Genetic variation in two rare endemic mexican trees, magnolia sharpii and magnolia schiedeana
Authors: Newton, A.C., Gow, J., Robertson, A., Williams-Linera, G., Ramírez-Marcial, N., González-Espinosa, M., Allnutt, T.R. and Ennos, R.
Journal: Silvae Genetica
Volume: 57
Issue: 6
Pages: 348-356
ISSN: 0037-5349
Abstract:Patterns of genetic variation were examined within two endemic tree species restricted to Mexican cloud forest, Magnolia sharpii and Magnolia schiedeana. Leaf samples collected from natural populations were analysed using PCR RFLP of cpDNA, Inter-SSR and isozyme genetic markers, which were used to test a series of hypotheses regarding patterns of intraspecific variation within the two species. Genetic diversity esti-mates derived from Inter-SSR markers (mean S pop of 0.56 and 0.50 for M. sharpii and M. schiedeana respectively) are comparable to values obtained for other tree species. As predicted on the basis of its larger geographic range, the degree of population differentiation was found to be higher within M. schiedeana than M. sharpii, with 12.9% and 3.4% of total variation recorded between populations for the two species respectively using isozymes, and 26% and 11% using Inter-SSR markers. Isozyme analyses indicated negative F is values, which may be suggestive of inbreeding in populations of M. sharpii, but provided less evidence of inbreeding in M. schiedeana. On the basis of PCR RFLP analysis of cpDNA, two chloroplast types were differentiated, type A being recorded for all of the individuals of both species, with the exception of one population of M. schiedeana that was fixed for type B. These results are consistent with recent evidence suggesting that some endemic plant taxa are able to maintain relatively high diversity within populations despite the occurrence of inbreeding and genetic drift, and that species with wider geographic ranges tend to exhibit relatively high genetic differentiation among populations. Conservation strategies for these species need to take into account the significant genetic differences recorded among the populations studied.
Source: Scopus
Genetic Variation in Two Rare Endemic Mexican Trees, <i>Magnolia sharpii</i> and <i>Magnolia schiedeana</i>
Authors: Newton, A.C., Gow, J., Robertson, A., Williams-Linera, G., Ramirez-Marcial, N., Gonzalez-Espinosa, M., Allnutt, T.R. and Ennos, R.
Journal: SILVAE GENETICA
Volume: 57
Issue: 6
Pages: 348-356
eISSN: 2509-8934
ISSN: 0037-5349
DOI: 10.1515/sg-2008-0049
Source: Web of Science (Lite)
Genetic Variation in Two Rare Endemic Mexican Trees, Magnolia Sharpii and Magnolia Schiedeana
Authors: Newton, A., Gow, J., Robertson, A., Williams-Linera, G., Ramirez-Marcial, N., Gonzalez-Espinosa, M., Allnutt, T.R. and Ennos, R.A.
Journal: Silvae Genetica
Volume: 57
Pages: 348-356
ISSN: 0037-5349
Abstract:Patterns of genetic variation were examined within two endemic tree species restricted to Mexican cloud forest, Magnolia sharpii and Magnolia schiedeana. Leaf samples collected from natural populations were analysed using PCR RFLP of cpDNA, Inter-SSR and isozyme genetic markers, which were used to test a series of hypotheses regarding patterns of intraspecific variation within the two species. Genetic diversity esti-mates derived from Inter-SSR markers (mean Spop of 0.56 and 0.50 for M. sharpii and M. schiedeana respectively) are comparable to values obtained for other tree species. As predicted on the basis of its larger geographic range, the degree of population differentiation was found to be higher within M. schiedeana than M. sharpii, with 12.9% and 3.4% of total variation recorded between populations for the two species respectively using isozymes, and 26% and 11% using Inter-SSR markers. Isozyme analyses indicated negative Fis values, which may be suggestive of inbreeding in populations of M. sharpii, but provided less evidence of inbreeding in M. schiedeana. On the basis of PCR RFLP analysis of cpDNA, two chloroplast types were differentiated, type A being recorded for all of the individuals of both species, with the exception of one population of M. schiedeana that was fixed for type B. These results are consistent with recent evidence suggesting that some endemic plant taxa are able to maintain relatively high diversity within populations despite the occurrence of inbreeding and genetic drift, and that species with wider geographic ranges tend to exhibit relatively high genetic differentiation among populations. Conservation strategies for these species need to take into account the significant genetic differences recorded among the populations studied.
Source: Manual
Preferred by: Adrian Newton