Colonization of beech leaves by two endophytic fungi in northern Japan

Leaves of Japanese beech (Fagus crenata) were collected monthly during the vegetation period at five sites in the Tohoku district in Japan to isolate endophytic fungi. Leaves were also collected only once at two additional sites. Two endophytic fungi were dominant, a Discula species and a sterile mycelium. This result strongly suggests that these two fungi are generally associated with leaves of the Japanese beech at different sites. At most sites the isolation frequency of Discula sp. was greatest in June and gradually decreased from July to October whereas the isolation frequency of the sterile mycelium increased during the vegetation period and remained at a high isolation frequency in October. Spores of Discula sp. were released for a very short time in late May, just after the disappearance of the snow cover on the forest floor. These spores may be important for the infection of newly sprouting leaves.     

套袋对黄冠梨品质的影响

通过对梨果主要内部品质进行了分析。结果显示:套袋降低果胶质、总酸度、水分、磷、Vc、总糖、葡萄糖、蔗糖的含量;提高干物质、比重、粗纤维、总灰分、钙、钾、果糖的含量及糖酸比。     

Accumulation of flavanols in yellowing beech leaves from forest decline sites

Beech leaves were sampled during two consecutive years from three sites characterized by forest decline. Both monomeric and oligomeric flavanols from green and yellowing leaves were determined quantitatively by reversed-phase, high-performance liquid chromatography (HPLC) combined with a chemical reaction detection technique (CRD). Yellowing leaves generally contained more than twice the quantity of flavanols than normal green leaves. The monomeric flavanols, epicatechin and (+)-catechin, comprised up to 80% of the total flavanol fraction. Histochemical staining with p-dimethylaminocinnamaldehyde was used to determine local deposition of flavanols, including insoluble oligomeric flavanols, in leaf tissues. The yellowing leaves stained intensely, whereas the green leaves stained lightly. Flavanol staining was strongest in the spongy parenchyma followed by the palisade cells. The upper epidermis stained more intensely than the lower epidermis. A 4-day treatment of small leaf pieces (5 x 5 mm) with 0.04 mM paraquat resulted in browning of the leaf pieces. The browning reaction was prevented when the paraquat treatment was carried out in the presence of 0.16 mM (+)-catechin, indicating an antioxidative property for this flavanol.     

Pyrolysis reactions of Japanese cedar and Japanese beech woods in a closed ampoule reactor

The chemical structures of hemicellulose and lignin are different for two distinct types of wood, i.e., softwood and hardwood. Such differences are expected to affect pyrolysis behavior. In this article, the differences are discussed for Japanese cedar wood (a softwood) and Japanese beech wood (a hardwood) pyrolyzed in a closed ampoule reactor (N₂/600°C/40–600 s). Oven-dried samples were used to eliminate the influence of initial water. Demineralized samples (prepared by acid washing) were also used to determine the influence of the minerals contained in the wood samples. As a result, some features were disclosed for secondary char (coke) formation, char reactivity, tar formation, and subsequent decomposition.     

Temporal variations in endophytic fungal assemblages of Ginkgo biloba L.

We isolated endophytic fungi from living healthy leaves, petioles, and current-year twigs of Ginkgo biloba L. from April to November 2004 with the objective of identifying the dominant endophytic fungal taxa, and monitoring their occurrence and frequency. A total of 9 fungal taxa were identified to the genus level. Diversity measures inferred from the Shannon–Wiener, Morisita–Horn, and S?rensen indices indicated that leaves and petioles harbored more diverse endophytic fungal assemblages than twigs, and that fungal taxa involved in twigs shared less with those in leaves and petioles. Among the organs, the occurrence pattern of overall endophytic fungi differed significantly, and two taxa, Phomopsis sp. and Phyllosticta sp., were the most frequently isolated and thus regarded as the dominant endophytic fungi. Phomopsis sp. was isolated frequently from twigs (84.8%) but rather few from leaves (16.1%) and petioles (24.3%). Phyllosticta sp. was isolated frequently from leaves (72.9%) and petioles (65.7%) but was never isolated from twigs. Temporal changes in relative frequency of total endophytic fungi tended to differ among sampling dates for all three organs. The occurrence of Phyllosticta sp. in both leaves and petioles was first detected in August and peaked in October. Phomopsis sp. was detected in twigs throughout the growing season. These results suggest that the distribution of the two dominant endophytic fungi was organ-specific and differed within seasons.     

