Population genetic structure of three tree species in the mangrove genus Ceriops (Rhizophoraceae) from the Indo West Pacific

Ceriops is a viviparous mangrove with widespread species Ceriops decandra and C. tagal, and an endemic species C. australis. Genetic diversity of the three species was screened in 30 populations collected from 23 locations in the Indo West Pacific (IWP) using Inter-simple sequence repeats (ISSR) and sequences of partial nuclear gene (G3pdh) and chloroplast DNA (trnV-trnM). At the species level, the total gene diversity (Ht) revealed by ISSRs was 0.270, 0.118, and 0.089 in C. decandra, C. tagal, and C. australis, respectively. A total of six haplotypes of G3pdh and five haplotypes of trnV-trnM were recognized among the three species. Only C. decandra was detected containing more than one haplotype from each sequence data set (four G3pdh haplotypes and three trnV-trnM haplotypes). At the population level, genetic diversity of Ceriops was relatively low inferred from ISSRs (He = 0.028, 0.023, and 0.053 in C. decandra, C. tagal, and C. australis, respectively). No haplotype diversity within population was detected from any of the three species. Cluster analysis based on ISSRs identified three major geographical groups in correspond to the East Indian Ocean (EIO), South China Sea (SCS), and North Australia (NA) in both C. decandra and C. tagal. The cladogram from DNA sequences also detected the same three geographical groups in C. decandra. Analysis of molecular variance (AMOVA) revealed that most of the total variation was accounted for by differentiation between the three major geographical regions of both C. decandra and C. tagal. The significant genetic structure may result from the geological events in these regions during the recent Pleistocene glaciations. This study also provided insights into the phylogenetics of Ceriops. Yelin Huang and Fengxiao Tan contributed equally to this work.     

Multivariate morphometric and allozymic analysis of theConospermum taxifolium (Proteaceae) species complex

A morphometric analysis of 18 attributes of 110 plants of theConospermum taxifolium complex suggests that it consists of three polythetically distinct taxa, corresponding to the traditional concepts ofC. taxifolium Smith s. str.,C. ericifolium Smith andC. ellipticum Smith. Discrimination is possible on the basis of leaf but not flower attributes. Analysis of allozymic variation indicates that the taxa are also genotypically differentiated.C. ericifolium andC. ellipticum are geographically isolated from each other but not fromC. taxifolium, andC. taxifolium is usually ecologically segregated from the other two taxa. Where this ecological segregation breaks down, morphological intermediates sometimes occur as the result of hybridization.     

基于SSR标记探讨三种金花茶植物的遗传多样性和遗传结构

薄叶金花茶、小花金花茶和小瓣金花茶是三种濒危金花茶植物,为了解珍稀濒危植物遗传多样性和遗传结构,该研究利用微卫星标记对他们的7个种群共184个个体进行了遗传多样性和遗传结构分析。结果表明:11个位点共检测到等位基因92个。在物种水平上,小瓣金花茶平均等位基因数(N_A)为3.9、有效等位基因数(N_E)为2.328、观测杂合度(H_o)为0.520、期望杂合度(H_e)为0.501,高于薄叶金花茶和小花金花茶。在种群水平上,有效等位基因数(N_E)在1.788～2.466之间,期望杂合度(H_e)在0.379～0.543之间;种群间遗传分化系数(FST)在0.143 7～0.453 3之间,种群间基因流(N_m)在0.301 5～1.488 9之间。AMOVA分子变异分析显示65.72%的变异存在于种群内。三种金花茶具有较低水平的遗传多样性和高水平的种群间遗传分化。STRUCTURE和PCoA种群遗传结构分析结果将取样种群分为2组,即薄叶金花茶和小花金花茶大部分个体分为一组,小瓣金花茶大部分个体分为一组。现存所有种群应根据实际情况尽快采取就地保护或迁地保护措施。     

