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Study on Allelopathy of Alfalfa

Author: ZhangWenJie
Tutor: LiXiangLin
School: Chinese Academy of Agricultural Sciences
Course: Grassland
Keywords: Alfalfa Allelopathic Autotoxicity Seedling Grow Chlorophyll Superoxide dismutase Peroxidase
CLC: S541.9
Type: Master's thesis
Year: 2010
Downloads: 190
Quote: 0
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Abstract

Allelopathy organism by producing one or more metabolites impact on the growth of surrounding plants, these metabolites is known that allelochemicals can be harmful or beneficial effect on surrounding plants. Alfalfa allelopathy of alfalfa seed germination and seedling growth autotoxicity. The impact of this research through field and greenhouse trials research alfalfa allelopathy of alfalfa (autotoxicity) and grasses (iso cytotoxicity). The main conclusions are as follows: 1. Sowing time impact on the the stubble after alfalfa autotoxicity role. Planting by tilling the land for five years alfalfa to study the impact of different tillage and planting interval after crop of alfalfa seedlings growth and physiological characteristics. The results show that: the plowing and sowing interval after crop of alfalfa growth conditions and physiological indicators have some impact. Intervals up to 90 days of treatment, post-crop alfalfa root length and shoot length was significantly greater than the other treatments (p lt; 0.05), and higher chlorophyll content, SOD and POD activity. Alfalfa autotoxicity spatial extent of the study (in situ). Plots planted five years of alfalfa, dropped my peripheral alfalfa detention center one, plowing the alfalfa plants and roots cleared out in a ring center alfalfa monoclonal around by different distance planting alfalfa from 20cm , 40cm, 60cm, 80cm, different distance after crop of alfalfa seedlings growth and physiological characteristics. The results show that: With the greater the distance, the alfalfa various morphological index has an increasing trend from 80cm to deal with various forms of indicators significantly (p lt; 0.05) is greater than the other treatments. Research the alfalfa autotoxicity spatial extent (transplanting). To not planted by a planted five years of alfalfa transplanting alfalfa ground in its surrounding ring seeding alfalfa from 20cm, 40cm, 60cm, 80cm, growth and physiological characteristics of different distances after crop of alfalfa seedlings the impact. The results show that: the farther from the center of alfalfa plants, the alfalfa various morphological index has an increasing trend from 80cm to deal with various forms of indicators significantly (p lt; 0.05) is greater than the other treatments. Extracts of grasses seedling growth. Certain effect of alfalfa extracts of different concentrations of orchardgrass seedling growth. With the increase of the concentration of cocksfoot seedling weight, root weight, root length decreased gradually, Elymus seedling weight, shoot length and root length performance to promote low concentration, high concentration inhibition. The germination rate is gradually reduced with the increase of the concentration of orchardgrass and Elymus control germination rate highest concentration of 5% minimum germination rate. Shows that alfalfa extracts containing the sensitive substance, the extraction and liquefaction of different concentrations of allelochemicals content, these allelochemicals grasses produce different degrees of impact. 5 isolation impact of grasses seedling growth. The alfalfa and cocksfoot species in the a pot, half planting alfalfa, half plant orchardgrass, middle separated by an impermeable partition, the control is not separated, the results show that: the alfalfa the ground and underground parts are to produce allelopathic different substances, above and below ground are separated or not the degree of Allelopathy. Separated root length, shoot length, fresh weight of seedlings were significantly higher than the up and down is not separated from the handle. The underground portion of the partition separating the seedlings fresh weight, shoot length was significantly higher than both the ground and aerial parts separated. The Banpen planting alfalfa the soil Banpen not planted alfalfa ordinary soil treatment with impermeable partition separated the control is not separated, orchardgrass grown in pots, the results showed that: ordinary soil treatment separated root weight seedling weight, root length, shoot length, leaf chlorophyll content was significantly higher than the ordinary soil Undivided POD activity was significantly lower than that every ordinary soil. The ordinary soil treatment separated leaf chlorophyll content was significantly higher than across the alfalfa soil. Shows that planting alfalfa soil allelochemicals, not separated from the processing of allelochemicals in the alfalfa soil through infiltration into ordinary soil, and in turn have an impact on orchardgrass. Separated processing, allelochemicals content of the alfalfa soil in the more than ordinary soil, stronger inhibition cocksfoot. 6. Replacement of alfalfa seedling growth of grasses. Different proportions of alfalfa and grasses planted in the same pot, control all the grasses, the different proportions of alfalfa of orchardgrass and Elymus seeds germination and seedling growth of certain effects. With the increase the proportion of alfalfa, orchardgrass and Elymus root length, shoot length, seedling fresh weight, root fresh weight of each morphological indicators have decreased. Orchardgrass and chlorophyll content of Elymus performance for first and decreased. Alfalfa and cocksfoot ratio of 1 to 3, the highest total chlorophyll b, chlorophyll a and b are significantly higher than other treatments, alfalfa Elymus ratio of 1 to 3, the chlorophyll a content, the content of chlorophyll b, total chlorophyll a and b are the highest. Replacement orchardgrass, biomass decreased replaced Elymus biomass decreased, but alfalfa cocksfoot ratio of 1 to 3, the increase in biomass. Germination test processing in Elymus root length, shoot length, seedling fresh weight, root fresh weight form of indicators are significantly lower than the control.

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