海洋真菌Arthrinium sp. UJNMF0008代谢产物的研究

为丰富海洋真菌的化学多样性,发现海洋真菌活性代谢产物,对海洋沉积物来源真菌Arthriniumsp.UJNMF0008的化学成分及其生物活性进行研究,采用硅胶柱色谱、凝胶柱色谱、反向柱色谱和高效液相色谱等方法从海洋沉积物来源真菌Arthriniumsp.UJNMF0008的发酵提取物中分离到5个化合物,通过核磁共振、质谱等方法,结合文献对照,鉴定了化合物的结构分别为arthoneF(1)、arthoneG(2)、sydoxanthoneC(3)、(3R,4R)-cis-4-hydroxymellein(4)和2-(2′S-hydroxypropyl)-5-methyl-7-hydroxychromone(5),其中化合物1和2是新化合物,化合物3首次从该属真菌中分离到。活性测试显示,化合物1~5在50μmoL/L的测试浓度下均没有表现出明显的抗氧自由基活性、抗菌活性以及NO释放抑制活性。     

Numbers of pink sugarcane mealy bug, Saccharicoccus sacchari (Cockerell) (Hemiptera: Pseudococcidae), differ within seasons and among regions and stages of the sugarcane crop cycle

Abstract  The pink sugarcane mealy bug (PSMB; Saccharicoccus sacchari ) is widespread on sugarcane globally. PSMB infest above-ground storage tissue as it develops, feeding on phloem and producing exudate. It is not known, however, whether the level of infestations is the same in different sugar growing regions, or how population size varies year to year within a region. Field surveys of the number of nodes infested were conducted over five seasons in three mill-regions in northern Australia (Macknade, Kalamia and Marian) on plant and ratoon crops. The pattern of infestation was very similar across seasons (only in 1 year of very low rainfall was the increase in population delayed). In all three regions the proportion of nodes infested was similar but reached the maximum 1 month later in the Marian region compared with the Kalamia and Macknade regions. The Kalamia region was distinguished by the rapid decline in the number of nodes infested down to a very low level by March. In the Macknade region mealy bugs persisted at higher levels than the other two regions. The PSMB infestation started earlier and was much greater in ratoon crops than plant crops throughout the sampling period. The differences were more pronounced in the Macknade and Marian districts. These observations provide a firm basis from which future strategies to control PSMB can be developed.     

我国首次发现的暗纹节菱孢所致皮肤真菌病的毒理实验及病理分析

从患者皮损处皮屑及活检组织中分离出的暗纹节菱孢Arthriniumphaeospermum（Corda）Ellis菌株制成混悬菌液,用兔、豚鼠及小鼠（LACA）进行动物毒理实验。表皮直接涂抹法接种,四周后未见皮肤损害;划破表皮涂沫法及皮下注射法接种,两周后实验动物的皮肤都出现浸润性斑块、小给节、皮下脓肿及脱毛的症状,对照组动物正常。再用腹腔注射法接种,小鼠两周后死亡,病解所见,腹膜、肠系膜、腹壁及肝等处,均出现散在的灰白色小脓肿;心、肺、肝、脾及肾均有病变。豚鼠两周后仍存活,当即处死解剖所见与小鼠病解改变相同。对实验动物皮损、腹膜、肠系膜、胃及肝等处的小脓肿组织进行了病理检查,结果发现皮损及器官组织均有明显的病理浸润,由多种细胞构成的浸润性肉芽肿。在病理浸润内可见大小不等的球形、卵圆形、棱形及晶体形的棕色、红色孢子．其病理改变与患者皮损病理改变相一致,其不同点是实验动物有小脓肿,肉芽肿内可见多核巨噬细胞,而在病人皮损中很少见到。     

高粱蚜灰色灾变长期预测模型

本文应用灰色系统灾变预测理论建立了吕梁地区高粱蚜发生量预测模型．     

高粱抗高粱蚜的生化基础

高粱中的可溶性总氮、可溶性总糖和绝大部分游离氨基酸,特别是必需氨基酸,在感性品种中的含量显著地比抗性品种中的含量高.感性品种叶液微偏酸,抗性品种近中性.多元回归分析表明,高梁对高粱蚜Melanaphis sacchari(Zehntner)的抗性与可溶性总氮、可溶性总糖和游离氨基酸的含量呈反相关.     

