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Wild Species (wild + species)

Distribution by Scientific Domains

Life Sciences	76%
Humanities and Social Sciences	7%
Earth and Environmental Science	7%

Distribution within Life Sciences

Plant Science	25%
Evolution	9%

Selected Abstracts

GENETIC DIVERSITY AND INTROGRESSION IN TWO CULTIVATED SPECIES (PORPHYRA YEZOENSIS AND PORPHYRA TENERA) AND CLOSELY RELATED WILD SPECIES OF PORPHYRA (BANGIALES, RHODOPHYTA),

JOURNAL OF PHYCOLOGY, Issue 2 2009
Kyosuke Niwa
We investigated the genetic variations of the samples that were tentatively identified as two cultivated Porphyra species (Porphyra yezoensis Ueda and Porphyra tenera Kjellm.) from various natural populations in Japan using molecular analyses of plastid and nuclear DNA. From PCR-RFLP analyses using nuclear internal transcribed spacer (ITS) rDNA and plastid RUBISCO spacer regions and phylogenetic analyses using plastid rbcL and nuclear ITS-1 rDNA sequences, our samples from natural populations of P. yezoensis and P. tenera showed remarkably higher genetic variations than found in strains that are currently used for cultivation. In addition, it is inferred that our samples contain four wild Porphyra species, and that three of the four species, containing Porphyra kinositae, are closely related to cultivated Porphyra species. Furthermore, our PCR-RFLP and molecular phylogenetic analyses using both the nuclear and plastid DNA demonstrated the occurrence of plastid introgression from P. yezoensis to P. tenera and suggested the possibility of plastid introgression from cultivated P. yezoensis to wild P. yezoensis. These results imply the importance of collecting and establishing more strains of cultivated Porphyra species and related wild species from natural populations as genetic resources for further improvement of cultivated Porphyra strains. [source]

Diversity of rice glutelin polypeptides in wild species assessed by the higher-temperature sodium dodecyl sulfate-polyacrylamide gel electrophoresis and subunit-specific antibodies

ELECTROPHORESIS, Issue 6 2008
Nadar Khan
Abstract In efforts to find genetic resources with high nutritional value of rice seed, we assessed the diversity of the major storage protein glutelin in 13 wild and 2 cultivated rice species by a unique SDS-PAGE method and subunit-specific antibodies. Maximum separation of microheterogeneous glutelin ,-polypeptides, which is a prerequisite for the diversity evaluation, could be attained by SDS-PAGE performed at higher temperature (45°C) than the generally employed temperatures (4,25°C). Seven antipeptide antibodies were raised against subunit-specific epitope sequences designed at five sites from four variable regions spanning the glutelin ,-polypeptides. High specificity of each antibody was confirmed using rice glutelin mutants, and demonstrated considerable variation in amino acid sequence and accumulation level of glutelin subunit in wild species, in combination with the higher-temperature SDS-PAGE. The degree of the variation was, however, changed according to the site of variable regions and the type of subunit. Some wild species accumulated nutritious GluB subunits more than cultivated rice. The wild species Oryza longiglumis and O. brachyantha had glutelin with low reactivity against most antibodies examined in this study, reflecting the significant divergence. Such wild species may hopefully serve as important genetic resources for nutritional improvement of cultivated rice. [source]

Forty-nine new host plant species for Bemisia tabaci (Hemiptera: Aleyrodidae)

