Genetic variation in nine Shorea species (Dipterocarpaceae) in Indonesia revealed by AFLPs

Shorea is the largest and most important genus of the Dipterocarpaceae. The genetic diversity and structure of nine Shorea species from two different locations, namely Nanjak Makmur in Sumatra and Sumalindo in Borneo, were evaluated using amplified fragment length polymorphism (AFLP) markers. A total of 274 trees were investigated at 85 polymorphic AFLP loci. Levels of genetic diversity of these species ranged from  = 0.100 for S. acuminata to  = 0.165 for S. blumutensis. The population of rare species S. blumutensis possessed the highest genetic diversity suggesting that geographically restricted species can have levels of genetic variation comparable to closely related widespread common congeners. Analyses of molecular variance revealed that the genetic variation was mainly found among species in both locations (57.7% in Sumatra; 56.3% in Borneo). The unweighted pairgroup method using arithmetic averages dendrogram of all samples revealed an almost complete separation of species. Thus, AFLP markers proved appropriate for phylogenetic studies of Shorea species. Specific markers have been detected showing high-frequency differences among species and between regions within species. Sequence information of these markers can be used to develop specific polymerase chain reaction markers for wood identification. The possibility of interspecific hybridization was discussed.     

Patterns of contemporary hybridization inferred from paternity analysis in a four-oak-species forest

Background  

Few studies address the issue of hybridization in a more than two-species context. The species-rich Quercus complex is one of the systems which can offer such an opportunity. To investigate the contemporary pattern of hybridization we sampled and genotyped 320 offspring from a natural mixed forest comprising four species of the European white oak complex: Quercus robur, Q. petraea, Q. pubescens, and Q. frainetto.     

Genetic variation of teak (Tectona grandis Linn. f.) in Myanmar revealed by microsatellites

Genetic variation of teak (Tectona grandis Linn. f.) in 16 populations in Myanmar was investigated using ten nuclear microsatellite markers. Eight population pairs from two main regions in the north and the south of Myanmar were sampled. Each population pair consisted of an unlogged and a recently logged forest, each represented by 50 adult trees and 50 seedlings from the natural regeneration. For comparison, two land races from Benin (West Africa) were included. The major objectives of the study are to characterize the patterns of genetic variation of teak in natural populations, to examine genetic differentiation between adult trees and natural regeneration, and to investigate the impact of selective logging on genetic structures of teak. Genetic variation was high in all investigated populations. Slightly elevated levels of inbreeding were observed in the regeneration in comparison to the adults. Populations from the northern and the southern regions were strongly differentiated, but the differentiation between adults and natural regeneration and between unlogged and logged forests was low and not significant. Mantel tests indicated an isolation by distance (IBD) within the northern and the southern regions. High genetic diversity was also observed within the land races from Benin, which grouped to the southern populations. We failed to detect effects of logging on genetic diversity patterns or inbreeding in adults and regeneration, suggesting that high genetic diversity can even be sampled and maintained in disturbed forests. The observation of significant IBD and high differentiation between the populations of the north and the south of Myanmar suggests to include populations from widely separated forests in conservation programs, and to delineate provenance regions for the harvest and transfer of teak seeds and seedlings.     

Extraction, amplification and characterization of wood DNA from dipterocarpaceae

A successful DNA extraction from wood yielding appropriate DNA quality for PCR amplification allows molecular genetic investigations of wood tissue. Genotypes, the origin of sampled material, and species can be identified based on an investigation of wood if suitable information on genetic variation patterns within and among species is available. Potential applications are in forensics and in the control of the timber and wood trade. We extracted DNA from wood of Dipterocarpaceae, a family that dominates rainforests and comprises many important timber species in Southeast Asia. Several different DNA isolation techniques were compared and optimized for wood samples from natural populations and from wood processing enterprises. The quality of the DNA was tested by spectrophotometry, PCR amplification, and PCR inhibitor tests. An average DNA yield of 2.2 μg was obtained per 50–100 mg of dried wood sample. Chloroplast DNA (cpDNA) regions of different length were amenable to PCR amplification from the extracted DNA. Modification of DNA isolation techniques by the addition of polyvinylpyrrolidone (PVP) addition up to 3.1% into lysis buffer reduced PCR inhibition effectively. In order to evaluate the extraction method, we analyzed leaves and wood from the same tree by PCR amplification, genotyping and sequencing of chloroplast microsatellites.     

