生态型蚕场轮伐枝干栽培滑子蘑的研究与开发

利用生态型蚕场轮伐下来的柞树枝干栽培滑子蘑比工业木屑栽培滑子蘑定植率高9.4%,生长速率高13.6%,产量高17.8%。同时提高了柞树枝干的利用价值,为蚕民增加养蚕总效益提供了一项新技术。     

日粮中添加胡麻油对育成羊干物质采食量和营养物质消化代谢的影响

选用3只育成蒙古羊,分期探讨了饲喂不同剂量的胡麻油(LF)对干物质采食量、纤维性物质消化率和能量转化卒的影响.每期设预饲期7 d,正试期3 d.基础日粮(BR)由玉米秸秆60%和混合精料40%组成.时照期喂BR(含脂质2.52%),I期喂BR+LF 15g/d(舍脂质4.32%),Ⅱ期喂BR+LF 30 g/d(含脂质6.31%).试验结果:I、Ⅱ期与对照组相比玉米秸秆采食量分别下降10.7%(P＜0.05)和17.1%(P＜0.05);I期干物质、粗蛋白质(CP)、粗纤维(CF)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)消化率无明显差异(P＞0.05),Ⅱ期的分别降低21.2%、16.7%、23.3%、26.9%和23.4%(均P＜0.01).对照组和I组氮沉积率、消化能占总能的比例无显著差异(P＞0.05),而Ⅱ组与对照组和I组比较显著下降(P＜0.05).以上结果表明:日粮中添加胡麻油降低DMI,添加1.8%的胡麻油使日粮脂肪含量达4.3%,对干物质、粗蛋白质和纤维物质消化率以及氮沉积率和总能向消化能的转化效率无负面影响.     

引种美国红橡幼龄材的物理力学性质研究

【目的】测定从北美引种的3种美国红橡木材的物理力学性质,以弥补我国家具和室内装修优质木材资源不足的现状。【方法】以引种的14年生(幼龄期)美国红橡纳塔栎(Quercus nuttallii)、舒玛栎(Quercus shumardii)和水栎(Quercus nigra)为研究对象,按照国家标准方法测定其木材的密度、干缩性、冲击韧性、顺纹抗压强度、抗弯强度和抗弯弹性模量等基本物理力学性能指标,分析各指标间的相关性,并采用隶属函数法对各树种木材材性进行综合评价。【结果】3种美国红橡幼龄材气干密度、体积气干干缩率、冲击韧性、顺纹抗压强度、抗弯强度和抗弯弹性模量分别为0.725～0.767 g/cm~3,9.650%～10.622%,216.59～255.14 kJ/m~2,45.57～54.44 MPa,104.24～105.40 MPa,7.11～7.77 GPa。3种美国红橡种间弦向全干干缩率差异极显著(P≤0.01),而种间径向全干干缩率和抗弯强度均差异不显著。相关性分析表明,红橡幼龄材气干密度与抗弯强度极显著相关;顺纹抗压强度与抗弯弹性模量极显著相关,与抗弯强度显著相关;抗弯强度与抗弯弹性模量极显著相关。3种红橡材性综合评价结果显示,纳塔栎和舒玛栎的材性略优于水栎。与其他栎属树种成熟材相比,引种的美国红橡幼龄材的大多数指标均接近其他栎属成熟材水平。【结论】3种美国红橡木材都属于高强度、高等级木材,材性优良,可作为制作家具和室内装修的优质用材。     

A multiplex real-time PCR assay enables simultaneous rapid detection and quantification of bacteria associated with acute oak decline

Acute oak decline (AOD) is a syndrome affecting mature oak trees and is characterized by stem bleeds from vertical fissures on trunks, and inner bark necrosis caused by a polybacterial consortium, in which Gibbsiella quercinecans and Brenneria goodwinii, and to a lesser extent Rahnella victoriana and Lonsdalea britannica, play key roles. Here we report a novel multiplex real-time PCR assay that enables simultaneous and rapid detection and quantification of these four bacterial species from stem bleed swabs. Experiments with axenic cultures were performed to determine specificity and sensitivity of the multiplex quantitative PCR (qPCR). Whilst the primer/probe set for B. goodwinii was species-specific, primer/probe sets for the other three species were able to identify other members of their respective genera. There was no cross detection of genera within the multiplex qPCR, and non-target bacteria were not detected. The multiplex AOD assay had differential sensitivity for each bacterial species. The assay was evaluated on swab samples collected from stem bleeds of declining oak trees at a site in south-east England and was able to detect all four bacterial species. Absolute quantification of the bacteria from swab samples was possible through the inclusion of a standard curve prepared from dilutions of gene copy standards. This diagnostic tool will facilitate rapid detection of AOD-associated bacteria from samples that can easily be taken by non-specialists without specific training, and will also find application in other experimental work such as pathogenicity and control trials.     

