信阳裸子植物枝栖真菌初步研究

[目的]了解信阳地区裸子植物枝栖真菌的生态分布特征。[方法]通过采样、分离培养与鉴定,对信阳地区裸子植物枝栖真菌进行了初步调查研究。[结果]信阳裸子植物枝栖真菌分属5科9属20种,以半知菌种类最多,其次为接合菌,未发现担子菌和子囊菌。在裸子植物枝上,木霉属真菌分布普遍,种类丰富。Rhizopus nigricans、R．oryzae、Trichoderma harzianum、T.aureoviride、Trichoderma sp．1、Trichoderma sp．2、Alternaria tenuis、Pestalotiopsis sinensis、Pestalotiopsis sp．和Fusarium oxysporum的分离率均高于10％。[结论]信阳裸子植物枝栖真菌由半知茵与接合菌构成,其中半知菌占多数。木霉为裸子植物常见的枝栖真菌,其种类多,分布广。信阳地区水杉枝栖真菌的种类最丰富,龙柏枝栖真菌的种类较少。     

杉木人工林凋落物中微生物数量对间伐的响应

为了明晰凋落物中微生物数量对间伐强度的响应程度,以南京溧水林场间伐7 a后25年生的杉木(Cunninghamia lanceolata(Lamb.)Hook.)人工林为对象,研究了不同间伐强度对凋落物中真菌、细菌、放线菌3类微生物数量季节性变化的影响。结果表明:不同强度间伐杉木人工林下凋落物中微生物的数量随季节变化差异显著,微生物数量在春季期间对间伐响应最为显著。与对照相比,春季内弱度间伐下细菌数量显著减少了61.05%(P0.01);而春季内中度间伐下的真菌和细菌数量分别减少了25.32%(P0.01)和36.14%(P0.01),放线菌则增加了30.97%(P0.05);春季内强度间伐下真菌量和放线菌数量分别增加了77.64%(P0.05)和59.35%(P0.01),细菌数量减少了42.11%(P0.01)。其中,凋落物层温度及林下植被层Margalef指数对微生物数量的影响最为显著。微生物数量的影响会导致凋落物向土壤中输送的养分不同,对提高林分生产力有重要意义。     

发展农田秸秆菌业的技术集成与资源循环利用管理对策

本文分析了我国草生菌业的生产实际, 深入探讨了农田秸秆菌业循环生产体系的主要环节和优化构建, 并详细阐述了各个环节的管理对策.通过对秸秆堆制发酵、优质高产栽培管理、菌渣循环利用和环境生态监测等关键环节的有效链接与整合优化, 建立"稻草(秸秆)-食用菌-菌渣-农田(园地)再循环-资源再利用"的农田秸秆菌业循环生产新体系的运作模式, 并展望了农田秸秆菌业的推广和开发前景.     

抗真菌转基因水稻根际土壤真菌群落结构的动态变化

以非转基因水稻"七丝软粘"为对照,采用传统平板计数法和变性梯度凝胶电泳技术,研究了抗真菌转基因水稻"转品1"和"转品8"生长周期内对根际土壤中可培养真菌数和真菌群落结构的影响。结果显示,相同生育期转基因水稻根际土壤可培养真菌数量与其非转基因对照水稻相比较无显著性差异,表明转基因水稻的种植没有对根际土壤真菌数量产生明显影响;18S rRNA真菌群落DGGE图谱分析显示,相同生育期转基因水稻与其非转基因对照水稻的根际土壤真菌DGGE条带数量和条带位置均无显著性差异,表明转基因水稻的种植没有对根际土壤真菌群落结构产生明显影响。进一步分析相同生育期转基因水稻与其非转基因对照水稻的根际土壤真菌群落香农多样性指数(Shannon diversity index)和均匀度指数(Evenness index)的动态变化,发现两者均没有显著性差异。以上研究结果表明,外源抗真菌基因的导入对水稻根际土壤中真菌群落数量和群落结构均没有明显影响。此外,将不同位置的真菌DGGE条带切胶回收,克隆、测序后,进行系统进化树分析,结果表明根际土壤真菌群落主要归属为子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、壶菌门(Chytridiomycota)、接合菌门(Zygomycota)和未知真菌(unknown fungi)5个类群。     

Fungal communities in bulk soil and stone compartments of different forest and soil types as revealed by a barcoding ITS rDNA and a functional laccase encoding gene marker

The soil fungal diversity and community partitioning between the bulk soil and stone compartments was investigated using PCR based approaches targeting the barcoding internal transcribed spacer (ITS) of rDNA and the laccase encoding functional gene as genetic markers. Soil samples were collected from the B-horizon of spruce and beech forests at the Hainich Biodiversity Exploratory, central Germany. The targeted markers were amplified from the respective DNA extracts using general fungal primers and basidiomycete laccase gene specific primers, cloned and sequenced. Differences in the fungal community composition between the two forest types and the soil compartments were indicated by both markers. When the effects of ecological factors were considered, the two markers produced different patterns of results. The ITS rDNA marker revealed communities principally influenced by forest type, while those detected with the functional marker were mainly affected by soil pH. The fungal communities detected by the functional marker in particular, differed significantly between soils and stones, indicating that laccase-producing fungi are specifically adapted to degrade organic matter in soils rather than weathering of stones. The study underlines the fact that coherent and complementary results may be obtained with both genetic markers used.     

