Lipid content and fatty acid composition in hypogeous organs ofHelleborus species (Ranunculaceae)

Root and rhizome of fourHelleborus species:H. viridis, H. odorus, H. niger, H. foetidus were examined throughout a two-year period in order to determine the variation of lipid content and fatty acid composition during the ontogenetic cycle. In the deciduous geophytesH. viridis andH. odorus subsp.laxus the lipid content reaches its maximum during the quiescent phase, whereas in the evergreen geophyteH. niger the lipid content is highest during the main growth period. In the chamaephyteH. foetidus lipid content is always very low and it does not show variation throughout the year. In all species the fatty acids detected in the neutral fraction are myristic, palmitic, stearic, oleic and linoleic acid. Palmitic and linoleic acid are always present in larger quantities. The pattern of the relative content of saturated/unsaturated fatty acids seems to be linked to the life form of these species.     

Characterization of expressed pigmented core light harvesting complex (LH 1) in a reaction center deficient mutant of Blastochloris viridis

The utility of photosynthetically defective mutants in the purple photosynthetic bacterium Blastochloris viridis (formerly Rhodopseudomonas viridis)was demonstrated with construction of a reaction-center deficient mutant, LH 1-H. This LH 1-H mutant has a photosynthetic apparatus in which most of the puf operon genes were deleted, resulting in an organism containing only the genes for the light harvesting polypeptides and the H subunit of the reaction center. This B. viridisstrain containing a truncation of the puf operon was characterized by gel electrophoresis, lipid-to-protein ratio analysis, optical spectroscopy, electron paramagnetic resonance and transmission electron microscopy. Optical and electron paramagnetic resonance spectroscopies revealed no photoactivity in this LH 1-H mutant consistent with the absence of intact reaction centers. Electron paramagnetic resonance evidence for assembled LH 1 complexes suggested that the interactions between light harvesting polypeptide complexes in membranes were largely unchanged despite the absence of their companion reaction center cores. The observed increase in the lipid-to-protein ratio was consistent with modified interactions between LH 1s, a view supported by transmission electron microscopy analysis of membrane fragments. The results show that B. viridis can serve as a practical system for investigating structure-function relationships in membranes and photosynthesis through the construction of photosynthetically defective mutants. This revised version was published online in August 2006 with corrections to the Cover Date.     

Micromorphological and chemical characterisation of Stachys recta L. subsp. serpentini (Fiori) Arrigoni in comparison to Stachys recta L. subsp. recta (Lamiaceae)

Stachys recta L. is a very polymorphous species in which numerous subspecies were recognised. S. recta L. subsp. serpentini (Fiori) Arrigoni is a typical endemism growing on serpentine soils in northern Apennines and particularly in Tuscany (Italy). In order to contribute to a better knowledge of this plant and to its differentiation with respect to S. recta L. subsp. recta, the micromorphological characters (non-glandular and glandular trichomes) and the essential oil composition of the two subspecies were investigated. Micromorphological characters were studied using scanning and transmission electron microscopy, while light microscopy was used for histochemical observations. Essential oil analysis was carried out by gas chromatography and mass spectrometry.In the two examined taxa, the morphology and distribution of glandular and non-glandular trichomes, and the different essential oil composition, may be considered distinctive characters at subspecies level. This is consistent with the taxonomic classification considering S. recta subsp. serpentini a subordinate taxon of S. recta.     

Electrophoretic study and genetic affinity in theCampanula elatines andC. fragilis (Campanulaceae) rock-plants group from Italy and W. Jugoslavia

Variability and genetic divergence of 11 field populations of seven species of theCampanula elatines andC. fragilis rock-plants group from the Mediterranean and pre-Alpine areas have been studied by starch-gel electrophoretic techniques.Campanula isophylla, C. elatines, C. elatinoides, C. fragilis subsp.fragilis and subs.cavolinii, C. garganica were collected in Italy, whilstC. fenestrellata subsp.istriaca andC. portenschlagiana came from W. Jugoslavia. Twelve enzymatic loci for each population were genetically analysed: PGI-1 and 2, PGM-2, IDH-1 and -2, SKDH, ME, ADH, GOT-2, MPI-1 and -2, SOD-1. The genetic distances among the above mentioned entities have been calculated by Nei's index and depicted in a dendrogram.     

