Research On The Influence Of Chemical Constituents In Carya Cathayensis Exocarp On Plants Growth

C.cathayensis,a Juglandaceae Carya Nutt plant,is an important nut in Zhejiang and Anhui mountain areas.While C.cathayensis brings great economic benefits to peasants,the discarded C.cathayensis exocarp severely pollute local agricultural ecological environment.This research aims to study the main inorganic and organic constituents in C.cathayensis exocarp and their bioactive influence on plants.1.Adopting wet digestion and dried digestion method respectively to decompose C.cathayensis exocarp,as well as the atomic absorption spectrometry to analyze the inorganic constituents in C.cathayensis exocarp,the result shows that there are ash elements—K,Ca,Fe, Mn,Zn,Mg,Cu,etc.—in C.cathayensis exocarp,among which,the content of K is about 1.61%. The research of adopting thermal treatment to prepare potassium carbonic acid shows that with material diameter＜10mm,ashing temperature 600℃,ashing time 6hr,the yield ratio of K is about 30%;with purified alkali calcination temperature 600℃,calcination time 0.5 hr,the content of potassium carbonic acid can be up to 98%.Adopting chemical synthesis to prepare pyrophosphate potassium,the result shows that the quality ratio of ash to phosphoric acid 2.24: 1～2.30:1,pH in neutralization reaction 9.0,dipotassium hydrogen phosphate polymerization temperature 500 and time 1.5hr,the content ofpyrophosphate potassium can be up to 97%.2.Adopting GC-MS,the result shows that there are many organic components in C.cathayensis exocarp—phenol,fatty acid,mellow,ester,hydrocarbon,ketone,sterides, vitamin E,quinoline etc,of which the content of phenol is relatively higher.This research extracts and separates flavone,tannin,quinones,and gets the optimal extraction condition of quinones:with 70%ethanol,solid-liquid ratio 1:10,temperature 60,and reflux time 4 hours, the extraction ratio of quinones is 0.84%;separating silica gel,liquid-solid ratio 3:1,absorption time 30 min,the purity of quinones compound is 86.08%.The optimal extraction condition of tannin is:using 50%ethanol as solvent,solid-liquid ratio 1:12(g/mL),lixiviation temperature 60,and lixiviation time 2 hours,the extraction ratio of tannin is 26.89%;using theine to produce salt precipitation,methanol to dissolve,removing impurity through fractional extraction by different polar organic solvent of aether,chloroform and ethyl acetate,the tannin purity is 86.42%.The optimal extraction condition of flavones is:70%ethanol,solid-liquid ratio 1:15 (g/mL),extraction time 3 hours,extraction temperature 60℃,the maximum extraction ratio of flavone compound is 0.997%;separating silica gel,liquid-solid ratio 3:1(mL/g),absorption time 30 min,gradiently eluted by 20,40,60,70,80,90%ethanol at the speed of 2mL/min,the recovery of flavone is 89.46%,and its purity is 83.76%.3.The study showed that after treatment with the lixiviation drench of C.cathayensis exocarp,the seed germination is accelerated at low concentration and delayed or inhibited at high concentration.The 0.1g/ml lixiviation drench obviously promotes seed germination and radicles elongation of wheat,corn,soybean and mung bean.The wheat and mung bean seeds germination rates are increased by 38%and 24%;the elongation of their radicles is increased by 21%,26%,29%,32%respectively,and the difference is significant.From 1.5g/ml on,the seed germination of wheat,corn and mung bean are greatly inhibited,with germination rate decreased by 100%,43%and 49%respectively.Meanwhile,the lixiviation drench exerts more inhibition on the elongation of radicles and hypocotyls.In addition,hypocotyls are less sensitive to the lixiviation drench than radicles.4.The study indicates that the 0.1 g/ml lixiviation drench stimulates the activity ofα-amylase and inhibits that of IAA oxidase.Consequently the respiratory rate of the seeds,the content of soluble sugar,amino acid,and indoleacetic acid(IAA) increase;the content of starch and protein decreases,and their conversion rates accelerate.In addition,the lixiviation drench with its concentration higher than 0.5g/ml reduces the activity ofα-amylase and stimulates that of IAA oxidase.Hence the respiratory rate of the seeds decreases,cellular IAA decreases,and the conversion process from starch to soluble sugar and that from protein to amino acid decelerate. Generally the sensitivity of seed germination of the above four crops to the lixiviation drench goes in a descending order as follows:wheat＞mung bean＞corn＞soybean.5.The lixiviation drench with low concentration promotes the absorption of the mineral elements of the seedling root systems,while the lixiviation drench with high concentration inhibits the absorption.The 0.1g/ml lixiviation drench and the 0.5g/ml lixiviation drench decrease the electric conductivity of the seedling root system,increase the activity of root system and nitrate reductase.With optimal concentration the lixiviation drench improves the absorption of nitrogen(N),potassium(K),calcium(Ca),magnesium(Mg),ferrum(Fe),manganese(Mn), and copper(Cu) of corn,the absorption of N,K,Ca,Fe,and Cu of wheat,the absorption of N,K, Mg,Fe,Mn,and Cu of soybean,and the absorption of N,K,Ca,Mg,Fe,Mn,and zinc(Zn) of mung bean.The optimal concentration of lixiviation drench varies according to different crops.6.The research analyzes the way in which photosynthetic performance of the leaves influences the seedling growth.The 0.1g/ml lixiviation drench and the 0.5g/ml lixiviation drench have increased the content of chlorophyll a and chlorophyll b and the total chlorophyll content, photosynthetic rate(Pn),stomatal conductance(Gs),and transpiration rate(Tr) in the