北美蓝云杉菌根化育苗技术研究

为提高北美蓝云杉引种成活率并促进其幼苗生长，于2007年进行了适宜菌种的筛选和菌根化育苗技术的研究。结果表明:1）普通裂褶菌和Pt菌剂为较适宜的菌种。2）接种Pt菌剂后，不同种源间的平均苗高差异不显著，不同接种时间的平均苗高差异极显著。3）不同种源的适宜Pt菌剂接种量不同。1号和3号种源施用1 g/株的菌剂，2号和4号种源施用0.5 g/株的菌剂促进生长的效果最好，2个月后1～4号种源幼苗的平均苗高分别为3.31、3.90、3.84和3.54 cm。4）在幼苗移植时接种Pt菌剂不仅可以提高移植成活率，还有助于保持观赏性状。接种Pt菌剂后移植成活率均达85%以上，其中4号种源移植成活率最高，为92.86%；与对照相比，接种Pt菌剂后1级苗增多，其中3号种源的1级苗率最高，为56.67%。      

玫烟色棒束孢几丁质酶基因上游调控序列克隆与结构预测分析

为探明玫烟色棒束孢几丁质酶基因Ifuchi1的表达调控机理，根据Ifuchi1基因组全长核苷酸序列，采用基因组步移方法，获得Ifuchi1的5′-上游区序列(总长为2 402 bp)。与cDNA 序列进行比对，其中含有2个内含子。TFSEARCH 1.3 软件分析转录因子结合位点的结果显示，该序列中没有明显的TATA和CAAT框，含有4个可能的碳调控因子的结合位点5＇>(g/c)YggRg<3＇和3个氮调控因子的结合位点-相隔很近的GATA。其中含有可能的葡萄糖抑制调控序列和压力反应元件。本研究结果为深入研究玫烟色棒束孢几丁质酶基因的表达调控机制及其分子机理奠定了一定基础。     

Senescence in sweet corn as influenced by phosphorous nutrition 1

Nutrient availability can affect the onset of senescence. Phosphate‐phosphorus (P) was added at the recommended and five times the recommended level to a Bernow fine‐loamy, siliceous, thermic Glossic Paleudalf soil at Lane, OK. Senescence in stalk and shank internodes and cobs was rated in shrunken‐2 sweet corn (Zea mays L.) cultivars at various developmental stages. Plant dry weight was determined at fresh market harvest. Stalk internode senescence rating increased through harvest. The internode subtending the ear node was almost completely senescent at anthesis. There were statistical, but likely not biologically important, differences in stalk internode senescence between cultivars. Increased P occasionally increased stalk internode senescence rating and reduced plant dry weight. Increased P either decreased, or had no effect on, shank internode or cob senescence.     

Suppressive effects of seed-applied fungicides on arbuscular mycorrhizal fungi (AMF) differ with fungicide mode of action and AMF species

Seed-applied fungicides are commonly used to prevent or suppress fungal disease organisms in pulse crop production. However, non-target beneficial fungi, such as arbuscular mycorrhizal fungi (AMF), also may be affected. Seed-applied fungicides Agrox^® FL (active ingredient: captan), Allegiance™ FL (metalaxyl), Apron Maxx^® RTA^® (fludioxonil and metalaxyl), Thiram 75WP (thiram), Vitaflo^® 280 (carbathiin and thiram), Crown^® (carbathiin and thiabendazole), and Trilex^® AL (trifloxystrobin and metalaxyl) were assessed in a greenhouse study for their effects on colonization and development of AMF in pea and chickpea, and the consequent impact on plant growth. In the absence of disease pressure, systemic fungicides Allegiance™ FL, Apron Maxx^® RTA^®, Vitaflo^® 280, Crown^® and Trilex^® AL restricted mycorrhizal colonization, host growth and P uptake to different levels. In contrast, contact fungicides Agrox^® FL and Thiram 75WP had minimal effects on mycorrhizal colonization, host growth and P uptake. Although consequent sporulation and glomalin-related protein production were not significantly affected by fungicides at an early host growth stage, the compositional structure of the AMF community in host roots was significantly altered in response to Agrox^® FL, Allegiance™ FL, Apron Maxx^® RTA^®, and Trilex^® AL as revealed by pyrosequencing-based analysis of fungal 18S rRNA. These results indicate that the suppressive effects of seed-applied fungicides on AMF development depend on specific fungicide-AMF interactions.     

Problems of using pines in <Emphasis Type="Italic">Tuber melanosporum</Emphasis> culture: soils and truffle harvest associated with <Emphasis Type="Italic">Pinus nigra</Emphasis> and <Emphasis Type="Italic">P. sylvestris</Emphasis>

In Mediterranean pine forests, truffles and mushrooms generate greater profits than any other woodland products. However, there are no studies on Tuber melanosporum Vittad. associated with pines. For this reason, we have carried out a study of this truffle in mountain woods with Pinus sylvestris L. and P. nigra Arnold subsp. salzmannii (Dunal) Franco, in central Spain. Two hundred and eight Tuber melanosporum burns were monitored for 7 years in five different habitats within the same geographical area. An ANOVA test confirmed significant differences in carpophore production. In higher producing habitats, pines were less abundant. We also confirmed that in 433 burns, T. melanosporum was always unequivocally associated with the root base of Quercus or Corylus trees. Similarly, 14 truffle collectors confirmed that they had never found a single burn with carpophore production associated exclusively with pines. Nevertheless, soil analyses indicated that the soil of these pine woods was very favourable to Tuber melanosporum. We therefore conclude that at present Pinus nigra salzmannii and P. sylvestris are of little interest to Tuber melanosporum culture, as they hinder carpophore production. However, this study has also confirmed that Pinus nigra salzmannii and P. sylvestris mycorrhize easily with Tuber melanosporum, both in the laboratory and in natural environments. On this basis, we propose that pines may act as transmitters of T. melanosporum, although they do not induce fruiting. As a result, the commercial cultivation of Pinus nigra salzmannii and P. sylvestris seedlings mycorrhized with Tuber melanosporum is not recommended in truffle culture at the present time.     