ENTOMOLOGICAL SCIENCE, Issue 4 2008
Alvin M. SIMMONS
Abstract The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a worldwide pest of numerous agricultural and ornamental crops. In addition to directly feeding on plants, it also acts as a vector of plant viruses of cultivated and uncultivated host plant species. Moreover, host plants can affect the population dynamics of whiteflies. An open-choice screening experiment was conducted with B-biotype B. tabaci on a diverse collection of crops, weeds, and other indigenous plant species. Five of the plant species were further evaluated in choice or no-choice tests in the laboratory. The results reveal 49 new reproductive host plant species for B. tabaci. This includes 11 new genera of host plants (Arenaria, Avena, Carduus, Dichondra, Glechoma, Gnaphalium, Molugo, Panicum, Parthenocissus, Trianthema, and Triticum) for this whitefly. All species that served as hosts were acceptable for feeding, oviposition, and development to the adult stage by B. tabaci. The new hosts include three cultivated crops [oats (Avena sativa L.), proso millet (Panicum miliaceum L.), and winter wheat (Triticum aestivum L.)], weeds and other wild species, including 32 Ipomoea species, which are relatives of sweetpotato [I. batatas (L.) Lam.)]. Yellow nutsedge, Cyperus esculentus L., did not serve as a host for B. tabaci in either open-choice or no-choice tests. The results presented herein have implications for whitefly ecology and the numerous viruses that B. tabaci spreads to and among cultivated plants. [source]

Fatty acid composition in wild and cultivated pacu and pintado fish

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2009
Augusto Tanamati
Abstract The fatty acid compositions of muscle tissue taken from wild strains of pintado (Pseudoplatystoma corruscans) and pacu (Piaractus mesopotamicus) fish, which were taken from the Brazilian Pantanal, were compared to the fatty acid compositions of tissue taken from two corresponding cultivated strains, which were fed commercial diets. The cultivated species possessed lipid contents of 12.2% (pacu) and 8.9% (pintado) while the wild species contained 7.9% (pacu) and 2.5% (pintado) lipids. Despite the high lipid contents of the cultivated pintado and pacu, the n -3 polyunsaturated fatty acid concentrations in muscle tissue were higher in wild pintado (224.9,mg/g flesh) and wild pacu (485.1,mg/g flesh) than in their respective cultivated strains (129.8 and 106.1,mg/g flesh, respectively). The n -6/n -3 ratios of pacu were 1.2 (wild) and 9.8 (cultivated), and those of pintado were 1.0 (wild) and 7.3 (cultivated). The fatty acid composition of pacu and pintado are strongly influenced by habitat and diet. [source]

Comparative development of fiber in wild and cultivated cotton

EVOLUTION AND DEVELOPMENT, Issue 1 2001
Wendy L. Applequist
SUMMARY One of the most striking examples of plant hairs is the single-celled epidermal seed trichome of cultivated cotton. The developmental morphology of these commercial "fibers" has been well-characterized in Gossypium hirsutum, but little is known about the pattern and tempo of fiber development in wild Gossypium species, all of which have short, agronomically inferior fiber. To identify developmental differences that account for variation in fiber length, and to place these differences in a phylogenetic context, we conducted SEM studies of ovules at and near the time of flowering, and generated growth curves for cultivated and wild diploid and tetraploid species. Trichome initiation was found to be similar in all taxa, with few notable differences in trichome density or early growth. Developmental profiles of the fibers of most wild species are similar, with fiber elongation terminating at about two weeks post-anthesis. In contrast, growth is extended to three weeks in the A- and F-genome diploids. This prolonged elongation period is diagnosed as a key evolutionary event in the origin of long fiber. A second evolutionary innovation is that absolute growth rate is higher in species with long fibers. Domestication of species is associated with a further prolongation of elongation at both the diploid and allopolyploid levels, suggesting the effects of parallel artificial selection. Comparative analysis of fiber growth curves lends developmental support to previous quantitative genetic suggestions that genes for fiber "improvement" in tetraploid cotton were contributed by the agronomically inferior D-genome diploid parent. [source]

Reciprocal insights into adaptation from agricultural and evolutionary studies in tomato

EVOLUTIONARY APPLICATIONS (ELECTRONIC), Issue 5-6 2010
Leonie C. Moyle
Abstract Although traditionally separated by different aims and methodologies, research on agricultural and evolutionary problems shares a common goal of understanding the mechanisms underlying functionally important traits. As such, research in both fields offers potential complementary and reciprocal insights. Here, we discuss adaptive stress responses (specifically to water stress) as an example of potentially fruitful research reciprocity, where agricultural research has clearly produced advances that could benefit evolutionary studies, while evolutionary studies offer approaches and insights underexplored in crop studies. We focus on research on Solanum species that include the domesticated tomato and its wild relatives. Integrated approaches to understanding ecological adaptation are particularly attractive in tomato and its wild relatives: many presumptively adaptive phenotypic differences characterize wild species, and the physiological and mechanistic basis of many relevant traits and environmental responses has already been examined in the context of cultivated tomato and some wild species. We highlight four specific instances where these reciprocal insights can be combined to better address questions that are fundamental both to agriculture and evolution. [source]

