Showing papers by "Adrian C. Newton published in 2001"

Effects of population disjunction on isozyme variation in the widespread Pilgerodendron uviferum

Abstract: Geographical range is considered a good predictor of the levels of isozyme variation in plants. Widespread species, often consisting of historically larger and more continuous populations, maintain higher polymorphism and are less affected by drift, which tends to erode genetic variation in more geographically restricted species. However, widespread species occurring in small and disjunct populations may not fit this pattern. In this study we examined genetic variation in Pilgerodendron uviferum, a conifer endemic to temperate forests of southern South America, and is such a widespread and habitat-restricted species. Twenty populations along the whole range of Pilgerodendron were analysed by isozyme electrophoresis to resolve 14 putative genetic loci. Eleven were polymorphic in at least one population although only six of them were polymorphic in more than one population. We found reduced within-population levels of isozyme variation, with only 11% polymorphic loci (0.95 criterion), 1.2 mean number of alleles per locus, and mean observed and expected heterozygosities of 0.024 and 0.033, respectively. Most genetic diversity was found within populations (HT=0.039, HS=0.033, FST 15%). Greater polymorphism and lower divergence was estimated in the more geographically restricted and closely related Fitzroya. Thus, total range, in combination with information on the degree of among-population isolation, may be a better predictor of the levels of polymorphism than range size alone.

The influence of stockplant environment on morphology, physiology and rooting of leafy stem cuttings of Albizia guachapele

Abstract: Studies in controlled environmentconditions investigated the effects ofirradiance and nutrients (NPK) on morphologicaland physiological characteristics of Albizia guachapele stockplants, and rootingability of subsequently severed cuttings innon-mist propagators. The study assessed gasexchange and chlorophyll fluorescence ofstockplants before cutting severance and ofcuttings during the propagation period. Anegative interaction was found betweenincreasing irradiance(200–500 μmol mminus 2 sminus 1) andincreasing nutrient supply (0.25–1.25% NPK)on stockplant growth, and a similar effect wasfound in the subsequent rooting of cuttings.Rooting percentage decreased from 53.8% withlow irradiance/low nutrients to 11.2% withhigh irradiance/high nutrients. Single-node,leafy cuttings from high irradiance/highnutrient stockplants were much shorter thanthose from any other treatment, whichnegatively affected their rooting ability. Nodifferences were found among treatments inchlorophyll fluorescence ratios duringpropagation, suggesting that A.guachapele cuttings are dependant for rootingnot only on current photosynthesis, but also ontheir initial pre-severance reserves ofcarbohydrate. It was concluded that A.guachapele, which can be propagated with thenon-mist propagation system utilized in thisstudy, was markedly affected by pre-severancestockplant environment through its impact oncutting size and products of photosynthesis.Growing stockplants under low irradiance andlow nutrients resulted in longer cuttings withhigher rooting ability.

Variability in pathotype, aggressiveness, RAPD profile, and rDNA ITS1 sequences of UK isolates of Rhynchosporium secalis

Abstract: A local population of Rhynchosporium secalis was sampled and the race structure, pathogenicity, RAPD profile and rDNA ITS sequence examined. RAPDs were also used to compare this population with a larger sample of isolates including some isolated more than 30 years ago. Both the local population and the wide sample revealed much variation for all characteristics with no two isolates identical. The reliability of detached leaf pathogenicity tests was improved over previous studies by pre-washing spores and brushing the leaves prior to inoculation. Isolate aggressiveness was highly correlated with lesion number but not lesion size. There was no correlation between race and aggressiveness. RAPD profiles showed high levels of variability but more similarity was observed within a site than between sites. Clusters of similarity were primarily associated with samples from the same locality but samples taken 8 years apart from within the same field were not closely related. ITS2 sequences were all identical whereas ITS 1 sequences showed 0.8 % polymorphism. ITS polymorphisms fell mostly within one RAPD cluster. ITS sequence comparisons with the EMBL database gave some indications of the taxonomic placement of R. secalis.

