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Plant Allelopathy (Allelopathy) refers to the higher plant secondary metabolism of chemicals released into the environment, and its neighboring plants or their own (ie his sense also known autotoxicity) adverse or beneficial role. Invasive plants by human activities, either intentionally or unintentionally introduced into the natural distributions, establishing populations outside the natural distribution of natural and semi-natural ecosystems or habitats, and pose a threat to biodiversity and the introduction of land, destruction of species diversity of plants and ecosystems. Allelopathy invasive plants has long been recognized allelopathic increasingly attracted attention as a kind of alien plant invasion mechanisms. (Chenopodium ambrosioides L.), also known as foul grass Aritaso insecticidal mustard, goose foot grass Chenopodiaceae Chenopodium annual or perennial herb, native to tropical America, now widespread in the world's tropical and temperate regions in China have shown a trend of very rapid expansion. Chenopodium ambrosioides as an invasive plant, belonging to the agriculture, gardening, general weed, a more serious impact on farmland, gardens, but little about the the Allelopathy study reported. Select Aritaso invasion of farmland common victims of crops wheat, rice, cabbage, pepper, cowpea as test material, the determination of the role 5 of different concentrations wormseed fresh samples and dry sample extracts crops seeds germination rate, seedling morphology, MDA content, antioxidant enzyme activity, adult morphology and biomass change, and were wormseed the root, stem, leaf, flower as a donor material above study to explore impact the Allelopathy Aritaso above five crops, in order for the crops of the fields weeding, the Chenopodium ambrosioides intrusion mechanisms, prevention and the use of some of the theoretical and practical basis. The results show that: 1) the soil of Nepeta fresh samples with different concentrations of dry sample extracts handle five crops, the different concentrations Aritaso extracts the test plant growth and physiological effects of, concluded as follows: fresh sample of soil Nepeta and dry sample extracts have an allelopathic effect, and the higher the concentration, the stronger the soil Nepeta allelopathy. The Chenopodium ambrosioides allelopathy can reduce the rate of seed germination, seedling root length and the higher the concentration of the more obvious effects of plant extracts; seedling stem height is concerned, wheat, cabbage, cowpea showed low concentrations to promote the growth of high concentrations of suppression growth phenomenon, rice and pepper with the concentration of the extracts increased inhibition enhanced. With the increase of the concentration of the extracts, the MDA content in the leaves of crops increased gradually leaves SOD, CAT, POD activity trends of the same, but high concentrations of extracts can inhibit the activity of antioxidant enzymes. The impact of the Chenopodium ambrosioides plant extracts on five crops adult plant morphology less than its impact on seedling morphology, five crops only in the processing of high concentrations of extracts stem height, diameter at breast height, root length by more obvious inhibition . For biomass changes a low concentration Aritaso extracts can effectively promote the biomass of wheat, cabbage aboveground biomass accumulation, but little pepper and cowpea biomass, and the inhibition of rice the biomass; the high concentration Aritaso extracts treatment under each recipient plants are not normal growth. 2) Chenopodium ambrosioides different organs of the fresh and dry sample extracts, processing crops research the different organs Aritaso extraction liquid physiological impact on the growth of test plants, concluded as follows: soil of Nepeta different organs differences extract on the same receptor Allelopathic inhibition potency order: flower> leaf) roots> stems is not absolute, but the order in which the intensity of the role of each organ, there may be differences between the different plants. Chenopodium ambrosioides organ extracts on seed germination, reduced seed germination rate of five crops, rice seed germination rate increased significantly only stems dry sample extracts processing. Root length and stem height is concerned, wormseed flower, leaf extracts of five crops of root length and stem height were significant inhibitory effect, but the stem size depends on inhibition of root extracts of the test plants varies. Under the Chenopodium ambrosioides flower, leaf extract treatment, the increase in MDA content in the leaves of crops magnitude higher than the the soil the Nepeta root, stem extracts processing. Leaf SOD, CAT, POD activity trends of the same flower and leaf extract antioxidant activity inhibition is the most obvious. Of the soil of Nepeta different organs extracts of adult plant morphology of five crops less than its impact on seedling morphology still flower, leaf extract on the crop adult plant stem height, diameter at breast height, root length. For biomass changes, in addition to the fresh stem extracts promote the accumulation of aboveground biomass of wheat root and cabbage, five kinds of biomass crops decreased and flower extracts of the various organs of the crop biomass The inhibition of the most obvious. In summary, different test plants of the significant differences in the sensitivity to the presence of Chenopodium ambrosioides allelochemicals; different manifestations of the same receptor concentration due allelochemicals obvious differences, the higher the concentration of allelopathy is more obvious; same subject body due to the different organs of the role of the Aritaso also showed significant differences, the most significant to the flowers and leaves of allelopathy. In addition, the the Chenopodium ambrosioides different treatments (fresh and dried processing) performance Allelopathy There are some differences, but the same trend of performance on crops allelopathy. Has strong allelopathy its weed characteristics given Aritaso Aritaso potentially harmful and should increase its efforts of controlling.
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