The influence of altitude on endophytic mycobiota in Quercus acuta leaves collected in two areas 1000 km apart

Endophytic fungi were isolated from healthy leaves of the evergreen oak Quercus acuta on Mt Takao in eastern Honshu and on Mt Osuzu in Kyushu, Japan, to study the effect of altitude on endophyte assemblages. Phomopsis sp. 1, Discula sp. and an unidentified species (QA-b) were isolated most frequently. Comparisons of the nucleotide sequence of the rDNA ITS regions of QA-b revealed a close match with species of Tubakia. On Mt Takao, Phomopsis sp. 1 and QA-b were isolated frequently, whereas on Mt Osuzu, Discula sp. and QA-b were dominant. The isolation frequency of QA-b decreased as altitude increased, whereas the isolation frequencies of Phomopsis sp. 1 and Discula sp. increased with altitude. In vitro, QA-b did not grow at temperatures <15°C whereas Phomopsis sp. 1 and Discula sp. still grew at 5°C. These results suggest that Phomopsis sp. 1 and Discula sp. are better adapted to lower temperatures and consequently to higher altitude than QA-b.     

蓖麻枝叶形态特征对蒴果性状的影响

为给蓖麻高产栽培提供参考,以‘淄蓖5号’为材料,测定蓖麻枝叶形态特征指标(开花时叶面积、灌浆期叶面积、收获时分枝直径)和蒴果性状指标(每穗果球数、果球质量、每果球种子数、种子质量、穗长、穗宽),分析蓖麻枝叶形态特征对蒴果性状的影响。相关性分析结果表明,按蓖麻枝叶形态特征的影响由大到小排序,各蒴果性状指标依次为果球质量、每穗果球数、种子质量、每果球种子数、穗长、穗宽。回归分析结果表明,蓖麻分枝直径对每穗果球数、果球质量变异的解释程度分别为31%、37%;开花时叶面积对每穗果球数、每果球种子数变异的解释程度分别为53%、51%;灌浆期叶面积对种子质量变异的解释程度为51%;开花时叶面积、灌浆期叶面积和收获时分枝直径对每穗果球数、果球质量、每果球种子数、种子质量变异的解释程度分别为67%、68%、76%、79%。修枝时保留粗壮枝条有利于获得更多果球、更大果球质量,开花时保持较大的叶片面积是获得更多果球和种子的重要保障,保持灌浆期较大叶面积利于获得饱满的种子。     

Effect of pressure on organic acid production from Japanese beech treated in supercritical water

The effect of pressure as described by density was studied on organic acid production from Japanese beech (Fagus crenata) treated in supercritical water. At a reaction temperature of 380°C, the maximum yield of organic acids was 35% at a pressure of 30 MPa (density of water: 0.53 g/ml) for 1 min in a batch-type system. Furthermore, the yield of organic acids decreased with increasing reaction pressure. It was also found that fragmented products from sugars such as methylglyoxal and glycolaldehyde could be more easily converted to organic acids than dehydrated products such as furfural and 5-hydroxymethyl furfural. This result suggests that organic acids can be mainly derived from fragmented products. Part of this article was presented at the 55th Annual Meeting of the Japan Wood Research Society (2005), and at the 17th Annual Meeting of Japan Institute of Energy (2007)     

Measurements of fungal wood decay on Scots pine and beech by means of X-ray microdensitometry

In this work, we present a fast and promising method to evaluate the natural durability of wood based on X-ray microdensitometry. Tested on beech and Scots pine wood samples, our findings show that this methodology and the traditional EN standards methodology based on mass loss are strongly correlated. X-ray methodology is less time consuming (we can detect the effectiveness of the attack within 5–6 weeks) and less expensive (very cheap plastic Petri dishes instead of the expensive glass Kolle flasks); moreover, the proposed method allows to thoroughly examine the phases and the kinetics of the fungal attack, and to investigate the spatial repartition of the attack within the samples due to the low thickness of the sample.     