Earthworms increase the ratio of bacteria to fungi in northern hardwood forest soils, primarily by eliminating the organic horizon

The exotic earthworm invasion in hardwood forests of the northern United States is associated with many ecosystem-level changes. However, less is known about the effects of the invasion on the composition of the soil microbial community through which ecosystem-level changes are mediated. Further, earthworm effects on soil microbial community composition have not been well studied in the field. To evaluate changes in bacterial and fungal abundance associated with the earthworm invasion we quantified bacterial and fungal biomass by microscopic counts in paired earthworm-invaded (earthworm) and earthworm-free (reference) plots in five forest stands in central New York (USA). Earthworms significantly increased the ratio of bacteria to fungi on an area basis (per m²), by more than two times in mid-summer and early autumn. While this effect was associated primarily with the lack of the fungal-dominated organic horizon in earthworm plots, a higher ratio of bacteria to fungi in the surface 5 cm mineral soil also contributed as it developed between spring and mid-summer. Earthworm reduction of fungal biomass was confirmed by substantially lower growth of fungal hyphae into mesh sand bags in earthworm compared to reference plots. Burrowing activity by the earthworm Lumbricus terrestris increased the ratio of bacteria to fungi over the short-term within earthworm plots, introducing small-scale spatial heterogeneity associated with burrows. Our study suggests that the exotic earthworm invasion in these northern hardwood forests markedly increased the ratio of bacteria to fungi by eliminating the fungal-rich organic horizon, and was associated localized increases in bacterial vs. fungal abundance in mineral soil, setting the stage for future research into linkages between the earthworm invasion, bacterial and fungal abundance, and ecosystem processes.     

Growth and Fruit Chemical Characteristics of Blackberry (Rubus Fruticosus) Cultivated with Vermicompost,Glomus Mosseae and Phosphate Rock

Abstract

The aim of this investigation was to determine the effect of vermicompost (V) and phosphate rock (PR) on blackberry (Rubus fruticosus L. agg.) plants inoculated with Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe (AMF). Plant growth parameters, total phenol compounds and total flavonoids were evaluated on leaves. Anthocyanin contents, soluble solids (SS), pH, titratable acidity (TA) and SS/TA ratio was evaluated in blackberries fruits. Blackberry plants were obtained from cuttings from field plants, which were distributed in soil according to a randomized complete block design with three repetitions. Treatments were vermicompost (10?g plant^?1), phosphate rock (1?g plant^?1), Glomus mosseae (AMF), (1?g plant^?1), PR + AMF, V + PR, V +AMF, V + PR+ AMF and control without any amended. Plant height and stem diameter were measured five months after treatments, while total phenols and total flavonoids in leaves were evaluated eight months later. Anthocyanins, SS, pH, and TA were determined in blackberry fruits ten months after. Plant height was not statistically affected (p≤0.05), although total phenol compounds were higher (21.1?mg g^?1 dry plant) in the V+PR+AMF treatment, whereas the V + AMF treatment produced more dry plant total flavonoids (1.4?mg g^?1), compared with control plants. Blackberries produced with the vermicompost treatment had more anthocyanins (9.54?mg g^?1) than control plants. Soluble solids, pH and titratable acidity were not statistically (p≤0.05) affected by any treatment.     

不同腐烂程度毛竹蔸微生物变化研究

研究不同腐烂程度毛竹蔸中的微生物菌群,结果发现细菌对数值最低为5.477,最高为7.380;真菌对数值最低为5.301,最高为6.903;放线菌对数值最低为5.740,最高为7.000;纤维素降解菌对数值最低为4.301,最高为6.477;木质素降解菌最低为4.415,最高为6.799。毛竹蔸腐烂过程中,前期各菌增长较快;中期细菌、真菌、放线菌对数值不断变化;后期菌对数值都较高;各菌之间存在着一定的协助和竞争。了解竹林砍伐前期的竹蔸腐烂规律,可为砍伐后的竹蔸降解提供参考,同时为竹蔸微生物在种级单位上的分离提供依据。     

真菌蛋白的提取及其对玉米病害的抗性诱导

以4种病原真菌为材料,提取其蛋白进行试验,比较了蛋白对玉米大斑病和玉米锈病的抗性作用。结果表明:烟草赤星病的病原菌链格孢属链格孢菌Alternariaalternata(Fries)keissler的提取蛋白对两种病害的抗性都极其显著,很好的应用前景和开发价值。     

轮作和连作田大豆胞囊线虫胞囊上真菌定殖动态

研究沈阳市汪家乡连作6年和轮作大豆田中胞囊数量以及大豆不同生长期胞囊上定殖真菌的种群及数量变化.结果表明:在整个大豆生长期中,不饱满胞囊量高于饱满胞囊量.连作田中胞囊总量、不饱满胞囊世高于轮作田.从胞囊上分离列的真菌以镰孢菌居多,在大豆不同生长时期镰孢菌属的分离频率不同,其中潦孢镰菌Fu-sarium.oxysporum为优势利,且连作田中数量多于轮作田;除镰孢菌属真菌外,轮作田中胞囊上分离到的青霉属和粘帚霉属真菌数量最多,还分离到毛霉属、毛壳菌属和拟青霉属;而连作用中胞囊上分离到的真菌中粘帚霉属数量最多,其他各属真菌的数量都很少,其中轮枝菌属和腐质霉属存轮作用胞囊上未分离到.镰孢菌的定殖数量与胞囊的饱满程度有关,而青霉、粘帚霉和拟青霉等其他真菌种群也影响到胞囊的饱满程度.