Genetic variation in wild chilean and cultivated british populations of podocarpus salignus d. don ( podocarpaceae )

Abstract: The threatened Chilean conifer Podocarpus salignus D Don is currently the focus of ex situ conservation eorts being undertaken by the Conifer Conservation Programme of the Royal Botanic Garden Edinburgh To assess variation within in and ex situ populations of the species, leaf material collected from four wild populations was analysed by random amplified polymorphic DNA (RAPD) A mova of RAPD profiles indicated that 93% of the variation occurred within, rather than between, populations Intraspecific genetic diversity, estimated using percentage polymorphic loci, Shannon's diversity index, and Nei's gene diversity, was relatively high (47%, 0692 and 0314, respectively) To assess genetic diversity in ex situ populations within the UK, RAPD analysis of parents and progeny at two Cornish arboreta was undertaken The results provided evidence of novel hybridization with suspected paternal trees ( P hallii Kirk and P totara G Benn ex D Don) endemic to New Zealand RAPD was found to be an effective tool for assessing the genetic structure of P salignus , for providing a guide to future germplasm-sampling strategies, and for hybrid identification Implications for genetic conservation of the species and the role of ex situ approaches are discussed

Agricultural composition and method for treatment of plants therewith

Abstract: The present invention relates to a new agricultural composition and a method for protecting, enhancing the resistance of plants to infections by plant pathogens and increasing abiotic stress tolerance against cold, salinity and drought. The composition comprises a formulated mixture of resistance elicitors stimulating a number of signal transduction pathways within the plant. The formulated mixture is acting to stimulate a number of such signal transduction pathways thereby maximising the plants' potential resistance-related response to infection. The composition gives a stronger, more sustainable, and broader range of pathogen control than an elicitor preparation based upon a single active ingredient. The active ingredients consist of chitosan (C), φ-3 fatty acids (O), phosphate (P) and seaweed-derived extracts (S) (COPS). The composition can be applied to the plants by spraying, via fertigation systems or by coating seeds and can be applied to the leaves of the plants or to the roots.

Current approaches to native woodland restoration in Scotland

Abstract: Summary A large number of projects have recently been initiated in Scotland aiming to restore native woodland, which are being undertaken by a variety of organisations, often in partnership, with environmental NGOs playing a leading role. The objectives, constraints and methodologies of these projects are critically reviewed, partly through a questionnaire survey. Most aim to restore ‘natural’ woodland, but the lack of appropriate reference ecosystems and uncertainty about the characteristics of the original forest hinder the development of precise objectives, and consequently the criteria for success are poorly defined. Most projects face major practical constraints, particularly browsing by herbivores and invasion by exotic species, indicating that they will require long-term management interventions. Most woodlands are isolated from other woodlands, which threatens their long-term viability, restricting colonisation by woodland organisms. Greater reference to ecological theory in practical restoration ...

Interactions between mycorrhizal colonisation, nodulation and growth of Calliandra calothyrsus seedlings supplied with different concentrations of phosphorus solution

Abstract: Interactions between arbuscular mycorrhizal colonisation, nodulation and growth of Calliandra calothyrsus were investigated in an experiment in which mycorrhizal and non-mycorrhizal seedlings were grown in a glasshouse environment, in pots containing a sterilised substrate and supplied with four different concentrations of phosphorus solution (0, 7.5, 15 and 30 mg l(-1) P). All seedlings were inoculated with Rhizobium. After eight weeks growth, assessments were made of stem, leaf and root growth, nodule dry mass and percentage mycorrhizal colonisation. Mycorrhizal colonisation was highest at 0 mg l(-1) P and was reduced with increasing phosphorus application. Mycorrhizal inoculation increased seedling growth and nodulation most at lower concentrations (0 and 7.5 mg l(-1) P) of phosphorus application. Phosphorus application improved growth and nodulation at 7.5 mg l(-1) P compared with 0 mg l(-1) P, but further increase in phosphorus application did not result in further growth benefits. Seedling growth was positively correlated with mycorrhizal colonisation and nodule dry mass with strongest relationships occurring far nodule dry mass. Growth response of seedlings to greater nodulation was maintained in mycorrhizal plants but not in nonmycorrhizal plants, even at high levels of P application when available P was not limiting. It is concluded that C, calothyrsus is dependent on mycorrhizal association in P-deficient soils, and that mycorrhizal inoculation has the potential to enhance its growth and nodulation under these conditions.

