20 research outputs found
Gene diversity in grevillea populations introduced in Brazil and its implication on management of genetic resources.
A variabilidade isoenzimática para seis populações de Grevillea robusta, oriundas de um teste de procedências/progenies, implantado no delineamento em blocos casualizados com 5 plantas por parcela, no Sul do Brasil, é descrita. A estrutura genética da população foi analisada utilizando-se marcadores bioquímicos, aos 5 anos de idade, especificamente para os locos MDH-3, PGM-2, DIA-2, PO-1, PO-2, SOD-1, e SKDH-1. As procedências do norte de ocorrência natural (Rathdowney e Woodenbong) apresentaram divergência genética superior, em relação à média das progênies, considerando o número de alelos por locus, (Ap), a riqueza alélica (Rs), a diversidade genética de Nei (H), e o coeficiente de endogamia (f). A endogamia foi detectada em diversos graus. A testemunha comercial apresentou o maior coeficiente de endogamia, (f = 0,4448), comparativamente à média das procedências (f = 0,2306), possivelmente devido à insuficiente amostragem populacional na região de origem (Austrália). Apesar de sua ocorrência natural restrita, observou-se correlação positiva entre divergência genética e distância geográfica entre as populações originais. A distância genética e análise de cluster, baseada no modelo bayesiano, mostrou três grupos de procedências distintos: 1) Rathdowney- QLD e Woodenbong-QLD; 2) Paddy?s Flat-NSW; e 3) Mann River-NSW, Boyd River-NSW e a testemunha comercial (material utilizado no Brasil). O agrupamento da testemunha com as procedências Mann River-NSW e Boyd River-NSW sugere um maior potencial das procedências do norte para o melhoramento genético visando à produção de madeira no Brasil, devido a sua elevada diversidade genética e baixo coeficiente de endogamia
Genetic and historical studies on the origin of Norway spruce in Białowieża Primeval Forest in Poland
Following the research of Wladyslaw Jedlinski – determination of the origin of spruce in the Skrwilno Forest District
Origin of Norway spruce in the territory of Skrwilno Forest District was studied with the use of mitochondrial mt−D02 region inherited through maternal line. The former suppositions of Jedliński, who claimed that the origin of spruce in this territory was natural, have been confirmed. Concurrently, it has been established that in the majority of tree stands subject to our study there occurs spruce of Carpathian origin. The obtained results together with the palinological data indicate that the northern border of spruce range in Poland runs right through the territory of Skrwilno Forest District and not about 100 km to the south from this place as has been claimed so far
Postglacial history of silver fir (Abies alba Mill.) in Poland as a result of migration from different refugia - the current state of knowledge
The paper reviews the current knowledge about the genetic variation, glacial and postglacial history of Polish populations of silver fir (Abies alba Mill.). This species occurs in the mountainous forests of central and southern Europe, from the Pyrenees up to the Balkans, where it is important from both ecological and economical points of view. The current knowledge about glacial and postglacial history of fir has been obtained from palynological and genetic studies. During the last ice age A. alba survived in the refugia in southern Europe, the central Apennines, the south of the Balkan Peninsula and the Central Massif in France. Two other refugia remained isolated – one in Calabria
in the south of the Apennines and one in the Pyrenees. Furthermore the most likely routes of postglacial recolonization of silver fir as well as the introgression zone between them have been identified. In Poland, silver fir reaches the north−eastern border of its natural range. Several earlier studies based on isozymes and DNA markers (mitochondrial and chloroplast) have reported that the Polish populations of fir are characterized by lower levels of genetic variation within populations and higher genetic differentiation between them than other coniferous species. Fir probably migrated to Poland from two glacial refugia located in the Balkan and Apennines Peninsula. Notwithstanding,
a recent study on Polish silver fir populations carried out with mtDNA marker, strictly maternally inherited, indicated that the species migrated to the Polish territory from the refugium in western Europe. However, this study did not take into account the possibility of participation of pollen pool of Balkan origin in the formation of the Polish populations of fir. Until now, there have been only a few reports concerning the gene pool of fir in Poland. Therefore, it is necessary to supplement the knowledge about its genetic variation. In the course of several episodes of silver fir decline during the past century, its populations have decreased in size and currently are scattered throughout the entire European range. Reliable information on the distribution of genetic variation is a prere−quisite for proper management of forest genetic resources in a short−term and long−term perspective. The recognition of the existing genetic diversity is also the preliminary phase in development
of an effective strategy for conservation of forest tree species gene pools
Origin of Norway spruce (Picea abies (L.) Karst.) in the Kartuzy Forest District
