increased 110.21%of the control,and 0.15 g·ml-1 flower extract was lower 45.95%than that of the CK,which was significantly different from 0.05 g·ml-1(p<0.05).The concentration of 0.05 g·ml-1 rhizosphere soil extract was higher 70.21%than that of the control(p<0.05).The effect of three kinds of extracts on ground diameter was not significant.(3)The effects of Chrysanthemum morifolium extract on the physiological and soil indexes of Camellia oleifera were examined in this study.Results showed that flower,stem-leaf mixture,and rhizosphere soil extracts significantly reduced the soluble sugar content of Camellia oleifera by a range of 20.21%-41.30%.The three extracts had no significant effect on the soluble starch content of the leaves.Flower,stem and leaf extract at 0.15 g·ml-1 reduced the soluble protein content of the leaves in a short time,with the treatment increased,the soluble sugar content of the leaves could be reduced.Rhizosphere soil extract at 0.15g·ml-1 increased soluble protein content in leaves.The proline content in leaves increased with the concentration of flower extract,and the promoting effect was weakened with the concentration of rhizosphere soil extract.The short-term treatment of rhizosphere soil extract had the promoting effect on chlorophyll content.The three kinds of extracts could increase the CAT in leaves.The treatment of stem and leaf extract increased significantly with the increase of concentration;The POD increased with the increase of flower extracts concentration.The promotion effect increased first and then decreased with the increase of stem and leaf extracts concentration.All the three extracts could significantly promote the activity of SOD in leaves and reduce the content of soil microbial N.(4)GC-MS analysis showed that the petroleum ether extractants of Chrysanthemum morifolium flower contained alkanes,alcohols,acids,camphor,ketones,and other substances.Among these compounds,camphor is the allelochemical.GC-MS analysis showed that the petroleum ether extractants of Chrysanthemum morifolium stem and leaf contained alkanes,alkenes,alcohols,ketones and other substances.Among which chlorophyllin,pinene,caryophyllene and carvone were reported as allelochemicals.GC-MS analysis showed that the petroleum ether extractants of Chrysanthemum morifolium rhizosphere soil contained alkanes,esters,aldehydes,ketones and other substances.Among which,neighboring substances dibutyl phthalate was a reported allelochemicals.(5)According to the comprehensive analysis of the principal components.The most significant effect on the physiological indexes of Camellia oleifera was flower extract,stem and leaf extract ranked the second and rhizosphere soil extract ranked the last.Each treatment has great influence on the activity of protective enzyme.On the 90 day of treatment,the top five comprehensive scores of physiological indexes of nine concentrations were:0.15 g·ml-1 flower extract,0.15 g·ml-1 stem and leaf extract,0.1 g·ml-1 stem leaf extract,0.1 g·ml-1 flower extract,and 0.15 g·ml-1 rhizosphere soil extract.The 0.1-0.15 g·ml-1 extracts from different parts of Chrysanthemum morifolium can still promote the growth of Camellia oleifera,while the 0.06-0.1 g·ml-1 extracts can significantly inhibit the weeds.Reasonable control of the density of Chrysanthemum morifolium under the Camellia oleifera forest can achieve the dual effects of inhibiting weeds and promoting the growth of Camellia oleifera. |
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