seedling leaves of the above four crops,and adequately increased the intercellular CO₂ concentration(Ci), with the 0.1g/ml lixiviation drench producing the most remarkable effect.The fresh weight and dry weight of their seedlings are obviously heavier than the control.The wheat and soybean treated with 0.1g/ml lixiviation drench accumulate the most dry substances,while the corn and mung bean treated with 0.5g/ml lixiviation drench accumulate the most dry substances. Treatment with the concentration higher than 0.5g/ml results in great decrease in the content of chlorophyll a and chlorophyll b and the total chlorophyll content,photosynthetic rate(Pn), stomatal conductance(Gs),and transpiration rate(Tr),and results in slight increase in the ratio of chlorophyll a:chlorophyll b,and rapid increase in the intercellular CO₂ concentration(Ci).The research believes that the lixiviation drench with high concentration,particularly the mesophyll limitation to photosynthesis,causes the decrease of photosynthetic rate of the seedling leaves. The reason for this may be that the lixiviation drench restrains the enzymatic activity in the dark reaction so as to hinder the assimilation of CO₂ or that the decrease of chlorophyll reduces the absorption of light energy,lowers the photochemical reaction rate,and decreases the assimilatory power.7.The study indicates that optimal concentration of flavone,tannin,quinones and their combinations as well as the lixiviation drench of C.cathayensis exocarp,can enhance the height of wheat,corn,soybean,and mung bean seedlings and the length of their nascent root systems, 6%to17.5%higher than the control in general.The allelopathy between the experiment and control has significant difference with P＜0.01～0.05 in terms of various active substances and their combinations.The research compares influences of three active substances and their combinations as well as lixiviation drench of C.eathayensis exocarp on the peroxidation of cellular membrane lipids of these four seedlings,and finds that active substances and their combinations with optimal concentration can decrease relative electric conductivity(the range of decreasing is 5%to 14%),and the content of MDA,hydrogen peroxide,and superoxide anion radical(O₂^-) nascent root systems and spires of seedlings,promote the activity of peroxidase (POD),catalase(CAT),and superoxide dismutase(SOD),increase the respiratory intensity of both nascent root systems and spires,and reinforce the vigor of nascent root systems.The order of influence on peroxidation of cellular membrane lipids of these four seedlings is as follows: unieus active substance＜two-active-substance combination＜three-active-substance combination≤lixiviation drench of C.cathayensis exocarp,which indicates that allelopathy of lixiviation drench of C.cathayensis exocarp on the above four seedlings is the result of many active substances working together.Active substances and their combinations with optimal concentration can strengthen the stability of cellular membrane structures by improving the ability of oxidation-reduction reaction activated protectase system in cells and effectively clearing harmful active substances in cells.8.The research studies the photosynthesis diurnalvariation dynamics of the Da Hu Hong leaf—a type of Da Tian peony—under natural sunlight of July and August:during the noon in early July,the photosynthetic rate(Pn) substantially declines,and the Pn diurnalvariation shows two peaks and there also appears a clear_photosynthetic noon break.On the measure day of early August the photosynthetic noon break is more severe than in July and the Pn diumalvariation of the peony leaves shows a trend of "declining straightly".During the phase when Pn declines at noon on the measure days of the two months,the declination of stomatal conductance is in a small scale,the Ci of CO₂ inside the cell gap does not fall but rises instead and the Mesophyll constraint is the main reason for photosynthetic noon break.Chlorophyll fluorescence test indicates that during noon time of the measure days,Fv/Fm and PSâ…¡photochemical efficiency(ΦPSâ…¡) decline obviously,the photochemical quenching factor(qP) of the two months decreases by 34.4%and 37.9%respectively;meanwhile,the non-photochemical quenching factor(NPQ) increases by 44.4%and 49%,the electronic transferring activity of chloroplast declines significantly,the absorbed light energy used for non-photochemical reaction substantially increases,and severe photosynthetic photoinhibition happens in peony leaves.9.Spraying the peony leaves with 0.06mg/mL juglone solution,the result indicates that Pn is more obvious than the control,the maximum Pn of the two months enhances 10.5%and 12.8% respectively than the control,and the maximum Pn in August appears one hour later than the control;Fv/Fm of the two months drops by 51%and 89%respectively and the processed leaf reduces by 20%and 26%separately,the contrastΦPSâ…¡of the two months decreases by 49.5% and 67%respectively,while the processed leaves only decreases by 18.1%and 19.9%;in the afternoon of July and August,ΦPSâ…¡of the leaf in control restores poorly or almost to the morning level,while the processed leaf can recover completely;in July,the compared qP and processed qP drop by 39%and 10%respectively and in August,they drop by 43%and 11.6% respectively;NPQ in July rises by 49.3%and 17.3%respectively and in August,it rises by 49% and 14.3%respectively.The research believes that juglone with optimal concentration can relieve peony leave photosynthetic photoinhibition,alleviate photosynthetic noon break,restore damage to the chloroplast and enhance the peony leaves' utilizing ratio of light.