971 resultados para Wild species


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The Mediterranean region is one of the major centres of origin and diversification of cultivated plants and many crop wild relatives are found there. In addition, many native species are still widely harvested from the wild for food, medicine and other uses and some of these have potential for development as alternative crop especially in marginal zones. While there have been several recent initiatives that address the cataloguing and conservation of these species, such as the Network on Identification, Conservation and Use of Wild Plants in the Mediterranean Region (MEDUSA and the Bioversity International (IPGRI) studies on Underutilized Mediterranean Species (VMS), no comprehensive assessment has yet been made and little work undertaken on their agricultural potential. It has been confidently predicted that consequences of global change in the Mediterranean region - population movements and migrations, changes in disturbance regimes, and climate change - will be serious. One the one hand, this will affect the survival prospects of many of these underutilized species and on the other hand it will enhance their importance as the source of potential new crop germplasm. The conservation and availability of genetic diversity of both crops and underutilized species is essential if we are to be able to meet the increasing demand for food and other crops that will be adapted to the new ecoclimatic envelopes that will develop in the region as a consequence of global change. The rapid rate of climatic and other change that is expected adds urgency to the task of assessing, conserving and sustainably using this rich diversity of wild species of economic value in the region but new strategies will be need to be developed to achieve this. The Mediterranean region has the potential of becoming a major source of new crop development in the coming decades.

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While only about 1-200 species are used intensively in commercial floriculture (e.g. carnations, chrysanthemums, gerbera, narcissus, orchids, tulips, lilies, roses, pansies and violas, saintpaulias, etc.) and 4-500 as house plants, several thousand species of herbs, shrubs and trees are traded commercially by nurseries and garden centres as ornamentals or amenity species. Most of these have been introduced from the wild with little selection or breeding. In Europe alone, 12 000 species are found in cultivation in general garden collections (i.e. excluding specialist collections and botanic gardens). In addition, specialist collections (often very large) of many other species and/or cultivars of groups such as orchids, bromeliads, cacti and succulents, primulas, rhododendrons, conifers and cycads are maintained in several centres such as botanic gardens and specialist nurseries, as are 'national collections' of cultivated species and cultivars in some countries. Specialist growers, both professional and amateur, also maintain collections of plants for cultivation, including, increasingly, native plants. The trade in ornamental and amenity horticulture cannot be fully estimated but runs into many billions of dollars annually and there is considerable potential for further development and the introduction of many new species into the trade. Despite this, most of the collections are ad hoc and no co-ordinated efforts have been made to ensure that adequate germplasm samples of these species are maintained for conservation purposes and few of them are represented at all adequately in seed banks. Few countries have paid much attention to germplasm needs of ornamentals and the Ornamental Plant Germplasm Center in conjunction with the USDA National Plant Germplasm System at The Ohio State University is an exception. Generally there is a serious gap in national and international germplasm strategies, which have tended to focus primarily on food plants and some forage and industrial crops. Adequate arrangements need to be put in place to ensure the long- and medium-term conservation of representative samples of the genetic diversity of ornamental species. The problems of achieving this will be discussed. In addition, a policy for the conservation of old cultivars or 'heritage' varieties of ornamentals needs to be formulated. The considerable potential for introduction of new ornamental species needs to be assessed. Consideration needs to be given to setting up a co-ordinating structure with overall responsibility for the conservation of germplasm of ornamental and amenity plants.

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Two wild diploid (2n = 20 chromosomes) and self-pollinating Arachis species, Arachis Pintoi Krapov and W.C.Gregory and A. villosulicarpa Hoehne were submmited to C-band technique to karyotype analyses. Root tips were employed in the analyses. Morphometric data chose that chromosome lengths varied from 3.12 in A. villosulicarpa to 1.45 in A. Pintoi. Karyotype formula obtained was 10sm to A. Pintoi and 9sm + 1m to A. villosulicarpa. There was a predominance of pericentromeric C-band in all mitotic metaphasic chromosomes in both species. Besides C-band values, both species still did not differ in respect to chromosome absolute and relative lengths, centromeric index, symmetry index and total karyotype haploid length. C-band and morphometric data did not show strong or significant differences which could separate these two species of peanut which belong to evolutive different sections.

