Development of genomic resources for Nothofagus species using next‐generation sequencing data

Using next‐generation sequencing, we developed the first whole‐genome resources for two hybridizing Nothofagus species of the Patagonian forests that crucially lack genomic data, despite their ecological and industrial value. A de novo assembly strategy combining base quality control and optimization of the putative chloroplast gene map yielded ~32 000 contigs from 43% of the reads produced. With 12.5% of assembled reads, we covered ~96% of the chloroplast genome and ~70% of the mitochondrial gene content, providing functional and structural annotations for 112 and 52 genes, respectively. Functional annotation was possible on 15% of the contigs, with ~1750 potentially novel nuclear genes identified for Nothofagus species. We estimated that the new resources (13.41 Mb in total) included ~4000 gene regions representing ~6.5% of the expected genic partition of the genome, the remaining contigs potentially being nongenic DNA. A high‐quality single nucleotide polymorphisms resource was developed by comparing various filtering methods, and preliminary results indicate a strong conservation of cpDNA genomes in contrast to numerous exclusive nuclear polymorphisms in both species. Finally, we characterized 2274 potential simple sequence repeat (SSR) loci, designed primers for 769 of them and validated nine of 29 loci in 42 individuals per species. Nothofagus obliqua had more alleles (4.89) on average than N. nervosa (2.89), 8 SSRs were efficient to discriminate species, and three were successfully transferred in three other Nothofagus species. These resources will greatly help for future inferences of demographic, adaptive and hybridizing events in Nothofagus species, and for conserving and managing natural populations.     

Shifting patterns of Nothofagus cunninghamii (Hook.) Oerst rainforest in the late quaternary of southeastern Australia: Evidence from pollen

An attempt is made to identify the location and nature of areas in which the cool temperate rainforest tree Nothofagus cunninghamii may have survived the glacial period, using fossil pollen data from sites at different altitudes in the Central Highlands of Victoria, Australia.

At one high altitude site Nothofagus has been recorded consistently through the latter part of the Pleistocence including the height of the last glacial. There was a postglacial expansion at most sites to a maximum extent in the early to middle Holocene, followed by a decline at all sites and elimination from two of the lower altitude sites.

The persistence of Nothofagus pollen through the height of the last glacial in a sheltered high altitude site supports the concept of glacial refugia, and leads to the query as to how Nothofagus survived the glacial under winter temperatures several degrees lower than those supporting the tree today. Evidence from evolutionary history, clinal variation in morphology and physiology along altitudinal or environmental gradients, and recent work on leaf physiognomy and ecophysiology contribute to possible explanations.

Elimination of Nothofagus from lower altitude sites after the middle Holocene raises the possibility of a shifting pattern of distribution, with long term survival dependent on the continued existence of locations suitable for the tree through the range of glacial and interglacial conditions. Fossil pollen data provide support for the occurrence of such locations in mountainous areas in sheltered gullies protected from fire.     

Contrasting responses to water deficits of Nothofagus species from tropical New Guinea and high‐latitude temperate forests: can rainfall regimes constrain latitudinal range?

Aim Comparative responses of Nothofagus species to water deficits were studied to determine whether rainfall regimes could limit the latitudinal ranges of tropical and temperate forest species. Location The study species are native to New Guinea, New Caledonia, Australia, New Zealand, Chile and Argentina. Methods Seedlings of Nothofagus species from a broad latitudinal range were grown in a common environment. Changes in conductance, relative water content and water potential were measured in detached shoots, and together with measurements of tissue injury and biomass allocation, were compared between tropical and temperate species. Results Differences in responses to water deficits between tropical and temperate species appear to reflect differences in climate regimes. In particular, species native to ever‐wet rainfall regimes in New Guinea, where water deficits are generally likely to be short‐lived, were effective at conserving water by reduced stomatal conductance. In contrast, high‐latitude evergreen species on average showed greater development of traits that should enhance water uptake. This was particularly evident in Nothofagus cunninghamii from southern Australia, which developed low water potentials at moderate levels of tissue water deficit and higher root:leaf biomass than tropical species, potentially allowing carbon assimilation to be maximized during warmer, but drier, summer months. However, water relations varied among high‐latitude species. In particular, deciduous species on average showed higher rates of conductance, even during moderate levels of tissue water deficit, than evergreen species. Main conclusions The tropical species appear to conserve water during periods of water deficit (relative to temperate species), which is unlikely to have substantial opportunity costs for growth in ever‐wet climates. However, spread of tropical species to higher latitudes may be limited by water conservation strategies that limit carbon gain in climates in which temperature seasonality is often paired with drier summers. Evergreen species from high latitudes, such as N. cunninghamii, commonly showed traits that should increase water uptake. However, this strategy, while probably maximizing growth in temperate climates with cool winters and drier summers, must limit competitiveness at lower latitudes in summer‐wet climates. We conclude that responses to water regimes may make a significant contribution to the latitudinal limits of some evergreen rain forest species.     