新侵入害虫蔗扁蛾生活史

蔗扁蛾Opogona sacchari (Bojer)是一种新传入我国的危险性外来害虫。在温度25.71±2.71℃和相对湿度(74.95±5.02)%的条件下,完成一个世代需要66～135天,全年约可发生4代。幼虫期是历史时最长的虫态,需要37～75天,共7龄,是该虫的为害虫期。成虫的交配和产卵需要一定的空间,产卵量为253.05±65.18 (n=20) 。     

Belowground organism activities affect plant aboveground phenotype, inducing plant tolerance to parasites

Soil fauna activities are probably more important than currently acknowledged in determining individual plant response to stresses and overall plant diversity. Here we demonstrate that the positive effect of earthworms on rice could be the result of a systemic effect on plant physiology. Moreover, this effect could improve tolerance to stressors such as parasitic nematodes. In a controlled experiment, an 82% decrease in the production of infested plants was suppressed when earthworms were present. Earthworms had no direct effect on nematode population size. In their presence, however, root biomass was not affected by nematodes and the expected inhibition of photosynthesis was suppressed. In the leaves, the expression of three stress‐responsive genes (coding for lipoxygenase, phospholipase D and cysteine protease) was modulated by the presence of belowground invertebrate activities. We document conflicting systemic effects of parasitic nematodes and beneficial earthworms, although we cannot precisely identify the mechanism involved. These results reveal the importance of non‐trophic belowground/aboveground interactions for plant health and response to stresses.     

Molecular detection of Gluconacetobacter sacchari associated with the pink sugarcane mealybug Saccharicoccus sacchari (Cockerell) and the sugarcane leaf sheath microenvironment by FISH and PCR

Molecular tools for the detection of the newly described acetic acid bacterium Gluconacetobacter sacchari from the pink sugarcane mealybug, Saccharicoccus sacchari Cockerell (Homiptera: Pseudococcidae), and in the sugarcane leaf sheath microenvironment were developed. G. sacchari specific 16S rRNA-targeted oligonucleotide primers were designed and used in PCR amplification of G. sacchari DNA directly from mealybugs, and in a nested PCR to detect low numbers of the bacteria from sugarcane leaf sheath fluid and cane internode scrapings. A sensitivity level of detection of 40-400 cells/reaction was obtained using PCR from exponentially grown bacterial cultures and of 1-10 cells in cane internode scrapings and leaf sheath fluid samples using nested PCR. The specificity of the primer set was demonstrated by the lack of amplification product formation in PCR by closely related acetic acid bacteria, including Gluconacetobacter liquefaciens, and Gluconacetobacter diazotrophicus. A Cy3 labeled probe for G. sacchari was designed and shown to be specific for the species. Investigation of the mealybug microenvironment by whole cell fluorescent in situ hybridization revealed that G. sacchari appears to represent only a minor proportion of the population of the microbiota in the mealybugs tested. This study has shown the usefulness of 16S rRNA-based molecular tools in the identification and detection of G. sacchari from environmental samples and will allow these tools to be used in further ecological research.     

Ecdysteroids in the adults and eggs of Opogona sacchari (Bojer), an invasive alien pest

In order to understand the composition and quantitative variation of ecdysteriods in the adults and eggs of Opogona sacchari (Bojer), an invasive alien pest, we analyzed the ecdysteroid composition and titers in the adult and egg of this pest. On day 4 after eclosion, the titer of ecdysteriods in the male adult was 0.080 ng/adult, much lower than 5.978 ng/adult in the female adult. During the development of ovaries, the titer of ecdysteriods was low on the first two days, and high in the late period, with the peak (10.48 ng/ovary) appearing on day 3. During the development of eggs, the titer of ecdysteriods was about 0.010 ng/egg from day 1 to day 3, and then decreased to 0.006 ng/egg on day 4. In both adults and eggs, three main components of ecdysteriods were found by identification of HPLC/RIA. They were 20-hydroxyecdysone, 26-hydroxyecdysone, and an unidentified component.     

A new strain of <Emphasis Type="Italic">Arthrinium phaeospermum</Emphasis> isolated from <Emphasis Type="Italic">Carex kobomugi</Emphasis> Ohwi is capable of gibberellin production

Plant growth-promoting endophytic fungi with gibberellin-producing ability were isolated from the roots of Carex kobomugi Ohwi, a common sand-dune plant, and bioassayed for plant growth-promotion. A new strain, Arthrinium phaeospermum KACC43901, promoted growth of waito-c rice and Atriplex gemelinii. Analysis of its culture filtrate showed the presence of bioactive GA₁ (0.5 ng/ml), GA₃ (8.8 ng/ml), GA₄ (4.7 ng/ml) and GA₇ (2.2 ng/ml) along with physiologically inactive GA₅ (0.4 ng/ml), GA₉ (0.6 ng/ml), GA₁₂ (0.4 ng/ml), GA₁₅ (0.4 ng/ml), GA₁₉ (0.9 ng/ml) and GA₂₄ (1.8 ng/ml). The fungal isolate was identified through sequence homology and phylogenetic analysis of 18S rDNA (internal transcribed region). Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.