Invasions of the Portuguese millipede,Ommatoiulus moreleti,in southern Australia

The Portuguese millipede, Ommatoiulus moreleti, was first recorded in Australia on Eyre Peninsula, South Australia in 1953. By the early 1980s, O. moreleti had spread to several sites across southern Australia where it had become a significant nuisance pest invading houses in large numbers in autumn and spring. At that time, it was predicted that O. moreleti would further expand its distribution to occupy most areas of southern Australia with mean annual rainfall of 300–2400 mm (excluding areas with summer rain maxima), mean daily minimum air temperatures in winter of 0–15 °C and mean daily maximum temperatures in summer of 18–33 °C, based on climatic matching of where it had already spread to. This paper reports the known distribution of O. moreleti in Australia in 2013 and confirms the earlier prediction. Whilst stadial age and body size (width) of O. moreleti now vary greatly between individual sites in Australia, geographic scale patterns in these traits are slight, with both age and size only weakly correlated with rainfall and temperature. Millipedes are smaller in Australia compared with Portugal. The importance of this size variation is discussed with reference to its likely influence on fecundity and the success of an introduced biological control agent (Pelidnoptera nigripennis: Diptera, Sciomyzidae).     

Taxonomy and genetic diversity of domesticated Capsicum species in the Andean region

The Capsicum genus is native to tropical America and consists of 27 species, five of which are used as fresh vegetables and spices: Capsicum annuum L., Capsicum chinense Jacq., Capsicum frutescens L., Capsicum baccatum L. and Capsicum pubescens R. et P. The study of the relationships among species of cultivate Capsicum species will be useful for breeding new cultivars or hybrids. This study is focused on the genetic diversity and relationships of these species that were collected in the Andean region. Ten microsatellites and four AFLP combinations were used to characterize 260 Capsicum accessions. The AFLP tree turned out to be informative regarding relationships among species. The data clearly showed the close relationships between C. chinense and C. frutescens. Moreover, C. cardenasii and C. eximium were indistinguishable as a single, morphologically variable species. Our data showed C. baccatum and C. praetermissum to be distinct species that form a compact group. In the present work, AFLP fingerprinting indicated that C. chacoense was placed in the C. baccatum complex and showed C. tovarii as a separate species. In addition, SSR data indicated that there is intraspecific differentiation in the species C. chinense, C. baccatum and C. pubescens, as the PCoA-based clustering showed a clear geographic division related to country. Even though Bolivia is considered to be the nuclear area for these species, we have found similar variability in Ecuador and Peru for several Capsicum species.     

Use of electrical conductivity to estimate effects of competing ions on radionuclide distribution coefficients

The distribution coefficient (K _d) between the soil solid phase and the liquid phase is a commonly used parameter to evaluate radionuclide behavior in soil. For reliable evaluation, the variability of the K _ddue to changes of environmental conditions should be clarified. In the present study, applicability of electrical conductivity (EC) to estimate effects of competing ions on K _dwas examined in batch experiments. The K _dof five radionuclides (⁶⁰Co, ⁵⁴Mn, ⁸⁵Sr, ¹³⁷Cs, ⁶⁵Zn) were found to be in inverse proportion to the supernatant EC. The K _dof ⁶⁰Co and ⁵⁴Mn were increasing at 7 days and no stable K _dcould be determined. For ⁸⁵Sr, ¹³⁷Cs, and ⁶³Zn, the regression equations obtained between the K _dof the equilibrium state and the supernatant EC were validated in another experiment; it is expected that their K _ds can be determined accurately using the EC. Because of its simplicity in measurements, using EC should be very practical for estimating effects of competing ions on K _dof selected radionuclides.     

Phylogenetic characterisation of Onobrychis species with special focus on the forage crop Onobrychis viciifolia Scop.

Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage legume that possesses beneficial properties in the context of sustainable agriculture. In order to initiate a pre-breeding programme, we have assembled a germplasm collection of O. viciifolia from many geographic regions, as well as a collection of Onobrychis species that might be crossed with O. viciifolia to improve its biological and agronomic properties. The objective of this study was to obtain DNA sequences from a representative sample of these accessions in order to characterise their genetic diversity and to assess the robustness of the Onobrychis taxonomy. Because of potential problems with copurification of tannins and polyphenols from Onobrychis leaf tissue, three methods for DNA extraction were assessed and the most appropriate one identified. DNA sequences were obtained for the nuclear internal transcribed spacer region and the trnH-psbA and trnT-trnL intergenic spacers of the chloroplast genome. Neighbour joining trees were constructed and accessions were assigned to operational taxonomic units. The results indicated that there is substantial genetic diversity among Onobrychis species. Redundancies in species nomenclature were identified, as well as possible overlap between some of the sections into which the Onobrychis genus has been divided. A genetic distinction was apparent between O. viciifolia accessions from western Europe and those from eastern Europe and Asia, reflecting a similar division based on agronomic properties. Recognition of these different though related germplasms will be valuable in the design of breeding programmes for the rational improvement of sainfoin as a forage crop for sustainable agriculture.     

