Penetration and infection processes in japanese cedar twig blight caused byStromatinia cryptomeriae

The diversity of host invasion mechanisms of the causal pathogen of Japanese cedar twig blight (Stromatinia cryptomeriae) was elucidated through detailed investigations of the disease cycle. Scanning electron microscopy (SEM) showed that ascospores began to germinate, and invade male strobilus tissue, within 24 h after arriving on the strobili. This involved direct penetration of the cuticle, and examination by SEM showed that cuticle degeneration had occurred around the point of penetration. A mucilage-like-substance was also observed around the tips of the germ tubes. Meanwhile field studies showed that incipient mycelial mat emerged from the bases of male strobilus in early June, and ceased growing onto the surface of the twig at the beginning of July. Macroscopically, the mycelial mat began to shed in mid-July, and disappeared completely during the summer season by the end of August. Immediately after the mat disappeared the first necrotic symptoms became evident on the twigs. This suggested strongly that these mats were involved in lesion formation. Observations of the mat’s behavior on the surface of twigs with light and differential interference microscopy, and SEM, showed thatS. cryptomeriae had two modes of invasion,i.e. stomatal and cuticular invasion. Hyphae from the mat were able to enter twig tissues through the stomata. Additionally, mycelial mat infected host tissue directly by hyphal penetration of the cuticle at the axes of cedar twigs. The mat was able to grow along the twig surface, then hyphae forming mat entered the host tissue and caused necrotic lesions. This paper describes the mechanisms of infection on both a strobilus and twig utilized by the pathogen of Japanese cedar twig blight.     

Forest biomass and bioenergy production and the role of CDM in Bangladesh

The use of forest biomass as a renewable energy source has received much attention as a response to climate change and the increasing global demands for energy. Local availability and conversion into secondary energy carriers with a lower capital investment shows more weights on its interests. The substitution of fossil fuel by biomass fuel can have a strong effect on the mitigation of climate change through reducing greenhouse gases, which can be an important consideration for CDM projects in Bangladesh. This study uses literature review to analyse the legal framework of carbon trading under CDM, CDM additionality, CDM and bioenergy promotion, land availability and technology for biomass production, and sustainability of CDM projects in Bangladesh. The barriers to CDM projects in Bangladesh are explained as well as measures for promoting biomass production. Biomass and bioenergy-based CDM projects can be attractive and support sustainable development in Bangladesh. The study suggests capacity building and policy changes needed in order to comply with CDM modalities. The study can be useful to the climate change mitigation and development policy makers in Bangladesh.     

白僵菌和肿腿蜂对松墨天牛幼虫的作用

在不同温度、不同剂量下用白僵菌侵染松墨天牛越冬4龄幼虫,结果表明:20～25 ℃是白僵菌作用松墨天牛的最适温度范围.20 ℃时3种浓度剂量的白僵菌孢悬液在松墨天牛体内有效继代校正宿存率均达最高,分别为58%、95%、100%.通过白僵菌、管氏肿腿蜂及携带白僵菌的管氏肿腿蜂分别对松墨天牛4龄幼虫的作用比较发现:第7天时,单独接种白僵菌的最高死亡率在25 ℃条件下是26.3%;单独接肿腿蜂的最高死亡率是55.0%;携菌肿腿蜂的最高致死率为94.4%.林间防治试验表明:肿腿蜂携带白僵菌使松墨天牛幼虫死亡率达到61.1%,而肿腿蜂使松墨天牛幼虫的林间致死率是40.8%,白僵菌的为0.肿腿蜂携带白僵菌可对松墨天牛幼虫起到更好的防治效果.     