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Two wild diploid (2n = 20 chromosomes) and self-pollinating Arachis species, Arachis Pintoi Krapov and W.C. Gregory and A. villosulicarpa Hoehne were submmited to C-band technique to karyotype analyses. Root tips were employed in the analyses. Morphometric data chose that chromosome lengths varied from 3.12 in A. villosulicarpa to 1.45 in A. Pintoi. Karyotype formula obtained was 10sm to A. Pintoi and 9sm + 1m to A. villosulicarpa. There was a predominance of pericentromeric C-band in all mitotic metaphasic chromosomes in both species. Besides C-band values, both species still did not differ in respect to chromosome absolute and relative lengths, centromeric index, symmetry index and total karyotype haploid length. C-band and morphometric data did not show strong or significant differences which could separate these two species of peanut which belong to evolutive different sections.

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Peanut is one of the few plants that synthesizes resveratrol, a phenolic compound of the stilbene class, which has been associated with reduced risk of developing chronic diseases, such as cancer, cardiovascular diseases, skin diseases, pulmonary diseases, diabetes and neurological diseases. Resveratrol was detected in different parts of the peanut plant, including roots, leaves, seeds and their derivatives. The wild species of the Arachis section are also strong candidates to synthesize resveratrol because they are phylogenetically closely related to cultivated peanut. Our objective was to characterize the resveratrol content in ten wild species of Arachis with three different genomes (A, B and K). The plant material was composed of leaves of the ten species treated (test) and not treated (control) with ultraviolet (UV) radiation. The test and control samples were extracted and the identification and quantification of resveratrol was performed using high performance liquid chromatography (HPLC). All species studied synthesized resveratrol and the concentrations ranged from 299.5 μg/g in A. kempff-mercadoi to 819.9 μg/g in A. cardenasii. DPPH antioxidant activity varied between 18.7 % for A. duranensis and 48.2 % in A. simpsonii. The results showed that wild Arachis species are a potential source of alleles for improvement of cultivated peanut, with the aim of achieving higher resveratrol content in leaves. © 2013 Springer Science+Business Media Dordrecht.

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The high copy dTph1 transposon system of Petunia (Solanaceae) is one of the most powerful insertion mutagens in plants, but its activity cannot be controlled in the commonly used mutator strains. We analysed the regulation of dTph1 activity by QTL analysis in recombinant inbred lines of the mutator strain W138 and a wild species (P. integrifolia spp. inflata). Two genetic factors were identified that control dTph1 transposition. One corresponded to the ACT1 locus on chromosome I. A second, previously undescribed locus ACT2 mapped on chromosome V. As a 6-cM introgression in W138, the P. i. inflata act1(S6) allele behaved as a single recessive locus that fully eliminated transposition of all dTph1 elements in all stages of plant development and in a heritable fashion. Weak dTph1 activity was restored in act1(S6)/ACT2(S6) double introgression lines, indicating that the P. i. inflata allele at ACT2 conferred a low level of transposition. Thus, the act1(S6) allele is useful for simple and predictable control of transposition of the entire dTph1 family when introgressed into an ultra-high copy W138 mutator strain. We demonstrate the use of the ACT1(W138)/act1(S6) allele pair in a two-element dTph1 transposition system by producing 10 000 unique and fixed dTph1 insertions in a population of 1250 co-isogenic lines. This Petunia system produces the highest per plant insertion number of any known two-element system, providing a powerful and logistically simple tool for transposon mutagenesis of qualitative as well as quantitative traits.

