Effects Of Soil With Different Previous Vegetation On Seedlings Of Pinus Elliottii By Cutting Root-Apexes Off And Inoculating With Pisolithus Tinctoriu

Effects of the soil with different previous vegetations on the seedlings of Pinus elliottii by cutting their root-apexes off and inoculating with Pisolithus tinctorius (Pt) was studied from 2003-2004 in Taihu county, and the relationship between the soil fertility and different previous vegetations and the mycorrhizal infectious incidence, the survival rate, growth, physiological index, indexes of resistance of inoculated seedlings were released in this experiment. More perfect soil types and the dosage of inoculums which are suited for growth of seedlings of Pinus elliottii was obtained in order to find the good methods for cultivating seedling and planting design of Pinus elliottii in Anhui Province.1. Mycorrhizal infection incidence of seedling had positive closely correlation to the growth of Pinus elliottii. In different seedling-growth index the increasing of length of lateral root was more significant than others. In different previous soils the miscellaneous shrub forest was more suit for the growth of seedlings by cutting their root-apexes off and inoculating with the linear recursive slope is 0.3167, the relationship coefficient is 0.9973, the linear regression slope for activity of super-oxide-dismutase(SOD, one of the resistant index) is 0.1988.2. The soil from different previous vegetations were used for cultivating seedling of Pinus elliottii by cutting their root-apexes off and inoculating with Pisolithus tinctorius (Pt)in this experiment. The results showed there were distinctly difference in different previous soils (p<0.01). According measure data of last stage of growth, mycorrihizal infection incidence of seedling in the soil from miscellaneous shrub forest achieved 99.5%. The height and the diameter at ground surface reached 24.84cm and 3.89mm respectively. The ratio of free water to bound water is the least (4.2). More resistance was showed under adversity. The blended soil is better than other seven previous vegetations of soil but is inferior to the soil from miscellaneous shrub forest and broad-leaved forest a little. As a result, soil from miscellaneous shrub forest and broad-leaved forest are the preferable soil for cultivating seedling and planting design of Pinus elliottii in Anhui Province. Those soils from herb garden, rice-field, hill and sand should be avoided.3. Growth of inoculated seedling was greatly affected by soil physical factors. In the clay the stimulative effect of soil humus on inoculated seedling is constrained. In the sand bulk density (0.83g/cm~3) deviates 1.20g/cm~3 farthest,the ratio of free water to bound water of seedling reached 8.8 and the resistance was the lowest in all experiment soil. It shows that water status and adaptability to adversity of inoculated seedlings were affected by the soil bulk densityMycorrihizal infection incidence of seedling was negative correlation to the value of pH. Mycorrihizal infection incidence of seedling is only 86.57% in the sand with the higher pH value. Every index of growth with inoculated seedling were strongly negative correlation to the value of pH in the soil of this experiment. Growth of seedling is restrained when the pH value increases. Soil acidification should be noticed when breeding seedlings with mycorrhizae especially in alkalescent soil.The contents of soil humus and nutritional elements had strongly positive correlation to mycorrihizal infection incidence and growth of seedling. mycorrihizal infection incidence of seedling reaches 99.6% in soil with highest content of soil humus (43.42g/kg). This shows that mycorrhiza also need well-fed soil to absorb and utilize. With the advancing of soil fertility , the survival rate enhances, root activity increases and chlorophyll content heightens. The decrease of the ratio that free water to bound water was accelerated at the condition of low temperature and drought. Drought resistance and chilling resistance of inoculated seedling was improved at a certain extent. Six resistant biochemical indexes of inoculated seedling affected by soil factors directly. Enzyme active develops with the contents of soil nutritional elements increasing. Regress equations about soil factor and index of growth were educed in this experimentation. All relationship coefficients are high. The degrees of simulations are all above 0.78. Soil used for breeding seedling can be confected hereby for the sake of the most perfect content of soil factor, the greatest effect of mycorrhizal, the optimal beneficial result of breeding seedlings and forestation.4. The best result of inoculated seedling can be made with the dosage of 1 ml ectomycorrhizae Pisolithus tinctorius inocula and in the soil from miscellaneous shrub forest. After three months from transplant, the diameter at ground surface, weight, height, and the total length of lateral root reaches 3.89mm, 10.38g, 24.48cm and 65.49cm respectively. Root activity is 5.0305g/g·h. Although the result of the dosage with 2 ml and 3 ml inoculum improves a little, there were obscure difference between them and the 1 ml dosage. Thereby 1 ml dosage is the best choice for its low consumption and higher efficiency. 5. Based on the survey of forestation with inoculated seedling in soil from miscellaneous shrub forest, the results show that survival rate of forestation increases greatly. It was increased to 136.9 percents of uninoculated seedling. Also there were distinctly different between inoculated seedling and uninoculated seedling on height, the root collar diameter and fresh weight and needles height.