DNA content,morphometric and molecular marker analyses of Citrus limonimedica, C. limon and C. medica for the determination of their variability and genetic relationships within the genus Citrus     

Diego Pessina  Rodolfo Gentili  Gianni Barcaccia  Silvia Nicolè  Graziano Rossi  Silvia Barbesti  Sergio Sgorbati 《Scientia Horticulturae》2011

This work investigated the fingerprinting and phenotyping of Citrus germplasm; species selected were of historical importance belonging to Citrus limonimedica Lush. and its supposed ancestors, along with some other species of the Citrus genus. An integrated approach based on the exploitation of nuclear DNA content, morphological traits and molecular markers, such as RAPD fingerprints and ITS-based SNPs, was employed. We studied a core collection of 54 distinct accessions, including 43 genotypes of the Citrus species (18 species or supposed species) and 11 genotypes of the Poncirus genus, which was used as the reference outgroup. Morphological trait analysis and statistical analysis of DNA content and markers were useful for reconstructing a Citrus phylogeny. In particular, our experiments aimed at estimating the genetic variation within and the genetic relatedness among C limon (L.) Burm., C. limonimedica and C. medica L. to shed light on the hybrid origin hypothesis of C. limonimedica. The results of the multidisciplinary analyses allowed us to confirm a remarkable differentiation between Poncirus and Citrus genera and to highlight a close relationship among the three investigated Citrus species but a distinct difference between these three species and other species in the Citrus genus. RAPD fingerprints and ITS polymorphisms enabled us to point out a variation gradient between lemon and citron, with C. limonimedica as a possible intermediate species. Some accessions of C. medica and C. limonimedica that deviate from such a trend suggest recurrent introgression and/or hybridisation with other species of Citrus.  相似文献   

The impact of fossils on the Evolutionary Distinctiveness and conservation status of the Australian lungfish     

Lionel Cavin  Anne Kemp 《Biological conservation》2011,144(12):3140-3142

The recognition of phylogenetic information for evaluating conservation priorities has stressed the importance of basal taxa. The “Evolutionary Distinctiveness” index (ED) is a species-specific index that includes branch length expressed as an absolute value measured in millions of years that can be applied to a single terminal taxon in a phylogeny. The ED depends on the tree pattern, i.e. of a cladogram included into a time-scale. When calculated for the Australian lungfish (Neoceratodusforsteri), a threatened dipnoan that occurs naturally only in southeast Queensland, the ED index shows variable value according to the chosen tree. On the basis of a recently proposed phylogeny including a new fossil find from the Early Cretaceous of Thailand, the ED value reaches the highest value for piscine sarcopterygians, and for all vertebrates, and thus reinforces the “originality” of this fish. This example points out the importance of fossils in the resolution of phylogenies and beyond, in the calculation of indexes supporting conservation decisions.  相似文献   

3种棱型大麦中脱水素6（DHN6）的性质、突变位点与蛋白质进化分析     

钱刚  平军娇  张珍  王乾兴  刘茂生 《广西农业生物科学》2011,30(3):322-329

脱水素（dehydrins,DHNs）是高等植物胚胎发育晚期产生的一类特异多肽,能够逆转细胞脱水所造成的伤害。为明确脱水素性质与功能的关系,本研究从3种棱型大麦分离到Dhn6基因,生物信息学分析其编码的蛋白质序列长度分别为523个（六棱）、502个（四棱）和486个（二棱）氨基酸残基;氨基酸突变位点分析发现该基因具有整体保守性和突变位点偏倚性。蛋白质性质与二级结构分析表明,DHN6是高度亲水的碱性蛋白质,线性结构和自由卷曲为二级结构的主要组分,K-片段参与α-螺旋结构的形成,由此推测DHN6的兼性α-螺旋结构域在稳定膜结构的水合保护体系过程中发挥着重要的生理功能。构建的21个物种DHN6蛋白质系统发生树,发现禾本科植物遗传距离较近,结合核苷酸序列的物种特异性,本研究认为Dhn6基因可作为物种鉴定依据。  相似文献   