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High salinity is a severe constraint on tomato growth and productivity in many regions and situations. To obtain an ideal gene donor for improving the salt tolerance of tomato cultivars, the potential of tolerance response to salinity were evaluated for 14 tomato accessions including wild and cultivated species. By investigation of seed germination and seedling survival, a common cultivar, Solanum lycopersicum 'moneymaker', is evidenced significantly salt-tolerant among them and correspondingly, a wild accession, Solanum cheesmanniae 'LA0317', is most vulnerable to salinity. The performance of Moneymaker and LA0317 upon salinity was then compared in detail for their growth inhibition and some physiological changes. Complete dominance of Moneymaker and its high gene identity in tomato species lead us to use it in microarray experiment and apply it as gene donor for salt tolerance. The results indicated some mechanism differences between Moneymaker and LA0317 in salt response, proposed the potentially high salt tolerance of cultivated tomato and implied that Moneymaker is a valuable gene donor in this field, potentially minimizing the growth inhibition and yield reduction in transgenic plants.

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In Australia, macadamia trees are commonly propagated by germinating rootstock seed and grafting when seedlings reach a suitable size. The production of grafted trees is a protracted and complex process, however, propagation of macadamia via cuttings represents a simpler and faster method of multiplication. Macadamias have traditionally proven difficult to propagate from cuttings, and while recent developments in the process have improved success rates, substantial variation in rooting ability between cultivars and species has been reported. The cultivar 'Beaumont' (Macadamia integrifolia × M. tetraphylla) is commonly propagated by cutting for use as a rootstock, and is relatively easy to strike while other cultivars are more difficult. There is speculation that Hawaiian cultivars are more difficult to strike from cuttings than Australian cultivars due to species and genetic composition. In this experiment, cuttings of 32 genotypes were evaluated for rooting ability. Each genotype's species profile was estimated using historical data, and used to determine species effects on survival (percentage) and rooting ability (rating 0-2). M. jansenii (100%), M. tetraphylla (84%) and M. integrifolia/tetraphylla hybrids (79%) had the highest success rates while M. integrifolia (54%) and M. ternifolia (43%) had the lowest survival. Rooting ability of M. jansenii (1.75) was significantly higher than M. ternifolia (0.49) but not significantly higher than M. tetraphylla × M. integrifolia with (1.09), M. tetraphylla (1.03) or M. integrifolia (0.88).

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The objective of the present work was to induce somatic embryogenesis from zygotic embryos of Passiflora cincinnata Masters. Zygotic embryos formed calli on media with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.5 mu M benzyladenine (BA) after 30 days of in vitro culture. A concentration of 18.1 mu M 2,4-D resulted in the largest number of somatic embryos. Embryogenic calli were yellowish and friable, forming whitish proembryogenic masses. Morphologically, embryogenic cells were small and had large nuclei and dense cytoplasm, whereas non-embryogenic cells were elongated, with small nuclei and less dense cytoplasm. Calli cultured under white light on basal Murashige and Skoog`s medium with activated charcoal produced embryos in all developmental stages. There were differences among the treatments, with some leading to the production of calli with embryos and some only to callus formation. Some abnormalities were associated with somatic embryos, including fused axes, fused cotyledons and polycotyledonary embryos. Production of secondary somatic embryos occurred in the first cycle of primary embryo development. Secondary embryos differentiated from the surface of the protodermal layer of primary embryos with intense cell proliferation, successive mitotic divisions in the initial phase of embryoid development, and a vascular system formed with no connection to the parental tissue. This secondary embryogenic system of P. cincinnata is characterized by intense proliferation and maintenance of embryogenic competence after successive subcultures. This reproducible protocol opens new prospects for massive propagation and is an alternative to the current organogenesis-based transformation protocol.