基于MaxEnt模型的中国沙棘潜在适宜分布区分析

中国沙棘主要分布于我国华北、西北、西南等地森林—草原过渡地带,是我国北方地区退耕还林、生态修复等工程的重要造林树种,对维持干旱、半干旱地区的生态环境稳定具有重要意义。探讨限制中国沙棘分布的主导气候因子,模拟其潜在适宜分布区,以期为中国沙棘在林业生态工程和生态经济林建设中的合理种植和推广提供理论依据。基于中国沙棘自然分布的328个地理样点,利用最大熵(MaxEnt)模型对中国沙棘的潜在分布区的主导气候因子进行分析,并预测中国沙棘的潜在分布范围。结果表明,基于气候变量的MaxEnt模型训练集和测试集受试者工作特征曲线下面积(AUC值)分别为0.962±0.001和0.949±0.001,均大于0.9,表明MaxEnt模型对中国沙棘潜在分布区的预测具有极高的准确度,可信度好。基于环境变量贡献率和刀切法的结果表明年降雨情况、生长季的水热状况、最干季降雨和最冷月最低温等是限制中国沙棘分布的主要气候因素,其中年降雨是限制中国沙棘分布的主导气候因子。通过模拟得到现代中国沙棘潜在地理分布的总适生区面积为165.1万km~2;其中高适生区和中适生区面积共93.3万km~2,主要集中分布于河北西部、北部,...     

Importation,colonization and establishment ofAnagyrus indicus [Hym.: Encyrtidae] onNipaecoccus viridis [Hom.: Pseudococcidae] in Jordan

Anagyrus indicus Shafeeet al. was collected on the island of Guam and released in the Jordan River Valley of Jordan in order to regulateNipaecoccus viridis (Newstead) on citrus.A. indicus was originally released in February 1984 and became colonized by April of the same year. It also dispersed by natural means up to 61 km following the original release and colonized that same year on infestedZizyphus sp. By spring of 1985 it became the dominant parasitoid attackingN. viridis. Another parasitoid,Anagyrus kamali Moursi, was collected in Jordan in June of 1985 for the first time. This latter parasitoid apparently moved into the Jordan River Valley by means of natural dispersal from a neighboring country. Infestations ofN. viridis have been greatly reduced in areas whereA. indicus became established. This paper reports the results of research only. Mention of a proprietary product does not constitute an endorsement for its use by USDA.     

Standard karyotypes ofAegilops uniaristata,Ae. mutica,Ae. comosa subspeciescomosa andheldreichii (Poaceae)

C-banding patterns and polymorphisms were analyzed in several accessions of the diploidAegilops speciesAe. uniaristata, Ae. mutica, andAe. comosa subsp.comosa and subsp.heldreichii, and standard karyotypes of these species were established. Variation in C-band size and location was observed between different accessions, but did not prevent chromosome identification. One accession ofAe. uniaristata was homozygous for whole-arm translocations involving chromosomes 1N and 5N. The homoeologous relationships of these chromosomes were established by comparison of chromosome morphologies and C-banding patterns to other diploidAegilops species with known chromosome homoeology. In addition, in situ hybridization analysis with a 5S rDNA probe was used to identify homoeologous groups 1 and 5 chromosomes. The present analysis permitted the assignment of allAe. mutica, comosa subsp.comosa, andAe. comosa subsp.heldreichii chromosomes, and three of the sevenAe. uniaristata chromosomes according to their homoeologous groups. The data presented will be useful analyzing genome differentiation in polyploidAegilops species.     

Favoured carbonyl binding regions around the QA and QB sites of Rps. viridis

The factors governing quinone protein binding in the photosynthetic bacterium Rps. viridis are investigated via use of empirical intermolecular energy calculations using the GRID method (PJ Goodford (1985) J Med Chem 28: 849–854). A probe atom corresponding to a carbonyl oxygen atom is used to investigate regions exhibiting preference for carbonyl binding in the Q_A and Q_B sites of Rps. viridis. Two distinct regions at the top and bottom of the sites are revealed to be most favourable for carbonyl binding. Overlay of the crystallographically determined positions for the quinone carbonyl groups shows that they lie within the regions predicted theoretically. The method is also shown to be able to give qualitative insight into the affect of amino acid mutations of quinone binding.     

Molecular Cloning of a cDNA Encoding Ribosome Inactivating Protein from Amaranthus viridis and Its Expression in E. coli

In order to isolate a cDNA clone of ribosome inactivating protein (RIP), a cDNA library was constructed in Uni-ZAP XL vector with poly(A) RNA purified from leaves of Amaranthus viridis. To get the probe for screening the library, PCR of phage DNA was conducted using the vector primer and degenerate primer designed from a conserved putative active site of the RIPs. Twenty-six cDNA clones from about 600,000 plaques were isolated, and one of these clones was fully sequenced. It was 1,047 bp and contained an open reading frame encoding 270 amino acids. The deduced amino acid sequence had a putative signal sequence of 17 amino acids and a putative active site (AIQMVAEAARFFKYIE) conserved in other RIPs. E. coli cells expressing A. viridis RIP cDNA did not grow well as compared to control cells, indicating that recombinant A. viridis RIP presumably inactivated E. coli ribosomes. In addition, recombinant A. viridis RIP cDNA produced by E. coli had translation inhibition activity in vitro.     

