Isozyme variation in tropical trees: patterns of genetic organization

Loveless, M. D.

doi:10.1007/978-94-011-2815-5_6

Cited by 65 publications

(55 citation statements)

References 65 publications

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“…A comparação dos valores de C. moschata com os apresentados em revisões de diversidade alozímica em táxons arbóreos, em geral (Hamrick et al 1992), e em táxons arbóreos tropicais, em particular (Hamrick & Loveless 1986, Loveless 1992, mostra que C. moschata possui uma diversidade genética populacional típica de uma espécie arbórea tropical. Além disto, o valor encontrado é bastante próximo do apresentado por outra espécie de Lauraceae da Costa Rica, Ocotea tenera (Gibson & Wheelwright 1995).…”

Section: Resultsunclassified

Conservação genética de populações de Cryptocarya moschata Nees (Lauraceae) na Mata Atlântica do estado de São Paulo

1999

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-(Genetic conservation of populations of Cryptocarya moschata Nees (Lauraceae) in the Atlantic Rain Forest of the State of São Paulo). This paper was aimed at studying the genetic structure of populations of Cryptocarya moschata and proposing conservation strategies for the species. Allozyme data of 18 polymorphic loci were collected from 214 trees sampled from four natural populations located in two regions of the State of São Paulo, Brazil. Estimates of Wright's F statistics were computed on the basis of observed and expected heterozygosities. The analysis of variance, pooled over loci and alleles, was also used to compare corresponding estimates of F (= F IT ), θ P (= F ST ) and f (= F IS ). Both methods provided similar results with F IT = 0.142, F ST = 0.140, F IS = 0.002 and F = 0.116, θ P = 0.123 and f = -0.008. Results indicated that individuals within populations are probably panmitic. Diversity among populations was very high, similar to what would be expected for groups of plants with a half-sib family structure. Estimates of θ P , obtained for populations taken two at a time, indicated that diversity tended to increase with distance and suggested that isolation by distance is a factor to be considered. An estimated gene flow of 0.9 migrants per generation corroborated to the pronounced divergence found among populations. Due to the negligible ˆf F ≅ IS value found, the variance effective size for each population is equivalent to its sampling number. In this case, management and conservation strategies aimed at preserving high intrapopulation genetic variation, will imply in the maintenance of large populations. In addition, due to the relatively large divergence detected among populations, the preservation of the species as a whole will also require the maintenance of many such populations. RESUMO -(Conservação genética de populações de Cryptocarya moschata Nees (Lauraceae) na Mata Atlântica do estado de São Paulo). Através da análise de 18 locos isoenzimáticos polimórficos, foram estimadas as freqüências alélicas referentes a 214 indiví-duos adultos de quatro populações naturais deCryptocarya moschata de duas regiões do estado de São Paulo. Com base nas heterozigosidades observadas e esperadas, foram obtidas estimativas das estatísticas F de Wright. Para fins de comparação, utilizou-se também o método da análise da variância para estimação dos parâmetros correspondentes F = F IT , θ P = F ST e f = F IS . Os dois métodos forneceram resultados bastante concordantes: F IT = 0,142; F ST = 0,140; F IS = 0,002 e F = 0,116; θ P = 0,123 e f = -0,008, indicando que os indivíduos dentro das populações devem ser panmíticos e que a diversidade entre populações é bastante alta, sendo similar à que se espera para famílias com estruturação de meios-irmãos. Calculando θ P com as populações tomadas duas a duas, notou-se tendência de θ P crescer com a distância geográfica o que sugere tendência de isolamento pela distância. O fluxo gênico foi estimado em 0,9 indivíduos por geração, o que corrobora a pronunci...

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Section: Resultsunclassified

Conservação genética de populações de Cryptocarya moschata Nees (Lauraceae) na Mata Atlântica do estado de São Paulo

1999

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“…In a recent review of isozyme variation in tropical woody species, Loveless (1992) found an average percentage polymorphic loci P100 of 39.0 (SD 24.3),…”

Section: Levels Of Enzymatic Polymorphism Within the Populationmentioning

confidence: 99%

“…Hence, the resulting spatial genetic structure is not easy to predict. Loveless (1992) stressed the importance and possible application of understanding genetic structure in the context of sustainable management of tropical forests. Ledig's (1992) report of local extirpation for some exploited forest tree species further supports the need to understand genetic structure in tropical forests.…”

Section: Introductionmentioning

confidence: 99%

Genetic diversity and spatial structure within a natural stand of a tropical forest tree species, Carapa procera (Meliaceae), in French Guiana