Canine Dimorphism and Interspecific Canine Form in Cebus

I investigated canine dimorphism and interspecific canine form in adult specimens from 4 capuchin species (Cebus albifrons, C. apella, C. capucinus, and C. olivaceus). I used various univariate and multivariate statistics, which are based on 6 variables, to test several hypotheses that are based upon the finding that canine dimorphism is strongly associated with intermale competition in platyrrhines (Kay et al., 1988), Greenfield (1992a), Plavcan and van Schaik (1992, 1994). Results from the indices of canine dimorphism and the unpaired t-tests corroborate the prediction that males of each species possess significantly larger canines than those of females. Large male canines are especially prominent in 2 variables, maxillary and mandibular canine height. Greene's t-test (1989) does not support the prediction that Cebus apella and C. olivaceus possess a larger degree of canine dimorphism relative to C. albifrons and C. capucinus. No interspecific differences in degree of canine dimorphism are indicated by this test. Results of the discriminant function analyses (DFA) do not find that Cebus apella and C. olivaceus possess different canine form relative to C. albifrons and C. capucinus as predicted. However, Cebus apella is differentiated from the untufted capuchins (C. albifrons, C. capucinus, and C. olivaceus) by the DFA. I suggest that intermale competition is the primary selective force underlying the observed morphological patterns; however, it does not explain all the variation associated with canine dimorphism in Cebus.     

Distribution of the ability for citrate utilization amongst Clostridia

44 species of the genus Clostridium were examined with regard to their ability to grow on citrate. In addition to Clostridium sphenoides, a known citrate utilizer, the following species were found to utilize citrate: C. sporosphaeroides, C. symbiosum, C. rectum, C. indolis, C. subterminale and C. sporogenes. The major products formed from citrate were acetate, ethanol and carbon dioxide (not measured). Minor products were butyrate, butanol, acetone and acetoin.The enzyme citrate lyase was detectable in cell extracts of C. sporosphaeroides and C. symbiosum using an optical assay. Evidence for the presence of this enzyme in the other species was obtained in immunological experiments and in experiments with [1,5-¹⁴C]citrate.     

Zwergstrauchige Arten der FlechtengattungCaloplaca

The frutescent species of the lichen genusCaloplaca are usually united in sect.Thamnoma, but they do not form a natural group. They are derived from different species groups within sect.Gasparrinia from different parts of the world, presumable from species having scleroplectenchymes in cortex and medulla. The algal cells are concentrated between the scleroplectenchymatic strands in large and dense groups, from where medullary plectenchyme extends to the cortex and forms characteristic pseudocyphellae there.—Most of the species seem to be ornithocoprophilous; they grow on rocks along marine coasts where much fog is induced by cold currents.—Caloplaca cribrosa is endemic in Tasmania and New Zealand,C. regalis and the doubtfulC. ambitiosa belong to the antarctic element.C. fragillima from central Chile seems to be propagated by thallus fragments.C. coralloides andC. thamnodes are endemic to California and Baja California respectively.C. cladodes from the Rocky Mountains deviates in many characteristics from the other species i.a. by it different ontogenetic development, reduced spore septum, and cementing amyloid polysaccharides within the scleroplectenchymatic strands. The African species are characterized by their distinctly dorsiventral lobes and usually possess oil cells in some of the paraphyses.Caloplaca bonae-spei, C. fragillima andC. thamnodes are new to science.

     

Effect of Calcium and Zinc on the Activity and Thermostability of Superoxide Dismutase

The effect of calcium and zinc ions on superoxide dismutase (SOD) from four plant species (Taxus baccata, Pinus sylvestris, Medicago rigidula, and Zea mays) was followed at three temperatures: optimal (20 °C), increased (50 °C), and high, inhibiting temperature (70 – 80 °C). At 20 and 50 °C in vitro added calcium increases SOD activity, but the degree was different for the plants investigated. The effect of zinc ions at the same temperatures varied in the investigated plants from activation to inhibition. An inhibiting effect of high temperature on SOD activity was diminished in the presence of calcium or zinc ions. It was shown that calcium and zinc ions can increase activity and thermostabilize different SOD isoforms.     