The late Quaternary vegetation history of the south‐central highlands of Victoria,Australia. II. Sites below 900 m

The late Quaternary vegetation communities of the south‐central highlands of Victoria are constructed from analyses of pollen and charcoal, and macroscopic plant remains preserved in Sphagnum bogs. The sites, located in eucalypt forest or woodland, form an altitudinal sequence with the component Eucalyptus species varying with altitude and with small pockets of Nothofagus cunninghamii (Hook.) Oerst. in close proximity to the higher sites. The record from the sites above 900 m covers the last 32 000 years, and the record from the lower sites extends from at least 12 000 BP . Around 32 000 BP the region was predominantly covered by a mosaic of alpine feldmark and herbfield, with small patches of Eucalyptus and Nothofagus woodland close to sea level when summer temperatures were probably 5°C lower than present. Lowest values, probably 7°–8°C below present, occurred between 19 800 and 16 900 BP , when alpine communities were most widespread and much of the Central Highlands was treeless. Around 12 000 BP alpine taxa disappeared or were greatly reduced, first at the lower sites. There was an associated rise in the treeline with the movement upslope of Nothofagus and eucalypt forest as a result of a general increase in temperature and probably effective precipitation. By 6000 BP wet eucalypt forest and Nothofagus reached their maximum postglacial extent at all sites, possibly related to a further increase in temperature, at least 2°C lower than present, and higher effective precipitation. A continuing increase in temperature, or an increase in continentality, and a decrease in effective precipitation led to increased fire hazard and retraction of rainforest and wet sclerophyll or tall open forest toward present‐day values. Nothofagus disappeared from the sites below 900 m. The activities of humans pose further threats to remaining forest communities. The record of vegetation and environmental change derived from the local and regional picture from eight sites reinforces and complements that from the individual sites. For example, combining the records overcomes to some extent taphonomic problems such as the effect of streams that flow close to all sites, and other limitations including problems of dating, poor preservation and variable sedimentation rates.     

Structural and floristic characteristics of some monodominant and adjacent mixed rainforests in New Caledonia

Nothofagus spp. dominate the upper canopy of some rainforests on ultramafic soils in New Caledonia. These monodominant forests typically occur within, or contiguous with, larger areas of mixed‐canopy rainforest. In this study the structure, diversity and composition of six Nothofagus‐dominated plots were investigated, and comparisons were made with three adjacent mixed rainforest plots. Stand density and basal area (all stems ≥ 1.3 m high) in the Nothofagus plots were in the range 16,056–27,550 stems/ha and 43.1–69.9 m²/ha, respectively. There was no significant difference (P ≥ 0.05) in total stand density or basal area between the paired Nothofagus and mixed rainforests, but there were consistently fewer trees and less basal area of trees ≥ 40 cm d.b.h. in the Nothofagus forests. Species richness, species diversity (Shannon‐Wiener, based on basal area) and equitability (based on basal area) of trees ≥ 20 cm d.b.h. on 0.1 ha Nothofagus plots were in the range 4–17, 0.96–3.76 and 0.45–0.87, respectively. No significant differences (P ≥ 0.05) were recorded in these three parameters between the paired Nothofagus and mixed rainforests, although species diversity was consistently lower in the paired Nothofagus forests. Comparison of dominance by density and basal area indicated that although the uppermost canopy of the Nothofagus forests was dominated by Nothofagus (70–95%), the basal area and density contribution was ≤ 55% except at Col de Yaté (≈ 85%). Analysis of similarity indicated no significant difference in stand composition of trees ≥ 20 cm d.b.h. (following removal of Nothofagus from the data set) between Nothofagus and mixed rainforests using basal area, density or presence‐absence data. It is concluded that the Nothofagus‐dominated forests differ from the adjacent mixed rainforests mainly by (1) dominance of the uppermost canopy, without necessarily dominance of the stand by basal area or density, and (2) the smaller basal area contributed by large trees (all species).     

