Showing papers by "Adrian C. Newton published in 2002"

Genetic variation in the vulnerable and endemic Monkey Puzzle tree, detected using RAPDs

Abstract: Araucaria araucana (Monkey Puzzle), a southern South American tree species of exceptional cultural and economic importance, is of conservation concern owing to extensive historical clearance and current human pressures. Random amplified polymorphic DNA (RAPD) markers were used to characterise genetic heterogeneity within and among 13 populations of this species from throughout its natural range. Extensive genetic variability was detected and partitioned by analysis of molecular variance, with the majority of variation existing within populations (87.2%), but significant differentiation was recorded among populations (12.8%). Estimates of Shannon's genetic diversity and percent polymorphism were relatively high for all populations and provide no evidence for a major reduction in genetic diversity from historical events, such as glaciation. All pairwise genetic distance values derived from analysis of molecular variance (Phi(ST)) were significant when individual pairs of populations were compared. Although populations are geographically divided into Chilean Coastal, Chilean Andes and Argentinean regions, this grouping explained only 1.77% of the total variation. Within Andean groups there was evidence of a trend of genetic distance with increasing latitude, and clustering of populations across the Andes, suggesting postglacial migration routes from multiple refugia. Implications of these results for the conservation and use of the genetic resource of this species are discussed.

Patterns of isozyme variation as indicators of biogeographic history in Pilgerodendron uviferum (D. Don) Florín

Abstract: . The effects of Pleistocene glaciations on the genetic characteristics of the most austral conifer in the world, Pilgerodendron uviferum, were analysed with specific reference to the hypothesis that the species persisted locally in ice-free areas in temperate South America. It was expected that genetic variation would decrease with latitude, given that ice fields were larger in southern Patagonia and thus refugia were probably located towards the northern distributional limit of the species as suggested by the fossil record. In addition, an increase in among-population genetic divergence was expected with increasing distance to putative glacial refugia. We examined the relationship between location and within-population variability indices of 20 Pilgerodendron populations derived from isozyme analyses. We analysed possible refugia hypotheses by the distribution of allele frequencies using multivariate discriminant analysis. The degree of genetic differentiation with geographical distance between all population pairs was investigated by Mantel tests. Results indicated that Pilgerodendron populations are highly monomorphic, probably reflecting past population bottlenecks and reduced gene flow. Southernmost populations tend to be the least genetically variable and were therefore probably more affected by glacial activity than northern ones. Populations located outside ice limits seem to have been isolated during the glacial period. The presence of centres of genetic diversity, together with the lack of a significant correlation between genetic and geographical distances and the absence of geographical patterns of allelic frequencies at most analysed alleles, may indicate that Pilgerodendron did not advance southward after the last glaciation from a unique northern refugium, but spread from several surviving populations in ice-free areas in Patagonia instead.

Patterns of genetic variation in Pinus chiapensis, a threatened Mexican pine, detected by RAPD and mitochondrial DNA RFLP markers

Abstract: Pinus chiapensis (Pinaceae) is a large conifer, endemic to central and southern Mexico and north-western Guatemala. In order to assess the extent of genetic variation within and between populations of this species, samples were obtained from throughout the natural range and analysed using random amplified polymorphic DNA (RAPD) and mtDNA RFLPs markers. Probes for the CoxI mitochondrial gene enabled two mitotypes to be observed. Populations from the eastern and western limit of the range of the species were fixed for one mitotype (‘A’), whereas two populations distributed near the centre of the range were fixed for another (‘B’). When the samples were screened with eight 10-mer RAPD primers, a total of 12 polymorphic bands were detected. The proportion of polymorphic bands was unusually low (24.5%) compared with other tree species. AMOVA analysis indicated that a significant proportion of the variation (P < 0.002) was distributed between populations; the extent of population differentiation detected (Φst = 0.226; GST = 0.194) was exceptionally high for a pine species. Pair-wise comparison of Φst values derived from AMOVA indicated that populations were significantly (P < 0.05) different from each other in virtually every case. These results are interpreted in the context of the evolutionary history of the species, and the implications for its in- and ex situ conservation are discussed.