Dual inoculation of a woody legume (Centrolobium tomentosum) with rhizobia and mycorrhizal fungi in south-eastern Brazil

The integration of N₂ fixing trees into stable agroforestry systems in the tropics is being tested due to their ability to produce high biomass N and P yields, when symbiotically associated with rhizobia and mycorrhizal fungi. The growth of Centrolobium tomentosum Guill. ex Benth, a native leguminous tree from the Brazilian Atlantic Forest, was assessed with dual inoculation of Rhizobium spp and mycorrhizal fungi under field conditions. Complete fertilization was compared to treatments of inoculation with selected rhizobia strains BHICB-Ab1 or BHICB-Ab3, associated or not to arbuscular mycorrhizal (AM) fungi. The dual inoculation increased the height and growth in relation to the plants treated with rhizobia alone. Plants inoculated with strain BHICB-Ab1 and arbuscular mycorrhizal fungi (AMF) exhibited an increase of 56% dry matter over uninoculated control and nitrogen accumulation was greater than with BHICB-Ab3 inoculated plants. Strain BHICB-Ab1 presented a synergetic relationship with mycorrhizal fungi since the combined inoculation with BHICB-Ab1 enhanced plant height and dry weight more than single inoculation while the growth of BHICB-Ab3 plants was not modified by AMF inoculation. Arbuscular mycorrhizal fungi enhanced plants survival and seemed to favour the nodule occupation by rhizobia strains as compared to the non-mycorrhizal plants. Inoculation with selected rhizobia and AMF improved the growth of C. tomentosum under field conditions. This revised version was published online in June 2006 with corrections to the Cover Date.     

松褐天牛成虫高毒力菌株的筛选试验

松褐天牛不仅本身对树木的生理和工艺造成损害,而且是松材线虫在松林间传播的媒介昆虫,对松木造成巨大危害。该文选用了7株虫生真菌对松褐天牛成虫进行了生物测定,结果表明不同菌株的毒力存在差别,其中以金龟子绿僵菌Ma83菌株的毒力最强,天牛的校正死亡率及感染率都最高,分别10 0 %和79% ,致死中时也最短,LT5 0为5 .2 4d ,致死中浓度LC5 0为1.3 8×10 - 6 孢子 ml.松墨天牛成虫虫体不同部位与无纺布菌条的接触感染实验表明,触角、口器、足和腹的感染率依次升高,致死中时依次下降。     

真菌降解木质素的研究现状

在介绍木质素结构的基础上 ,从降解木质素的菌种及主要酶、产酶的条件 ,分析了真菌降解木质素的研究现状 ,介绍了真菌降解木质素及其酶的应用 ,并提出了存在的问题及发展方向     

植物铝毒害的产生及防治研究进展

土壤中的活性铝积累到一定程度时,即对植物产生毒害。土壤酸化是引起活性铝浓度增加的主要原因。土壤的酸度、富铝化程度、阳离子交换量、有机质含量、微生物种群和数量等因素都会影响到土壤中活性铝的释放,而增加钙的供应、施入有机质、增施磷肥或硅酸、种植牧草和绿肥、接种菌根菌剂、选育和种植耐铝植物等可防治铝对植物的毒害。     

紫金山两种主要林型有机物层中丝状真菌多样性

本文对紫金山两种主要林型,栓皮栎林(Quercus variabilis)和马尾松-枫香(Pinus massoniana-Liguidam barformasana)混交林的有机物层(L, F, H层及土壤淋溶A层)可培养丝状真菌多样性进行了研究。通过分离鉴定,共得到真菌67种,其中接合菌3种、子囊菌5种、半知菌类56种和未确定种3种,半知菌类最为丰富。两种林型分解真菌优势种群为链格孢(Alternaria sp.)、曲霉(Aspergillus spp.)、枝孢(Cladosporium sp.)、毛霉(Mucor sp.)、青霉(Penicillium sp.)、木霉(Trichoderma spp.)、根霉(Rhizopus sp.)、粘帚霉(Gliocladium sp.)。混交林型中真菌的种类和数量明显高于栓皮栎林。两个林型均以F层真菌种类最多,但F层之间和L层之间真菌多样性差异较大。在混交林型中从马尾松针叶上分离的真菌种类和数量比从枫香上分离得到的少; 从马尾松针叶上分离的真菌丰富度随着有机物层深度增加而增加,枫香则反之。比较两个林型以及混交林的两种落叶上真菌种类发现,随着有机物层深度的增加,真菌的种类差异性却随之减少,即同时出现在两个林型或两种针叶上的真菌种类增多。真菌种类随着分解过程的进行具有明显的演替现象。混交林型中同一层内不同落叶上分解真菌多样性的差异,表明凋落物基质的差异是决定真菌种类和数量的重要因素