Intraspecific Variation of Eysarcoris guttigerus (Hemiptera: Pentatomidae) in Japanese Southwest Population Based on Mitochondrial DNA

The white-spotted globular bug Eysarcoris guttigerus (Thunberg) (Hemiptera: Pentatomidae) is widely distributed in East Asia and the Pacific region. In Japan, the species is found in grassy or composite weeds in the western area of the main islands and Ryukyu Islands of Japan. One notable characteristic of the Eysarcoris genus is the two white spots on the scutellum. This is not the case with the Ishigaki Island population, however, which sports red spots instead of white, suggesting that intraspecific variation exists in the species. Therefore, we investigated intraspecific variation in E. guttigerus using mitochondrial NADH dehydrogenase subunit 2 (ND2), cytochrome oxidase subunit 1 (CO1), cytochrome b (Cytb), tRNA-Serine (tRNA^ser), NADH dehydrogenase subunit 1 (ND1), and 16S ribosomal RNA (16SrRNA) genes from 13 populations of Japan. The obtained maximum likelihood phylogenetic tree was divided into three groups—Group 1: Mainland, Group 2: Central Ryukyu Islands (Okinawa-Amamioshima Islands), and Group 3: South Ryukyu Islands (Ishigaki Island). The Ishigaki population was significantly separated from the other populations with consistent differences in spot color. The estimated period of divergence between the Ishigaki population and the other populations was consistent with the period of formation of the Kerama Gap in the Ryukyu arc. Thus, the process of formation of the Kerama Gap may have influenced the intraspecific variation of E. guttigerus.     

基于多种DNA序列的霉梨起源初探

为了探索霉梨（Pyrus spp.）品种群的起源,基于叶绿体片段（accD-psaI,trnL-F）及低拷贝核基因LEY2第二内含子（LFY2int2-N）DNA序列信息对相关的梨属植物进行了系统发育分析。结果表明：除了‘小霉梨’,其它样本均为同一种叶绿体单倍型,与大多数砂梨品种的单倍型一样;基于LFY2int2-N的系统发育树显示霉梨和浙江原产砂梨均非单系类群,但两者关系密切;霉梨并非种间杂种,豆梨很可能没有直接参与其起源。     

河南省不同产地3种菊头蝠RAPD分析

用随机引物对河南省角菊头蝠（Rhinolophus cornutus）、不同产地的中菊头蝠（Rhinolophus affinis）和马铁菊头蝠（Rhinolophus ferrumequinum）进行DNA多态性研究,以探讨它们之间的亲缘关系。从20个随机引物中优化出15个引物对基因组DNA进行扩增,10个标本共扩增出184条DNA谱带,平均每个引物扩增出12条谱带,其中多态性谱带173条,多态率为94%。聚类结果表明：对同种蝙蝠,同一地理区域的个体之间分化较小,不同地理区域的个体之间分化较大;中菊头蝠与角菊头蝠之间的亲缘关系较近,而与马铁菊头蝠之间的亲缘关系较远。     

香蕉野生种质资源的分类、分布和分子系统发育研究进展

野生芭蕉物种是栽培香蕉育种的重要种质资源,探究其分类、分布及物种间系统发育关系,特别是揭示栽培香蕉亲本小果野蕉（Musa acuminata）和长梗蕉（M. balbisiana）与其他野生物种间的亲缘关系,对香蕉育种及品种改良具有非常重要的意义。综述了香蕉野生种质资源的形态学分类、不同分类方法的应用及分子系统发育研究等方面的进展,并对世界香蕉野生种质资源收集、分类鉴定和系统发育研究提出建议,旨在为香蕉种质资源研究和开发利用提供参考依据。     

Molecular Phylogeny of the ＂True Citrus Fruit Trees＂ Group （Aurantioideae,Rutaceae） as Inferred from Chloroplast DNA Sequence

The genus Citrus L.has a long controversial taxonomy history,and a well-resolved molecular phylogeny of the "true citrus fruit trees" group in the future will provide new information for advancing breeding techniques and developing better conservation strategies.In the present study,three cpDNA fragments(TrnL-TrnF,PsbH-PetB,and TrnS-TrnG)of 30 genotypes chosen from the six genera of the "true citrus fruit trees" group were analyzed.A molecular phylogenetic tree of the "true citrus fruit trees" group was reconstructed based on plastid DNA sequences.The results confirmed that the "true citrus fruit trees" group was monophyletic,and thereby the group was divided into genera as previously suggested based on morphological characters.The cpDNA data also suggested that Poncirus might be the first genus separated from the other five genera in the group.The genus Fortunella were of hybrid origin and Citrus might be as its putative paternal parent.The genera Microcitrus,Eremocitrus,and Clymenia were possibly monophyletic and their common ancestor might branch out from Citrus.Furthermore,the phylogenetic relationships within the Citrus genus were discussed.     