Paleofloristic assemblage from the Paleogene Río Guillermo Formation,Argentina: preliminary results of phylogenetic relationships of Nothofagus in South America

Hünicken's paleobotanical collection is one of the most important in South America because it was the first one to be related to a documented stratigraphic profile. This floristic assemblage (Oligocene) recovered from Río Guillermo Formation, at Estancia Tres Marías, Río Guillermo Valley, Santa Cruz, Argentina, is described by the first time in this paper. Five species of genus Nothofagus (N. subferruginea, N. serrulata, N. crenulata, N. elongata and N. variabilis) together with Myrcia bagualense are components of the assemblage. The presence of Acaena brandmayri is confirmed for the first time for the area. Paleoenviromental and paleoclimate implications are also discussed. Characteristic species from a temperate-cold climate such as the genus Nothofagus are present in the material studied. A phylogenetic study of the fossil species herein described and the extant South American species of Nothofagus is presented. The preliminary results support the hypothesis that fossil species of Nothogafus are closely related to the modern species.     

Panbiogeography of Nothofagus (Nothofagaceae): analysis of the main species massings

Aim The aim of this paper is to analyse the biogeography of Nothofagus and its subgenera in the light of molecular phylogenies and revisions of fossil taxa. Location Cooler parts of the South Pacific: Australia, Tasmania, New Zealand, montane New Guinea and New Caledonia, and southern South America. Methods Panbiogeographical analysis is used. This involves comparative study of the geographic distributions of the Nothofagus taxa and other organisms in the region, and correlation of the main patterns with historical geology. Results The four subgenera of Nothofagus have their main massings of extant species in the same localities as the main massings of all (fossil plus extant) species. These main massings are vicariant, with subgen. Lophozonia most diverse in southern South America (north of Chiloé I.), subgen. Fuscospora in New Zealand, subgen. Nothofagus in southern South America (south of Valdivia), and subgen. Brassospora in New Guinea and New Caledonia. The main massings of subgen. Brassospora and of the clade subgen. Brassospora/subgen. Nothofagus (New Guinea–New Caledonia–southern South America) conform to standard biogeographical patterns. Main conclusions The vicariant main massings of the four subgenera are compatible with largely allopatric differentiation and no substantial dispersal since at least the Upper Cretaceous (Upper Campanian), by which time the fossil record shows that the four subgenera had evolved. The New Guinea–New Caledonia distribution of subgenus Brassospora is equivalent to its total main massing through geological time and is explained by different respective relationships of different component terranes of the two countries. Global vicariance at family level suggests that Nothofagaceae/Nothofagus evolved largely as the South Pacific/Antarctic vicariant in the breakup of a world‐wide Fagales ancestor.     

Mass loss and nutrient release from decomposing evergreen and deciduous Nothofagus litters from the Chilean Andes

Abstract Leaf litter decomposition experiments were conducted on two deciduous (Nothofagus obliqua (roble)) and Nothofagus pumilio (lenga)) and one evergreen (Nothofagus dombeyi) Nothofagus (Nothofagaceae) species from a single Chilean forest in order to understand how congeneric trees with differing leaf lifespans impact the soil in which they grow. Single‐species litter samples were decomposed in a mixed hardwood forest in Ohio and in a deciduous‐evergreen Nothofagus forest in Chile. In the Ohio forest, the two deciduous species’ litters decomposed at k ≈ 1.00 per year and the evergreen at k ≈ 0.75 per year. In Chile k ranged from k ≈ 0.06 (N. obliqua) to k ≈ 0.23 (N. pumilio) per year. In both experiments, N and P were released faster from the deciduous litters than from evergreen litter. In Ohio, evergreen litter immobilized more N and P for a longer time period than did deciduous litter. As N. dombeyi stands tend to have lower available soil N and P in this particular mixed Nothofagus forest, the increased time of N and P immobilization by N. dombeyi litter suggests a feedback role of the tree itself in perpetuating low N and P soil conditions.     

