| Robinia pseudoacacia is one of the most important reforestation trees in northern China. The field investigation suggested that Robinia pseudoacacia had poor establishment and low productivity, and would lead to soil degradation when grown after it again. So, the bioassays seed germination was used to assays the effect of Robinia pseudoacacia rhizosphere soil, Robinia pseudoacacia litter and Ailanthus altissima rhizosphere soil allelochemicals extracted by different solvent on Robinia pseudoacacia seed germination and growth of seedling. To verify the existence of autointoxicational; and then on this basis to study the effection of Robinia pseudoacacia litter, Robinia pseudoacacia rhizosphere soil and Ailanthus altissima rhizosphere soil on external form of Robinia pseudoacacia seedlings and some physiological indicators. Explore the relation between Robinia pseudoacacia and Ailanthus altissima , and it have great theoretical and practical significance of reference value that resolve the issue of Robinia pseudoacacia plantation obstacles and achieve the sustainable management of woodlands Robinia pseudoacacia, Robinia pseudoacacia plantation to prevent a decline in productivity Through the research on the main role in various biological and chemical reactions between Robinia pseudoacacia with others. The results show that:(1) The extract of Robinia pseudoacacia rhizosphere soil, Robinia pseudoacacia litter and Ailanthus altissima rhizosphere soil can inhibit effect at low concentrations but less than significant level on Robinia pseudoacacia seed germination rate,seed vigor and seedling root length, and even some of the performance of to promote the role of inhibition in the higher concentration increased and gradually reached a significant level, to 0.2 gDW?ml-1 basically completely inhibited seed germination and seedling root length growth.No matter in what concentration, the three extracts on the inhibition of Robinia pseudoacacia in general as follows: Robinia pseudoacacia rhizosphere soil> litter Robinia pseudoacacia> Ailanthus altissima rhizosphere soil. Three extracts of Robinia pseudoacacia seedling growth than on the promotion of the role of promoting the role of seed germination.(2) The effect of Ailanthus altissima rhizosphere soil extract on the one-year-old Robinia pseudoacacia seedling height and diameter growth is large, low concentration (0.005 gDW?ml-1 and 0.01 gDW?ml-1), to promote Robinia pseudoacacia seedlings growth, but with increasing concentration, and promote the role of inhibition gradually changed, and inhibition gradually increased, to 0.1gDW?ml-1 when the level of inhibition was significant. The effect of Robinia pseudoacacia rhizosphere soil extract on its own seedlings role at low concentrations was not obvious, only when in higher concentrations were inhibitory, and inhibitory concentration greater than the same rhizosphere soil Ailanthus altissima inhibition. Ailanthus altissima rhizosphere soil and Robinia pseudoacacia rhizosphere soil play different role on the effect of Robinia pseudoacacia height, and the inhibition on height than on the diameter.(3) Robinia pseudoacacia rhizosphere soil can inhibit photosynthesis of itself, and the concentration of the more significant the greater the inhibition. Ailanthus altissima rhizosphere soil extract also can inhibit photosynthesis of Robinia pseudoacacia seedlings, but smaller than Robinia pseudoacacia rhizosphere soil in the inhibition of, even in low concentrations have no significant role in promoting(4) Robinia pseudoacacia rhizosphere soil extract have inhibition on the synthesis chlorophyll a and chlorophyll b of Robinia pseudoacacia seedlings,and the inhibition of chlorophyll a is greater than to chlorophyll b. The Robinia pseudoacacia rhizosphere soil extract can cause damage to the formation of the chlorophyll and impact the balance between synthesis and decomposition of chlorophyll. Ailanthus altissima rhizosphere soil extracts for chlorophyll a and chlorophyll b main role is to advance the role, only in very low concentrations (0.005 gDW?ml-1) show a certain degree of inhibition of the Agency, the effects are not significant. In other concentrations the influence of chlorophyll content has a certain degree of increase.(5) Robinia pseudoacacia rhizosphere soil extract and Ailanthus altissima rhizosphere soil extract can effect membrane permeability of Robinia pseudoacacia seedlings, but not too great, with the increase in concentration, membrane permeability gradually become larger, and slow to change, when the concentration is 0.1gDW?ml-1 the effects of Robinia pseudoacacia rhizosphere soil extract on electrical conductivity of Robinia pseudoacacia seedlings reach a significant level. no matter under what the concentration, the effections Ailanthus altissima rhizosphere soil extract on Robinia pseudoacacia seedlings membrane is less than the destruction of the role of Robinia pseudoacacia rhizosphere soil extract its impact, so the destructive effects of Ailanthus altissima rhizosphere soil to cell membrane of Robinia pseudoacacia seedlings smaller than Robinia pseudoacacia rhizosphere soil.(6) In the impact of Robinia pseudoacacia and Ailanthus altissima rhizosphere soil rhizosphere soil extracts, the cell superoxide dismutase activity and the superoxide dismutase of Robinia pseudoacacia seedlings in general is rising, only when present in low concentrations to reduce. In the role of allelochemicals, the plant cells affected, or cell membrane damaged, cell superoxide dismutase activity increased, peroxidase activity rise, but change less, and effections of Ailanthus altissima rhizosphere soil was significantly less than Ailanthus altissima in itself. So with the increased of concentration both extracts on the growth of Robinia pseudoacacia for the inhibitory effect of a gradual change, And the effection of Robinia pseudoacacia has been obvious than Ailanthus altissima.(7) Robinia pseudoacacia rhizosphere soil extracts of the soluble sugar content did not affect, in the autotoxicity, the increased of soluble sugar content of Robinia pseudoacacia small, but the increased significantly under Ailanthus altissima, As the concentration increases, the content increased gradually. Allelopathy of Ailanthus altissima can stimulate the accumulation of sugar of Robinia pseudoacacia, which improve the ability of Robinia pseudoacacia Anti-Stress to a certain extent, contribute to the rapid growth of the future.In both the effects of extracts, cells MDA in Robinia pseudoacacia seedlings have a certain increase. In two extracts of the cell membrane systems have a certain degree of damage. However, in low concentration (0.005gDW?ml-1), the cells MDA in Robinia pseudoacacia seedlings declined or increased very little, the damage of membrane gradually increased, and the destructive effects of Ailanthus altissima rhizosphere soil extract to Robinia pseudoacacia membrane less than Robinia pseudoacacia rhizosphere soil in the destructive effects.(8)In low concentration, the free proline content lower, with the higher concentration, a gradual increase in proline content. Generally in the same concentration, Robinia pseudoacacia seedlings with a high level of proline under the effection of Robinia pseudoacacia rhizosphere soil extract. So the inhibition of Robinia pseudoacacia rhizosphere soil extracts on Robinia pseudoacacia seedlings is larger. When the concentration reached 0.1 gDW?ml-1, the effection of two rhizosphere soil extracts close to the same size, we can see that when the concentration of relatively large, the two extracts on the growth of Robinia pseudoacacia seedlings have similar inhibitory effect.
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