Leaf fungi of two wild plants in Assiut, Egypt

FEDDES REPERTORIUM, Issue 7-8 2004
S. K. Hemida
Leaves of two wild species of the flora of Egypt: Calotropis procera (Ait.) Ait., Asclepiadaceae and Chrozophora plicata (Vahl) A.Juss. ex Spreng., Euphorbiaceae have been studied morphologically and mycologically, in addtion to air borne fungi. Fifty five species and two varieties belonging to 26 genera of phyllosphere and phylloplane fungi were isolated from both plant species on glucose- and cellulose-agar media. Mycological analysis was done monthly over six months (July to December, 2003). Alternariaalternata, Aspergillus fumigatus, A. flavus and A. niger were the basic fungal species found on leaf surfaces. Phylloplane of C. plicata caught specifically Chaetomiumglobosum, C.,spirale, Cochliobolus lunatus, Drechslera halodes, Fusarium incarnatum, F. oxysporum, Memnoniella echinata and Papulaspora sepedonioides. The total counts of phyllosphere fungi of C.,plicata were nearly twice as much as those of C.,procera regardless medium's type. Forty species and one variety belonging to 22 genera of air borne fungi were recovered all over the experimental period (six months). Alternaria, Aspergillus, Cladosporium and Penicillium were the most frequently isolated species. The presented results revealed that, leaf shape and density (hair density and type) may be the most important factors of the biodiversity of the fungal species on the studied taxa. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Die Blätter zweier Wildarten aus der Flora Ägyptens: Calotropis procera (Ait.) Ait., Asclepiadeceae, und Chrozophora plicata(Vahl) A.Juss. ex Spreng., Euphorbiaceae, wurden in Bezug auf ihre Morphologie und Mykologie untersucht sowie zusätzlich auf ihre "luftgeborenen" Pilze. Auf beiden Arten wurden auf einem Glukose- bzw. Cellulose-Medium insgesamt 55 Arten und zwei Varietäten aus 26 Gattungen phyllosphärer und phylloplaner Pilze nachgewiesen. Die mykologischen Analysen wurden über einen Zeitraum von sechs Monaten (Juli bis Dezember 2003) durchgeführt. Alternariaalternata, Aspergillus fumigatus, A. flavus und A. niger waren die Basis-Pilzarten, die auf den Blattoberflächen ermittelt wurden. Auf C. plicata waren Chaetomiumglobosum, C. spirale, Cochliobolus lunatus, Drechslera halodes, Fusarium incarnatum, F. oxysporum, Memnoniella echinata und Papulaspora sepedonioides die häufigsten phylloplanen Arten. Ungeachtet des Mediumtyps war die Anzahl phyllosphärischer Pilze auf C. plicata etwa zweimal so hoch wie auf C. procera. Über die gesamte Versuchszeit von sechs Monaten wurden 40 Arten und eine Varietät aus 22 Gattungen "luftgeborener" Pilze beobachtet. Mit Alternaria, Aspergillus, Cladosporium und Penicillium fanden sich die am häufigsten isolierten Arten. Aus den erzielten Ergebnissen kann man ableiten, dass Blattform und Haare (Dichte und Typ) die wichtigsten Faktoren für die Biodiversität der untersuchten Pilzarten sind. [source]

Estimating age and season of death of pronghorn antelope (Antilocapra americana Ord) by means of tooth eruption and wear

INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2001
Patrick M. Lubinski
Abstract Age and season of death information for prey animals at archaeological sites can address issues such as season of site occupation and prey hunting or harvesting strategies. Unfortunately, adequate reference information for estimating age and season is lacking for many wild species, including pronghorn antelope. To address this problem, new methods of scoring tooth eruption and wear have been developed and have been applied to a sample of over 500 pronghorn mandibles to obtain improved eruption and wear schedules. One implication of this study is that ,age class discreteness' is an unreliable method for demonstrating mass mortality of prey. This study provides a much larger comparative sample than previously available, although larger known-age mandible samples are still needed for pronghorn and many other wild species. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Testing the use of interviews as a tool for monitoring trends in the harvesting of wild species

JOURNAL OF APPLIED ECOLOGY, Issue 4 2008
Julia P. G. Jones
Summary 1Many aspects of human behaviour impact on ecological systems. Ecologists therefore need information on changes in these behaviours and are increasingly using methods more familiar to social scientists. 2Understanding patterns of wildlife harvesting is important for assessing the sustainability of harvests. Interviews are commonly used in which informants are asked to summarize their activities over a period of time. However, few studies have investigated the reliability of such data, the usefulness of interviews for monitoring trends, and how their information content can be maximized. 3We carried out rapid assessment interviews with villagers in Madagascar about the quantity, timing and spatial patterns of crayfish Astacoides granulimanus and firewood collection. We compared the results with information from daily interviews with the same informants. We used mixed models to investigate how accurately people reported their activities in the rapid assessment interviews, and estimated the probability of detecting a change in harvesting from two such interviews using a Bayesian approach. 4The interviews provided reliable information on quantities, effort, and the spatial pattern of harvesting. Simulations suggested the interviews would detect changes in catches and harvesting effort with reasonable power; for example, a 20% change in the amount of time spent crayfish harvesting could be detected with 90% power. Power is higher when the same informants are questioned in repeat interviews. 5Synthesis and applications. Ecologists are increasingly using social techniques and it is vital that they are subject to rigorous testing to ensure robustness in trend detection. This study suggests that interviews can be used to monitor changes in harvesting patterns by resource users, but whether the power is adequate will depend on the needs of the study. To maximize the power of interviews, informants should be interviewed independently and the same informants interviewed in subsequent years. [source]

An investigation into the prevalence of Renibacterium salmoninarum in farmed rainbow trout, Oncorhynchus mykiss (Walbaum), and wild fish populations in selected river catchments in England and Wales between 1998 and 2000

JOURNAL OF FISH DISEASES, Issue 2 2008
E Chambers
Abstract A cross-sectional survey of Renibacterium salmoninarum infection in farmed rainbow trout (RBT) and wild fish populations was carried out in 10 farms and six river catchments, respectively, in England and Wales. The majority of the wild fish were sampled in 1998 and the farmed fish in 2000. Grayling, Thymallus thymallus, and brown trout, Salmo trutta, were the main wild species sampled. Two fish, one grayling and one salmon, Salmo salar, were R. salmoninarum culture-positive, compared with 40 confirmed polymerase chain reaction-positive wild fish. The highest prevalence of R. salmoninarum infection was found in grayling in rivers with RBT farms with a history of R. salmoninarum infection. One hundred and fifty fish were sampled from each RBT farm, but none of the fish was found to be R. salmoninarum -positive. Evidence was found, for the first time, for the presence of R. salmoninarum in an eel, Anguilla anguilla. [source]

GENETIC DIVERSITY AND INTROGRESSION IN TWO CULTIVATED SPECIES (PORPHYRA YEZOENSIS AND PORPHYRA TENERA) AND CLOSELY RELATED WILD SPECIES OF PORPHYRA (BANGIALES, RHODOPHYTA),