Differentiation between the two subspecies of Atherosperma moschatum Labill. (Atherospermataceae) from their leaf oils

The leaf oils of both subspecies of Atherosperma moschatum have been investigated to determine if there were any chemical differences between the two subspecies. While both subspecies of A. moschatum contained methyl eugenol (55–87%), safrole (5–20%) and linalool (1–6%), camphor (5–10%) was found to be only in the oils of A. moschatum subsp. moschatum and to be either absent or, at most, less than 0.5% in the oils of A. moschatum subsp. integrifolium. There was also a range of monoterpene hydrocarbons and 1,8-cineole, all in the range of 0.1–5%, that were present in subspecies moschatum but virtually absent in subspecies integrifolium.     

Distribution and life cycle of the North American Spionid polychaeteMarenzelleria viridis (Verrill, 1873) in the Ems estuary

In 1983 the first specimens of the North American spionid polychaeteMarenzelleria viridis were found along the European mainland shore in the Ems estuary. Since then, this polychaete has spread over several estuaries around the North Sea and the Baltic. In the inner part of the Ems estuary juveniles were predominantly present in muddy sediments high in the intertidal zone; in more sandy sediments at higher salinities juveniles and adults co-occured. Detailed information was obtained at a muddy and at a sandy station. Gametes were present in the coelomic fluid from November through March. In May new recruits were found in the sediment samples, reaching densities of over 10⁵ M⁻² at the muddy station, andc. 2000 m⁻² at the sandy station. During summer, densities decreased at the muddy station, coinciding with a density increase at the sandy station, suggesting migration of juveniles from a nursery to the adult habitat. Cage experiments showed that the decrease of juveniles at the muddy station could be attributed to migration and not to mortality due to predation. At the sandy habitat palps and anterior parts ofM. viridis made up 4–11% of the stomach content of juvenile plaice (Pleuronectes platessa). In juvenile flounder (Platichthys flesus) only in Aprilc. 10% of the stomach content consisted ofM. viridis. During 1983–1990 increasing densities ofM. viridis at the sandy habitat coincided with a reduced abundance ofNereis diversicolor, however, this inverse relationship was not found to be statistically significant. Density fluctuations ofM. viridis andCorophium volutator showed a significant positive relationship, the cause of which is not yet understood.     

Differentiation patterns in the E. MediterraneanScutellaria rubicunda group (Lamiaceae)

Strict sterility barriers where found between theScutellaria populations on Sicily and the Greek populations. The material from Samos is separated by a strict sterility barrier from the other Greek populations. In contrast, the populations on mainland Greece and adjacent islands are all ± interfertile. Three species are recognized,S. rubicunda Hornem., endemic to Sicily, andS. brevibracteata subsp.icarica, endemic to Samos and Ikaria. All other populations are referred toS. rupestris with eight subspecies, most of which are endemic to one island or to one mountain. Three new subspecies are described, viz. subsp.rechingeri and subsp.olympica, endemic to mt Vourinos and mt Olympus in North Greece, respectively, and subsp.caroli-henrici, native to the Malea peninsula of Peloponnisos. The phytogeographical connections and genetic differentiation within and between populations are discussed.Dedicated to Prof. DrK. H. Rechinger on the occasion of his 80th birthday.     

Phylogeographical structure and conservation genetics of wild grapevine

The distribution of Vitis vinifera subsp. silvestris, the wild grapevine subspecies of Vitis vinifera L., has been dramatically reduced in its major sites of diffusion, at first by the spread, over the last 150 years, of pathogens from North America and, more recently, with fragmentation of habitat and disbranching by humans. In this work, 418 wild grapevine samples, belonging to 78 populations, were collected in their main Mediterranean distribution areas, including the Caucasus area, and the extent of their genetic variability evaluated by analysing plastid microsatellite DNA polymorphism. Results show low haplotype diversity value, with five haplotypes detected within the analysed populations. The highest within-population haplotypic diversity, with the presence of all five detected haplotypes, was found in the Caucasus regions and in the central regions of Italy. The distribution of all detected haplotypes suggests the Caucasian region as the possible center of origin of Vitis vinifera subsp. silvestris. A principal plastid lineage was found to be fixed in several locations, in the Northernmost European countries and in the Southern island of Sardinia. These results draw attention to two different refugium sites in the Mediterranean basin and suggest that conservation priority should be given to grapevine populations still preserved in hotspots of these regions.     

