瑞昌市林业有害生物发生情况及防治对策

随着林业的快速发展，林业有害生物所造成的生态损失和经济损失愈加突出，已经严重地影响了森林质量和系统功能的发挥，成为制约生态建设和林业快速发展的一大障碍。减轻有害生物所造成的损失，保护农民利益，促进农村经济发展是林业工作面临的重大课题。     

森林害虫的发生、治理与环境的关系

本文分析了森林害虫的发生规律及与环境的关系，并从生态学的角度提出了控制森林害虫数量增长的措施。     

有害赤潮藻对鱼类影响的研究进展

赤潮灾害的多发性和普遍性极大危害了海产养殖业和渔业资源,严重破坏了正常的海洋生态系统,直接威胁着人类的生存环境和健康水平[1,2]。在赤潮灾害中,鱼类的大量死亡带来的危害和损失占相当大的比重[3],在我国,1998年春季南海的一次特大赤潮造成了大规模的养殖鱼死亡,直接经济损失超过3亿元。在这类赤潮灾害中不仅渔业资源和鱼类养殖业遭受了极大的破坏,海洋生物的种群结构乃至整个海洋生态系统也受到了影响,毒素在鱼类体内的累积威胁着食用者的生命安全[4]。因此,科学家们针对有害赤潮藻及其毒素对鱼类的影响开展了一些调查和研究工作…     

Evaluation of nutritive value and in vitro rumen fermentation gas accumulation of de-oiled algal residues

Background：Algae are widely recognized for their high oil content and for exponentially accumulating biomass with particular potential to provide single cell protein for human consumption or animal feed.It is believed that along with biodiesel from algae,the high protein de-oiled algal residue may become an alternative feed supplement option in the future.This study was conducted to investigate de-oiled algal residue obtained from the common Chlorella species,Thalassiosira weissflogii,Selenarstrum capricornutum,Scenedesmus sp.,and Scenedesmus dimorphus for assessment as potential feed supplements for ruminants by comparing with soybean（Glycine max） meal and alfalfa（Medicago sativa） hay.Results：With the exception of T.weissflogii,algal residue had higher concentrations of Cu,Zn,and Mn and lower concentration of Ca,Mg,and K than soybean meal and alfalfa hay.The algal residue CP（crude protein）concentrations ranged from 140 to 445 g/kg DM and varied among the de-oiled residues.In vitro rumen fermentation gas accumulation curves indicated that algal biomass degradation potential was less than that of soybean meal or alfalfa hay by up to 41.7%.The gas production curve,interpreted with a dual pool logistic model,confirmed that the fraction sizes for fast fermenting and slow fermenting of de-oiled algal residues were smaller than those in soybean meal and alfalfa hay,and the fermenting rate of the fractions was also low.Conclusions：Inferior in vitro rumen gas accumulation from the five de-oiled algal residues suggests that these algal byproducts are less degradable in the rumen.     

Evolution and Distribution of Saxitoxin Biosynthesis in Dinoflagellates

Numerous species of marine dinoflagellates synthesize the potent environmental neurotoxic alkaloid, saxitoxin, the agent of the human illness, paralytic shellfish poisoning. In addition, certain freshwater species of cyanobacteria also synthesize the same toxic compound, with the biosynthetic pathway and genes responsible being recently reported. Three theories have been postulated to explain the origin of saxitoxin in dinoflagellates: The production of saxitoxin by co-cultured bacteria rather than the dinoflagellates themselves, convergent evolution within both dinoflagellates and bacteria and horizontal gene transfer between dinoflagellates and bacteria. The discovery of cyanobacterial saxitoxin homologs in dinoflagellates has enabled us for the first time to evaluate these theories. Here, we review the distribution of saxitoxin within the dinoflagellates and our knowledge of its genetic basis to determine the likely evolutionary origins of this potent neurotoxin.     

Exploitation of Marine-Derived Robust Biological Molecules to Manage Inflammatory Bowel Disease

Naturally occurring biological entities with extractable and tunable structural and functional characteristics, along with therapeutic attributes, are of supreme interest for strengthening the twenty-first-century biomedical settings. Irrespective of ongoing technological and clinical advancement, traditional medicinal practices to address and manage inflammatory bowel disease (IBD) are inefficient and the effect of the administered therapeutic cues is limited. The reasonable immune response or invasion should also be circumvented for successful clinical translation of engineered cues as highly efficient and robust bioactive entities. In this context, research is underway worldwide, and researchers have redirected or regained their interests in valorizing the naturally occurring biological entities/resources, for example, algal biome so-called “treasure of untouched or underexploited sources”. Algal biome from the marine environment is an immense source of excellence that has also been demonstrated as a source of bioactive compounds with unique chemical, structural, and functional features. Moreover, the molecular modeling and synthesis of new drugs based on marine-derived therapeutic and biological cues can show greater efficacy and specificity for the therapeutics. Herein, an effort has been made to cover the existing literature gap on the exploitation of naturally occurring biological entities/resources to address and efficiently manage IBD. Following a brief background study, a focus was given to design characteristics, performance evaluation of engineered cues, and point-of-care IBD therapeutics of diverse bioactive compounds from the algal biome. Noteworthy potentialities of marine-derived biologically active compounds have also been spotlighted to underlying the impact role of bio-active elements with the related pathways. The current review is also focused on the applied standpoint and clinical translation of marine-derived bioactive compounds. Furthermore, a detailed overview of clinical applications and future perspectives are also given in this review.     