Detecting hybridization between wild species and their domesticated relatives

MOLECULAR ECOLOGY, Issue 1 2008
ETTORE RANDI
Abstract The widespread occurrence of free-ranging domestic or feral carnivores (dogs, cats) or ungulates (pigs, goats), and massive releases of captive-reproduced game stocks (galliforms, waterfowl) is raising fear that introgressive hybridization with wild populations might disrupt local adaptations, leading to population decline and loss of biodiversity. Detecting introgression through hybridization is problematic if the parental populations cannot be sampled (unlike in classical stable hybrid zones), or if hybridization is sporadic. However, the use of hypervariable DNA markers (microsatellites) and new statistical methods (Bayesian models), have dramatically improved the assessment of cryptic population structure, admixture analyses and individual assignment testing. In this paper, I summarize results of projects aimed to identify occurrence and extent of introgressive hybridization in European populations of wolves (Canis lupus), wildcats (Felis silvestris), rock partridges and red-legged partridges (Alectoris graeca and Alectoris rufa), using genetic methods. Results indicate that introgressive hybridization can be locally pervasive, and that conservation plans should be implemented to preserve the integrity of the gene pools of wild populations. Population genetic methods can be fruitfully used to identify introgressed individuals and hybridizing populations, providing data which allow evaluating risks of outbreeding depression. The diffusion in the wild of invasive feral animals, and massive restocking with captive-reproduced game species, should be carefully controlled to avoid loss of genetic diversity and disruption of local adaptations. [source]

Tomato yellow leaf curl virus, the intracellular dynamics of a plant DNA virus

MOLECULAR PLANT PATHOLOGY, Issue 1 2003
Yedidya Gafni
SUMMARY Tomato yellow leaf curl virus is a geminivirus, transmitted by whitefly ( Bemisia tabaci ) and causing the most destructive disease of tomato throughout the Mediterranean region, the Middle East and the tropical regions of Africa and Central America. Affected plants produce either no fruits or a few small fruits. Since it is an ssDNA virus which replicates in the host cell nucleus, the molecular mechanisms involved in the viral nuclear import have been the focus of our studies in recent years and results as well as prospects will be discussed. Taxonomy:Tomato yellow leaf curl virus (TYLCV) is a ssDNA plant virus, a member of the family Geminiviridae , of the genus Begomovirus. Physical properties: ,TYLCV, like all members of Geminiviridae, has geminate (twinned) particles, 18,20 nm in diameter, 30 nm long, apparently consisting of two incomplete T = 1 icosahedra joined together in a structure with 22 pentameric capsomers and 110 identical protein subunits (Fig. 1). Figure 1. Particles of TYLCV. Electron micrograph of purified, negatively stained TYLCV particles. Bar = 100 nm. Disease symptoms: ,Symptoms become visible in tomato in approximately 2,3 weeks after infection (Fig. 2). Leaf symptoms include chlorotic margins, small leaves that are cupped, thick and rubbery. The majority (up to 90%) of flowers abscise after infection, and therefore few fruits are produced. In Israel and elsewhere, weeds bridge the gap as potential perennial host and source of the virus between tomato growing seasons. Figure 2. Tomato yellow leaf curl symptoms on tomato plant. Leaves show yellowing on the edges accompanied by upward curling. Disease control: ,Control of TYLCV is currently based on insecticide treatments and/or physical barriers against the insect vector (Bemisia tabaci), and on tomato breeding programs based on introgression of resistance or tolerance from wild species to cultivated tomato. Useful website: , [source]

Sex determination in cattle based on simultaneous amplification of a new male-specific DNA sequence and an autosomal locus using the same primers

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2001
Rosemarie Weikard
Abstract A PCR-based method for sex determination of bovine DNA samples and embryo biopsies is presented. Using only one primer pair both the male-specific sequence FBNY (127 bp) and a sex-independent control PCR-fragment, the microsatellite marker FBN17 (136,140 bp) are generated in the same PCR reaction. Synteny mapping assigned the male-specific sequence to bovine chromosome Y (BTA Y), whereas FBN17 was mapped to bovine chromosome 2. Localisation of FBNY on BTA Y was confirmed by fluorescence in hybridisation of two BAC clones containing the male-specific sequence. There was no amplification of the male-specific target sequence FBNY in sheep, pig, goat, mice, man, and several wild species of the tribe Bovini. The bovine male-specific fragment was detected in dilutions containing as little as 10 pg genomic DNA and in blastomeres from embryo biopsies. The PCR assay presented here does require neither restriction endonuclease digestion of the PCR product nor additional nested PCR steps. Owing to the advantage of parallel amplification of the autosomal locus FBN17 no additional control fragment is necessary to detect PCR failure. The results of sex determination in embryo biopsies using FBNY were in agreement with the outcome from a reference assay used in commercial breeding programs. Mol. Reprod. Dev. 60: 13,19, 2001. © 2001 Wiley-Liss, Inc. [source]

