Genetic structure of Brazilian wild rice (Oryza glumaepatula Steud., Poaceae) populations analyzed using microsatellite markers

Genetics and Molecular Biology

Marines M.g. Karasawa²  Roland Vencovsky²  Cynthia M. Silva²  Maria Imaculada Zucchi¹  Giancarlo C.x. Oliveira²  Elizabeth A. Veasey² 

[1] ,Universidade de São Paulo Escola Superior de Agricultura Luiz de Queiroz Departamento de GenéticaPiracicaba SP ,Brazil

关键词: conservation;    gene flow;    genetic diversity;    microsatellites;    Oryza glumaepatula;   

DOI  :  10.1590/S1415-47572007000300017

来源: SciELO

【 摘 要 】

Knowledge of the genetic structure and diversity of natural populations is important in developing strategies for in situ and ex situ conservation. We used eight microsatellite loci to estimate genetic structure and investigate within and between population genetic variation in eleven Brazilian wild rice (Oryza glumaepatula) populations. The study showed the following genetic diversity parameters: average number of 3.1 alleles per locus; 77.3% polymorphic loci; 0.091 observed heterozygosity and 0.393 gene diversity. F-statistics detected by microsatellite loci were: F ST = 0.491 (and R ST = 0.608), F IS = 0.780 and F IT = 0.888. No population was in Hardy-Weinberg equilibrium. The estimated apparent outcrossing rate (0.143) indicated a predominance of self-fertilization. The gene flow values were low (Nm = 0.259 and 0.161 for F ST and R ST, respectively). Populations were spatially structured but without a correlation between genetic and geographic distances. Five populations (PG-4, PG-2, PU-1, SO-4, NE-18) were identified as priorities for conservation strategies. Populations from the Amazon biome showed heterogeneity with respect to intrapopulation diversity. The high level of genetic differentiation between populations and the high number of private alleles suggested that sampling should be carried out on a large number of O. glumaepatula populations for ex situ conservation purposes.

【 授权许可】

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