Resistance in natural populations of three wild Lactuca species from Israel to highly virulent Californian isolates of Bremia lactucae

Seedlings of 213 accessions representing 9, 14, and 10 Israeli natural populations of the wild Lactuca serriola, L. saligna, and L. aculeata, respectively, were initially screened for their resistance to a pathotype CAVIII isolate of Bremia lactucae. All 60 L. serriola accessions were susceptible while all 83 accessions of L. saligna were resistant. Out of the 69 L. aculeata accessions, 36 (52.2 %) were resistant. From those resistant accessions, 56 L. saligna and 23 L. aculeata accessions were then tested at the seedling stage for their reaction against five highly virulent isolates originating from California and representing the two current major pathotypes and a novel type of B. lactucae; true leaves of adult plants were also tested with two out of these five isolates. Our study supports previous observations that L. saligna is highly resistant to B. lactucae. However, our results provide additional evidence that L. saligna may not be an absolutely non-host plant for B. lactucae at least at a seedling stage, which is in agreement with other recent data for this species. Sixteen (69.6 %) out of the 23 L. aculeata accessions expressed resistance against all isolates tested, even in seedling stage as well as in true leaves of adult plants. This study is probably the first report of detailed screening of resistance to some B. lactucae isolates in natural populations of L. aculeata. These patterns of resistance reactions show that L. aculeata, a species within the primary lettuce gene pool, should be considered as an attractive source of germplasm for resistance breeding of cultivated lettuce (L. sativa).     

Population baseline data for monitoring genetic diversity loss for 2010: A case study for Brassica species in the UK

The Convention on Biological Diversity and the subsequent International Treaty on Plant Genetic Resources for Food and Agriculture have proved a watershed in plant genetic resources (PGR) conservation and consequent initiatives have set various PGR conservation targets to be met by 2010. The aim of our paper is to develop ideas and issues concerning the monitoring of natural genetic resources: particularly in terms of developing a baseline from which to measure levels of genetic diversity. Three species of Brassica (B. nigra, B. oleracea, B. rapa) found wild in the UK were assessed for levels of genetic diversity using AFLP. The relationship between genetic distribution and ecogeographic distribution was considered for each species to determine patterns that may be useful in formulating conservation strategies. Genetic distance between populations of B. nigra and B. rapa were correlated to geographic distance. Levels of genetic polymorphism in B. oleracea were correlated to soil pH while in B. rapa they were correlated to soil coarseness. In terms of PGR conservation these findings may suggest an emphasis toward in situ conservation of a selection of disparate populations would be appropriate where possible as such adaptations may be lost in ex situ collections.     

Mycorrhizal fungi of Pseudotsuga menziesii in the south island of New Zealand

Mycorrhizal fungi of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) in the South Island of New Zealand were studied using field observation of sporocarps, examination of mycorrhizas. and isolation of fungi from mycorrhizas. Sporocarps of Hebeloma crustuliniforme (Bull, ex St. Am) Quél, and Laccaria laccata (Scop, ex Fr.) Berk & Br. were the most commonly seen in the nursery but Rhizopogon parksii A.H. Smith and Suillus lakei (Murrill) A.H. Smith & Thiers were the most common in plantations. Mycorrhizas formed by H. crustuliniforme, Endogone flammicorona Trappe & Gerdemann, and Tuber sp. were found to be the most abundant in the nursery and those formed by R. parksii, S. lakei, and Tuber sp. the most common in plantations. Rhizopogon parksii, S. lakei and Tuber sp. were consistently isolated from mycorrhizas of trees of all ages. Suillus lakei appears to be a common mycorrhizal fungus of Douglas fir in the South Island of New Zealand, whereas this association is rare in the North Island.     