木麻黄枝叶中单宁含量的快速测定

采用皮粉法与胶体滴定法测得pH=7时木麻黄树皮单宁的胶体滴定值与单宁质量的标准曲线,所得标准曲线的线性回归方程为:y=0.4852x+0.8755,线性系数R2=0.9997。再用胶体滴定法滴定来自同一株木麻黄树的叶、粗枝和细枝的浸提液,根据胶体滴定值在标准曲线上对应的单宁质量计算出干体各部位的单宁含量。木麻黄的叶、粗枝和细枝的单宁含量分别为12.11%、7.31%和6.29%,相对极差R小于2%。     

杜鹃花属植物内生真菌对毛棉杜鹃幼苗生长的影响

对来自粤北3种野生杜鹃花属植物根样中的聚多曲霉（Aspergillus sydowii）（菌株号：YJ1,YS2）、杂色曲霉A. versicolor（菌株号：GD1）3个内生真菌菌株及其混合菌剂进行瓶内接种试验,比较其对毛棉杜鹃（Rhododendron moulmainense）幼苗的菌根侵染率、苗高和生物量的影响。结果表明,3个菌株及其混合菌剂均可与毛棉杜鹃幼苗根系形成菌根共生体,但不同菌剂在不同培养基上对毛棉杜鹃幼苗根系的侵染力、苗高增长和生物量增重效果存在显著差异（P<0.05）。多数菌剂（YS2、M3、M1、M2）在MMN培养基上对幼苗根系侵染力显著高于WPM培养基和混合基质培养基（P<0.05）,而多数接菌苗（YJ1、GD1、M2、M3）在WPM培养基上生长显著优于MMN培养基（P<0.05）,YS2、GD1和混合菌剂M2（YS2+GD1）对毛棉杜鹃幼苗的增高和增重具有明显的促生作用。     

霍城县大西沟野杏枝叶形态多样性

为给进一步开展野杏种质资源多样性及亲缘关系研究提供参考,选取新疆霍城大西沟不同区域分布的野杏单株,利用DPS7.05数据处理软件对枝叶形态性状指标进行聚类分析和主成分分析,探讨新疆野杏株间枝叶形态特征差异。聚类分析结果显示,系统聚类将62个野杏单株的15个枝叶形态性状分为4大类;主成分分析结果表明,前7个主成分的累计贡献率约为89.04%,影响较大的因子是叶片长度、叶片宽度、长宽比、叶柄长、叶面积、叶背绒毛、叶缘形态、新梢长度和粗度等。数量分类结果能反映出各单株间的遗传差异,大西沟野杏具有丰富的多样性,通过主成分分析选出了野杏分类的主要性状。通过聚类分析能清楚反映出所选野杏单株间的亲缘关系。     

银杏不同类型枝条叶片萜内酯含量年周期变化规律

为了了解不同时期银杏不同枝型叶片萜内酯的含量,采用气相色谱法对银杏雄叶丛枝、雌叶丛枝、雄长枝、雌长枝和雌短枝银杏叶萜内酯含量的年周期变化进行了测定。结果表明:不同枝型按照银杏叶的总萜内酯含量由大到小排列依次为:雄叶丛枝、雌长枝、雌叶丛枝、雄长枝、雌短枝,除雌短枝外,其它枝型总萜内酯含量均在9月初达到1年中的最大值;GA是所测4种萜内酯中含量最丰富的,不同枝型按照GA含量由大到小排列依次为:雄叶丛枝、雄长枝、雌叶丛枝、雌长枝、雌短枝,除雌短枝GA含量在10月初到达含量的高峰外,其它均在9月初达到高峰;GB、GC和BB含量低,变化规律较一致,落叶前含量基本稳定。     

苹果果实袋性能对袋内温湿度及果实品质的影响

该试验比较了不同类型的苹果果实袋的透光率、透气度和表面吸水率,调查了不同类型的苹果果实袋对袋内温湿度以及果实品质的影响。结果表明:外层袋外黄内黑、内层红蜡纸的双层纸袋具有一定的遮光性,且透气度和表面吸水率较低,套此类袋的果实果个和可溶性固形物含量比不套袋的降低较少,且果面光洁、果点较小,着色好。     

Differences in composition of endophytic mycobiota in twigs and leaves of healthy and declining Quercus species in Italy