The late Quaternary vegetation history of the south-central highlands of Victoria,Australia. I. Sites above 900 m

Abstract The late Quaternary vegetation communities of the south-central highlands of Victoria are reconstructed from analyses of pollen and charcoal, and associated environmental conditions derived from the record of Nothofagus cunninghamii and alpine and sclerophyll taxa preserved in four subalpine Sphagnum bogs. The highest site occurs amid Eucalyptus paudflora woodland, the two intermediate sites are surrounded by Eucalyptus delegatensis forest and the lowest by a mixed forest of E. delegatensis/Eucalyptus regnans. Small pockets of N. cunninghamii occur within the eucalypt forests, and in close proximity to all four sites. Around 32 000 BP the vegetation consisted of a mosaic of alpine feldmark and herbfield, with small scattered groves of Nothofagus and Eucalyptus well below 1100m. Summer temperatures were probably 5°C lower than present with lowest values, probably 7° to 8°C below present, possibly between 17 000 and 13 500 BP, at which time alpine communities reached their greatest extent and much of the Central Highlands was treeless. After ca 13 500 BP herbaceous alpine taxa disappeared and there was an associated movement upslope of Nothofagus and tall open forest taxa to their maximum post-glacial extent, as temperatures and effective precipitation increased, ca 6000 BP. The retraction of cool temperate rainforest and wet sclerophyll or tall open forest towards present day values indicates lower effective precipitation, generally rising temperatures and increased fire hazard. More recently, European activities have increased the stress on the remaining forests. The study of four sites has demonstrated die importance of analysing a number of sites within a given area in order to overcome the limitations imposed by sites which were sub-optimal due to one or more factors including poor preservation, problems of dating, variable sedimentation rates, and the influence of streams which flow close to all sites. While die local environment varies between sites, and some vegetation changes are successional, this study shows that the local records complement one another, to some extent reinforcing die regional picture of vegetation and environmental change.     

Dynamics of Nothofagus-dominated rainforest on mainland Australia and lowland Tasmania

Cool temperate rainforest in Australia is commonly dominated by Nothofagus species. In Victoria and Tasmania, Nothofagus cunninghamii dominates old rainforest on optimal sites and is able to regenerate continuously. Size structure analysis of the major lowland tree species in this forest suggest that no major changes in species composition or dominance are occurring. This contrasts with the status of Nothofagus in lowland rainforest in New Zealand and rainforest below about 1000 m a.s.l. in south-central Chile. N. cunninghamii is a relatively light-demanding species, and is maintaining its dominance by seedling regeneration in canopy gaps created by the death of old individuals. The dynamics of the cool temperate rainforest in northern New South Wales are more complex. These forests are dominated by Nothofagus moorei, and size structure analysis indicates that persistence of this species within the rainforest is dependent on vegetative regeneration. On some sites this rainforest is being actively invaded by warm temperate and sub-tropical elements from lower altitudes. In these areas N. moorei in unable to regenerate beneath the canopy.Nomenclature follows Curtis (1963, 1967), Curtis & Morris (1975) and Williams (1982).We thank Mr. A. Floyd of the N.S.W. National Parks and Wildlife Service for his assistance in identifying species from the N.S.W. rainforests, and Mr. J. Hickey of the Tasmanian Forestry Commission for suggesting study sites in north-west Tasmania. Thanks are also due to the N.S.W. National Parks and Wildlife Service for allowing us access to National Parks for the purpose of this study. J. R. is supported by a Commonwealth Forestry Post-graduate Research Award.     

Structure and tree-fall gap dynamics of old-growth Nothofagus forests in Tierra del Fuego,Argentina

Abstract. Tree size and age structure, tree-fall and gap characteristics, and regeneration in gaps were studied in Nothofagus-dominated old-growth forests in Tierra del Fuego, Argentina. Gap-phase regeneration has resulted in all-aged populations for N. pumilio, N. betuloides, and Drimys winteri, and regeneration in gaps appears to be maintaining coexistence between species in mixed stands. N. betuloides fills many gaps via advance regeneration and some individuals persist for > 150 yr in the understory. Multiple periods of release and suppression indicate that N. betuloides may take advantage of several gap events to reach the main canopy. Likewise, Drimys grows well under closed canopy and can rapidly respond to gap formation, sometimes impeding the regeneration of N. betuloides. In contrast, N. pumilio regenerates in gaps mainly from seed or from advance regeneration of small, ephemeral seedlings. Gap turnover times in Fuegian forests were estimated at 300 - 500 yr, although gap formation was highly episodic and possibly associated with regionally extensive windstorms, earthquakes, and stand-level dieback. 92 % of gaps involved multiple tree-falls, and at least 53 % involved secondary expansion. Gap and tree-fall characteristics in Tierra del Fuego were similar to results from northern Patagonia, Chile, and New Zealand; however, we emphasize that regeneration of Nothofagus spp. and Drimys winteri in gaps depends on associated vegetation and varies along both local and regional environmental gradients.     

