Molecular phylogeny of Bactrocera species （Diptera： Tephritidae） inferred from mitochondrial 16s rDNA sequences

The fruit flies of the Bactrocera （Diptera： Tephritidae） are one of the major economically important insects in Asia. So far, there are at least seven species found in Chongqing, China. By using mitochondrial 16s rDNA sequences, the phylogenetic relationships among seven Bactrocera species, Bactrocera cucurbitae （Coquillett）, B. tau （Walker）, B. diaphora （Hendel）, B. caudata （Fabricius）, B. scutellata （Hendel）, B. dorsalis （Hendel）, and B. minax （Enderlein） were investigated. Nucleotide diversity within species ranged from 0.3% to 10.9%. According to the result, B. cucurbitae （Coquillett）, B. tau （Walker）, B. diaphora （Hendel）, and B. caudata （Fabricius） have no enough sites to be distinguished among the other species in the 347bp nucleotide sequences of the 16s rDNA gene. At the same time, excluding B. scutellata （Hendel） and B. minax （Enderlein）, the other species recognition sites are not only too little but also discontinuous. Phylogenetic trees calculated from both maximum parsimony and neighbor-joining phylogenetic analysis methods showed that B. cucurbitae and B. tau were closely related, B. diaphora （Hendel） and B. caudata （Fabricius） also had a close relationship. B. minax （Enderlein） has a furthest relationship from the other 6 species. From the results, we can infer that the our data supports previous classification of Bactrocera based on morphological characters in other words, but the Bactrocera subgenera, Zeugodacus is polyphyletic.     

Molecular Taxonomy of Conogethes punctiferalis and Conogethes pinicolalis（Lepidoptera： Crambidae） Based on Mitochondrial DNA Sequences

Conogethes punctiferalis（Guenée）（Lepidoptera： Crambidae） was originally considered as one species with fruit-feeding type（FFT） and pinaceae-feeding type（PFT）, but it has subsequently been divided into two different species of Conogethes punctiferalis and Conogethes pinicolalis. The relationship between the two species was investigated by phylogenetic reconstruction using maximum-likelihood（ML） parameter estimations. The phylogenetic tree and network were constructed based upon sequence data from concatenation of three genes of mitochondrial cytochrome c oxidase subunits I, II and cytochrome b which were derived from 118 samples of C. punctiferalis and 24 samples of C. pinicolalis. The phylogenetic tree and network showed that conspecific sequences were clustering together despite intraspecific variability. Here we report the results of a combined analysis of mitochondrial DNA sequences from three genes and morphological data representing powerful evidence that C. pinicolalisand C. punctiferalis are significantly different.     

柑桔类植物起源的初探

本文简要描述了柑桔类植物和其近缘植物;回顾了以往有关起源的论述.根据大陆漂移理论,分析各有关大陆的古生态气候和地史变迁.推测柑桔类植物祖先可能起源于四川、康滇和江南古陆以及印度支那半岛一带地域,然后传播至印度、非洲和澳洲.从柑桔类植物的形态特征、分布及生态状况等分析,认为金柑属、枳属和柑桔属起源于中国,而澳砂檬属、多蕊桔属和澳指蒙属则起源于澳州.     

一种适合于成熟脐橙果皮和果肉的RNA提取方法

研究了一种适合脐橙果实成熟过程中有效的RNA提取方法。结果表明利用该方法从不同成熟时期果实的果皮和果肉中提取的RNA可以有效用于RT-PC,cDNA-AFLP和RNA杂交。其A260/A230的比值超过2.0,A260/A280的比值在1.65-1.92的范围之间。另外该方法也证明可以广泛用于柑橘叶片,未成熟的幼果,枳壳幼苗和柑橘愈伤组织的RNA提取,是一种安全、方便和适用性较广的RNA提取方法。     

粘质沙雷氏菌中乙偶姻合成途径基因克隆、序列分析及表达

运用生物信息学和PCR方法,鉴定了粘质沙雷氏菌乙偶姻生物合成途径中编码α-乙酰乳酸脱羧酶(a- ALDC)和α-乙酰乳酸合成酶(α- ALS)的基因(aceA和aceB)序列.经测序和序列分析显示aceA和aceB基因的开放阅读框(ORF)长度为780 bp和1 686bp,编码259和561个氨基酸,编码蛋白分子量和...