Investigation of the mating‐type distribution of Raffaelea quercus‐mongolicae in South Korea

Raffaelea quercus‐mongolicae is a mycangial symbiont of a wood‐boring ambrosia beetle, Platypus koryoensis (Coleoptera: Curculionidae: Platypodidae), which is believed to be associated with oak mortality in South Korea. Since the first discovery of the disease in 2004, oak mortality has continued to spread across the country, and the pathogen has had a significant impact on forest ecosystems in the country; however, little is known regarding the biology of the fungus. The aim of this study was to develop markers to determine the mating types of individual isolates of R. quercus‐mongolicae collected across the country and then determine the mating‐type ratio in natural populations. To achieve this, partial sequences of MAT1‐1–3 and MAT1‐2–1 genes were amplified using degenerate primers and cloned. The new primer sets, which were specific to each mating‐type idiomorph, identified isolates as MAT1‐1 and MAT1‐2 mating types. The roughly equal frequencies of the two mating types suggest that sexual reproduction might have occurred in natural populations of R. quercus‐mongolicae in South Korea.     

Monitoring genetic stability inQuercus serrata Thunb. somatic embryogenesis using RAPD markers

Genetic stability of propagules regeneratedvia somatic embryogenesis is of paramount importance for its application to clonal forestry. Random amplified polymorphic DNA (RAPD) markers were used to determine the genetic stability in somatic embryogenesis ofQuercus serrata Thunb. (Japanese white oak). Forty samples from an embryogenic line, consisting of regenerated plantlets, somatic embryos, and embryogenic calli, were examined using 54 decanucleotide primers. A total of 6520 clear reproducible bands obtained from these studies exhibited no aberration in RAPD banding pattern among the tested samples. Our results show that somaclonal variation is absent in our plant propagation system. The genetic stability is discussed in terms of the origin of somatic embryos.     

柞蚕微孢子虫单克隆抗体的研制及诊断

研究报告了柞蚕微孢子虫Nosemaantheraeae(简称N .a)单克隆抗体制备及免疫胶体金银染色法 (IGSS)诊断的结果。用抗N .a的单抗结合间接免疫胶体金银染色法 (IGSS)对 6种微孢子虫进行检测 ,在光学显微镜下柞蚕微孢子呈现特异的褐色 ,能与包括家蚕微孢子虫在内的其它 5种微孢子虫加以区别。     

闽北36年生栓皮栎人工造林效果调查

对福建省浦城县36a生栓皮栎人工造林效果进行了调查研究。结果表明,栓皮栎人工林具有较高的林分生产量,林分总生物量达266.560t/hm~2,乔木层为257.149t/hm~2;林分平均树高20.4m,平均胸径19.5cm,蓄积量达201.87m~3/hm~2。与杉木人工林相比,栓皮栎人工林具有良好的土壤结构和较强的养分供应能力。其表层土壤>0.25mm水稳性团聚体含量比杉木人工林高9.99％,土壤有机质含量比杉木人工林高0.695％。栓皮栎人工林还具有良好的水源涵养能力,林分总持水量比杉木人工林高10％。     

Comparison of the Susceptibility of Quercus petraea, Q. robur and Q. rubra to Collybia fusipes

Collybia fusipes is the cause of a root rot of Quercus petraea (sessile oak), Q. robur (pedunculate oak) and Q. rubra (red oak). This parasite is often reported to cause problems in stands of red oaks and field evidence suggests that this North American oak species is more susceptible than the two European oak species. Young saplings of the three oak species and of chestnut, Castanea sativa, in the glasshouse, and also mature sessile and red oaks growing in the same stand were inoculated with C. fusipes to compare their susceptibility. Red oak, both as young seedlings and mature trees, was more susceptible to C. fusipes than sessile oak. Chestnut seedlings were as susceptible as sessile oak. Susceptibility of pedunculate oak seedlings was intermediate between red oak and sessile oak. In one experiment this species was significantly less susceptible than red oak, and in the other it was as susceptible.