Catapyrenium (Verrucariaceae) species from South America

13 species of the lichen genusCatapyrenium are reported from South America. Five species (C. analogicum, C. andicolum, C. exaratum, C. lachneoides, andC. podolepis) are described as new. A key to the species known from South America is presented. Remarks on taxonomy, ecology and distribution of the species are given.Studies on the lichen genusCatapyrenium (Verrucariaceae) III. For second part seeBreuss (1991).     

Distribution of alkanes and fatty acids in theCondalia montana (Rhamnaceae) species complex

The alkane and fatty acid composition of the lipid extracts from leaves of 14 populations ofCondalia: C. microphylla f.xanthocarpa, C. microphylla f.erythrocarpa, C. microphylla f.melanocarpa, C. montana, andC. buxifolia, were determined by gas chromatography. Seventeen alkanes and 14 fatty acids were investigated and a predominance of nonacosane, hentriacontane, palmitic and linoleic acids in all species was found.     

Meiotic analyses ofCucumis hybrids and an evolutionary evaluation of the genusCucumis (Cucurbitaceae)

Meiosis in seven interspecificCucumis hybrids has been analysed i.a. inC. metuliferus ×C. zeyheri, where the parents belong to different sections. In the triploid hybrids a remarkably high number of trivalents has been found. Additional data from literature on geographical distribution, cucurbitacins, flavonoid patterns, isozymes, C-banding, genome size, DNA amount and chloroplast DNA are used to discuss species relationships and evolution. The African cross-compatible group is divided into theMyriocarpus subgroup with the diploid speciesC. africanus, C. myriocarpus subsp.leptodermis and subsp.myriocarpus, and theAnguria subgroup withC. anguria, C. dipsaceus, C. ficifolius, C. prophetarum, C. zeyheri and all polyploids (exceptC. heptadactylus). It is argued that the Asian subg.Melo with x = 7 is derived from the African subg.Cucumis with x = 12; the latter contains all the polyploid species and has the most common basic chromosome number of theCucurbitaceae. This phylogenetic advance is interpreted with concepts of the quantum model of evolution.     

Inheritance of resistance to the two-spotted spider mite from L. pimpinellifolium (Jusl.) Mill. accession ‘TO-937’

The two-spotted spider mite (Tetranychus urticae Koch) is an important pest of tomato (Lycopersicon esculentum Mill.) crops in temperate regions as this spider mite has a very large capacity for population increase and causes severe tomato yield losses. There is no described tomato cultivar fully resistant to this pest, although resistant accessions have been reported within the green-fruited tomato wild species L. pennellii (Corr.) D’Arcy and L. hirsutum Humb. & Bonpl. We observed a L. pimpinellifolium (Jusl.) Mill. accession, ‘TO-937’, which seemed to be completely resistant to mite attacks and we crossed it with the susceptible L. esculentum cultivar. ‘Moneymaker’ to obtain a family of generations consisting of the two parents, the F₁, the F₂, the BC₁ to L. esculentum, and the BC₁ to L. pimpinellifolium. This family was evaluated for mite resistance in a polyethylene greenhouse using an experimental design in 60 small complete blocks distributed along 12 double rows. Each block consisted of five F₂ plants in one row and one plant of each of the two parents, the F₁, the BC₁ to L. esculentum, and the BC₁ to L. pimpinellifolium in the adjacent row. Plants at the 10–15 leaf stage were artificially infested by putting on them two pieces of French bean leaf heavily infested with T. urticae. After two months, evaluations of infestation were made by visual observation of mite nets and leaf damage. Plants that were free of signs of mite reproduction on the top half were considered as resistant, plants with silky nets only on their basal leaves, intermediate, and plants with mite reproduction on both basal and top canopies were scored as susceptible. Dominance for resistance appeared because all the ‘To-937’, BC₁ to L. pimpinellifolium, and F₁ plants were resistant. Not all ‘Moneymaker’ plants behaved as susceptible because 35% of plants were intermediate. In the BC₁ to L. pimpinellifolium and the F₂, most plants were scored as resistant, only 7 % BC₁ and 3 % F₂ plants were intermediate, and a single F₂ plant (0.3 %) was susceptible. With these figures, resistance seemed to be controlled by either four or two genes according to whether segregation in the BC₁ or in the F₂, respectively, were considered. These results could in part be explained because of appearance of negative interplot interference due to the high frequency of resistant genotypes within most of the generations. Therefore, the family was evaluated again but using a different experimental design. In the new experiment, 16 ‘TO-937’, 17 ‘Moneymaker’, 17 F₁, 37 BC₁ to L. pimpinellifolium, 38 BC₁ to L. esculentum, and 125 F₂ plants were included. Each of these test plants was grown besides a susceptible ‘Moneymaker’ auxilliary plant that served to keep mite population high and homogeneous in the greenhouse. Negative interplot interference was avoided with this design and all the ‘TO-937’, F₁, and BC₁ to L. pimpinellifolium plants were resistant, all ‘Moneymaker’ test plants were susceptible, and 52 % BC₁ to L. esculentum and 25 % F₂ plants were susceptible, which fitted very well with the expected for resistance governed by a single dominant gene. The simple inheritance mode found will favour sucessful introgression of mite resistance into commercial tomatoes from the very close relative L. pimpinellifolium.     