Researching factors that influence successful commercialisation of non timber forest products (NTFPs)

Abstract: The commercialisation of NTFPs is not consistently successful in alleviating poverty by providing benefits to producers, processors and traders. In order to determine the characteristics associated with success in terms of NTFP commercialisation, this project will evaluate the opportunities and constraints to commercialisation of NTFPs at the community and household level, though comparative analysis of case studies. In addition, market structure will be analysed for selected NTFPs, to identify interventions necessary for successful commercialisation. Gender issues and community perceptions of success will receive particular attention. The selection of two countries, Bolivia and Mexico, that differ in social and cultural structures will enable comparative analysis of the factors influencing NTFP commercialisation, thereby permitting implications for other countries in the region to be drawn. Resumen La comercicalizacion de PFNMs no siempre contribuye efectivamente a aliviar la pobreza atravez de los benficios que brinda a los productores, comercialzadores y procesadores. Para determinar las caracteristicas asociadas con el exito en la comercializacion de estos productos, este proyecto evalua las oportunidades y restricciones a nivel de las comunidades recolectoras y de los hogares involucrados mediante estudios de caso. Adicionalmente se analizan las estrucuturas de mercado de productos selecccionados, y se identifica los tipos de intervenciones que se requieren para hacer proyectos exitosos. Aspectos de genero y las percepciones de las comunidades son debidamente analizadas. El hecho de haber seleccionado a Bolivia y a Mexico permitira analizar estos factores bajo condiciones socio-culturales diferentes, y por lo tanto se deribaran las implicaciones para otros paises o regiones con condicones relacionadas. Bussmann, R.W. & Lange, S. Conservacion de Biodiversidad en los Andes y la Amazonia 566 Marshall, E., K.. Schreckenberg, A.C. Newton & A. Bojanic Research project objectives and collaborators This 3 year research project (November 2000 October 2003), funded by the Forestry Research Programme of the UK Department for International Development, will explore the relationship between poverty, gender and successful commercialisation of NTFPs. It will provide an important understanding of how domestic markets function and identify the type of information necessary to provide the basis for designing market interventions, which result in increasing benefits to rural communities. NTFPs differ in a number of characteristics including yield, perishability, value, and seasonality of availability etc. In addition, the local communities harvesting these resources differ in social structures (including gender influence), culture, degree of marginalisation, as does access to capital resources. A comparative analysis of different NTFPs, considering such variables can therefore enable key criteria for successful commercialisation to be identified. The main collaborators on this project are the LTNEP World Conservation Monitoring Centre and the Overseas Development Institute in the UK: Grupo de Estudios Ambientales, Grupo Mesofilo, Methodus Consultora, SEMARNAP and PROCYMAF in Mexico; Universidad Nur, Care-Bolivia and the Super Intendencia Forestal in Bolivia; and Fauna & Flora International in Nicaragua. The role of NTFPs in promoting forest resource conservation and poverty alleviation Non-timber forest products (NTFPs) are biological resources derived from both natural and managed forests and other wooded areas (Peters, 1996). NTFPs are an important tool in addressing poverty issues for marginalised, forest dependant communities, by contributing to livelihood outcomes, including food security, health and well being, and income (FAO, 1995; Falconer, 1997). In many parts of the world these resources are critical, especially for the rural poor and women, and may provide them with the only source of personal income (Rodda, 1993; Falconer, 1997). It is the socially most marginalised people who are the main actors in NTFP extraction (Ros-Tonen, 1999). Despite this, the contribution of women, especially from indigenous populations, to rural development in Latin America, remains largely undervalued and understudied. Interest in NTFPs has grown with increasing awareness of tropical forest deforestation and increasing recognition of the need to add value to forest resources, in order to compete with other land uses. Through the holistic management of NTFPs, an attempt is made to maintain and sustain the resource and its users; contribute to sustainable development; conserve forests and biodiversity, and to promote non-traditional enterprises to improve local economies and diversify the economic base of the rural poor (Falconer, 1997). There are at least five distinctive features of forest product conservation