Response of young plants to mercury

Young individuals of three plant species viz., Pennisetum typhoideum Stapf. var. PHB-14, Medicago sativa L. var. Raska and Abelmoschus esculentus Moench. var. Pusa-savni, were tested for their response to Hg. All of them were found to be affected, Pennisetum being the most sensitive, followed by Medicago and Abelmoschus in that order. The visible injury to leaves of plants, chlorophyll content and total dry matter was found to be affected in proportion to the metal doses administered. Measurement of Leaf Injury Index (LII) as a simple parameter of the susceptibility of the species is discussed.     

Cytological characterisation of the underutilized forage crop Onobrychis viciifolia Scop. and other members of the Onobrychis genus

Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage legume that possesses beneficial properties in the context of sustainable agriculture. A germplasm collection of O. viciifolia was assembled from many geographic regions, as well as a collection of Onobrychis species that might be crossed with O. viciifolia to improve its biological and agronomic properties. The objective of the present study was to obtain cytological information for a broad range of O. viciifolia varieties and related species, in order to confirm and extend previous findings. The study set was 143 accessions of O. viciifolia as well as 34 accessions of 17 other species from the Onobrychis genus. Three of the O. viciifolia accessions were diploid (2n = 2x = 14) and the remainder tetraploid (2n = 4x = 28). Chromosomes were <5 μm in length. Among the other Onobrychis species, roughly half were found to be diploid and the other half tetraploid, with two species, O. arenaria (Kit.) DC. and O. alba subsp. laconica (Orph. ex Boiss.) Hayek, including a mixture of diploid and tetraploid accessions. The basic number of chromosomes was seven, except for O. aequidentata (Sm.) d’Urv. and O. crista-galli Lam., where it was eight. The 2C value for O. viciifolia was estimated at 2.5 pg. These cytological data will be valuable as part of a pre-breeding programme aimed at the eventual production of improved O. viciifolia varieties for use in sustainable agriculture.     

Accuracy of methods for field assessment of rill and ephemeral gully erosion

To properly assess soil erosion in agricultural areas, it is necessary to determine precisely the volume of ephemeral gullies and rills in the field by using direct measurement procedures. However, little information is available on the accuracy of the different methods used. The main purpose of this paper is to provide information for a suitable assessment of rill and ephemeral gully erosion with such direct measurement methods. To achieve this objective: a) the measurement errors associated to three methods used for field assessment of channel cross sectional areas are explored; b) the influence of the number of cross sections used per unit channel length on the assessment accuracy, is analysed and; c) the effect of the channel size and shape on measurement errors is examined. The three methods considered to determine the cross sectional areas were: the micro-topographic profile meter (1); the detailed measurement of section characteristic lengths with a tape (2); and the measurement of cross section width and depth with a tape (3). Five reaches of different ephemeral gully types 14.0 or 30.0 m long and a set of six 20.4 to 29.4 m long rill reaches were selected. On each gully reach, the cross sectional areas were measured using the three above mentioned methods, with a separation (s) between cross sections of 1 m. For rills, the cross sectional areas were measured with methods 1 and 3, with s = 2 m. Then, the corresponding total erosion volumes were computed. The volume calculated with method 1 with s = 1 m for gullies and s = 2 m for rills was taken as the reference method. For each channel, and for each one of the possible combinations of s and measurement method (m), the relative measurement error and the absolute value of the relative measurement error (E_sm^r and |E_sm^r|), defined with respect to the reference one, was calculated. |E_sm^r| much higher than 10% were obtained very easily, even for small s values and for apparently quasi prismatic channels. Channel size and shape had a great influence on measurement errors. In fact, the selection of the more suitable method for a certain gully shape and size seemed to be much more important than s, at least when s < 10 m. Method 1 always provided the most precise measurements, and its results were the less dependent on s. However, s must be < 5 m to guarantee an error smaller than 10%. Method 2 is not recommended, because it is difficult, time consuming and can lead to large errors. Method 3 seems to be enough for small, wide and shallow gullies, and for small rills, but only if s is shorter than 5 m. Results obtained after the analysis of rill measurement errors were similar to those of gullies. The analysis of E_sm^r and |E_sm^r| when calculating channel volumes using a unique representative cross section highlighted the importance of correctly selecting the adequate cross section. Due to the high error values that this method can entail, it is not considered as advisable whenever accurate erosion measurements are pursued.     