Fire history of Araucaria–Nothofagus forests in Villarrica National Park, Chile

Aim In this study we examine fire history (i.e. c. 500 yr bp to present) of Araucaria–Nothofagus forests in the Andes cordillera of Chile. This is the first fire history developed from tree rings for an Araucaria–Nothofagus forest landscape. Location The fire history was determined for the Quillelhue watershed on the north side of Lanin volcano in Villarrica National Park, Chile. The long‐lived Araucaria araucana was commonly associated with Nothofagus pumilio and N. antarctica in more mesic and drier sites respectively. Methods Based on a combination of fire‐scar proxy records and forest stand ages, we reconstructed fire frequency, severity, and the spatial extent of burned areas for an c. 4000 ha study area. We used a composite fire chronology for the purpose of determining centennial‐scale changes in fire regimes and comparing the pre‐settlement (pre‐1883) and post‐settlement fire regimes. In addition, we contrasted Araucaria and Nothofagus species as fire‐scar recorders. Results In the study area, we dated a total of 144 fire‐scarred trees, representing 46 fire years from ad 1446 to the present. For the period from ad 1696 to 2000, using fire dates from Araucaria and Nothofagus species, the composite mean fire interval varied from 7 years for all fires to 62 years for widespread events (i.e. years in which ≥ 25% of recorder trees were scarred). Sensitivity to fire was different for Araucaria and Nothofagus species. More than 98% of the fires recorded by Nothofagus species occurred during the 1900s. The lack of evidence for older fire dates (pre‐1900) in Nothofagus species was due to their shorter longevity and greater susceptibility to being killed by more severe fires. Whereas the thin‐barked N. pumilio and N. antarctica are often destroyed in catastrophic fire events, large and thick‐barked Araucaria trees typically survive. The spatial extent of fires ranged from small patchy events to those that burned more than 40% of the entire landscape (c. > 1500 ha). Main conclusions Fire is the most important disturbance shaping the Araucaria–Nothofagus landscape in the Araucarian region. The forest landscape has been shaped by a mixed‐severity fire regime that includes surface and crown fires. High‐severity widespread events were relatively infrequent (e.g. 1827, 1909 and 1944) and primarily affected tall Araucaria–N. pumilio forests and woodlands dominated by Araucaria–N. antarctica. Although there is abundant evidence of the impact of Euro‐Chilean settlers on the area, the relative influence of this settlement on the temporal pattern of fire could only be tentatively established due to the relatively small number of pre‐1900 fire dates. An apparent increase in fire occurrence is evident in the fire record during Euro‐Chilean settlement (post‐1880s) compared with the Native American era, but it may also be the result of the destruction of evidence of older fires by more recent stand‐devastating fires (e.g. 1909 and 1944). Overall, the severe and widespread fires that burned in Araucaria–Nothofagus forests of this region in 2002, previously interpreted as an ecological novelty, are within the range of the historic fire regimes that have shaped this forested landscape.     

Influence of fire severity on stand development of Araucaria araucana–Nothofagus pumilio stands in the Andean cordillera of south‐central Chile

Fire is the prevalent disturbance in the Araucaria–Nothofagus forested landscape in south‐central Chile. Although both surface and stand‐replacing fires are known to characterize these ecosystems, the variability of fire severity in shaping forest structure has not previously been investigated in Araucaria–Nothofagus forests. Age structures of 16 stands, in which the ages of approximately 650 trees were determined, indicate that variability in fire severity and frequency is key to explaining the mosaic of forest patches across the Araucaria–Nothofagus landscape. High levels of tree mortality in moderate‐ to high‐severity fires followed by new establishment of Nothofagus pumilio typically result in stands characterized by one or two cohorts of this species. Large Araucaria trees are highly resistant to fire, and this species typically survives moderate‐ to high‐severity fires either as dispersed individuals or as small groups of multi‐aged trees. Small post‐fire cohorts of Araucaria may establish, depending on seed availability and the effects of subsequent fires. Araucaria's great longevity (often >700 years) and resistance to fire allow some individuals to survive fires that kill and then trigger new Nothofagus cohorts. Even in relatively mesic habitats, where fires are less frequent, the oldest Araucaria–Nothofagus pumilio stands originated after high‐severity fires. Overall, stand development patterns of subalpine Araucaria–N. pumilio forests are largely controlled by moderate‐ to high‐severity fires, and therefore tree regeneration dynamics is strongly dominated by a catastrophic regeneration mode.     