The origin of the Norway spruce in the Kartuzy Forest District was verified using the maternally inherited mitochondrial DNA marker mt15−D02 that shows distinct geographical distribution in Europe. We analyzed 462 trees from 26 populations. The majority of trees were of Alpine origin and they were present in all populations at a frequency of 6−90% (mean 59%). About 30% of trees were of the Carpathian origin and the least abundant (11%) were trees of north−eastern origin. The trees carrying north−eastern type of the mitochondial DNA marker were found only in 13 populations, but at a very different frequency (from 5 to 88%). The possibility of natural origin of Norway spruce in the area of Kartuzy Forest District was shortly discussed
Utility of two mitochondrial markers for identification of Picea abies refugial origin
Picea abies (L.) Karst is one of the most important coniferous species of Europe from both ecological and economical points of view. Traditional methods for the gene pool conservation and biodiversity maintenance in forest ecosystems have been practiced in many countries. For progress in this field using highly polymorphic genetic molecular markers is needed. Our goal was to demonstrate the utility of two polymorphic mitochondrial markers mt15-D02 and nad1 b/c in identification native Norway spruce stands. This molecular markers were tested in 1401 individuals from 59 Polish Norway spruce populations. We detected three alleles, which are called1, 2 and3, for locus mt15-D02 and two alleles , which are called1 and2, for locus nad1 b/c in our material. All five variants of alleles indicate the natural origin of P. abies. Result of this study shows that molecular marker mt15-D02 is easy to use and more informative in compare to marker nad1 b/c
Importance of genetic variation for conservation of English yew genetic resources in Europe
The genetic variation is considered to be a key factor for long−term survival of the species. The recognition of the existing genetic diversity is the preliminary phase in development of an effective strategy for conservation of forest tree species gene pools. Taxus baccata L. with a wide but scattered distribution in Europe is an example of rare and endangered species that needs both ex situ and in situ protection. The increase in fragmentation and isolation of populations and reduction in effective population size can cause erosion of the gene pool through increased genetic drift, increased inbreeding, reduced gene flow and decreased migration rate. As a result, local populations may be responsible for the loss of genetic variation, hence a decrease in their viability and adaptability. A few genetic analyses based on isozymes and DNA markers indicate that the yew, both in Poland and in other regions of Europe, is characterized by high levels of genetic variation within populations and moderate genetic differentiation between populations
Genetic status of Polish larch (Larix decidua subsp. polonica (Racib. Domin)) from Chełmowa Mountain: implications for gene conservation
The Polish larch (Larix decidua subsp. polonica (Racib. Domin), a subspecies of European larch, is
one of the most valuable forest-forming trees in Poland. It was first discovered on the Chełmowa Mountain
where Natural Reserve has been established to protect this subspecies. Currently, this unique population is
at risk of extinction. Nonetheless, the knowledge on the genetic diversity of this population and surround-
ing larch forests is insufficient to undertake actions aimed at conservation of genetic resources. In this
study, we examined the level of genetic diversity and differentiation of four subpopulations of Polish larch
from Nature Reserve on the Chełmowa Mountain and surrounding areas.
We used eleven nuclear microsatellite markers (SSRs) combined in two multiplex PCR reactions. In total,
344 individuals of Polish larch were genotyped and subjected to further population genetic analyses.
We found the high level of genetic diversity (average: He = 0.752, Ho = 0.720) and low levels of genetic
differentiation (average: Fst = 0.022). The effective population size was large and homogeneous across
subpopulations (mean Ne=90.7), and we found no sign of inbreeding. The spatial genetic structure was
detected in two older subpopulations but not in the younger one, suggesting its artificial origin. The old
larch subpopulations were genetically homogeneous and they were related to the ancestral group of Polish
lowland populations.
The old larch core populations growing on Chełmowa Mountain are relatively homogeneous and they well
represent the ancestral genetic group of Polish lowland larch populations. However, they still exhibit rela-
tively high genetic diversity and sufficiently large effective population sizes assuring their adaptive potential
for a long-term existence. Surrounding larch populations are even more genetically diverse but this might
be the effect of an admixture of seed sources from various populations from a wider area of Central Europe.
We recommend that specific conservation efforts should be undertaken to promote natural regeneration of
the core larch populations, even supplemented by the planting of seedlings derived from the oldest larch
trees. Other management actions should focus on limiting external gene flow to this unique population of
Polish larch
Verification of the origin of Norway spruce (Picea abies) stands in the Goldap Forest District
The origin of the Norway spruce in the Gołdap Forest District from the north−eastern part of Poland was verified using the maternally inherited mitochondrial marker mt15−D02, which in Poland displays a geo−graphical specifity. We analyzed 730 trees from 29 populations and 21 plus trees. These populations included four reserves, four registered seed stand and 21 managed tree−stands. As a result of the performed
analyses it was found that 8 out of 21 plus trees were non−native. Also 11 out of the 29 investigated pop−ulations contained trees of non−native origin. The scale of this phenomenon varies, although it encom−passes the entire region of the forest district