Some photosynthetic responses to salinity resistance are transferred into the somatic hybrid descendants from the wild soybean Glycine cyrtoloba ACC547

PHYSIOLOGIA PLANTARUM, Issue 3 2007
Yong Yang
The somatic hybrid descendants between a cultivated soybean Glycine max Melrose and a wild species Glycine cyrtoloba ACC547 were found to possess some salinity-resistant traits of the wild soybean. Under salt stress, two of the descendants as well as their wild parent grew better than their cultivated parent. In addition, salinity-induced decline in the net photosynthetic rate and the maximum photochemical efficiency was much less in the wild species and the descendants than in Melrose when stressed for more than 5 days. Analysis of the postillumination transient increase in chlorophyll fluorescence and the dark rereduction of the oxidized primary electron donor in photosystem I (PSI) (P700+) indicated that salinity induced a significant upregulation of the cyclic electron flow around PSI (CEF1) in the wild species and the hybrid descendants. Similar to their wild parent, the descendants maintained higher non-photochemical dissipation of excess excitation energy than their cultivated parent under salt stress. As a consequence, there were lower levels of superoxide radical and membrane lipid peroxidation in the plants of the descendants and the wild species. Based on these results, we proposed that the high salinity resistance of the descendants might be because of, at least partially, the trait inherited from the wild species of the enhanced CEF1 which contributed to the sufficient dissipation of excess excitation energy to protect photosynthetic apparatus from the damage of reactive oxygen species. [source]

Metabolomic analysis of host plant resistance to thrips in wild and cultivated tomatoes,

PHYTOCHEMICAL ANALYSIS, Issue 1 2010
Mohammad Mirnezhad
Abstract Introduction , Western flower thrips (Frankliniella occidentalis) are among the most serious crop pests worldwide. Control of thrips mainly depends on pesticides, excessive use of which leads to human health risks and environmental contamination. As an alternative, we study host plant resistance to thrips. Objective , To apply nuclear magnetic resonance spectroscopy (NMR) metabolomics to study host plant resistance to thrips in wild and cultivated tomatoes. Methodology , Ten wild species and 10 cultivated tomato lines were compared. Five replicates of each species and lines were used for a thrips bioassay while another five replicates were used for the metabolomic analysis. The three most resistant and susceptible wild species, and cultivated lines, as identified by the thrips bioassay, were used for the metabolomics, performed by 1H NMR spectroscopy followed by principal component analysis. Results , Wild and cultivated tomatoes differed significantly in thrips resistance. Only wild tomatoes were thrips-resistant, among which Lycopersicon pennellii and L. hirsutum exhibited the lowest thrips damage. Their 1H NMR-based metabolomic profiles were significantly different from those of thrips-susceptible tomatoes. Thrips-resistant tomatoes contained acylsugars, which are known for their negative effect on herbivores. Conclusion , The identification of acylsugars as a resistance factor for thrips in tomato proves that NMR-based metabolomics an important tool to study plant defences, providing fundamental information for the development and realisation of herbivore resistance breeding programmes in agricultural crops. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Prefertilization barriers to interspecific hybridization involving Gossypium hirsutum and four diploid wild species

PLANT BREEDING, Issue 3 2008
S. Ganesh Ram
Abstract Interspecific hybridization among species of cotton has lead to improvement in productivity, earliness, fibre quality and resistance to pests and diseases. However, wide crosses is often limited by the operation of either pre- or/and post-fertilization barriers. An investigation on pollen tube behaviour of four wild species in the pistils of Gossypium hirsutum was taken up. Pollen germination was normal in crosses involving Gossypium triphyllum and Gossypium armourianum and markedly inhibited in the crosses involving Gossypium davidsonii and Gossypium thurberi. Pollen tubes reached the pistils and fertilization was accomplished within 8 h after pollination (HAP) in control cross. Even though delay in pollen tube was a common phenomenon in all the four crosses successful fertilization was observed in crosses involving G. triphyllum and G. armourianum, as they reached the ovary at 24 HAP. In crosses with G. davidsonii and G. thurberi, pollen tubes failed to reach the ovary even at 24 HAP indicating the presence of strong stylar and ovarian incompatibility. Measures to overcome such barriers to interspecific hybridization in the incompatible crosses are discussed. [source]

Post-infection development and histopathology of Meloidogyne arenaria race 1 on Arachis spp.

