IUFRO Biodiversity in Forest Ecosystems Conference, Canada 2008
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The Population Genetic Consequences for Conservation of an Endangered Taxus baccata L. population in Austria
![The Population Genetic Consequences for Conservation of an Endangered Taxus baccata L . population in Austria Amalesh DHAR*, Raphael KLUMPP, Herwig RUPRECHT, Harald VACIK Institute of Silviculture, Department of Forest and Soil Sciences, University of Natural Resources and Applied Life Sciences, Peter-Jordan Str. 82, A-1190 Vienna, Austria. *Corresponding author (amalesh.dhar@boku.ac.at) References (selected) Cao Von C.-P., Leinemann M. Z., Finkeldy R. 2003. Study of the genetic variation and differentiation of yew ( Taxus baccata L.)Stands using Isozyme and DNA Marker. Allg.Forst-u.J.Ztg.,1/2:21-28 Cheliak W.M., Pitel J.A., 1984.Techniques for starch gel electrophoresis of enzymes from forest tree species. Inf. Rep. PI-X-2, Petawawa Nat. For. Inst., Canadian For. Service., Agric. Canada Dhar A., Ruprecht H., Klumpp R., Vacik H. 2008. On the structures and genetics of an Austrian relict population of English yew (Taxus baccata L.). In: University of Cambridge (Eds.), Student Conference for Conservation Science, 9th Student Conference for Conservation Science, 25-27 March 2008, University of Cambridge, Cambridge, UK. p 30.. Dhar, A., Ruprecht, H., Klumpp, R., Vacik, H., 2006. Stand structure and natural regeneration of English yew ( Taxus baccata L.) at Stiwollgraben in Austria, Dendrobiolog, 56,19-26. Dhar, A., Ruprecht, H., Klumpp, R., Vacik, H., 2007. Comparison of ecological condition and conservation status of English yew population in two Austrian gene conservation forests. Journal of Forestry Research, 18 (3), 181-186. Hamrick JL, Godt MJW, Sherman-Broyles SL (1992) Factors influencing level of genetic diversity in woody plant species. New Forests 6: 95-124. Hertel H., 1996. Vererbung von Isoenzymmarkern bei Eibe ( Taxus baccata L). Silvae Genetica 45:284-290. Herz H., Bernhard A., Nebenführ W., Slunsky R., Litschauer R., Heinze B. ,2005. Das Eibenvorkommen in den Österreichischen Generhaltungswäldern. Poster bei der “12. Tagung der Eibenfreunde”, 2005 Sept 29 –Oct 2; Kempten in Allgäu. Klumpp R ,Dhar A., Aigner B.,Ruprecht H.,., Vacik H. 2008. 1.Genetics and Population structure on an English yew gene conservation forest at foothills of the Eastern Alpine Mountains [Eds.], From the Mountain to Sea, Electronic PDF Abstracts, 22nd Annual meeting Society for Conservation Biology, 13th to 17th July, The University of Tennessee at Chattanooga, USA. Lewandowski A., Burczyk J., Mejnartowicz L., 1995. Genetic structure of English yew ( Taxus baccata L .) in the Wierzchlas Reserve:implications for genetic conservation. Forest Ecology and Management 1995 ;73:221-227. Svenning, J.-Ch., Magárd E., 1999. Population Ecology and conservation status of the last natural population of English yew Taxus baccata in Denmark. Biological Conservation, 88, 173-182. Result s and Discussion We observed in total 135 no of individual yew with DBH ≥ 5 cm in 1.0 ha of natural forest, the average and maximum DBH was 13.77 and 31.5 cm which indicating the relatively the old stand See Fig-2. For evaluating the genetic structure of the yew population 9 isozyme gene loci and 27 alleles were studied where the mean number of alleles per locus was 2.7 and 78 % of the gene loci were polymorphic. Among these 9 loci only two loci AAT-A and LAP-A are monomorphic (Table-2). T he average expected heterozygosity was estimated to be ( He ) 0. 299 and the mean observed heterozygosity ( Ho ) 0.2 72 respectively (Table 3 ). Comparing the other studies on yew in Austria Losenstein population showed less difference between the observed and expected heterozygosity (Dhar et al. 2008, Klumpp et al. 2008) but same level within the European range of observations (Table-4). The average Wright‘s fixation index was 0.089 exhibiting a defeciency of heterozygotes compared with a population in Hardy-Weinberg equilibrium. So the level of inbreeding as measured by average Wright‘s fixation index is positive. Because Taxus baccata is a dioecious species any observed inbreeding must be the result of mating between relatives. Consangunity among progeny is often explained by limited seed dispersal (gravity and animal-ingestion in typical for yew) and mating between close neighbours ( see Hamrick 1992) From the overall observation it is concluded that the Losenstein population has high genetic diversity in respect of number of alleles per locus. Considering the in-situ consevation effort, the gene conservation forest Losenstein represents high endurance ability and a valuable gene pool for future conservation of Taxus baccata in Austria. Table 1 . Enzyme system used for electrophoretic analysis of the yew population Acknowledgement We would like to thank FD. Jasser from local forest authority for making the site available to us, Ing. Monika Lex for technical support during lab work and the Forest Province Office of Upper Austria. We also thank the Österreichische