Release of nutrient from fish food and effects on Microcystis aeruginosa growth

This study aimed to explore the relationship between Microcystis aeruginosa growth and nutrients released from fish food, which mainly simulates the effect of uneaten food on algae growth and water quality variables during aquaculture activities. Fish food (0, 0.1, 0.2, 0.5 and 1 g dosages tested) of different grain sizes (original; 0.147 ≤ d ≤ 0.85 mm; d ≤ 0.147 mm) was added each into M‐II culturing medium (nitrogen and phosphorus absent). During the experimental running period, the concentrations of total phosphorus (TP), orthophosphate phosphorus (PO₄^3?‐P), total nitrogen and ammonia‐nitrogen (NH₄⁺‐N) increased significantly with increasing fish food dosages regardless of their grain sizes. Furthermore, grain size had a negligible effect on nutrient release from fish food with the same dosage. Based on the above experiment, M. aeruginosa was introduced into the culturing media at different dosages (nitrogen and phosphorus absent) with 0, 0.05, 0.1, 0.2 and 0.5 g fish food to assess algae growth characteristics. Algae cell density significantly increased with the dosage ranging from 0 to 0.2 g. NH₄⁺‐N and PO₄^3?‐P were the main fractions of available nutrients used by M. aeruginosa in the fish food. In comparison to the growth dynamics of algae in M‐II culturing medium, the lag phase for M. aeruginosa in the presence of fish food extended significantly when calculating the time from the addition of fish food and insignificantly when the time for nutrient release from fish food was excluded.     

重庆忠县柑橘有毒有害元素迁移性研究

[目的]探讨重庆沿江经济带特色农产品忠县柑橘植株的根、干、叶、果实各个器官对有毒有害元素的迁移性。[方法]以哈姆林和忠县锦橙为研究对象,分别采集这2种柑橘植株的根、干、叶、果实及相应的根系土壤样本,分别测定Cr、Pb、Ni、Cd、As、Hg等有毒有害元素的含量特征。[结果]柑橘哈姆林和忠县锦橙表现出同样的特性,即柑橘植株不同器官中各种有毒有害元素的迁移性具有差异性,如柑橘根对Cd的迁移性较强,柑橘干对Pb的迁移性较强。柑橘植株同一器官因品种不同对各种有毒有害元素的迁移性强弱也具有差异性。如哈姆林根系相对忠县锦橙更易迁移Cd;而忠县锦橙干相对哈姆林更易迁移Cd。[结论]该研究为改进忠县柑橘品种质量、加强病虫害防治、扩大种植规模等提供了一定的科学依据。     

Above- and below-ground biomass and carbon stocks of different tree plantations in central Iran

In arid and semi-arid lands using industrial wastewater for irrigating tree plantations offers a great opportunity to fulfill the purpose of Clean Development Mechanism by sequestering carbon in living tissues as well as in soil. Selection of tree for plantation has a great effect on the goal achievements, especially when the managers deal with afforestation projects rather than reforestation projects. The objective of this study was to quantify the above- and below-ground biomass accumulation and carbon storages of the 17-year-old monoculture plantations of mulberry(Morus alba L.), black locust(Robinia pseudoacacia L.), Eldar pine(Pinus eldarica Medw.) and Arizona cypress(Cupressus arizonica Greene) planted in central Iran. To assess the potential carbon storage, we destructively measured individual above- and below-ground tree biomass and developed and scaled models at stand level. Furthermore, carbon content at three soil depths(0–15, 15–30, 30–45 cm), the litter and the understory were assessed in sample plots. The results showed that the total amount of carbon stored by Eldar pine(36.8 Mg/hm2) was higher than those stored by the trees in the other three plantations, which were 23.7, 10.0, and 9.6 Mg/hm2 for Arizona cypress, mulberry and black locust plantations, respectively. For all the species, the above-ground biomass accumulations were higher than those of the below-ground. The root mass fractions of the deciduous were larger than those of the coniferous. Accordingly, the results indicate that the potential carbon storages of the coniferous were higher than those of the deciduous in arid regions.