Genetics of Brazil nut (Bertholletia excelsa Humb. & Bonpl.: Lecythidaceae)

Buckley, D.P. and O'Malley, D.M. and Apsit, V. and et al, . (1988) Genetics of Brazil nut (Bertholletia excelsa Humb. & Bonpl.: Lecythidaceae). Theoretical and Applied Genetics, 76 (6). pp. 923-928.

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We provide an estimate of genetic variation within and between two populations of Bertholletia excelsa (Brazil nut), a large canopy tree found in the rain forests of South America. Average heterozygosity is 0.190, and 54.3% of the sampled loci are polymorphic. The population structure deviates significantly from Hardy-Weinberg expectations for Fest2 and Pgm2 (F =0.405 and 0.443, respectively) in one population, and highly significantly (F=-0.341) for Gdh in the other population. Although allele frequencies of the two populations differ significantly for Aat2, Est5, Mdh1, and Mdh2B, Nei's coefficient of gene differentiation (Gst) indicates that the between-population component (Dst) of genic diversity represents only 3.75% of the size of the within-population component (Hs). The implications of these findings in terms of conservation genetics are that much of the genetic diversity of this species may be preserved within one or a few populations. However, such populations must be very large because it appears that the large amount of genetic variation in Brazil nut populations is maintained by extensive gene flow and bonds of mating over a large area. The genetic architecture of Bertholletia excelsa is similar to that expected for an extensively diploidized paleopolyploid species.

Item Type: Article
Additional Information: Supported by NSF grants BSR 8300343, BSR 8414295, a Healey grant from the University of Massachusetts, and a Biomedical Research support grant from the University of Massachusetts, Botson.
Uncontrolled Keywords: Genetic diversity, Population genetics, Bertholletia excelsa, Brazil nut, Isozyme analysis.
Author Affiliation: Department of Biology, University of Massachusetts/Boston, 02125, Boston, MA, USA
Subjects: Crop Improvement > Genetics/Genomics
Crop Improvement > Biotechnology
Divisions: Groundnut
Depositing User: Mr Balakrishna Garadasu
Date Deposited: 07 Mar 2013 03:01
Last Modified: 15 Mar 2013 10:51
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