Molecular cloning and expression of a proteinase gene from Lactococcus lactis subsp. cremoris H2 and construction of a new lactococcal vector pFX1

The 6.5 kb HindIII DNA fragment of the Lactococcus lactis subsp. cremoris H2 plasmid pDI21 was cloned into Escherichia coli POP13 with NM1149, and also directly into Lactococcus lactis subsp. lactis 4125 using a newly-constructed broad host-range vector pFX1. Proteinase was experessed in both transformed organisms. The proteinase resembles a PI type since it preferentially degraded -casein. The restriction map of the 6.5 kb proteinase gene fragment has minor differences from those of published plamid proteinase genes. High-efficiency electroporation with pFX1 provides a direct approach for gene cloning in lactococci.Abbreviations cfu colony forming units - HEPES N-[2-hydroxyethyl]piperazine-N-[2-ethanesulphonic acid] Dedicated to Prof. Dr. G. Drews on the occasion of his 65th birthday     

Embryogenesis and plantlet development in the bamboo Phyllostachys viridis (Young) McClure

Leaf explants of Phyllostachys viridis (Young) McClure were cultured on Murashige and Skoog medium supplemented with 9×10^-6 M 2,4-dichlorophenoxyacetic acid. Numerous embryoids were observed. On transfer to Murashige and Skoog medium lacking hormones, plantlets developed within two weeks and were later successfully transferred to the field.     

Allozyme variation in the annual weed species complexPolygonum aviculare (Polygonaceae) in relation to ploidy level and colonizing ability

Variation at six polymorphic enzymatic loci was studied in 50 populations of the selfing annualPolygonum aviculare from Belgium. The results show that theP. aviculare complex has an allopolyploid origin and comprises two main genetic entities, viz.P. aviculare subsp.depressum (2n = 4x = 40), restricted to urban sites subject to trampling stress, andP. aviculare subsp.aviculare (2n = 4x = 40, 2n = 6x = 60), with a wider ecological amplitude. The latter had a higher genetic diversity and a higher frequency of fixed heterozygosity than the former. WithinP. aviculare subsp.aviculare, genetic diversity and ecological amplitude correlated positively with ploidy level. Additionally, stronger genetic differentiation among and lower variation within populations was found in urban areas than in cultivated fields.     

Frontiers in mycoplasma pathogenicity

Four different strains ofLactobacillus delbrueckii subsp.bulgaricus (Ss₁ and Yop₁₂) andStreptococcus salivarius subsp.thermophilus (Ss₂ and Yop₉) were isolated from two different yogurt sources in Argentina. In medium containing different carbon sources: lactose, fructose, sucrose or glucose plus fructose, the growth of a mixed culture (Yop₁₂+Ss₂) shows stimulation ofS. thermophilus and inhibition ofL. bulgaricus with respect to pure cultures. Both microorganisms in mixed culture grew less well on glucose plus galactose. However, in medium with glucose or galactose, both microorganisms were stimulated.     

Accumulation, depuration and distribution of cadmium and zinc in the green-lipped mussel Perna viridis (Linnaeus) under laboratory conditions

Ecotoxicological tests were conducted in the green-lipped mussel Perna viridis under laboratory conditions. Different rates of accumulation and depuration in soft tissues are found and this might be due to different mechanisms of metal binding and regulation. At the end of depuration, Cd levels in soft tissues of P. viridis were 10–30 times higher than before exposure, while Zn levels in soft tissues were almost similar to levels before exposure. These results indicate that P. viridis is a good biomonitoring organism for Cd but Zn levels might be actively regulated. It remains uncertain whether P. viridis is a good biomonitoring organism of environmental Zn contamination. However, the positive patterns, although different rates, of accumulation and depuration for Cd and Zn support the use of P. viridis as a biomonitoring agent for such metals.     

Local evolution of obligate autogamy inEpipactis helleborine subsp.neerlandica (Orchidaceae)

Isozyme analysis was used to assess the origin of the DanishEpipactis renzii, a local endemic of open coastal dunes. It seems to have evolved recently in several local populations of the more or less allogamousE. helleborine subsp.neerlandica. The obligately autogamousE. renzii is restricted to the easternmost part of the Danish range ofE. helleborine subsp.neerlandica, indicating that transition to obligate autogamy has been a selective advantage in that area. This may be explained by water stress, caused by a higher evapotranspiration (cf. the mean temperature of July which increases towards the east) — obligate autogamy shortens the time span from anthesis to fruit set due to a rapid pollination process. We propose thatE. renzii should only be recognized as a variety ofE. helleborine subsp.neerlandica.     

Cytology ofCrocus sativus and its allies (Iridaceae)

Populations ofC. cartwrightianus, C. hadriaticus andC. thomasii from the Balkans have 2n = 16 as has the Middle EasternC. pallasii subsp.haussknechtii. C. dispathaceus andC. pallasii subsp.pallasii have 2n = 14 whileC. pallasii subsp.turcicus has 2n = 12.C. niveus has 2n = 28 andC. sativus is an autotriploid with 2n = 24. Karyotype variation was found between populations ofC. pallasii subsp.pallasii in Central Turkey and also inC. pallasii subsp.turcicus.