and development initiatives which were identified as needing further research to promote successful NTFP commercialisation, from a CIFOR meeting sponsored by the NTFP network (adapted from Wollenberg and Ingles, 1998): Forest products are often managed under sensitive and complex social arrangements, or with multiple management objectives. Bussmann, R.W. & Lange, S. Conservation of Biodiversity in the Andes and the Amazon Researching factors that influence successful commercialisation of Non timber forest products 567 Forest products usually involve strategies based on multiple products, therefore the costs of collecting the information can be high relative to the benefits gained Forest products are often collected in remote areas requiring high transport costs, and production and collection can be irregular. There is often a lack of formal skills in business, ecological and impact social assessment. The ecology, management and demand for many forest products is poorly understood, and many forest products have not been well studied or documented. Constraints to successful commercialisation Within the scope of this research project, we have chosen to define commercialisation as an exchange of money resulting from the sale of a product outside the community of origin. Although NTFP commercialisation has been widely promoted by development organisations, success of such initiatives has been highly variable. Existing research suggests that the main constraints to successful NTFP development are related to limited access to the following types of capital asset by small-scale poor farmers and landless poor families (especially women): natural: secure tenure or usufruct rights over land and resources (Clay, 1992; Richards, 1993; Ruiz-Perez and Byron, 1999); human: labour constraints (especially time spent away from home by women), awareness of the commercialisation potential of some products, knowledge about processing and storage, and market information and marketing know-how (Southeimer, 1991; Falconer, 1997; Tommich, 1998; Banana, 1998); financial: to invest in improved physical capital (FAO, 1991; ILO, 1995; Verheij and Reindeers, 1998); physical: market access (especially transport), inputs for new processing/ storage techniques (Dixon, 1991; Clay, 1992; Paddock, 1992, Falconer, 1997; Fontana, 1998; van Dick, 1998; Tommich, 1998); social: negotiating power (especially for female producers with respect to male market intermediaries), and willingness to collaborate in order to secure improved marketing outcomes (Arnold and Ruiz Perez, 1999; Marshall and Newton, 2000); Available evidence indicates that information pertaining to marketing processes and structures is one of the most significant constraints to successful development of NTFP activities as part of livelihood strategies (Tommich, 1998; Ruiz-Perez and Byron, 1999). Research project case studies We are collaboratively undertaking research with the following partners in Bolivia and Mexico, in case study communities where NTFPs are already commercialised to some extent, and with varying degrees of success, and as an activity, represent one of the most important income generating options available. MEXICO Grupo de Estudios Ambientales, State of Guerrero Brahea dulcis (Palma soyote) & Agave cupreata Maguey); Bussmann, R.W. & Lange, S. Conservacion de Biodiversidad en los Andes y la Amazonia 568 Marshall, E., K. Schreckenberg, A.C. Newton & A. Bojanic Grupo Mesofilo, State of Oaxaca Chamaedorea tepejilote & Chamaedorea elegans, C. concolor, C. Oblongata; Methodus consultora, State of Oaxaca Thcholoma magnivelare (White mushroom, Boletus edulis (Boletus) and Amonita coesarea (Yellow mushroom), & Aechaemia magdalaneae, Pita.

Composition agricole et methode de traitement de plantes l'utilisant

Abstract: La presente invention concerne une nouvelle composition agricole et un procede permettant d'une part de proteger les plantes et d'augmenter leur resistance aux infections dues aux agents pathogenes de vegetaux, et d'autre part d'augmenter leur tolerance au stress abiotique du au froid, a la salinite et a la secheresse. Cette composition contient un melange compose d'eliciteurs de resistance qui stimule un certain nombre de processus de transduction de signaux chez la plante. Ce melange agit de facon a stimuler un certain nombre de ces processus de transduction de signaux, potentialisant ainsi la capacite des plantes a repondre et a resister aux infections. Cette composition permet de supprimer les agents pathogenes de facon plus intense, plus durable et sur un spectre plus large qu'avec une preparation d'eliciteurs a un seul principe actif. Ces principes actifs sont le chitosane (C), les acides gras φ-3 (O), le phosphate (P) et des extraits d'algue marine (S) (COPS). Par ailleurs, on peut appliquer cette composition sur les feuilles ou les racines des plantes par vaporisation, par des systemes d'irrigation fertilisante ou par enrobage de semences.