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When genome sections of wild Solanum species are bred into the cultivated potato (S. tuberosum L.) to obtain improved potato cultivars, the new cultivars must be evaluated for their beneficial and undesirable traits. Glycoalkaloids present in Solanum species are known for their toxic as well as for beneficial effects on mammals. On the other hand, glycoalkaloids in potato leaves provide natural protection against pests. Due to breeding, glycoalkaloid profile of the plant is affected. In addition, the starch properties in potato tubers can be affected as a result of breeding, because the crystalline properties are determined by the botanical source of the starch. Starch content and composition affect the texture of cooked and processed potatoes. In order to determine glycoalkaloid contents in Solanum species, simultaneous separation of glycoalkaloids and aglycones using reversed-phase high-performance liquid chromatography (HPLC) was developed. Clean-up of foliage samples was improved using a silica-based strong cation exchanger instead of octadecyl phases in solid-phase extraction. Glycoalkaloids alpha-solanine and alpha-chaconine were detected in potato tubers of cvs. Satu and Sini. The total glycoalkaloid concentration of non-peeled and immature tubers was at an acceptable level (under 20 mg/100 g of FW) in the cv. Satu, whereas concentration in cv. Sini was 23 mg/100 g FW. Solanum species (S. tuberosum, S. brevidens, S. acaule, and S. commersonii) and interspecific somatic hybrids (brd + tbr, acl + tbr, cmm + tbr) were analyzed for their glycoalkaloid contents using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). The concentrations in the tubers of the brd + tbr and acl + tbr hybrids remained under 20 mg/100 g FW. Glycoalkaloid concentration in the foliage of the Solanum species was between 110 mg and 890 mg/100 g FW. However, the concentration in the foliage of S. acaule was as low as 26 mg/100 g FW. The total concentrations of brd + tbr, acl + tbr, and cmm + tbr hybrid foliages were 88 mg, 180 mg, and 685 mg/100 g FW, respectively. Glycoalkaloids of both parental plants as well as new combinations of aglycones and saccharides were detected in somatic hybrids. The hybrids contained mainly spirosolanes, and glycoalkaloid structures having no 5,6-double bond in the aglycone. Based on these results, the glycoalkaloid profiles of the hybrids may represent a safer and more beneficial spectrum of glycoalkaloids than that found in currently cultivated varieties. Starch nanostructure of three different cultivars (Satu, Saturna, and Lady Rosetta), a wild species S. acaule, and interspecific somatic hybrids were examined by wide-angle and small-angle X-ray scattering (WAXS, SAXS). For the first time, the measurements were conducted on fresh potato tuber samples. Crystallinity of starch, average crystallite size, and lamellar distance were determined from the X-ray patterns. No differences in the starch nanostructure between the three different cultivars were detected. However, tuber immaturity was detected by X-ray scattering methods when large numbers of immature and mature samples were measured and the results were compared. The present study shows that no significant changes occurred in the nanostructures of starches resulting from hybridizations of potato cultivars.

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The construction and characterization of two genome-specific recombinant DNA clones from B. nigra are described. Southern analysis showed that the two clones belong to a dispersed repeat family. They differ from each other in their length, distribution and sequence, though the average GC content is nearly the same (45%). These B genome-specific repeats have been used to analyse the phylogenetic relationships between cultivated and wild species of the family Brassicaceae.

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Aims: Thymus species are wild species mostly found in the arid lands of Portugal. Possible antimicrobial properties of Thymus essential oils have been investigated. The chemical composition of the essential oils and the antimicrobial activity of Thymus mastichina (L) L. subsp. mastichina , T. camphoratus and T. lotocephalus from different regions of Portugal were analysed. Methods and Results: Hydrodistillation was used to isolate the essential oils and the chemical analyses were performed by gas chromatography (GC) and GC coupled to mass spectrometry. The antimicrobial activity was tested by the disc agar diffusion technique against Candida albicans , Escherichia coli , Listeria monocytogenes , Proteus mirabilis , Salmonella spp. and Staphylococcus aureus . Pure linalool, 1,8-cineole and a mixture (1:1) of these compounds were included. Linalool, 1,8-cineole or linalool/1,8-cineole and linalool/1,8-cineole/linalyl acetate were the major components of the essential oils, depending on the species or sampling place. The essential oils isolated from the Thymus species studied demonstrated antimicrobial activity but the micro-organisms tested had significantly different sensitivities. Conclusions: The antimicrobial activity of essential oils may be related to more than one component. Significance and Impact of the Study: Portuguese endemic species of Thymus can be used for essential oil production for food spoilage control, cosmetics and pharmaceutical use. Further studies will be required to elucidate the cell targets of the essential oil components.

