【作者】 叶少萍；

【导师】 辛国荣；

【作者基本信息】 中山大学 ， 生态学， 2011， 硕士

【摘要】 本研究以“意大利黑麦草-水稻”轮作系统为研究对象,在水稻土壤和竹园土壤上种植黑麦草和后作水稻,研究了两方面的内容:一是通过多室根箱试验,研究接种菌根真菌菌剂(以Glomus mosseae为主)对黑麦草生长和根际微域环境的影响,包括土壤酶活性、有机酸含量、放线菌数量和土壤化学性质等指标的变化规律。二是通过盆栽试验,从系统上追踪接种菌剂和冬种黑麦草对后作早稻和晚稻生长的效应,包括产量、株高和分蘖动态变化等,进一步探讨菌根菌剂在轮作系统中的作用。主要研究结果如下:(1)由于土壤本底化学性质的差异,供试的水稻土壤和竹园土壤间差异显著(p < 0.05),黑麦草和后作水稻的生长均表现为水稻土壤优于竹园土壤。此外,两种土壤上早晚稻产量变化规律与生长指标变化不一致,如水稻土壤上水稻生物量、分蘖数和株高表现为早稻<晚稻,而产量则是早稻>晚稻,竹园土壤上情况则相反。(2)根箱试验中,各指标在根箱区域间呈现出一定的变化规律,尤其是根际与非根际之间土壤碱性磷酸酶活性、放线菌数量和基本化学性质差异明显。同样,区域间土壤有机酸种类和含量也存在差异,在水稻土壤上,根际土壤乙酸含量均高于非根际土壤;竹园土壤上,根际土壤乙酸含量比非根际土壤低37.45%-68.91%,而且柠檬酸和琥珀酸则是根际土壤>>非根际土壤,差别十分明显。(3)接种菌剂对黑麦草和水稻生长表现出明显的效应。接种菌剂处理下黑麦草和水稻根系出现AMF和DSE两种感染形式,并且以DSE感染为主。在根箱试验中,接种菌剂处理的黑麦草干重、植株全N和全P、土壤有机酸含量、碱性磷酸酶和转化酶活性均高于不接种处理;同时,水稻土壤上根际放线菌数量表现为接种>不接种,在竹园土壤上则相反。根系总感染率与土壤碱性磷酸酶间正相关性显著(p < 0.05)。类似地,在盆栽试验中,接种菌剂也增加了黑麦草株高、分蘖数和干重。而且,接种菌剂对后作水稻生长有明显的促进效应,不仅能够提高后作水稻的产量及产量相关指标,同时也提高了分蘖数、株高、生物量和早稻抽穗期最大叶宽、叶面积等指标。此外,早稻根系总感染率与土壤全磷水平间呈显著正相关(p < 0.05),表明总感染率受土壤化学性质影响极大。(4)与冬闲对照相比,盆栽冬种黑麦草提高了水稻土壤上后作早晚稻的产量及降低了竹园土壤上水稻产量,显示黑麦草根茬腐解产生了促进或抑制后作水稻生长的组分,而促进或抑制作用的选择可能与土壤化学性质密切相关。更多还原

【Abstract】 Two experiments were conducted to study the effects of arbuscular mycorrhizal fungi (AMF) inoculation on the rhizosphere microenvironment of Italian Ryegrass and growth of subsequent paddy rice. First, a root box experiment was designed to calculate effects of AMF (mainly Glomus mosseae) inoculation on growth of ryegrass and changes of the rhizosphere microenvironment, including soil enzyme activities, organic acid contents, actinomycetes numbers and chemical properties. Second, through pot experiment, influences of AMF inoculation and ryegrass cultivation in winter on growth of subsequent paddy rice including yields, plant weights and tiller numbers were systematically evaluated. The results were as follows:(1) Growth of ryegrass and subsequent paddy rice on rice soil were significantly better than zhuyuan soil, mainly due to difference of background chemical properties. Moreover, changes of yields and growth of subsequent paddy rice on these two tested soils were different. In rice soil, dried biomass, tiller numbers and plant weights of early rice were all less than those of late rice, while yield of early rice was higher than that of late rice. However, differences between early rice and late rice in zhuyuan soil were opposite.(2) In root box experiment, soil alkaline phosphatase activities, actinomycetes numbers and chemical properties changed significantly among three zones (p < 0.05). Meanwhile, contents and species of soil organic acid were different between rhizosphere and non-rhizosphere soil. In rice soil, compared with non-rhizosphere soil, acetic acid contents in rhizosphere soil were higher. Besides, in zhuyuan soil, acetic acid contents in rhizosphere soil were lower, while citric acid and succinic acid contents were much higher than those in non-rhizosphere soil.(3) AMF inoculation influenced growth of ryegrass and subsequent paddy rice greatly. AMF and DSE colonization were both observed in roots of ryegrass and subsequent paddy rice, and most roots were colonized by DSE colonization.In root box experiment, dried plant biomass, total P and N contents of ryegrass, soil organic acid contents, alkaline phosphatase and invertase activities under AMF inoculation treatments were all higher than those under treatments without inoculation. Moreover, compared with treatments without inoculation, AMF inoculation increased actinomycetes numbers in rice soil but reduced actinomycetes numbers in zhuyuan soil. Besides, total colonization of roots of ryegrass positively correlated with soil alkaline phosphatase activities (p < 0.05).Similarly, plant weights, tiller numbers and dried biomass of ryegrass with AMF inoculation in pot experiments also increased. Meanwhile, AMF inoculation promoted growth of subsequent paddy rice, including yields, plant weights, tiller numbers, dried biomass of rice, and maximum width of blade and leaf area of subsequent early rice. In addition, correlation between total colonization in roots of subsequent early rice and soil total P contents was both significant (p < 0.05), indicating that total colonization might greatly influenced by soil chemical properties.(4) Compared to winter fallow treatments, ryegrass planting increased rice yields in rice soil but reduced rice yields in zhuyuan soil on the contrary. This result showed that decomposition of roots of ryegrass might release components which would promote or inhibit growth of subsequent paddy rice, which was also related to soil chemical properties.更多还原