High frequency oligonucleotides: targeting active gene (HFO-TAG) markers revealed wide genetic diversity among Citrullus spp. accessions useful for enhancing disease or pest resistance in watermelon cultivars

There is a continuous need to enhance watermelon cultivars for disease and pest resistance. Different U.S. Plant Introductions (PIs) of Citrullus lanatus subsp. lanatus var. lanatus [also known as C. lanatus (Thunb.) Matsum. et Nakai subsp. lanatus var. citroides (Bailey) Mansf. ex Greb.] (CLC) collected in southern Africa are a useful source for enhancing disease or pest resistance in watermelon cultivars. They are also valuable as rootstocks for grafted watermelon, particularly in fields infested with root-knot nematodes or Fusarium wilt. However, there is little information about genetic relationships among these PIs. In this study, genetic diversity was examined among 74 CLC PIs collected from their center of origin in southern Africa. Also, 15 Citrullus lanatus subsp. lanatus (CLL) PIs and the American heirloom cultivars Charleston Gray and Black Diamond (Citrullus lanatus subsp. vulgaris (Schrader ex Eckl. et Zeyh.) Fursa) (CLV) and five Citrullus colocynthis (L.) Schrader (CC) PIs collected in different locations throughout the world were used as out-groups in the phylogenetic analysis for the CLC PIs. Twenty-three high frequency oligonucleotides—targeting active gene (HFO-TAG) primers were used in polymerase chain reaction (PCR) experiments to produce a total of 562 polymorphic markers among the Citrullus PIs and cultivars. Cluster and multidimensional scaling plot analysis produced distinct groups of CLC, CLL, and CC PIs. Several PIs that were designated as CLC or CLL were in transitional positions, indicating that they are the result of gene flow between the major Citrullus groups or subgroups. Population structure analysis indicated that CLC comprises two subgroups; each containing a set of unique alleles. Also, unique alleles exist in the CLL and the CC genotypes. Overall, broad genetic diversity exists among the Citrullus PIs. The data in this study should be useful for identifying PIs with a wide genetic distance between them that could be used in breeding programs aiming to develop heterotic F₁ hybrid rootstock lines for grafted watermelon.     

Wheat-rhizoplane pseudomonads as antagonists of Gaeumannomyces graminis

The role of rhizoplane-inhabiting Pseudomonas spp as inhibitors of take-all on wheat was investigated. Apparent numbers of pseudomonads in wheat rhizoplanes and numbers that were antagonistic in vitro toward Gaeumannomyces graminis var, tritici did not differ when wheat was supplied with NH⁺₄-N or NO^?₃-N. More intense antagonism was expressed by colonies selected from soil treated with NH⁺₄-N than with NO^?₃-N, and from isolation media prepared at pH 5.5 rather than at 7.0. Antagonists were not recovered from methyl bromide-treated soil. Highly antagonistic pseudomonads were recovered from a wheat-monoculture soil which is considered suppressive toward the pathogen in the field, and were not recovered from a “nonsuppressive” soil. Pseudomonad antagonism ratings were inversely correlated with take-all severity in the suppressive soil, but not in the nonsuppressive soil. Pseudomonads were considered to be antagonists of G. graminis on rhizoplanes of wheat in a soil exhibiting the “take-all decline” phenomenon, but the significance of this interaction remains to be determined.     

White-tailed sea eagle Haliaeetus albicilla reintroduction to the Isle of Rhum,Scotland, 1975–1977

An attempt to reintroduce the white-tailed sea eagle to the west of Scotland was initiated by the Nature Conservancy Council in 1975, on the Isle of Rhum. Four eaglets were obtained from Norway that year; one of them died in captivity and the other three (all females) were released. Ten more were acquired in 1976 and a further four in 1977. Of these a total of 13 (8♀ and 5♂) had been released into the wild by May 1977. Two have since been recovered dead, but the others apparently adapted readily to a free-living existence. Eight more are to be released during 1978. The first nesting attempts can be expected once the young birds reach sexual maturity at 5 years of age (possibly in 1980 or 1981).     