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In the present study on natural antioxidants, the focus has been kept mainly on oil seeds, especially sesame and its by-products. Sesame, which has been under cultivation in India for centuries is called the 'Queen of oil seed crops' because of the high yield of oil obtained and the nutritional qualities of the seed, oil, and meal. Though India is the largest producer of sesame in the world, research on the various health benefits of sesame has been carried out by Japanese Sesame has an important place in the foods and tradit..ional medicine of India from time immemorial. Foreseeing the potential of sesame and its byproducts as an important antioxidant source and its availability in bulk, the present study was focussed on Sesamum species. There are not many reports on the wild species of Sesamum in India, especially of the Kerala region. Hence, in the present study we also included antioxidants of Sesamurnrnalabaricumdistributed throughout the coastal region.The important characteristics of sesame are attributed to the presence of the umquc compounds lignans. Lignans arc a group of natural products of phenyl propanoid ongm, whieh are widely distributed in nature. They display important physiological functions in plants, in human nutrition and medicine, given their extensive health promotive and curative properties. Much interest has been focussed on their effectiveness as antineoplastic agents and research in this area has revealed several modes of action by which they can regulate the growth of mammalian cells. Sesame is an important source of furofuran lignans, of which sesamin and the rare oxygenated derivative sesamoIin are the most abundant. Others include sesamol and glucosides of lignans. Sesarnin and episesamin are reported to have hypocholesterolemic effect, suppressive effect on chemically induced cancer, alleviation of allergy symptoms etc. Sesamol, sesamolin and the lignan glycosides are reported to inhibit lipid peroxidation. Present investigation on sesame and its byproducts have been carried out to explore the possibility of developing a natural antioxidant extract from available resources to be used as a substitute to synthetic ones in vegetable oils and foods. Preliminary analysis showed that sesame cake, a byproduct could still be utilized as a major source of lignans. Sesame cake, which is now used only as a cattlefeed, can be better utilized in the form of a valuable antioxidant source. The present study explains the development of a feasible process for the extraction of antioxidant compounds from sesame cake. The antioxidant extract so prepared from sesame cake has been tested for vegetable oil protection and is found to be effective at low concentration. In addition, studies also include the antioxidant, radical scavenging, anticancer, mosquitocidal and pesticidal activities of extract and individual compounds.

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Diversity in the chloroplast genome of 171 accessions representing the Brassica 'C' (n = 9) genome, including domesticated and wild B. oleracea and nine inter-fertile related wild species, was investigated using six chloroplast SSR (microsatellite) markers. The lack of diversity detected among 105 cultivated and wild accessions of B. oleracea contrasted starkly with that found within its wild relatives. The vast majority of B. oleracea accessions shared a single haplotype, whereas as many as six haplotypes were detected in two wild species, B. villosa Biv. and B. cretica Lam.. The SSRs proved to be highly polymorphic across haplotypes, with calculated genetic diversity values (H) of 0.23-0.87. In total, 23 different haplotypes were detected in C genome species, with an additional five haplotypes detected in B. rapa L. (A genome n = 10) and another in B. nigra L. (B genome, n = 8). The low chloroplast diversity of B. oleracea is not suggestive of multiple domestication events. The predominant B. oleracea haplotype was also common in B. incana Ten. and present in low frequencies in B. villosa, B. macrocarpa Guss, B. rupestris Raf. and B. cretica. The chloroplast SSRs reveal a wealth of diversity within wild Brassica species that will facilitate further evolutionary and phylogeographic studies of this important crop genus.