国产驴蹄草的细胞地理学研究

为探讨国产毛茛科(Ranunculaceae)驴蹄草属(Caltha)两种植物的演化,该文利用传统染色体压片技术和流式细胞术,并结合前人染色体研究结果,对我国驴蹄草23个居群和花葶驴蹄草10个居群进行了细胞学研究。结果表明:驴蹄草是由四倍体(2n=4x=32)、六倍体(2n=6x=48)和八倍体(2n=8x=64)构成的多倍体复合群,花葶驴蹄草具有四倍体(2n=4x=32)和八倍体(2n=8x=64)两种倍性水平。驴蹄草和花葶驴蹄草均是四倍体较为常见,目前尚未见有二倍体报道。由于驴蹄草和花葶驴蹄草大部分居群采自中国青藏高原地区,可能在冰期时存在古二倍体,其适应性较弱,逐渐被其他的倍性取代,这是由于不同细胞型对环境适应性的结果。驴蹄草可能存在两条进化路线:一条是从甘肃到达云南;另一条是从西藏到达云南。前期分子系统学研究显示花葶驴蹄草与驴蹄草的亲缘关系较近,该研究结果中花葶驴蹄草染色体比驴蹄草要小,花葶驴蹄草可能比驴蹄草相对进化。目前花葶驴蹄草只有10个居群,还需进一步增加居群量来解析其演化路线。     

Influence of the food plants on the degree of parasitism of larvae ofHeliothis armigera byCotesia kazak

Influence of the food plants ofHeliothis armigera (Hb.) on the degree of parasitism by exotic parasiteCotesia kazak Telenga (Hymenoptera: Braconidae) was studied in cages in the laboratory on 7 food plants such as cotton (Gossypium hirsutum L.), tomato (Lycopersicon esculentum Mill), okra [Abelmoschus esculentus (L.) Moench], Dolichos (dolichos lablab L.), pigeonpea [Cajanus cajan (L.) Millsp.], Cowpea (Vigna unquiculata (L.) and chickpea (Cicer arietium L.). To determine the preference of the parasite 2 test methods were employed. In single plant choice test cotton was most preferred. Next in order of preference were tomato and okra. Dolichos, pigeonpea, cowpea and chickpea were least preferred. In multiple choice test, however, cotton and okra were preferred followed by tomato. Parasites were seen visiting these plants very frequently and high parasitism was recorded on these plants. Chick pea, pigeon pea, cowpea and Dolichos were the least preferred food plants. There appears to be some difference in fecundity as affected by some food plants. Exposure on okra, cotton and tomato resulted in higher cocoon production as compared to pigeonpea, Dolichos, cowpea and chickpea. There was, however, no difference in sex-ratio and longevity of the progeny as affected by food plants. This exotic parasite should be released first in crops such as cotton, okra and tomato on whichH. armigera is a very serious pest in India and elsewhere. Contribution No. 140/86 of the Indian institute of Horticultural Research, Bangalore-560 089     