Significant patterns of fine-scale spatial genetic structure in a narrow endemic wind-dispersed tree species, <Emphasis Type="Italic">Cedrus brevifolia</Emphasis> Henry

Cedrus brevifolia is a narrowly distributed conifer species, currently limited to a single mountain in Cyprus, growing in restricted habitats on sites of different densities and sizes. This study assessed the influence of seed and pollen dispersal, as well as the effect of demographic and genetic features on the magnitude of fine-scale spatial genetic structure (SGS). Sampling was performed in 11 plots where 50 neighboring adult trees were sampled from each plot, while biparentally and paternally inherited genomes were used for analysis with microsatellites. Fine-scale SGS was significant but showed contrasting patterns among plots. Although the magnitude of SGS in C. brevifolia mainly results from restricted seed dispersal, short-distance pollen dispersal could also explain fine-scale SGS in some plots, which is rather uncommon in wind-pollinated conifer species. The lack of a general and consistent trend of SGS among plots and between genomes indicates that pollen and seed dispersal varies at plot level. The complex SGS patterns in C. brevifolia may result from the unequal ratio of male and female strobilies of trees within the same plots, at different reproductive periods. Demographic features such as habitat fragmentation did not influence the magnitude of SGS in C. brevifolia, whereas low tree aggregation reduced it. Further, the significant correlation observed between linkage disequilibrium (LD) and plots with significant SGS supports the assumption that under specific conditions, LD is likely to be caused by the magnitude of SGS.     

Molecular phylogeny of Dipterocarpaceae in Indonesia based on chloroplast DNA

In order to construct a molecular phylogeny of Indonesian Dipterocarpoideae (Dipterocarpaceae), PCR-RFLP of the chloroplast regions rbcL, petB, psbA, psaA, and trnL-F was performed with seven restriction enzymes in 129 samples including 58 species from nine genera. In the strict consensus tree with Monotes kerstingii as outgroup Indonesian Dipterocarpaceae were divided into two major clades. One clade (bootstrap value=71) consisted of Upuna, Cotylelobium, Anisoptera, Vatica, Dipterocarpus (tribe Dipterocarpeae, bootstrap value=83) and Dryobalanops (tribe Shoreae, bootstrap value=99) in a basal position. The second clade consisted of Hopea, Parashorea, and Shorea (tribe Shoreae) with 95% bootstrap support. Tribe Dipterocarpeae is monophyletic, tribe Shoreae is polyphyletic since Dryobalanops is sister to tribe Dipterocarpeae. In the neighbour-joining tree the sister group position of Dryobalanops to tribe Dipterocarpeae is not supported by the bootstrap analysis. Alternatively, we used Upuna borneensis as outgroup. The effect of outgroup selection on tree topology, taxonomic classification and the interpretation of character evolution is discussed.     

High chloroplast haplotype diversity in Greek populations of beech (Fagus sylvatica L.)

The distribution of chloroplast DNA (cpDNA) variations in Greek beech ( Fagus sylvatica L.) populations was studied using chloroplast microsatellite markers. Thirteen haplotypes were identified from 40 populations by combining three different primers. Most of the cpDNA variation was distributed among populations, but a considerable variation was also observed within populations. The total diversity was very high for all regions. The N_st/G_st comparison was significant, indicating phylogenetic subdivision, but no strong spatial structure was detected, suggesting complex post-glacial migration patterns. Possible scenarios explaining this diversity pattern include the existence of several separated refugia in the region, the recolonisation of mountains by different beech lineages and the formation of an introgression zone between two different beech subspecies in the eastern part of the country.     

Uses,traditional management,perception of variation and preferences in ackee (Blighia sapida K.D. Koenig) fruit traits in Benin: implications for domestication and conservation

Background

Changing lifestyles have recently caused a severe reduction of the gathering of wild food plants. Knowledge about wild food plants and the local environment becomes lost when plants are no longer gathered. In Central Europe popular scientific publications have tried to counter this trend. However, detailed and systematic scientific investigations in distinct regions are needed to understand and preserve wild food uses. This study aims to contribute to these investigations.