Feeding of the panphytophagous oribatid mite Scheloribates laevigatus (Acari: Oribatida) on cyanobacterial and algal diets in laboratory experiments

The feeding of Scheloribates laevigatus on green algae and cyanobacteria was observed under laboratory conditions using food preference tests, microanatomy of the digestive tract and epifluorescence microscopy. The level of consumption of the algal species studied — Klebsormidium flaccidum, Protosiphon botryoides, Chlorella ellipsoidea and Desmococcus vulgaris — differed. The cyanobacterium Trichormus variabilis was rejected by the mite. The most preferred alga D. vulgaris (syn. Protococcus viridis) was digested only partly, in a manner similar to C. ellipsoidea. Probably, only the contents of cells mechanically damaged by chelicerae were digested, as living cells were observed in faecal pellets on both diets. On the other hand, no living cells of K. flaccidum and P. botryoides were detected after gut passage. Intact cell walls of ruptured cells of P. botryoides, C. ellipsoidea and D. vulgaris were found in the faecal pellets in the rectum. K. flaccidum cell walls were observed in the food boli in the mesenteron, but they were more fragmented in comparison with P. botryoides cell walls. This indicates that the observed algal cell walls were not digested, while the contents were. The starch inside the algal cells seems to be the main energy source for the mites. Extrapolation to natural conditions is discussed. Although S. laevigatus is regarded as a fungivorous grazer, its feeding on algae indicates an alternative feeding guild for this species — algivorous browser.     

Dietary switching of collembola in grassland soil food webs

Soil food webs are characterised by complex direct and indirect effects among the organisms. Consumption of microorganisms by soil animals is considered as an important factor that contributes to the stability of communities, though cascading effects within the food web can be difficult to detect. In a greenhouse experiment, an addition of a high number the fungal feeding collembola Folsomia quadrioculata was applied to grassland soil food webs in monocultures of three plant species: Plantago lanceolata (forb), Lotus corniculatus (legume) and Holcus lanatus (grass). The abundance of microorganisms, determined as the abundances of phospholipid fatty acids (PLFAs) and the abundances of resident invertebrates, nematodes and collembolans, did not change due to the addition of F. quadrioculata. Trophic positions of collembolans were determined by analyses of natural abundances of ¹⁵N stable isotopes. The use of food resources by microorganisms and collembolans was determined by ¹³C analysis of microbial PLFAs and solid samples of collembolans. δ¹³C values of the resident collembola Folsomia fimetaria were lower in the presence of F. quadrioculata than in the control food webs indicating a use of more depleted ¹³C food resources by F. fimetaria. The δ¹⁵N values of F. fimetaria did not change at the addition of F. quadrioculata thus no change of trophic levels was detected. The switch of F. fimetaria to a different food resource could be due to indirect interactions in the food web as the two collembolan species were positioned on different trophic positions, according to different δ¹⁵N values.     

Comparison of the influences of vegetation stem parameters on hydraulic variables and sediment transport capacity

The hydraulic variables (Hv) and sediment transport capacity (Tc) of overland flow have changed immensely due to large-scale revegetation. However, research comparing the influences of stem parameters (diameter, cover, and arrangement) on Hv and Tc is limited. The objectives of this study were to explore and compare the influences of stem parameters on Hv and Tc. Data on three treatment groups with varying stem diameters, covers, arrangements, flow discharges and slopes were collected in this study. With increasing stem diameter, Hv and Tc increased; Hv included the Reynolds and Froude numbers, flow velocity (v), shear stress (τ), stream power (Ω), and unit stream power (ω). However, the trend of the Darcy-Weisbach friction coefficient (f) was opposite. Hv and Tc were significantly influenced by stem diameter and cover. The effect of stem diameter on Hv and Tc was greater than the effects of cover and arrangement. Stem cover as a variable could not be used to adequately estimate the Tc when there were various stem diameters. A new exponential equation involving stem cover and stem diameter was demonstrated to be an appropriate predictor of Tc. Stem diameter and arrangement had no obvious influence on the relationship between Tc and v, and v as an indicator could explain the effect of stem parameters on Hv and Tc. This result could illustrate why the variables, including v, were able to predict Tc under vegetation stem and litter cover.     