商河县林下经济种养模式及效益分析

通过对商河县林下经济发展的调查研究,明晰了商河县林下经济的主要种养模式,其中包括林禽模式、林兔模式、林狐模式、林药模式和林菌模式等,重点介绍了林兔模式的关键技术措施;综合分析了林下种养模式的经济、社会和生态效益。     

Chemical composition and antioxidant capacity of the aqueous extract of Phellodendron amurense

The aqueous extract of Phellodendron amurense Rupr.(Amur Cork Tree) provides a rich source of antioxidants and chemical compounds, and can be used for food and wood preservative materials.In this study, we characterized the chemical composition of this extract by GC and GC/MS.The antioxidant capacity was evaluated using a variety of antioxidant assays(superoxide radical,hydroxyl radical, nitric oxide radical, and DPPH radical scavenging activity).Additionally, total polyphenolic content was determined.Phenolic acids and acetone derivatives were major compounds of the extract capable of scavenging the DPPH free radical and reducing ferric ions.DPPH and ferric ion reduction results were strongly correlated with total phenolic content of the extract which also exhibited strong nitric oxide, hydroxyl radical scavenging and superoxide anion radical scavenging activities.     

Suppression of phytopathogenic fungi by hexane extract of Nepenthes ventricosa x maxima leaf

The hexane extract of Nepenthes ventricosa x maxima leaf exhibited antifungal activity against Alternaria alternata, Aspergillus niger, Bipolaris oryzae, Fusarium oxysporum, Phytophthora capsici, Rhizoctonia solani, Rhizopus stolonifer var. stolonifer and Sclerotinia sclerotiorum.     

Formaldehyde emission and high-temperature stability of cured urea-formaldehyde resins

A test method for measuring formaldehyde from urea-formaldehyde (UF) resins at high temperature was developed and used to assess the influence of the reaction pH on the formaldehyde emission and heat stability of the cured resins. Additionally, solid-state¹³C CP/MAS nuclear magnetic resonance (NMR) techniques were used to investigate the structure of cured UF resins before and after high temperature heating. Formaldehyde emissions during the cure were related to the UF resins' methylol group content. The heat stability of cured UF resins synthesized under strongly acidic conditions was much higher than that of the other resins, which were prepared in weakly acidic and alkaline media. Solid-state¹³C CP/MAS NMR spectra showed that formaldehyde emission from cured UF resins after heating is mainly ascribable to decreased methylol groups and dimethylene ether linkages. Significantly, it was revealed that uron structures characteristically found in the cured UF resin synthesized under strongly acidic medium indicated high heat stability.Parts of this paper were presented at the 44th annual meeting of the Japan Wood Research Society, Nara, April 1994; and at the 52nd annual meeting of the Forest Products Society, Merida, Mexico, June 1998     

Interchangeability of phosphorylation coupling factors in photosynthetic and respiratory energy conversion

The nonsulfur purple photosynthetic bacterium Rhodopseudomonas capsulata can obtain energy for growth either by anaerobic photophosphorylation or dark oxidative (aerobic) phosphorylation. Successful resolution of phosphorylation coupling factors from energy-converting membranes of this bacterium permitted tests for reciprocal function of such protein factors in oxidative-and photophosphorylation processes. Evidence was obtained for the interchangeability of coupling factor preparations from dark-grown and photosynthetically grown cells in both kinds of energy conversion.     

骊山森林公园种子植物的研究

骊山森林公园拥有种子植物357种(含种下等级),隶属74科235属.通过对其属分布区类型的分析,认为有15种分布类型.其中北温带分布68属,占总属数的34.2,其次为泛热带分布28属、旧世界温带分布23属、东亚和北美间断分布17属、东亚分布16属,分别占总属数的14.1、11.6、8.5和8.0.同时,还分析了主要的分布类型,阐明了骊山种子植物区系的基本特征.     

分子标记在植物遗传育种中的应用原理及现状

分子标记是继形态标记、细胞标记和生化标记之后发展起来的一种新的较为理想的遗传标记 ,已被广泛地应用于生命科学研究的各个领域。在植物遗传育种中 ,分子标记主要用于基因组图谱构建、基因定位、辅助标记选择、种质资源评价、基因克隆、杂种优势预测、杂交育种及跟踪育种过程等方面。文章主要介绍了分子标记在植物遗传育种中的应用原理及分析方法 ,并对其应用前景进行了展望。