Spatial and taxonomic correlates of species and species trait assemblages in soil invertebrate communities     

J.F. Ponge  S. Salmon 《Pedobiologia》2013

Whether dispersal limitation and phylogenetic conservatism influence soil species assemblages is still a debated question. We hypothesized that spatial and phylogenetic patterns influence communities in a hump-backed fashion, maximizing their impact at intermediate spatial and phylogenetic distances. Species–environment relationships are blurred by dispersal limitation and restricted habitat choice at long and short spatial distances, respectively (Hypothesis 1). Co-occurrence of species/traits is limited by divergent evolution of species/traits and competitive exclusion at long and short phylogenetic distances, respectively (Hypothesis 2). Springtails were sampled over a wide array of environmental gradients, between-sample distance varying from a few cm to several km. We compared communities using species composition, habitat features, and geo-localization. We compared species using co-occurrence, habitat preference, traits and phylogeny. Mantel tests identified which factors contributed the best to species/traits assemblages. Within the studied area, species composition was influenced by habitat more than space. Traits displayed a strong phylogenetic signal, but they contributed less than habitat preferences to species co-occurrence. Species–environment relationships were better displayed within a 200 m distance, supporting Hypothesis 1. Occurrence-habitat preference relationships were better displayed at family level, supporting Hypothesis 2.  相似文献   

20世纪我国风景园林学科发展史     

黄谦  牛泽慧 《农业科技与信息》2007,(2)

本文从风景园林学科的诞生入手,主要研究20世纪该学科在中国的发展,阐明了随着社会与科学的不断进步,风景园林学科的内涵与外延都在不断扩大的规律及其对社会发展的巨大作用。  相似文献   

石斑鱼遗传多样性及其系统发育分析     

李庆  黄毅昌  闫秀英  简纪常  吴灶和 《安徽农业科学》2015,(29):75-79

石斑鱼不仅是重要的海水经济鱼类,而且具有重要的生态地位.但是,石斑鱼的分类、物种多样性、资源保护及其合理开发等需要对石斑鱼系统发育的分析与研究.线粒体基因是研究石斑鱼系统进化的理想分子标记,因此获得了青石斑鱼E.awoara长度为1 039bp的16S rDNA、tRNA-Leu和NA1部分序列,基于其及ND2、cyt b对石斑鱼系统发育进行了分析,结果表明石斑鱼遗传多样性与地域分布关系不大,不同系统树分析都表明同一石斑鱼物种的系统发生关系基本一致,石斑鱼种间亲缘关系较近.此外,也发现某些异种间亲缘关系比同种间亲缘关系近的现象.  相似文献   

Mineral characteristics of leaves of plants from different phylogeny grown in various soil types in the temperate region   总被引：2，自引：0，他引：2  

Osaki M  Yamada S  Ishizawa T  Watanabe T  Shinano T  Tuah SJ  Urayama M 《Plant foods for human nutrition (Dordrecht, Netherlands)》2003,58(2):117-137

The objective of this research was to analyze selected minerals in leavesof plants, belonging to 166 species growing in alluvial, low pH, brownforest and serpentine soils. Mineral characteristics of the soils involved werealso determined.For the macronutrients, in trees grown in alluvial soil, N, P, Ca, and Mgconcentrations of leaves were higher in recently evolved plants than inplants with a longer period of evolution; K concentration remained constantregardless of evolution. In grasses grown in alluvial soil, it was difficult todetect the general tendency of mineral concentration. N, P, and Kconcentrations in alluvial soil were closely related to those in low pH andserpentine soils. Ca concentration in alluvial soil was lower than that in lowpH and serpentine soils. Mg concentration in alluvial soils was higher thanthat in low pH soils, while lower than that in serpentine soil. Therefore, N,P, and K accumulated according to the plant characteristics for theseelements, while Ca and Mg accumulation was strongly affected by the soilproperties.For the micronutrients, in trees, Fe and Mn remained constant regardlessof evolution; Zn concentration was lower in recently-evolved plants than inplants with a longer period of evolution. In grasses, Fe, Mn, and Znconcentrations in Caryophyllids were high. Except for Caryophyllids, Fe andCu concentrations remained constant, Mn concentration decreased withevolution, Zn concentration was higher in recently-evolved plants than inplants with a longer period of evolution.  相似文献   