Dehalogenation of 2-Chloronapthalene by Cast Iron

Aqueous 2-chloronapthalene was contacted with cast iron in batch systems, resulting in an initial rapid increase in the sorbed 2-chloronapthalene concentration (C _s ) followed by a slow decline, and an initial rapid decline in the aqueous 2-chloronapthalene concentration (C _a ) followed by a slower decline. The initial rapid partitioning of 2-chloronapthalene to the solid phase was due to its adsorption on elemental carbon present on the cast iron surface, while the residual aqueous phase 2-chloronapthalene underwent reductive dehalogenation at a slower rate through interaction with the metallic iron surface. The overall rate of change of total 2-chloronapthalene concentration (C _T = C _s +C _a ) with time, i.e., (d/C _T }{{d}t}) could be described by the expression,?k ₁ ?M? (C _a ) ⁿ , where M is the concentration of cast iron. The values of k ₁ and n were determined to be 1.576 × 10^?5 hr^?1 g^?1 iron L and 1.945 respectively. Equilibrium partitioning of 2-chloronapthalene between solid and aqueous phases could be described by a Freundlich isotherm, C _s = K? [C _a ] ^m , where m and K were determined to be 0.55 and 4.92 × 10^?3 L g^?1. Considering K to be the ratio of the adsorption (k ₂) and desorption (k ₃) rate constants, expressions were developed for describing the evolution of C _s and C _a with time. Putting k ₃ = 1 hr^?1 in these expressions resulted in adequate model fit to the experimental data. Napthalene was identified as the major dehalogenation by-product, with greater than 99 percent of the naphthalene produced partitioning to carbon present on the cast iron surface. No competition between 2-chloronapthalene and naphthalene for adsorption on the carbon surface was observed, suggesting non-specific adsorption of these compounds restricted only by the physical size of the molecules and the available carbon surface area.     

Selection of phosphorus solubilizing bacteria with biocontrol potential for growth in phosphorus rich animal bone charcoal

Bacteria with the ability to solubilize phosphorus (P) and to improve plant health were selected and tested for growth and survival in P-rich animal bone charcoal (ABC). ABC is suggested to be suitable as a carrier for biocontrol agents, offering them a protected niche as well as delivering phosphate to plants, meanwhile re-using P from waste of the food chain. Ninety-seven bacterial isolates from different soils were tested for their potential to dissolve P from ABC. Of these isolates, 60% showed positive scores; they belonged to the genera Arthrobacter, Bacillus, Burkholderia, Collimonas, Paenibacillus, Pseudomonas, Serratia, and Streptomyces. Twelve isolates from different taxonomic groups were selected for further research on growth ability and survival in ABC, and on their potential to control plant pathogens. The highest concentrations of P were dissolved by Pseudomonas chlororaphis and Bacillus pumilus, followed by Paenibacillus polymyxa, Burkholderia pyrrocinia and three Streptomyces isolates. P. chlororaphis and P. polymyxa showed strongest growth inhibition of plant pathogenic Pythium and Fusarium sp., followed by the Streptomyces spp. isolates.     

Isolation and identification of iron-reducing bacteria from gley soils

Seventy-one facultative anaerobic bacteria, capable of reducing iron oxide in pure culture, were isolated from three differently gleyed subsoils. The bacteria were picked at random from poured plates (10⁻⁵ and 10⁻⁶) inoculated with serially diluted soil samples. An attempt was made to identify these strains by morphological and biochemical tests. Among these 71 iron-reducing bacteria, all except three were capable of reducing nitrate to nitrite and 35 reduced nitrite further into gaseous compounds (denitrification), but only one strain (Bacillus subtilis) produced H₂S. Based upon their physiological and morphological properties, 38 strains were allotted to the genus Pseudomonas, 31 sporeformers to the genus Bacillus and two were regarded to be coryneform (Arthrobacter?) bacteria. Species identified were Ps. denitrificans (23), ps. stutzeri (8) ps. fluorescens-putida (5), Bacillus cereus (6), B. cereus var. mycoides (14) and Bacillus subtilis (9). Two spore-forming bacilli, two non-pigmented pseudomonads and two coryneform type of bacteria could not be identified. The significance of the enzyme nitrate reductase (nitratase) of these bacteria for anaerobic respiration and as a mechanism of iron reduction is discussed.     

Molecular characterization of a novel waxy allele (Wx-A u 1a) from Triticum urartu Thum. ex Gandil.

Granule Bound Starch Synthase I, or waxy protein, is the sole enzyme responsible for the accumulation of amylose during the development of starch granules in wheat. The full coding region of the waxy (Wx) gene was sequenced in Triticum urartu, (a wild diploid species) and is related to the A genome of polyploid wheats. The Wx gene of T. urartu (Wx-A ^u 1) showed a homology of ~88.0?% with Wx-A1 from polyploid wheats. A greater homology was found with Wx-A ^m 1 from the diploid cultivated wheat einkorn. Most of the differences were found in introns although several changes were also detected in exons that led to amino acid changes in the transit peptide and mature protein. These results show the potential of T. urartu as a source of new alleles that could be used in the breeding of durum and common wheat in order to synthesize starches with different properties.