14种AM真菌对枳生长的影响

在盆栽条件下,以柑橘砧木枳（Fructus aurantii）幼苗为试验材料,在基质中接种从广西土壤中分离得到的不同丛枝菌根（AM）真菌菌株,探讨不同AM真菌对枳根系的侵染能力和植株生长的影响。结果表明：用于试验的14个AM真菌菌株均能与枳根系形成共生关系,平均侵染率为36.16%,其中侵染率最高的菌株是黄雷德克囊霉（Redeckera fulvum, Rf）,侵染率高达92.83%,侵染率最低的菌株是副冠球囊霉（Glomus coronatum, Gc）,侵染率仅为0.23%;接种黄雷德克囊霉、摩西斗管囊霉（Funneliformis mosseae, Fm2）和副冠球囊霉这3个菌株处理的枳植株的株高、茎粗、叶片数和叶柄长均高于CK,是枳的优势菌株,能促进枳的生长。     

暗球腔菌属的2个中国新记录种

本文报道了中国黄海黄岛海域潮间带木上的暗球腔菌属中的2个中国新记录种:新海暗球腔菌Phaeosphaeria neomaritima和高山暗球腔菌P.subalpina。文中对它们的形态特征及分布情况进行了描述和讨论。标本存放在青岛农业大学真菌标本室(MHQAU)。     

柑橘褐斑病的病原分离和药物筛选

从云南马关近2 a来发生的一种柑橘褐斑病的病理组织中分离得到1株病原菌,依其培养性状和形态特征,初步鉴定为径点霉属,并比较了其对11种市售农药的敏感性。结果表明:氟硅唑、中生菌素、多抗霉素、丙森锌、氟菌唑、异菌脲6种药物对病菌菌丝生长的抑制活性较高,其中氟硅唑最灵敏,其EC50为0.03μg/mL;丙森锌和中生菌素次之,EC50分别为1.8μg/mL和3.14μg/mL;氟硅唑和百菌清对孢子的抑制效果较好,1μg/mL抑制率均在80%以上;丙森锌、佳爽和多抗霉素也有一定的保护作用。     

中韩食用菌生产态势及贸易竞争力分析

针对中韩两国食用菌生产和贸易竞争关系,利用联合国商品与贸易统计数据,从两国食用菌贸易总量、食用菌种类、运输方式和进出口贸易国家等角度进行比较分析,提出了开拓国际贸易市场的一些方法,为提升我国食用菌国际贸易竞争力提供参考。     

Phylogenetic structure of arbuscular mycorrhizal community shifts in response to increasing soil fertility

Understanding the underlying mechanisms driving responses of belowground communities to increasing soil fertility will facilitate predictions of ecosystem responses to anthropogenic eutrophication of terrestrial systems. We studied the impact of fertilization of an alpine meadow on arbuscular mycorrhizal (AM) fungi, a group of root-associated microorganisms that are important in maintaining sustainable ecosystems. Species and phylogenetic composition of AM fungal communities in soils were compared across a soil fertility gradient generated by 8 years of combined nitrogen and phosphorus fertilization. Phylogenetic patterns were used to infer the ecological processes structuring the fungal communities. We identified 37 AM fungal virtual taxa, mostly in the genus Glomus. High fertilizer treatments caused a dramatic loss of Glomus species, but a significant increase in genus richness and a shift towards dominance of the lineage of Diversispora. AM fungal communities were phylogenetically clustered in unfertilized soil, random in the low fertilizer treatment and over-dispersed in the high fertilizer treatments, suggesting that the primary ecological process structuring communities shifted from environmental filtering (selection by host plants and fungal niches) to a stochastic process and finally to competitive exclusion across the fertilization gradient. Our findings elucidate the community shifts associated with increased soil fertility, and suggest that high fertilizer inputs may change the dominant ecological processes responsible for the assembly of AM fungal communities towards increased competition as photosynthate from host plants becomes an increasingly limited resource.     

Antitumor Profile of Carbon-Bridged Steroids (CBS) and Triterpenoids

This review focuses on the rare group of carbon-bridged steroids (CBS) and triterpenoids found in various natural sources such as green, yellow-green, and red algae, marine sponges, soft corals, ascidians, starfish, and other marine invertebrates. In addition, this group of rare lipids is found in amoebas, fungi, fungal endophytes, and plants. For convenience, the presented CBS and triterpenoids are divided into four groups, which include: (a) CBS and triterpenoids containing a cyclopropane group; (b) CBS and triterpenoids with cyclopropane ring in the side chain; (c) CBS and triterpenoids containing a cyclobutane group; (d) CBS and triterpenoids containing cyclopentane, cyclohexane or cycloheptane moieties. For the comparative characterization of the antitumor profile, we have added several semi- and synthetic CBS and triterpenoids, with various additional rings, to identify possible promising sources for pharmacologists and the pharmaceutical industry. About 300 CBS and triterpenoids are presented in this review, which demonstrate a wide range of biological activities, but the most pronounced antitumor profile. The review summarizes biological activities both determined experimentally and estimated using the well-known PASS software. According to the data obtained, two-thirds of CBS and triterpenoids show moderate activity levels with a confidence level of 70 to 90%; however, one third of these lipids demonstrate strong antitumor activity with a confidence level exceeding 90%. Several CBS and triterpenoids, from different lipid groups, demonstrate selective action on different types of tumor cells such as renal cancer, sarcoma, pancreatic cancer, prostate cancer, lymphocytic leukemia, myeloid leukemia, liver cancer, and genitourinary cancer with varying degrees of confidence. In addition, the review presents graphical images of the antitumor profile of both individual CBS and triterpenoids groups and individual compounds.     

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。     

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.