PLANT PATHOLOGY, Issue 5 2008
K. Proite
The reproductive behaviour of the root-knot nematode Meloidogyne arenaria race 1 was compared on two wild species of Arachis (A. duranensis and A. stenosperma) and cultivated peanut (A. hypogaea cv. IAC-Tatu-ST). The three species were considered moderately susceptible, resistant, and susceptible, respectively. Penetration and development of the root-knot nematode in the resistant species was reduced in comparison with that occurring in susceptible plants. Several cell features, including dark blue cytoplasm and altered organelle structure were observed in the central cylinder of A. stenosperma, indicating a hypersensitive-like response (HR) of infested host cells. Neither giant cells, nor nematodes developed beyond the second stage, were found on A. stenosperma. Arachis duranensis showed a delay in the development of nematodes in the roots compared to A. hypogaea. The two wild peanut species were chosen to be the contrasting parents of a segregating population for mapping and further investigation of resistance genes. [source]

Sympatric ascochyta complex of wild Cicer judaicum and domesticated chickpea

PLANT PATHOLOGY, Issue 3 2007
O. Frenkel
The aim of this study was to isolate, identify and characterize ascochyta blight pathogens from Cicer judaicum, a wild annual Cicer species which grows in Israel and other Mediterranean countries in sympatric distribution with legume crops, and determine their virulence and aggressiveness to other wild and domesticated legumes. Native C. judaicum plants exhibited symptoms resembling ascochyta diseases of grain legume crops. Two distinct pathogens were isolated and identified as Phoma pinodella and Didymella rabiei using morphological and molecular tools; their infectivity was verified using Koch's postulates. The virulence of these pathogens was examined on 13 legume species, of which P. pinodella was virulent to Pisum sativum, P. fulvum, C. judaicum, C. arietinum, C. reticulatum, C. pinnatifidum and C. bijugum. Didymella rabiei infected all these Cicer species, but not the other legume species tested. Aggressiveness of the pathogens was tested on wild and domesticated chickpea and pea. Didymella rabiei isolated from C. judaicum had significantly higher (P < 0·001) aggressiveness than P. pinodella from C. judaicum on both wild and domesticated chickpea. Disease severity on the former species ranged from 62·5% to 70% and on the latter from 41% to 56%. Phoma pinodella isolates from C. judaicum were more aggressive on C. arietinum and P. sativum than on C. judaicum and P. fulvum. Results of the current study suggest that C. judaicum may serve as an alternative host to ascochyta pathogens that endanger chickpea and possibly other crops and wild species growing in close proximity. [source]

High mitochondrial differentiation levels between wild and domestic Bactrian camels: a basis for rapid detection of maternal hybridization

ANIMAL GENETICS, Issue 3 2010
K. Silbermayr
Summary Hybridization between wild species and their domestic congeners often threatens the gene pool of the wild species. The last wild Bactrian camel (Camelus ferus) populations in Mongolia and China are examples of populations facing such a hybridization threat. To address this key issue in the conservation of wild camels, we analysed wild, hybrid and domestic Bactrian camels (Camelus bactrianus) originating from Mongolia, China and Austria. Through screening of an 804-base-pair mitochondrial fragment, we identified eight mitochondrial haplotypes and found high sequence divergence (1.9%) between C. ferus and C. bactrianus. On the basis of a mitochondrial DNA sequence fixed difference, we developed a diagnostic PCR restriction fragment length polymorphism (PCR-RFLP) assay to differentiate between wild and domestic camel samples. We applied the assay to 81 individuals and confirmed the origin of all samples including five hybrids with known maternal ancestry. The PCR-RFLP system was effective for both traditional (blood, skin) and non-invasive samples (faeces, hair), as well as for museum specimens. Our results demonstrate high levels of mitochondrial differentiation between wild and domestic Bactrian camels and that maternal hybridization can be detected by a rapid and reliable PCR-RFLP system. [source]