Orient-Gesellschaft (ÖOG) for the One-World Scholarship ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Introduction English yew ( Taxus baccata L. Taxaceae ) is a dioecious gymnosperm widely distributed in Europe, but often forming small and scattered populations (Hilfikar et al. 2004) . It grows as a subordinate but sometimes habitat-determining species in a range of different forest types (Thomas and Polwart 2003). The yew is predominantly found in Beech and Norway spruce-dominating montane forest s in Austria . In recent time the distribution of yew species has been severely reduced due to natural disturbance and human intervention s . The reasons for the yew decline have been discussed by many articles (see Svenning and Magard 1999, Bugala, 1978, Dhar et al., 2006; 2007 ). Some of them suspected that a low level of genetic variation might be one of the main reasons f or a yew decline . H owever Lewandowski et al. (1995) observed high level of genetic variation at the Wierzchlas reserve in Poland although it is a declining population . The estimation of genetic variation for allozymes of plants within and among populations components can provide the basis for the conservation of genetic diversity of plant programmes (Hamrick et al.1991). These estimates of allozyme diversity, along with information on population biology and ecology of plants, can also be used as yardstick to measure the effectiveness of in-situ and ex-situ conservation programmes of tree species. The “Losenstein” was identified as an gene conservation forest in 2004 ( Herz et al.2005 ) for in-situ conservation of yew. Here we try to study the population genetic structure for possible conservation initiatives of this endangered yew population in Austria. Objectives The main goal of this study is to characterize the genetic variation of English yew by using the isozyme biochemical marker s which help to develope a sound silvicultural management strategy for this yew population. . Materials and Method The “Losenstein” is situated in the North-Eastern Alpine mountains (Fig.1) with estimated 1.0 ha of land at 5 4 0 to 680 m a.s.l. elevation . The Diameter at breast height (DBH) was measured from all yew individual to predict the stand age. A total bud sample from 122 trees were taken for isozyme analysis. Horizontal starch gel electrophoresis was applied for separating the isozymes and six enzyme systems (Table 1) were chosen for this study, which are known to exhibit polymorphism in at least one of the encoding gene loci (Hertel 1996) . Electrophoretic procedures and staining protocols followed the methods described by Cheliak & Pitel ( 1984 ) and Hertel ( 1996 ) . We used the GSED-1.1 (Gillet 1998) computer programme to analyse the genetic data. Genetic diversity was assessed by following parameters: percentages of polymorphic loci ( P = 0.95 ), average number of alleles per locus ( A/L ), average expected ( He ) and observed ( Ho ) heterozygosities per locus and hypothetical gamate diversity and effective number of allelle per locuse ( Ne ). Table 2 . Allele frequencies of 9 investigated gene loci of English yew and their genetic multiplicity over all observed gene loci Table 4. Comparison of average allozyme variation in different Taxus species Table 3. Comparison of average allozyme variation in different studies in Austria Figure 2. DBH distribution of Taxus baccata population Figure 1. Location of the study population Enzyme Gene locus Allele no E. C. number Aspartate-aminotransferase AAT- A AAT- B 2 3 2.6.1.1 Isocitrate-dehydrogenase IDH-A IDH-B 3 4 1.1.1.42 Leucine-aminopeptidase LAP-A LAP-B 4 5 3.4.11.1 Phosphoglucomutase PGM - A 4 2.7.5.1 6-Phosphogluconate-dehydrogenase 6-PGDH- A 2 1.1.1.44 Shikimate-dehydrogenase SKDH-A 3 1.1.1.25 Locus Allele 1 2 3 4 AAT-A 1.00 AAT-B 0.451 0.549 IDH-A 0.086 0.828 0.082 0.004 IDH-B 0.123 0.078 0.766 0.003 LAP-B 1.00 LAP-B 0.492 0.508 PGM-A 0.016 0.111 0.025 0.848 6-PGDH-A 0.369 0.631 SKDH-A 0.057 0.857 0.066 0.020 Species No of Gene loci Parameters Hypo. gamete diversity Literature Polim loci P 95 (%) A/L Ne Ho He T.baccata 9 78 2.7 1.42 0.272 0.299 31.98 This study 18 61 2.2 1.37 0.286 0.279 -- Lewandowski et at. 1995 6 81 2.6 1.48 0.340 0.316 -- Cao et al. 2003 5 -- 1.45 0.302 0.308 7.84 Tröber et al. 2004 T. Cuspidata 23 45 1.4 1.78 0.154 0.192 -- Chung et al. 1999 14 46 1.7 -- 0.172 0.168 -- Lee et al. 1999 T. Brevifolia 21 42 1.7 -- 0.085 0.166 -- El-Kassaby & Yanchuk 1994 22 34 1.5 -- 0.122 0.124 -- Wheeler et al. 1995 T. Canadensis 22 27 1.3 -- 0.102 0.098 -- Senneville et al. 2000 Sample size Parameter Poly.Loci P 95(%) A/L Ne Hypo. Gamete. Diversity Ho He F IS Literature 122 78 2.7 1.42 31.98 0.272 0.299 0.089 This study 95 78 2.4 1.43 42.6 0.257 0.304 0.155 Klumpp et al. (2008) 109 100 2.8 1.39 17.26 0.232 0.267 0.124 Dhar et al. (2008)](https://image.slidesharecdn.com/posterdhariufro-100513233027-phpapp01/85/IUFRO-Biodiversity-in-Forest-Ecosystems-Conference-Canada-2008-1-320.jpg)
The Population Genetic Consequences for Conservation of an Endangered Taxus baccata L. population in Austria
