| Effective methods are required to repair and restore ecosystems in rocky desertification area where environment deterioration has been a serious issue. The application of mycorrhizal container seedlings, as a combination of many techniques, is of scientific rationale and has demonstrated utilities. Appropriate seedling matrix formula is the basis of cultivating high quality seedlings and determines the success of seed-rearing. Mulberry, as a native species in rocky areas,is considered both ecologically functional and economically feasible.. Arbuscular mycorrhizal(AM) fungi is ubiquitous in all types of soil and is able to form mycorrhizal symbiosis structure with most plants. This study seeked the best combination of a matrix formulation and AM fungi that is suitable for mulberry establishment and growth. We also tested the effectiveness of afforestation by application ofmycorrhizal container seedling of mulberry. This study obtained a seedlings matrix formulation suitable for No.12Guisangyou mulberrythrough a screening test of seedling substrate. Based on this, the effect on the growth of mulberry from the advantageous AM fungi and its rhizospheric micro-environment have been also studied by pot simulation experiments. Field study was conducted to verify the effectiveness of applying mycorrhizal container seedling of mulberry on afforestation. The technical feasibility of combing seedling substrate and AM fungi was being further discussed as well.(1) Using mushroom residue instead of peat as organic substrate materials,we studied that effects of different substrates with different proportions of mushroom residue on the physical and chemical properties of compound-substrates, and seedlings growth of mulberry.The results were showed that the treatments of T3, T4and T6(volume ratio of mushroom residue, peat, vermiculite and perlite was2:1:0:1,3:0:0:1,2:0:1:1, respectively) as a whole was superior to the compound-substrates of peat with corresponding proportion, involved the chemical properties such as organic matter, total nitrogen, total phosphorus, total postassium, and alkaline hydrolysis nitrogen, and the physical properties such as total porosity, aeration porosity and water-holding porosity. Comparison to the control treatment the growth indices of T6formula which involved plant height stem diameter, total root surface area and root tips number were significantly enhanced at106.21%,80.56%,644.11%,1044.31%and256.75%, respectively. Seedling dry weight, furthermore, reached at0.1811g.plant-1. The results strongly suggested that the compound-substrate of mushroom residue with rational ratio could be expected and applied in the cultivation of container seedling breeding of mulberry.(2) The rhizospheric micro-environment of several AM fungi and their effects on the growth of mulberry were studied by pot simulation experiments in purple soil. The results showed that AM fungi can significantly improve the absorption of nitrogen, phosphorus and potassium from soil, increase the accumulation of dry weight and promote the root development of mulberry. The significant increase of the content of leaf chlorophyll a, chlorophyll b and total chlorophyll in mulberry, resulting in the increase of photosynthetic, transpiration rate and stomatal conductance, and the decrease of CO2concentration, has also been observed. Thus, the photosynthesis of mulberry leaf was improved. Mycorrhizal fungi inoculation significantly increased the amount of mulberry rhizospheric microorganisms and enhanced the soil enzyme activities including catalase, urease, invertase andacid phosphatase, and therefore forming more active rhizospheric microflora compared to those without inoculation Inoculation of mycorrihizal fungi thus accelerated the decomposition of soil organic matter, improved nitrogen accumulation and phosphorus content. Among the three AM inoculation treatment, G.mosseae inoculation has shown the best ecological effect of mycorrhiza through various indicators, followed by G.intraradices and G. etunicatum.(3) According to preliminary research results, suitable composite matrix was choosed as the matrix of mulberry container seedlings and several AM fungi showed better effect on the growth of mulberry when applied with this matrix. Non-woven biodegradable bags was applied to studythe growth of mulberry and non-mycorrhizal container vessel mycorrhizal seedlings under field conditions. The results showed that in the four sample plots, the mulberry mycorrhizal container seedlings generated better afforestation effect and two inoculations still had a high infection status. The mycorrhizal effect was more directly reflected in G.mosseae and it can be potentially applied as a reference to industrial production of mulberry mycorrhizal container seedlings. |
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