Alsodes Australis,A New Species of Leptodactylid Frog from the Temperate Nothofagus Forest of Southern Chile and Argentina

A new species of frog, Alsodes australis, is described from the temperate Nothofagus forest of southern Chile and Argentina, based on adults and tadpoles. Up to now, no sympatric occurrence of another congeneric species is known from the type locality. The genus comprises three species groups. From a karyological point of view this species is included in the monticola group, whose species have 26 chromosomes.     

Polymorphic microsatellite loci in the European subterranean termite,Reticulitermes santonensis Feytaud

We report on the identification and characterization of two dinucleotide, two trinucleotide and eight tetranucleotide microsatellite DNA loci isolated from the European subterranean termite Reticulitermes santonensis. We tested the loci on 51–92 individuals from 46 colonies from different regions of France. Eleven loci were polymorphic with 2–8 alleles per locus and low observed heterozygosities (0.10–0.48). We also tested the loci on 17–20 individuals from 10 colonies in the closely related North American species R. flavipes and found significantly more alleles (2–9 alleles per locus) and higher observed heterozygosities (0.15–0.80) than in R. santonensis. The lower observed heterozygosities in R. santonensis are consistent with higher levels of inbreeding in these colonies due to the presence of numerous inbred replacement reproductives.     

The abundance,distribution and structural characteristics of tree‐holes in Nothofagus forest,New Zealand

Tree‐holes provide an important microhabitat that is used for feeding, roosting and breeding by numerous species around the world. Yet despite their ecological importance for many of New Zealand's endangered species, few studies have investigated the abundance or distribution of tree‐holes in native forests. We used complementary ground and climbed tree surveys to determine the abundance, distribution and characteristics of tree‐holes in undisturbed Nothofagus forest in the Lewis Pass, New Zealand. We found that hole‐bearing trees were surprisingly abundant compared with many other studies, including Australian Eucalyptus species and American beech. In fact, we estimated as many as 3906 tree‐holes per hectare, of which 963 holes per hectare were potentially large enough to provide roost sites for hole‐nesting bats in New Zealand, while only eight holes per hectare were potentially suitable for specialist hole‐nesting birds. This was of great interest as primary cavity‐excavating animals are absent from New Zealand forests, compared with North America and Australia. Moreover, tree‐hole formation in New Zealand is likely to be dominated by abiotic processes, such as branch breakage from windstorms and snow damage. As has been found in many other studies, tree‐holes were not uniformly distributed throughout the forest. Tree‐holes were significantly more abundant on the least abundant tree species, Nothofagus fusca, than on either N. menziesii or N. solandri. In addition to tree species, tree size was also an important factor influencing the structural characteristics of tree‐holes and their abundance in this forest. Moreover, these trends were not fully evident without climbed tree surveys. Our results revealed that ground‐based surveys consistently underestimated the number of tree‐holes present on Nothofagus trees, and illustrate the importance of using climbed inspections where possible in tree‐hole surveys. We compare our results with other studies overseas and discuss how these are linked to the biotic and abiotic processes involved in tree‐hole formation. We consider the potential implications of our findings for New Zealand's hole‐dwelling fauna and how stand dynamics and past and future forest management practices will influence the structural characteristics of tree‐holes and their abundance in remnant forest throughout New Zealand.     