Progress towards implementing the Biodiversity Action Plan for stipitate hydnoid fungi in Scotland

Abstract: Summary Stipitate hydnoid (‘tooth’) fungi are considered to be threatened throughout much of central and northern Europe. In response to concern about the status of these fungi in the UK, a Biodiversity Action Plan has been developed for 14 species in this group. As a first step towards implementation of this plan, a number of surveys have been initiated, to determine the current status and distribution of hydnoid fungi. An overview of the results of these surveys is described. A series of distribution maps are presented, based on a compilation of early records and the results of a recent field survey in Scottish coniferous forests. The difficulties of interpreting early records are discussed, with particular reference to the taxonomie confusion that has surrounded this group of fungi. Although available data provide little evidence for decline of hydnoid fungi, a number of species display very restricted distributions within Scotland. The recent discovery of several species new to Britain emphasises the ...

Biodiversity indicators in national forest inventories

Abstract: Future global forest assessments should incorporate a greater emphasis on biodiversity. This could be partly achieved through use of indicators, which should be appropriate for use at the local scale, but enable information to be aggregated at larger scales. Many indicators of forest biodiversity have been developed in recent years, within the various processes focusing on sustainable forest management. Here we identify eight generalised indicators common to some or all of these processes, which are appropriate for implementation at the local scale. Methods are highlighted by which data to support these indicators might be derived from standard forest inventories. In addition, we suggest that information collected at the local scale may be aggregated by summarizing data in categorical form, and presenting them in relation to forest area. Such an approach would assist countries in contributing to the C&I processes of which they are a part, as well as meeting their reporting obligations to international conventions.

The Effect of Inoculum Pressure, Germplasm Selection and Environment on Spring Barley Cultivar Mixtures Efficacy

Abstract: A range of mixtures including one set made from cultivars grown in the UK and one from cultivars grown in Poland, were included, along with their component cultivars, in nine trials at Scottish Crop Research Institute, Dundee, UK or at the Experimental Plant Breeding Station of the IHAR, Bakow near Kluczbork, Poland, over five seasons. The effects of inoculum pressure, plot size, fertiliser level and germplasm on mixture efficacy were investigated. In the four trials where inoculum pressure was controlled, mixtures reduced infection more at lower inoculum pressures, but this did not translate into yield benefit. Smaller plots increased mildew in monocultures but not mixtures. Fertiliser levels increased mildew levels but did not affect mixture efficacy. There were large differences between both Polish and UK germplasm, and between Polish and UK trial sites, but the performance of the mixtures compared with their respective monoculture components was similar within both germplasm groups and trial sites. Mixtures reduced lodging and affected plant height and heading date. The advantages of mixtures for improving yield, reducing fungicide applications and improving agronomic characteristics was demonstrated and there seems to be great potential for their further improvement and exploitation.

The Gaharu Trade in Indonesia: Is It Sustainable?1

Abstract: When subjected to fungal attack, Aquilaria spp (Thymelaeaceae) produce a fragrant resin that is traded internationally as gaharu Socioeconomic aspects of the gaharu trade were investigated via interviews with collectors and local and international traders In addition, the extent of local and international trade was evaluated by reference to official government statistics Evidence that gaharu resources are declining was obtained from the personal experience of gaharu collectors, and official statistics relating to the declining number of gaharu export companies in operation Traders also reported that the main source of gaharu has recently switched from Sumatra and Kalimantan to sources in eastern Indonesia (Maluku and Irian Jaya), a finding supported by official statistics Disparities recorded between official figures for the price and volume of gaharu in local and international trade, supported by comments made by export traders, indicate that a high proportion of the more valuable, high-grade gaharu is traded illegally by personal transaction Interviews with gaharu collectors indicated that traditional approaches to harvesting are declining, as more nonlocal people become involved in collection, leading to more intensive harvesting practices Together, these findings suggest that the current Indonesian trade in gaharu is not sustainable

Effects of artificial shade on attack by the mahogany shoot borer, Hypsipyla robusta (Moore)