Arbuscular mycorrhizal fungal communities associated with some pioneer plants in the lahar area of Mt. Pinatubo,Philippines

An extensive area has been buried due to the repeated occurrence of mud flows (lahars) derived from volcanic deposits during the eruption of Mt. Pinatubo in the Philippines. Most of the area was covered with sparse vegetation consisting of only a few gramineous pioneer plants such as Saccharum spontaneum (site SV). However dense vegetation consisting of wild leguminous plants such as Calpogonium mucunoides showed a patch distribution (site DV). In 1999, we investigated the community composition of AMF at these two sites. S. spontaneum at both sites was slightly colonized with AMF while the leguminous plants were highly colonized. Spores of AMF were collected from the rhizosphere of these plants. Eight spore morphotypes were identified; one each for Acaulospora and Entrophospora colombiana, two for Glomus, one for Paraglomus, and three for Scutellospora. Part of the 18S rRNA gene of AMF colonizing the plant roots was amplified with AMF-specific primers, NS31 and AM1, cloned and sequenced. Fifty-three AMF clones were phylogenetically classified into 8 phylotypes as follows: one each for Acaulospora and E. colombiana, five for Glomus, and one for Scutellospora. Both molecular and morphological examinations showed that the diversity of AMF was comparable to that in other temperate ecosystems with abundant vegetation and did not differ significantly between sites SV and DV, regardless of the vegetation cover. Furthermore, S. spontaneum supported diverse AMF species in spite of its scant growth at site SV. E. colombiana was mostly associated with C. mucunoides. Significance of AMF for the primary plant succession in the lahar area was analyzed.     

玉米SPXs家族基因的鉴定与表达规律分析

 SPXs(SPX-domain-containing proteins)家族基因在真核生物无机磷酸盐(Pi)的传感、信号转导和转运中发挥着重要作用,但玉米SPXs家族基因的相关研究未见报道。本研究利用生物信息学手段鉴定了15个玉米SPXs家族基因,通过系统进化和保守结构域分析将其分为SPX-EXS、SPX、SPX-Zinc finger和SPX-MFS 4个亚家族。通过表达谱数据分析,发现ZmSPXs家族基因具有明显的组织特异性表达。同时,我们还发现ZmSPXs家族基因在生物胁迫和非生物胁迫过程中表达模式也具有很大差异,说明这些基因可能在不同的生物过程中发挥重要作用。最后,利用荧光实时定量PCR技术,对玉米SPXs家族基因在磷胁迫处理下的表达规律进行分析,结果发现大部分基因在磷胁迫处理下呈现高水平表达。本研究鉴定了玉米SPXs家族基因,明确了该家族基因的系统进化关系、保守结构域、组织表达特性以及在生物和非生物胁迫条件下的表达规律,为阐明玉米SPXs家族基因的功能及其机制奠定了理论基础。     

Putative effector genes detected in Fusarium oxysporum from natural ecosystems of Australia

The Fusarium oxysporum species complex (FOSC) causes disease in plants and animals, but is also widely dispersed in natural ecosystems without evidence of disease. The present study screened a population representing natural ecosystems across the Australian continent for the putative effector genes pisatin demethylase 1 (PDA1), pectate lyase (pelD), secreted gene expression (SGE1) and secreted in xylem (SIX). The genes pelD and SGE1 were prevalent in the natural isolates, PDA1 was present at an intermediate level, whereas SIX genes were detected at low levels. Phylogenies of these putative effector genes were compared to the EF‐1α species phylogeny to determine the likely modes of gene transmission: vertical gene transfer (VGT) and horizontal gene transfer (HGT). There was evidence of both modes of gene transmission within the F. oxysporum isolates. PDA1, pelD and SGE1 were likely to be only vertically inherited, whereas the SIX genes had evidence for both VGT and HGT. The phylogenetic relationships of SIX genes in isolates from natural ecosystems and formae speciales from agro‐ecosystems were also established. These findings have important implications for the evolution of effectors in the FOSC.     

Fusarium oxysporum f. sp. canariensis: evidence for horizontal gene transfer of putative pathogenicity genes

Fusarium wilt is a serious disease of the date palm Phoenix canariensis, caused by Fusarium oxysporum f. sp. canariensis (Foc). A previous study that characterized and compared the genetic diversity of the Australian Foc population with international strains suggested that the Australian population may have had an independent evolutionary origin. The current study compared the species phylogeny of the Australian and international populations and determined that Foc is not monophyletic, separating into three supported lineages across the two phylogenetic species of the Fusarium oxysporum species complex. This confirms an independent evolutionary origin for Foc in Australia. However, phylogenetic analysis of the putative pathogenicity genes Secreted In Xylem (SIX) did not reveal any separation of the Australian and international Foc strains. Furthermore, there was very low SIX sequence diversity within Foc. Horizontal gene transfer is argued to be the most parsimonious explanation for the incongruence between the species and SIX gene phylogenies.     

线粒体DNA标记在头足纲动物分子系统学中的应用

动物线粒体DNA(mtDNA)基因组具有在细胞中大量存在、缺少重组、多为母系遗传、缺少内含子以及进化速率高等特点,广泛应用于比较和进化基因组、分子进化、种群遗传、物种鉴定和不同分类水平上的系统发生学研究。头足类作为软体动物门中的重要经济种类,其分类和系统进化研究历来是热点领域。本文主要对头足类动物mtDNA组成与特点(包括基因组成、重排等)、常用mtDNA标记对其不同分类阶元的适用性以及线粒体基因片段和全基因组在头足类系统演化中的作用进行了阐述,并对未来发展进行展望。