Methods

Research was conducted in the hill country east of Graz, Styria, in Austria. Fifteen farmers, most using organic methods, were interviewed in two distinct field research periods between July and November 2008. Data gathering was realized through freelisting and subsequent semi-structured interviews. The culinary use value (CUV) was developed to quantify the culinary importance of plant species. Hierarchical cluster analysis was performed on gathering and use variables to identify culture-specific logical entities of plants. The study presented was conducted within the framework of the master's thesis about wild plant gathering of the first author. Solely data on gathered wild food species is presented here.

Results

Thirty-nine wild food plant and mushroom species were identified as being gathered, whereas 11 species were mentioned by at least 40 percent of the respondents. Fruits and mushrooms are listed frequently, while wild leafy vegetables are gathered rarely. Wild foods are mainly eaten boiled, fried or raw. Three main clusters of wild gathered food species were identified: leaves (used in salads and soups), mushrooms (used in diverse ways) and fruits (eaten raw, with milk (products) or as a jam).

Conclusions

Knowledge about gathering and use of some wild food species is common among farmers in the hill country east of Graz. However, most uses are known by few farmers only. The CUV facilitates the evaluation of the culinary importance of species and makes comparisons between regions and over time possible. The classification following gathering and use variables can be used to better understand how people classify the elements of their environment. The findings of this study add to discussions about food heritage, popularized by organizations like Slow Food, and bear significant potential for organic farmers.     

Results on quantitative trait loci for flushing date in oaks can be transferred to different segregating progenies

Flushing date (bud burst) is one of the most important traits for the adaptation to different environments and climates in the temperate zone. Because of their wide geographic distribution, Quercus robur L. and Q. petraea (Matt.) Liebl. are suitable as model plants to study the genetic basis of bud burst. QTLs (Quantitative Trait Loci) with comparatively large effects have been mapped in a former study in a Q. robur x Q. robur full-sib family (French cross). In the present study, we performed a Bulked Segregant Analysis (BSA) in the F (1) progeny comprising 144 seedlings derived from a cross between a single Q. robur tree as common seed parent and five different pollen donors both from Q. robur and Q. petraea (Q. robur x Q. spp., Diekholzen crosses). In addition, markers linked to two bud burst QTLs with comparably strong effect in the above-mentioned full-sib family (French cross) were tested for their association with bud burst in the Q. robur x Q. spp. (Diekholzen) progeny. Using three microsatellite markers as anchor points, we could map QTLs on linkage group 7 and on linkage group 2, together explaining 16.2 % of the total phenotypic variance (PVE) in 1999 and 38.1 % in 2003. Out of 10 markers that segregated in both mapping progenies, four markers including the two microsatellite markers, showed a significant effect on bud burst in both materials. At microsatellite loci ssrQpZAG1/5 (linkage group 7) and ssrQpZAG119 (linkage group 2) alleles associated with early (allele 166 bp in ssrQpZAG1/5) and late bud burst (allele 57 bp in ssrQpZAG119) in the Q. robur x Q. robur full-sib family (French cross) showed a highly significant association with the same polarity of the effect in the Q. robur x Q. spp. (Diekholzen) progeny. The usefulness of these markers for marker-assisted selection in full-sib and half-sib families is discussed.     

Mutation rates in scots pine (Pinus sylvestris L.) from the Chernobyl exclusion zone evaluated with amplified fragment-length polymorphisms (AFLPs) and microsatellite markers

Ionizing radiation is a strong mutagenic factor and, accordingly, elevated mutation rates would be expected in plants exposed to high chronic or acute radiation after the Chernobyl accident in 1986. Somatic mutations were analyzed in pines (Pinus sylvestris L.) planted before and after the Chernobyl accident and in control material of the same origin planted in sites with natural radiation. Microsatellites (SSRs) and amplified fragment-length polymorphisms (AFLPs) were investigated. The mutation rates for microsatellites were estimated as 2.8 × 10(-4)-7.1 × 10(-4) per locus for different irradiated tree populations; no mutations were detected in the controls. In the case of AFLPs, the observed mutation rates were 3.74 × 10(-3) -3.99 × 10(-3) and 1.06 × 10(-3) per locus for contaminated and control areas, respectively. Thus a statistically highly significant three-fold increase in number of mutations was found by the use of AFLP markers, indicating that ionizing radiation causes strong DNA damage across the entire genome and that AFLPs may be the appropriate marker system for this kind of analysis.