Doligez

Joly

1997

Heredity

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Isozyme markers were used to characterize levels of diversity, genotypic structure and spatial genetic structure for the low-density tree species, Carapa procera (five adults per ha), within 300 ha of a continuous tropical rain forest stand. Both seed and adult stages were investigated, a high level of genetic diversity being found in both. Fixation indices showed excess homozygosity in seeds, and excess heterozygosity in adults, which might be caused by selection in favour of heterozygotes. Autocorrelation analysis of the spatial distribution of genotypes revealed no significant pattern in adults or in seeds before dispersal, and there was a high variability in correlogram shapes among alleles. This suggests that gene flow is extensive in C. procera, probably mainly through long-distance pollen dispersal, as seed dispersal is expected to be rather limited in this species (maximum distances of about 50 m). No clear-cut spatial pattern was observed in pollen allele frequencies, which supports the hypothesis of extensive pollen flow. This overall lack of structure is consistent with the data already available on the mating system of this predominantly outcrossing species.

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“…Until recently, research on the genetics of tropical trees was confined largely to allozyme studies of the genetic structure of adults in continuous forests [12,13]. The first DNA marker exploited is referred to as Restriction Fragment Length polymorphism [14].…”

Section: Grewia Tenax (Forssk) Fiori Belonging To Thementioning

confidence: 99%

“…1350 IJBPAS, July, 2018, 7(7) Group 4 contained three subgroups, the first and second were from Northern Kordofan (Abuhraz and Almnzfa), (2,5,16,7,8,14,12,17,18,15,10,13,9,35,36,37,38,3,4,6,11), the third from Northern Kordofan (Abuhraz, Almnzfa and Elobaid1), ( 3,4,6,11,21,22,34,23,24,33,25,27,26,28,29,30,32,31). In the present study, 14 of RAPD markers (Table 3) the studies in Grewia optiva species [37].…”

Section: Principal Coordinate Analysis Of the 144mentioning

confidence: 99%

GENETIC DIVERSITY AND POPULATION STRUCTURE AMONG Grewia tenax GENOTYPES IN SUDAN USING RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) MARKERS

2018

IJBPAS

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Random Amplified polymorphic DNA (RAPD) markers were used to characterize the genetic diversity and relationships within and among Grewia tenax populations. 144 Grewia spp genotypes were collected from different localities of Sudan extending from the western, central and eastern Sudan with different ecological zones. DNA was isolated from Grewia spp genotypes according to modified phenol: chloroform: isoamyl alchohol. A total of 14 RAPD primers were selected and used to evaluate the degree of polymorphism and genetic relationships within and among all the Grewia spp under study. Total of 119 amplified July, 2018, 7(7) fragments were distinguished across the selected primers and the statistical analysis showed 112 polymorphic bands among the 144 genotypes with an average of 8 polymorphic bands per primer. The maximum numbers of fragment bands were produced by the primer OPA-17 (13) with 100% polymorphism while the minimum numbers of fragments were produced by the primers PF-08 (6) with 100% polymorphism, OPA-04(6) with 83% polymorphism, OPF-15 (6) with 100% polymorphism and OPA-09 (6) bands with 83% polymorphism. The total genetic diversity (He) and Shannon's diversity information index (I) for the populations were 0.340 and 0.234 respectively. Analysis of molecular variance within populations revealed higher genetic diversity (71%) of the total genetic diversity compared to 29% among populations. This research could be a good step towards to characterize the genetic diversity found within the Grewia tenax genotypes. High level of polymorphism within individuals suggested that RAPD technique can be useful tool for characterization and maintenance of Grewia genotypes for efficient selection of parents for breeding. Such information about the genetic relation is valuable for breeders that can be used to improve adaptive and agronomic traits through marker-assisted selection techniques.

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Isozyme variation in tropical trees: patterns of genetic organization

Cited by 65 publications

References 65 publications

Conservação genética de populações de Cryptocarya moschata Nees (Lauraceae) na Mata Atlântica do estado de São Paulo

Conservação genética de populações de Cryptocarya moschata Nees (Lauraceae) na Mata Atlântica do estado de São Paulo

Genetic diversity and spatial structure within a natural stand of a tropical forest tree species, Carapa procera (Meliaceae), in French Guiana

GENETIC DIVERSITY AND POPULATION STRUCTURE AMONG Grewia tenax GENOTYPES IN SUDAN USING RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) MARKERS

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