云南省角蝉科二新属二新种

最近我们从全国动物学科研单位和高等院校借调来大批的角蝉科标本,进行系统的分类研究,从中发现有二新属及二新种,均采自云南西双版纳,现在先把它们加以记载。     

角蝉科一新属一新种

角蝉科的昆虫,是世界著名的富于拟态性的昆虫。它们的畸形发达的前胸背板给人们以明显的识别的特征。这一科不少种类是果树、森林或农业的重要害虫,造成相当严重的灾害。角蝉科截至目前为止,全世界已记载的共324属2500余种;中国已知的20属152种。 本文记述角蝉科一新属及一新种。     

中国的广翅蜡蝉科附八新种

广翅蜡蝉科的种类,多数为害木本植物,少数为害禾本科草本植物,有的是果树、森林和农作物的害虫。但关于广翅蜡蝉科的研究,过去很不充分,我国的种类、分布与寄主关系,至今还不清楚。1935年胡经甫的昆虫名录中列入11种(包括3种同物异名),1959年《中国果树病虫志》中列了5种。 我们根据三十年来在全国各地的采集调查,和全国兄弟单位提供的标本,共鉴定出26种。本文着重记录它们的分布及其为害植物,并记载新种8种。     

金翅夜蛾亚科的研究

近年来,我们又获得大量金翅夜蛾亚科的标本。这些标本有的是我们区系组的同志从全国各地采集的,有的是兄弟单位赠送或借给的。 标本共77,085号,我们逐一进行了外部特征的观察,每种作了雌雄生殖器的解剖研究。除前一报告已记载的相同种类外,新增加的种类有36种。如下:     

金翅夜蛾亚科八新种及一些种类的订正

金翅夜蛾亚科的种类,有的在外形上非常相似,因之过去文献记载常有混淆的地方和鉴定上的错误。本文讨论了一些种类的区别,纠正某些错误的记载,并报道8个新种。 所有新种的模式标本都暂在西北农学院昆虫标本室保存。     

18S-25S rDNA variation in tissue culture of some Gentiana L. species

18S-25S rDNA of intact plants and tissue cultures of G. acaulis, G. punctata and G. lutea have been investigated by using blot-hybridization. The decrease of rDNA amount was found in the callus cultures as compared with the plants. In contrast to other species, G. lutea showed intragenome heterogeneity of rRNA genes as well as qualitative rDNA changes in tissue culture, in particular appearance of altered repeats. The relationship between the peculiarities of rRNA gene structure and their rearrangements in in vitro culture was suggested.     

Variability of nuclear 18S-25S rDNA of Gentiana lutea L. in nature and in tissue culture in vitro

18S-25S rDNA sequence in genomes of G. lutea plants from different natural populations and from tissue culture has been studied with blot-hybridization method. It was shown that ribosomal repeats are represented by the variants which differ for their size and for the presence of additional HindIII restriction site. Genome of individual plant usually possesses several variants of DNA repeats. Interpopulation variability according to their quantitative ratio and to the presence of some of them has been shown. Modifications of the range of rDNA repeats not exceeding intraspecific variability were observed in callus tissues in comparison with the plants of initial population. Non-randomness of genome modifications in the course of cell adaptation to in vitro conditions makes it possible to some extent to forecast these modifications in tissue culture.     

The investigation of genomes of some species of the genus Gentiana in nature and in vitro cell culture

The comparative study of the genomes of intact plants-representatives of some species of the genus Gentiana L. as well as cultured cells of G. lutea and G. punctata was performed using restriction analysis. Species specificity of restriction fragment patterns for studied representatives of this genus was revealed. The differences between electrophoretic patterns of digested DNA purified from rhizome and leaves of G. lutea and G. punctata were found. The changes in genomes of G. lutea and G. punctata cells cultured in vitro compared with the genomes of intact plants were detected. The data obtained evidence that some of them may be of nonrandom character.     

Restriction mapping and variability of 18S-25S ribosomal genes in some species of Gentiana genus

Mapping of rRNA genes in four species of Gentiana genus has been carried out by blot-hybridization method using some restriction endonucleases. The following characteristics of Gentiana rDNA structural organization have been revealed: 1) interspecific and intragenomic variability of the length of ribosomic repeats; 2) conservativity of the transcribed region; 3) variability of the length and location of Hind-III site in non-transcribed spacer; 4) interspecific variability of the number of copies. Comparative analysis of the constructed restriction maps of Gentiana species and some other plants revealed the similarity of restriction site location in the transcribed DNA region.     

Occurrence and distribution of organochlorine pesticide residue levels in water,sediment and aquatic weeds in the Nyando River catchment,Lake Victoria,Kenya

Samples of water, sediments and aquatic weeds were collected from 26 sites in the Nyando River catchment of the Lake Victoria basin in 2005–2006. The objective was to investigate levels of organochlorine pesticides that have either been banned or are restricted for use in Kenya. The pesticides investigated were lindane, aldrin, endosulfan, endrin, dieldrin, DDT, heptachlor and methoxychlor. These pesticides had previously found wide applications in public health and agriculture in Kenya for control of disease vectors and crop pests respectively. Results showed that mean concentrations were highest for methoxychlor (8.817 ± 0.020?µg l^?1) in water, sediments (92.893 ± 3.039 µg kg^?1), and weeds (39.641 ± 3.045?µg kg^?1), the weeds also tended to accumulate aldrin (15.519 ± 3.756?µg kg^?1). The results show that the pesticides are still in use and are detected in the catchment. Stringent management and public awareness measures are required to enforce the ban on the organochlorine pesticides in order to safeguard the environment and ecosystems of Lake Victoria.