Full-length genome analysis of G2, G9 and G11 porcine group A rotaviruses     

Olivier Martel-Paradis  Marc-André Laurin  Vito Martella  Jagdip Singh Sohal  Yvan L’Homme 《Veterinary microbiology》2013

Group A rotaviruses with G2 and G9 VP7 specificity are common in humans, while G11 strains have been detected only sporadically. G2, G9 and G11 rotaviruses also circulate in pigs and swine rotaviruses have been suspected of interspecies and zoonotic transmissions in numerous studies. However, the complete gene constellation of G2 and G9 porcine rotaviruses has not yet been determined. In order to start filling this gap, the genomic make up of two G2, one G9 and one G11 porcine rotavirus strains, detected in Canada in 2005–2007, was determined. With the exception of a G2P[34] strain, with E9 NSP4 type and mixed I5 + I14 VP6 type, the constellation of genomic segments was rather conserved and were closely related to prototype porcine strains in the four viruses characterized (I5-R1-C1-M1-A8-N1-T7-E1-H1). Most notably, all the viruses displayed a rare NSP3 genotype, T7, which has also been identified in rare human reassortant strains and in the reference strain RVA/Cow-tc/GBR/UK/1973/G6P[5]. This study provides crucial genetic data on these complex viruses and will help understand the origin and ecological niche of gene segments and the role played by pigs in their evolution.  相似文献   

两个玉米新CIPK基因的鉴定     

巩东营  方志军  赵苏娴  刘铁山  刘强  李利斌 《山东农业科学》2011,(11):9-12

利用生物信息学的方法从玉米的基因组中鉴定出两个新的CIPK基因,并对这两个新基因的位置、结构、遗传进化和顺式调控元件进行了分析,为深入挖掘它们的功能提供了有益信息。  相似文献   

可可西里豆科植物根瘤内生细菌系统发育及促生特性研究     

王金平  齐雅琳  韩素贞 《安徽农业科学》2016,44(17):177-180

[目的]研究可可西里豆科植物根瘤内生细菌系统发育、抗菌特性和分泌IAA能力。[方法]对分离自可可西里的豆科植物Oxytropis falcate Bunge的根瘤内生细菌进行了16S r DNA全序列分析、抗菌试验以及IAA分泌能力检测。[结果]16S r DNA全序列分析结果表明,17株供试菌有12株属于芽孢杆菌属(Bacillus);有1株供试菌CNU097903与短杆菌属Brevibacterium halotolerans处于同一分支,相似性达99.9%;菌株CNU097916与Agrobacterium tumefaciens处于同一分支,相似性达99.8%;菌株CNU097914和CNU097915处于一个单独的分支,其系统发育地位有待进一步确定。抗菌试验结果表明,10株供试菌对G-黄单胞杆菌(Xanthomonas Campestris)、G+金黄色葡萄球菌(Staphylococcus aureus)、番茄灰霉(Botrytis cinerea)和瓜果腐霉(Pythium aphanidermatum)4种指示菌表现出不同程度的抗性:菌株CNU097906抗菌谱最广,对4种指示菌都有抗性;菌株CNU097902对番茄灰霉的抗性最强,抑菌圈直径达38 mm;菌株CNU097908对黄单胞杆菌的抗性最强,抑菌圈直径达38 mm;菌株CNU097901对金黄色葡萄球菌的抗性最强,抑菌圈直径达41 mm。采用Salkowski比色法测定供试菌分泌IAA的能力,结果表明,10供试菌都具有分泌IAA的能力。[结论]该研究为进一步探究内生细菌的生防机制和途径奠定基础,为可可西里内生菌资源的研究和合理开发利用提供理论依据。  相似文献