Ornibactin production and transport properties in strains of Burkholderia vietnamiensis and Burkholderia cepacia (formerly Pseudomonas cepacia)

Several strains of Burkholderia vietnamiensis, isolated from the rhizosphere of rice plants, and four strains formerly known as Pseudomonas cepacia including two collection strains and two clinical isolates were compared for siderophore production and iron uptake. The B. vietnamiensis (TVV strains) as well as the B. cepacia strains (ATCC 25416 and ATCC 17759) and the clinical isolates K132 and LMG 6999 were all found to produce ornibactins under iron starvation. The two ATCC strains of B. cepacia additionally produced the previously described siderophores, pyochelin and cepabactin. Analysis of the ratio of isolated ornibactins (C4, C6 and C8) by HPLC revealed nearly identical profiles. Supplementation of the production medium with ornithine (20 mm) resulted in a 2.5-fold increase in ornibactin synthesis. Ornibactin-mediated iron uptake was independent of the length of the acyl side chain and was observed with all strains of B. vietnamiensis and B. cepacia, but was absent with strains of Pseudomonas aeruginosa, Pseudomonas fluorescens and Pseudomonas stutzeri, known to produce pyoverdines or desferriferrioxamines as siderophores. These results suggest that ornibactin production is a common feature of all Burkholderia strains and that these strains develop an ornibactin-specific iron transport system which is distinct from the pyoverdine-specific transport in Pseudomonas strains.     

Characterization of a Novel Phosphoinositide-Specific Phospholipase C from <Emphasis Type="Italic">Zea mays</Emphasis> and its Expression in <Emphasis Type="Italic">Escherichia coli</Emphasis>

A cDNA encoding a phosphoinositide-specific phospholipase C (PI-PLC) has been isolated from Zea mays by screening a cDNA library. The cDNA, designated ZmPLC, encodes a polypeptide of 586 amino acids, containing the catalytic X, Y and C2 domains found in all PI-PLCs from plants. Northern blot analysis showed that the expression of the ZmPLC gene in roots is up-regulated under conditions of high salt, dehydration, cold or low osmotic stress conditions. Recombinant ZmPLC protein was expressed in Esch- erichia coli, purified and used to produce polyclonal antibody, this polyclonal antibody is important for further studies to assess the ultimate function of the ZmPLC gene in plants.     

Phytophthora parsiana sp. nov., a new high-temperature tolerant species

As part of a study to examine the phylogenetic history of the taxonomically challenging species Phytophthora cryptogea and P. drechsleri, a distinct monophyletic group of isolates, previously described as P. drechsleri or P. cryptogea, were characterised. Analysis of their rDNA ITS sequences indicated that these isolates were distinct from P. drechsleri, P. cryptogea, and all members of Phytophthora ITS clades 1–8, clustering instead alongside basal groups previously described as clades 9 and 10. This group comprised six isolates all of which were isolated from woody plants, such as pistachio (Pistacia vera, Iran and USA), fig (Ficus carica, Iran), and almond (Prunus dulcis, Greece). Analysis of sequence data from nuclear (β-tubulin and translation elongation factor 1α) and mitochondrial (cytochrome c oxidase subunit I) genes confirmed the ITS-based analysis as these isolates formed a distinct monophyletic group in all NJ trees. The isolates were fast growing with a relatively high optimum growth temperature of 30 °C and, in most cases, rapid colony growth even at 37 °C. The isolates produced complex colony patterns on almost all media, especially corn meal agar (CMA). Phylogenetic analysis and examination of all the other morphological and physiological data lead us to infer that this taxon has not been described previously. As this taxon was first isolated and described from Iran we propose that this taxon be formally designated as Phytophthora parsiana.     