Low efficiency of pseudotestcross mapping design was consistent with limited genetic diversity and low heterozygosity in hoop pine (<Emphasis Type="Italic">Araucaria cunninghamii</Emphasis>, Araucariaceae)

Linkage maps were prepared for two Araucaria cunninghamii individuals (coded H15 and Gil24) using the pseudotestcross strategy in a wide interprovenance cross. The maternal map for individual H15 contains 14 linkage groups (haploid chromosome number=13), comprising 51 amplified fragment length polymorphisms (AFLP) and 1 microsatellite; 17 markers remain unlinked. The map covered 1,290 cM [Kosambi (K)], representing 89% of the estimated genome size. The paternal map for individual Gil24 was shorter, 633 cM (K), consisted of eight linkage groups, with an average interval of 19.8 cM (K). The difference in map lengths was due to the larger number of informative markers for maternal parent (52 loci compared with 25 loci in the paternal parent). There was no significant difference in map lengths once maps were corrected for different numbers of loci. Overall, the number of segregating markers identified was surprisingly low for a wide interprovenance cross in an outcrossing tree species. For AFLP, a low average of 2.2 segregating markers per primer combination was obtained, and only 4 out of 29 microsatellite loci were informative in the cross. This low level of marker variation appears to be the result of low levels of heterozygosity in the parents and low levels of genetic divergence within A. cunninghamii. This result was consistent with other recent molecular studies of A. cunninghamii that indicate that the species may have low genetic diversity and possibly experiences localised inbreeding.     

<Emphasis Type="Italic">Erysiphe patagoniaca</Emphasis>: a new species of <Emphasis Type="Italic">Erysiphe </Emphasis>sect. <Emphasis Type="Italic">Uncinula </Emphasis>from Patagonia,Argentina

 A new species of Erysiphe sect. Uncinula is described and illustrated from Patagonia, Argentina. Erysiphe patagoniaca sp. nov., found on leaves of Nothofagus × antarctica, is similar to E. nothofagi and E. kenjiana, but differs in its appendages being twisted throughout their length and the number of appendages, asci, and ascospores. The two endemic species of Erysiphe sect. Uncinula, E. magellanica and E. nothofagi, coexisted on the same leaves together with Erysiphe patagoniaca. Received: September 19, 2002 / Accepted: November 28, 2002 Acknowledgments The authors are grateful to Ms. Seiko Niinomi for providing the micrographs of ascomata of Erysiphe spp. on Nothofagus. Correspondence to:S. Takamatsu     

Population genetic structure,genetic diversity,and natural history of the South American species of Nothofagus subgenus Lophozonia (Nothofagaceae) inferred from nuclear microsatellite data

The effect of glaciation on the levels and patterns of genetic variation has been well studied in the Northern Hemisphere. However, although glaciation has undoubtedly shaped the genetic structure of plants in the Southern Hemisphere, fewer studies have characterized the effect, and almost none of them using microsatellites. Particularly, complex patterns of genetic structure might be expected in areas such as the Andes, where both latitudinal and altitudinal glacial advance and retreat have molded modern plant communities. We therefore studied the population genetics of three closely related, hybridizing species of Nothofagus (N. obliqua, N. alpina, and N. glauca, all of subgenus Lophozonia; Nothofagaceae) from Chile. To estimate population genetic parameters and infer the influence of the last ice age on the spatial and genetic distribution of these species, we examined and analyzed genetic variability at seven polymorphic microsatellite DNA loci in 640 individuals from 40 populations covering most of the ranges of these species in Chile. Populations showed no significant inbreeding and exhibited relatively high levels of genetic diversity (H_E = 0.502–0.662) and slight, but significant, genetic structure (R_ST = 8.7–16.0%). However, in N. obliqua, the small amount of genetic structure was spatially organized into three well‐defined latitudinal groups. Our data may also suggest some introgression of N. alpina genes into N. obliqua in the northern populations. These results allowed us to reconstruct the influence of the last ice age on the genetic structure of these species, suggesting several centers of genetic diversity for N. obliqua and N. alpina, in agreement with the multiple refugia hypothesis.     

Isolation and characterization of microsatellite markers in Phytophthora ramorum,the causal agent of sudden oak death

We describe specific primers and conditions to amplify two dinucleotide and five trinucleotide microsatellite DNA loci isolated from the oomycete Phytophthora ramorum, the causal agent of sudden oak death. The primer sets were tested on 14–30 isolates from North America and Europe. Seven of 14 loci differentiated between A1 and A2 mating types. All seven loci successfully amplified DNA isolated from infected plant tissue. Four loci may be useful for the diagnosis of P. ramorum because they do not amplify closely related Phytophthora species.