Molecular divergence and application of the ITS-5.8S rDNA and RUBISCO spacer in <Emphasis Type="Italic">Porphyra haitanensis</Emphasis> Chang et Zheng (Bangiales,Rhodophyta)

To select a reliable and sensitive method for discriminating strains of Porphyra haitanensis, the nucleotide sequence of the internal transcribed spacer 1 to internal transcribed spacer 2 regions (ITS-5.8S) of nuclear ribosomal DNA and the intergenic spacer region of RUBISCO were compared in five wild and five cultivated Porphyra haitanensis strains. Based on molecular analyses, sequences of ITS-5.8S (about 1,210 bp) could be divided into three regions: ITS1, 5.8S, and ITS2. The ITS1 and ITS2 sequences of each strain differed, even between individuals collected from the same site. In contrast, 5.8S rDNA and RUBISCO spacer sequences were identical among the ten P. haitanensis strains, although differences were found among different Porphyra species. Phylogenetic analysis also supported these conclusions. These sequence features of highly conserved regions and diversified regions that occurred repeatedly in ITS-5.8S could be useful in discriminating germplasm of P. haitanensis strains or Porphyra species. In contrast, the RUBISCO spacer is only suitable for identifying Porphyra species. New coupled primers were designed to amplify only the 5.8S rDNA and ITS2 region of Porphyra. The sequences of these amplified fragments can be readily used to identify germplasm or to perform phylogenetic analysis of Porphyra spp.     

李子栽培分析探讨

做好李子的栽培,为农民增收,做好特色经济林的发展开辟新的路子。     

公共图书馆员职业倦怠的成因及对策探析——以广州图书馆为例

公共图书馆员职业倦怠是中国图书馆行业中普遍存在的问题,分析图书馆员职业倦怠的成因,以广州图书馆为例,探析解决公共图书馆员职业倦怠的对策。     

Identification and Analysis of Physiological Races of Magnaporthe oryzae in Heilongjiang Province

A totatl of 116 isolates of rice blast fungus, Magnaporthe oryzae, were collected from 45 samples in different counties of Heilongjiang Province, and 20 Chinese physiological races belonging to seven groups were identified by using seven standard Chinese rice blast identifying varieties. Results showed that the dominant groups could be ranked as ZA, ZD, and ZB, with the occurrence frequencies of 47.41%, 22.41% and 15.52%, respectively. The race ZA₄₉ was the dominant race with the occurrence frequency of 26.72%. The occurrence frequencies of the races ZD₅ and ZD₁ were 10.34% and 8.62%, respectively. The rising occurrence frequencies of these three dominant species were the most important reasons that causing Kongyu-131 more sensitive to rice blast. The results of virulence frequency indicated that the race harboring Pi-k, Pi-i, Pi-a gene were more susceptible to rice blast in Heilongjiang Province, and they should not be large-scale cultivated.     

浅谈河北省农村秸秆能源化利用新技术及推广与应用

农村秸秆能源化利用新技术在满足人们生活需求的同时可实现农业的循环和可持续发展,应加快其推广与应用。现对农村秸秆能源化利用的新技术(秸秆成型燃料炊事采暖技术与秸秆沼气联户供气技术)及目前发展现状进行阐述,提出了新技术推广与应用过程中存在的问题及解决问题的建议。     

Biological activity of the essential oil from the leaves of Piper sarmentosum Roxb. (Piperaceae) and its chemical constituents on Brontispa longissima (Gestro) (Coleoptera: Hispidae)

The results showed that the essential oil from Piper sarmentosum has strong antifeedant and toxicity effects on Brontispa longissima. The best antifeedant and contact toxicity effects were observed in the 1st-2nd instar larvae. The essential oil also displayed a notable fumigation effect on the eggs and pupae of B. longissima. It took the control-treated insects 43.34 d to complete one generation, while the insects treated with 2000 mg/L essential oil needed 73.58 d. The essential oil was analyzed by gas chromatography/mass spectrometry and 41 components were identified. Myristicin (65.22%) and trans-caryophyllene (13.89%) were the major components. Myristicin exhibited strong antifeedant and contact toxicity effects on both the 3rd instar larvae and the imagoes of B. longissima, when it showed a significant fumigation effect on the eggs and pupae of B. longissima. Another P. sarmentosum essential oil and myristicin all showed a strong inhibiting effect on the growth and development of B. longissima along with the activity of AChE, CarE, GSTs and Na⁺, K⁺-ATPase in B. longissima larvae.     

有机黄瓜生产中霜霉病的防控技术

根据防治黄瓜霜霉病的实践经验,系统总结有机黄瓜霜霉病综合防控技术,解决有机黄瓜生产中遇到的首要问题,助推有机农业的健康发展。     

切实加强森林资源管理 提高凭证采伐率

凭证采伐率是体现一个地方森林资源管理的重要指标，文章对重点林区凭证采伐率的现状及下降原因作了分析，提出提高凭证采伐率的对策，这对森林采伐限额管理有一定的参考价值。     

牛乳头状瘤的病理学观察及其病毒基因型分析

为研究牛乳头状瘤病毒(BPV)在我国对牛的致病性及基因型,本研究选取某奶牛场发病的犊牛,通过对皮肤肿瘤样物进行临床观察、组织病理学及免疫组织化学检查,并应用DNA提取及PCR等技术对其进行鉴定.组织病理学结果显示牛乳头状瘤呈现角化过度和细胞空泡化现象；免疫组织化学结果显示胞浆棕染呈BPV阳性；应用PCR对其DNA进行扩增,检测出阳性样品,测序结果表明与BPV-1和BPV-2同源性达98％～99％.表明该奶牛场犊牛发病由BPV-1和BPV-2引起的.