| Pinellia ternata(Thunb.)Breit.is a commonly used medicinal herb that the continuous cropping will lead to continuous cropping obstacle and seriously restricting the development of production.It is a key problem to study the influence factors and solutions of continuous cropping obstacles to ensure the sustainable development of Pinellia ternata.In this paper,takes Pinellia ternata as the research object,to study the effects of continuous cropping on the yield,quality,physiological and biochemical indexes;analyzes the effects of continuous cropping on rhizosphere soil nutrient content,rhizosphere soil microorganism and rhizosphere soil enzyme activity;combining with the allelopathy to discuss the causes of the continuous cropping obstacles and analyze formation mechanism from studying the effects of different parts of Pinellia ternata and rhizosphere soil extracts on the tuber germination and seedling growth of Pinellia ternata.The main results are as follows:1.The effects of continuous cropping on the growth and physiological and biochemical indexes of Pinellia ternata.Continuous cropping made the plant growth restrained,the chlorophyll mass fraction were reduced,SOD,POD,CAT activities decreased,MDA,proline,soluble sugar and soluble protein contents higher,yield and quality reduced.The plant height,tubers diameter,aboveground biomass and underground biomass that continuous cropping lower than rotation cropping were38.53 %,24.42 %,64.74 % and 44.32 %,respectively;the leaf chlorophyll,chlorophyll a,chlorophyll b and carotenoid mass fraction decreased than rotation cropping were49.06 %,46.63 %,55.41 %and 16.13 %,respectively;the leaf protective enzyme SOD,POD,CAT activities decreased than rotation cropping were 23.22 %,20.54 %,and29.51 %,respectively;the membrane lipid peroxidation product MDA content increased than rotation cropping was 31.07 %;the proline,soluble sugar and soluble protein contents increased than rotation cropping were 102.61 %,19.89 % and15.95 %,respectively,all the above indexes achieved significant difference between the two treatments in the late growth period of Pinellia ternata.The yield and extract content of continuous cropping were significantly lower than that of rotation cropping,which decreased by 87.77 %,20.75 %,respectively.2.The effects of continuous cropping in rhizosphere soil nutrient of Pinellia ternata.The continuous cropping led the contents of total nitrogen,total phosphorus,available phosphorus and organic matter decreased in rhizosphere soil of Pinelliaternata,while the content of available potassium increased.Among them,the contents of total nitrogen,total phosphorus,available phosphorus and organic matter that continuous cropping lower than rotation cropping were 3.78 %,17.42 %,16.38 %,and14.16 %,respectively,and the available potassium content higher than rotation cropping was 15.61 % in rhizosphere soil,and in addition to total nitrogen and total phosphorus outside the rest of the indicators have reached significant differences between the two treatments in the late growth period of Pinellia ternata.In terms of the whole growth period,the above indicators in the rotation and continuous cropping of Pinellia ternata were decreased with the extension of the growth period.3.The effects of continuous cropping in rhizosphere microorganisms of Pinellia ternata.The number of bacteria,actinomycetes and the total number of microorganism were decreased,the number of fungi increased in the rhizosphere soil of continuous cropping of Pinellia ternata,and the indexes were significantly different between the two treatments;the B/F,A/F,and microbial diversity index decreased.The number of bacteria,actinomycetes,microorganism and microbial diversity index in the rhizosphere soil of continuous cropping decreased by 18.66 %,54.52 %,21.01 %,and30.86 %than that of rotation,respectively,and the number of fungi increased by112.42 % than that of rotation,in the late growth period of Pinellia ternata.With the extension of growth period of Pinellia ternata,the numbers of bacteria,actinomycetes and total number of microorganisms increased first and then decreased,the number of fungi decreased and the index of microbial diversity decreased in rhizosphere soil of rotation and continuous cropping of Pinellia ternata.4.The effects of continuous cropping on the activity of enzyme in rhizosphere soil of Pinellia ternata.The activities of catalase,urease and neutral phosphatase in rhizosphere soil of continuous cropping were declined,while the activitie of polyphenol oxidase were significantly increased.Among them,the activities of catalase,urease and neutral phosphatase were decreased by 6.21 %,18.80 %and21.49 %,respectively,while the activity of polyphenol oxidase were increased62.96 %in continuous cropping than that of rotation cropping in the late growth period of Pinellia ternata.With the extension of growth period of Pinellia ternate,the activity of catalase increased gradually,the activities of urease and phosphatase increased first and then decreased and the activity of polyphenol oxidase decreased first and then increased.5.The effect of Pinellia ternate plants and rhizosphere soil extract on the growthof Pinellia ternata.They have different inhibitory effects on the stems germination and seedling growth of plant above ground,underground and rhizosphere soil extract of Pinellia ternata,and the different treatment leaching solution with increasing concentration,inhibition enhanced.Among them,the extract from aboveground part had stronger inhibitory effect than the extract from underground part. |
PDF Full Text Request