Abstract: Swietenia macrophylla King (Meliaceae: Swietenioideae) provides one of the premier timbers of the world. The mahogany shoot borer Hypsipyla robusta Moore (Lepidoptera: Pyralidae) is an economically important pest of S. macrophylla throughout Asia, Africa and the Pacific. No viable method of controlling this pest is known. Previous observations have suggested that the presence of overhead shade may reduce attack by H. robusta, but this has not been investigated experimentally. This research was therefore designed to assess the influence of light availability on shoot-borer attack on S. macrophylla, by establishing seedlings under three different artificial shade regimes, then using these seedlings to test oviposition preference of adult moths, neonate larval survival and growth and development of shoot borer larvae. Oviposition preference of shoot borer moths was tested on leaves from seedlings grown under artificial shade for 63 weeks. A significant difference in choice was recorded between treatments, with 27.4 ± 1.5 eggs laid under high shade and 87.1 ± 1.8 under low shade. Neonate larval survival on early flushing leaflets of S. macrophylla did not differ significantly between shade treatments. Larval growth rate, estimated by measuring daily frass width, was significantly higher for those larvae fed on seedlings from the high and medium shade treatments (0.1 mm/day), than the low shade treatment (0.06 mm/day). In laboratory-reared larvae, the total mass of frass produced was significantly higher in the high shade treatment (0.4 g) than under the low shade treatment (0.2 g). Longer tunnel lengths were bored by larvae in plants grown under high shade (12.0 ± 2.4 cm) than under low shade (7.07 ± 1.9 cm). However, pupal mass under low shade was 48% higher than that under the high shade treatment, suggesting that plants grown under high shade were of lower nutritional quality for shoot borer larvae. These results indicate that shading of mahogany seedlings may reduce the incidence of shoot borer attack, by influencing both oviposition and larval development. The establishment of mahogany under suitable shade regimes may therefore provide a basis for controlling shoot borer attack using silvicultural approaches.

Estado de conservación del ciprés de las Guaitecas (Pilgerodendron uviferum (Don) Florín) en Argentina

Abstract: Pilgerodendron uviferum (Don) Flor., Cupressaceae (common name "cipres de las Guaitecas") is the native conifer with the widest geographic range in the temperate forests in southern South America, particularly when compared with its only two close relatives, Austrocedrus chilensis ((Don) Florin et Boutleje) and Fitzroya cupressoides ((Mol.) Johnst.). In Argentina, Pilgerodendron is restricted to a small number of isolated populations along its distribution. This study analyzes the conservation status of known Pilgerodendron populations in Argentina, based on information about the physical characteristics of the habitats, vegetation and disturbance types in eight different locations. The majority of the studied populations are protected within national parks, where they are generally restricted to waterlogged sites, and they consist of small groups of individual trees and not continuous forests. At some of the locations, signs of human-induced disturbances were observed, mainly logging or browsing by cattle. This was the case for the Cordon Serrucho population, which is not currently included in any protected area. Adequate strategies for a better preservation and restoration of degraded Pilgerodendron populations include cattle grazing exclusion and the creation of a protected area.

The need for a standard nomenclature for gene classification (a Nucleotide Function Code) and an automated data-based tool to assist in understanding the molecular associations in cell signalling in plant-pathogen interactions.

Abstract: summary Despite the adoption of Arabidopsis thaliana as a model plant system and the plethora of molecular information being obtained from its use, it is disappointing that the scientific community has not devised a cell signalling model integrating and visualizing these data. Lack of common systems of nomenclature and the sheer size and complexity of the task inhibit any individual from bringing together the knowledge into a unified structure. There are clearly many aspects of cell biology that are similar, even between plants and animals, that could facilitate development of a generic model. A gene-coding or nucleotide classification system which is 'user-friendly' would be beneficial to building such a model and enable rapid identification of orthologues of genes from different organisms. Whilst some international projects seek to address the problem of assigning unique numbers to genes, none suggest a nucleotide classification system that provides biological information that is transparent within the code. This paper discusses these issues and identifies the need for a more formal, semi-automated approach to modelling signal transduction utilizing the strengths of the proposed classification approach. By way of illustration, an example of a possible nucleotide function code is suggested, to demonstrate more clearly the benefits of such a system. Further discussion of this topic will be encouraged on websites ( and ).