The composition of the endophytic fungal assemblages in Quercus cerris, Q. pubescens and Q. robur, three oak species most susceptible to decline, was investigated in Fagarè (Padova), Ulignano (Pisa), and Radda in Chianti (Firenze). The endophytic assemblages were studied as a function of health status of the whole tree and of twigs and leaves. The effect of station altitude was tested on Q. cerris. Samples were gathered from healthy and declining trees. In April (bud opening time) 20 twigs and 10 leaves were collected from each tree. Fungi were isolated from twig segments and leaf portions. A total of 23 fungal genera with 27 different species were isolated, in addition to a few sterile mycelia. Eleven species were found to be common to all three oak species, while other species were found only on one oak species, suggesting host specificity. Among the fungal species isolated, some were known to be pathogenic (Apiognomonia quercina, Colpoma quercinum, Diplodia mutila, Phomopsis quercina). The colonization frequency (CF) of pathogenic species varied between 0.9% for A. quercina in Q. cerris and 60.2% for P. quercina in Q. robur. Analysis of variance showed a statistically significant difference among the oak species tested. The CF was higher in declining trees in comparison with healthy trees, and also in twigs vs. leaves. The CF was found to be higher for Q. cerris trees growing at sea level as compared with those situated at an elevation of 350–400 m. In stands where, on account of particular ecological conditions, pathogenic behaviour is displayed simultaneously by more than one endophytic fungal species, trees accentuate their decline.     

Quantification of fungal infection in spruce needles from different sourcesc

A large number of batches of green as well as of chlorotic spruce needles were tested for fungal infection. Using ergosterol as a biochemical indicator for fungal colonization, the highest ergosterol contents were always found in partially or uniformly necrotized needles. However, no correlation was found between the ergosterol concentration and the chlorophyll content i. e. the degree of bleaching.     

Variation in pathogenicity among the three subspecies of Phytophthora alni on detached leaves,twigs and branches of Alnus glutinosa

Pathogenicity tests were carried out on leaves, twigs and branches of Alnus glutinosa using several isolates of Phytophthora alni ssp. alni, P. alni ssp. multiformis and P. alni ssp. uniformis in vitro. Healthy fresh leaves were collected from disease‐free areas and inoculated with mycelium on agar discs or by dipping in zoospore suspensions. In addition, twigs and branches were collected from both disease‐free and disease‐affected areas, inoculated with mycelium on agar discs and incubated at four temperatures (15, 20, 25, 30°C). All subspecies tested were pathogenic but with varied level of virulence. In inoculation tests on foliage, wounding was a key factor in causing infections: lesions on inoculated wounded leaves were larger than on non‐wounded leaves. In the twig and branch inoculation tests, no differences in virulence were observed among the P. alni subspecies in terms of sampling locations, but lesions differed in size according to incubation temperature, with the largest lesions occurring on tissues incubated at 25°C. The work is the first to report foliar necrosis caused by P. alni on A. glutinosa. P. alni ssp. uniformis was the least virulent of the subspecies in branch inoculations. These findings demonstrate that various tissues of A. glutinosa could act as sources of pathogen inoculum and may disseminate alder Phytophthora in natural ecosystems.     

The effect of single-tree selction system on soil properties in an oriental beech stand of Hyrcanian forest,north of Iran

A case study was conducted in beech forests of northern Iran to determine the effect of the created gaps on some soil properties in beech stand. Changes of soil properties in small (60 150 m 2 ), medium (151 241 m 2 ), large (242 332 m 2 ) and very large (333 550 m 2 ) gaps, as well as under closed stands were studied eight years after the gap creation. Soil samples were taken from three depths, 0 10, 10 20 and 20 30 cm. The gaps were different from their around undisturbed stands in terms of the following soil parameters: Mg +2 concentration of 0 10 cm at medium gap size, bulk density of 10 20 cm at very large gap size as well as K + and Ca +2 concentrations at 20 30 cm at small and large gap sizes, respectively. Furthermore, the size of the gaps had no effect on soil characteristics through the whole profile. Water saturation percent (Sp %) at 0 10cm as well as P and Mg +2 at 20 30 cm was different amongst undisturbed stands around different gap sizes. The center and the edges of the gap were different only in terms of organic carbon at the depth of 10 20 cm. Significant differences were observed between gaps andclosed canopy regarding P and Ca +2 at depth 0 10 cm and 10 20 cm, respectively. It can be concluded that applied silvicultural system for harvesting trees which created these gaps might be suitable for conservation and forest management in the region.