Re-sequencing regions of the ovine Y chromosome in domestic and wild sheep reveals novel paternal haplotypes

ANIMAL GENETICS, Issue 1 2009
J. R. S. Meadows
Summary The male-specific region of the ovine Y chromosome (MSY) remains poorly characterized, yet sequence variants from this region have the potential to reveal the wild progenitor of domestic sheep or examples of domestic and wild paternal introgression. The 5, promoter region of the sex-determining gene SRY was re-sequenced using a subset of wild sheep including bighorn (Ovis canadensis), thinhorn (Ovis dalli spp.), urial (Ovis vignei), argali (Ovis ammon), mouflon (Ovis musimon) and domestic sheep (Ovis aries). Seven novel SNPs (oY2,oY8) were revealed; these were polymorphic between but not within species. Re-sequencing and fragment analysis was applied to the MSY microsatellite SRYM18. It contains a complex compound repeat structure and sequencing of three novel size fragments revealed that a pentanucleotide element remained fixed, whilst a dinucleotide element displayed variability within species. Comparison of the sequence between species revealed that urial and argali sheep grouped more closely to the mouflon and domestic breeds than the pachyceriforms (bighorn and thinhorn). SNP and microsatellite data were combined to define six previously undetected haplotypes. Analysis revealed the mouflon as the only species to share a haplotype with domestic sheep, consistent with its status as a feral domesticate that has undergone male-mediated exchange with domestic animals. A comparison of the remaining wild species and domestic sheep revealed that O. aries is free from signatures of wild sheep introgression. [source]

High levels of nucleotide diversity in the European rabbit (Oryctolagus cuniculus) SRY gene

ANIMAL GENETICS, Issue 4 2005
A. Geraldes
Summary We have sequenced 2388 bp of the European rabbit sex determining region Y (SRY) gene. These data provide a 10-fold increase in the coverage of the Y chromosome in this species, including the entire open reading frame of the SRY, the polyadenylation signal, and two repetitive sequences in the 5, -region. A survey of 2021 bp of this gene in eight domestic breeds and four wild individuals revealed a total of nine single nucleotide polymorphisms and one indel, defining two deeply divergent lineages. The resulting estimation of nucleotide diversity (, = 1.34 × 10,3) is very high when compared with other species, but no variability was detected among the domestic breeds. This study represents a first step in the characterization of the European rabbit Y chromosome and its variability. These sequences can be used in additional phylogeographical analyses of the European rabbit and other Leporid species, as well as in evolutionary studies of sex determination and the Y chromosome in wild species. [source]

Biotechnology in Aquaculture: Transgenics and Polyploidy

COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2007
Rosalee S. Rasmussen
ABSTRACT:, Although capture fisheries have experienced slow to stagnant growth in recent years, the world population has been increasing, with subsequent rises in demands for marine-based foods. One possibility for alleviating potential food shortages and price increases is through aquaculture, which has experienced rapid worldwide expansion. A major focus of research in the aquaculture industry is on the use of biotechnology to increase food availability and reduce production costs, specifically through the manipulation of the genes and chromosomes of cultivated species. Examples include transgenic fish with properties such as increased growth rates, feed conversion efficiency, disease resistance, cold tolerance, and improved metabolism of land-based plants. However, use of transgenic organisms in aquaculture is a very controversial topic due to a number of environmental and human health concerns such as escapement and introduction of genetically modified organisms into the food chain. In response, some transgenic research has also been focused on inducing sterility to reduce the risk of transgenic organisms breeding with wild species. A method of chromosome manipulation, referred to as polyploidy, provides the option of creating sterile organisms, some of which also exhibit increased growth rates. This review paper will discuss recent advances in biotechnology research, specifically in regards to the manipulation of genes and chromosomes, for enhanced cultivation of fish and invertebrates. Major environmental and human health concerns will also be addressed. [source]