Dispersion pattern of the medfly from its geographic centre of origin and genetic relationships of the medfly with two close relatives

We used three different approaches, a phylogenetic analysis, the principal component analysis, and Gabriel Graphs, to study the dispersion of the medfly from its geographic centre of origin. Our analysis was based on 13 enzyme polymorphisms detected electrophoretically in 15 natural populations coming from distinct geographic areas. The results indicate that (i) there is a clear-cut separation of the native African from the introduced populations, (ii) the population from Spain seems to connect the African and the Mediterranean or American populations, and (iii) the Mediterranean populations as well as the American ones comprise two distinct groups of closely related populations.We have also estimated a phylogenetic tree for 3 species of the genus Ceratitis: C. capitata, C. rosa and C. nigra, based on electrophoretic data under the assumption of a molecular clock. The results suggest that C. capitata and C. rosa are more closely related to each other than either is to C. nigra.     

Interactions and effects of multiple biological control insects on diffuse and spotted knapweed in the Front Range of Colorado

Abundances and interactions among biological control insects and their effects on target invasive plants were monitored within the flower heads and roots of diffuse knapweed, Centaurea diffusa, and in spotted knapweed, Centaurea stoebe, along the Colorado Front Range. Flower weevils, (Larinus species) and root-feeders (Cyphocleonus achates and Sphenoptera jugoslavica) were released on knapweed that already supported biological control gall flies (Urophora species). At a single monitoring site, seed production by C. diffusa declined from 4400 seeds m⁻² in 1997 to zero seeds m⁻² on the monitoring sites in 2006, while the flowering stem density of C. diffusa declined from a peak of almost 30 stems m⁻² in 2000 to zero stems m⁻² in 2006. The average abundance of Urophora and Larinus in flower heads fluctuated independently during the 2001–2006 interval, while the relative abundance of C. achates and S. jugoslavica in roots exhibited a weak inverse relationship that appeared driven by climate effects. The relative abundance of insects on a population of C. stoebe was monitored for five years as Larinus species and C. achates became established on spotted knapweed that already supported Urophora species. Spotted knapweed seed production on our monitoring site declined from 4600 seeds m⁻² in 2003 to zero seeds m⁻² in 2006. Unlike C. diffusa, substantial numbers of rosettes of C. stoebe remained present. Larinus consumed almost all Urophora encountered in C. diffusa, and consumed about 40% of the Urophora in co-infested flower heads of C. stoebe (ca. 10–15% of the total Urophora population). No negative correlations between the relative densities of flower head and root-feeding insects were observed. The effects of these insects on target plants have produced results consistent with the ‘cumulative stress hypothesis’ for biological control of Centaurea species.     

Karyosystematic studies on threeCrepis species (Asteraceae) endemic to Greece

This work examines the cytogeographical distribution, the morphological characters, and the karyotypes of threeCrepis species endemic to Greece (C. sibthorpiana, C. incana, andC. heldreichiana). C. sibthorpiana is diploid (2n = 2x = 8),C. incana is diploid (2n = 2x = 8) and tetraploid (2n = 4x = 16, 17), andC. heldreichiana is always dekaploid (2n = 10x = 40). The Giemsa positive bands, usually pairs of dots, are mainly centromeric inC. incana, while they are terminal inC. sibthorpiana (on the short arm of all chromosomes) and inC. heldreichiana (on both arms of all chromosomes). Intercalary C-bands are scarce and usually variable within karyotypes, individuals, and species. The most variable karyotype both in Feulgen and Giemsa preparations is that ofC. incana, in which also supernumerary chromosomes were observed, which are polysomic to standard set members. On the basis of morphological and karyological data the evolutionary relationships among the threeCrepis taxa are discussed.