Composition Of Root Exudates Of Forage Grass And Crops And Their Allelopathy Effects

The paper uses sand culture to grow test forages and crop varieties,uses dichloromethane polar organic solvents to extract the root exudates of the test variety seedlings,and uses meteorological chromatography-mass spectrometry?GC-MS?to secrete the test variety seedlings.Four weeks after planting the test forage and crop varieties in the sand culture pot method,Using forage and crop seedlings to prepare seedling extracts,the extract concentration is divided into:0.25dwg·L^-1,0.5dwg·L^-1,1dwg·L^-1,2dwg·L^-1?1dwg·L^-11 represents 1g seedling dry matter extract contained in1L of distilled water?.distilled water was used as a blank test control for a total of 5concentration gradients,then all test varieties were tested for seed germination in pairs.Through the determination of the composition of other substances in the root exudates of 23 different varieties of forage and crop seedlings and the detection of the effects of other substances in the tested varieties,the purpose is to understand the types and components of other substances and to screen for obvious effects of other substances.Forages and crop varieties can provide theoretical basis for further research on the mechanism of allelopathic effects,prolong the cultivation of forages and crops,field management,reasonable rotation,and selection and breeding of low-self-toxic species.The main research results obtained are as follows:1?The composition of the root exudates of 23 forage and crop varieties differed greatly.67 species of root secretions of Medicago sativa L.cv.Gannong No.5 were determined;55 species of Medicago sativa L.cv.Gannong No.9;104 species of Medicago sativa algonquin;37 species of Medicago truncatula;59 species of avena sativa L.cv.Longyan No.1;124 species of avena sativa L.cv.baiyan No.7;49 species of avena sativa L.cv.danmai444;60 species of Zea mays L.cv.demeiya;34 species of Zea mays L.cv.Longdan 339;69 species of Zea mays L.cv.Longdan No.8;52 species of Sorghum bicolor?L.?Moench desheng;51 species of Sorghum bicolor?L.?Moench Hainiu;35 species of Sorghum bicolor?L.?Moench Niumowang;37 species of Triticum aestivum L.cv.LongchunBJ-103;33 species of Triticum aestivum L.cv.Xihan No.3;36 species of Hordeum vulgare L.cv.Ganpi No.5;13 species of Onobrychis viciaefolia Scop.Gansu;19 species of Lolium perenne L.Jieda;60 species of Sorghum sudanense?Piper?.Ningnong;29 species of Sorghum hybrid sudangrass.deli;92 species of Purus frumentum;22 species of Poapretensis.Nuglade and 95 species of Sorghum vulgare.2?Heteropathic effects among forage or crop varieties are generally shown as negative effects,and the intensity of the heteropathic effect increases with the increase of extract concentration,which is the strongest when the seedling extract concentration is 2dwg·L^-1;different The effect of heterosexuality among pastures or crop varieties is mostly manifested as low concentration promoting growth,high concentration inhibiting growth,and“low promoting high inhibition”phenomenon,When the concentration of extract is lower than 0.5dwg·L^-1,it shows a positive effect,and when the concentration of extract is higher than 1dWg·L^-1,it shows a negative effect.and the intensity of the negative effect increases with the increase of the concentration of the extract(2dwg·L^-1>1dwg·L^-1).3.Some pastures and crops have special effects.When 4 kinds of alfalfa are used as donor varieties and Oat-baiyan No.7 are used as the recipient varieties,the change of the heterosexual effect between the alfalfa and Oat-baiyan No.7 is not obvious;the change of the heterosexual effect between alfalfa and sorghum varieties is not obvious;the heterosexual effect between corn and sorghum varieties generally shows a negative effect;Sorghum sudanense?Piper?.Ningnong as the extract liquid donor has a side effect on most other forages and crop varieties,while as a recipient,other forages and crop varieties have low performance and high inhibition on Sorghum sudanense?Piper?.Ningnong,There are also negative effects;when Poapretensis is used as the recipient variety,all other varieties have a negative effect on it;Hordeum vulgare L.cv.Ganpi No.5 is used as a donor,and it has a negative effect on many varieties?Medicago sativa,avena sativa L.,Zea mays L.,Onobrychis viciaefolia Scop.,Lolium perenne L.,Sorghum sudanense?Piper?.?all performed low,promoted and suppressed.4?The relationship between the effects of forage and crop allergy and the composition of root exudates.The difference in the performance of the allopathic effect between the test materials depends on the similarity of the root exudates.The more root exudates that are shared between the test materials,the more common the concentration of the root exudates in the detection of the other effect increases due to the cumulative effect The hematosensory effect appears as a negative effect;the less the root exudates shared among the test materials,the less cumulative effect of the root exudates concentration when the hematosensory effect is detected,so the hematosensory effect appears as low concentration promotion and high concentration suppression.