Molecular Biology and Genetics
Electronic Journal of Biotechnology ISSN: 0717-3458 Vol. 11 No. 5, Special Issue, 2008
© 2008 by Pontificia Universidad Católica de Valparaíso -- Chile  
DOI: 10.2225/vol11-issue5-fulltext-6
RESEARCH ARTICLE

Assessment of genetic diversity in Venezuelan rice cultivars using simple sequence repeats markers

Thaura Ghneim Herrera
Laboratorio de Ecofisiología Vegetal & Unidad de Ecología Genética
Centro de Ecología
Instituto Venezolano de Investigaciones Científicas
Apartado Postal 21827, Caracas 1020-A
Caracas, Venezuela
Tel: 58 212 5041246
Fax: 58 212 5041203
E-mail: tghneim@ivic.ve

Duina Posso Duque*
Unidad de Biotecnología y Agrobiodiversidad
Centro Internacional de Agricultura Tropical
A.A. 6713, Cali, Colombia
Tel: 57 2 4450000
Fax: 57 2 4450073 

Iris Pérez Almeida
Instituto Nacional de Investigaciones Agrícolas
INIA-CENIAP
Apartado Postal 4653, Maracay 2101-A
Edo. Aragua, Venezuela
Tel: 58 243 2471066
Fax: 58 243 2474111
E-mail: i.perez@inia.gob.ve 

Gelis Torrealba Núñez
Instituto Nacional de Investigaciones Agrícolas
INIA-Guárico
Apartado Postal No. 14, Calabozo 2312
Edo. Guárico, Venezuela
E-mail: gtorrealba@inia.gob.ve

 Alejandro J. Pieters
Laboratorio de Ecofisiología Vegetal & Unidad de Ecología Genética
Centro de Ecología
Instituto Venezolano de Investigaciones Científicas
Apartado Postal 21827. Caracas 1020-A
Caracas, Venezuela
Tel: 58 212 5041246
Fax: 58 212 5041203
E-mail: apieter@ivic.ve

César P. Martinez
Unidad de Biotecnología y Agrobiodiversidad
Centro Internacional de Agricultura Tropical
A.A. 6713, Cali, Colombia
Tel: 57 2 4450000
Fax: 57 2 4450073
E-mail: c.p.martinez@ciat.cgiar.org

Joe M. Tohme
Unidad de Biotecnología y Agrobiodiversidad
Centro Internacional de Agricultura Tropical
A.A. 6713, Cali, Colombia
Tel: 57 2 4450000
Fax: 57 2 4450073
E-mail: j.tohme@ciat.cgiar.org

*Corresponding author

Financial support: Agricultural Biotechnology Program BID-FONACIT II (Project 2004000371), Science and Technology Ministry of Venezuela.

Keywords: DNA fingerprinting, genetic diversity, rice, SSR.

Abbreviations:

AFLP: amplified fragment length polymorphism
H: genic diversity
NA: number of alleles
SSR: simple sequence repeat

Abstract   Full Text

In Venezuela, pedigree analyses indicate that the rice varieties currently under cultivation are closely related. Effective breeding programs, based on knowledge of the genetic diversity of cultivars, are needed to broaden the genetic bases of rice germplasm in the country. In this study, we used a set of 48 simple-sequence-repeat (SSR) markers to assess the genetic diversity of 11 Venezuelan rice cultivars, released by the National Rice Breeding Program between 1978 and 2007. A total of 203 alleles were detected, the number of alleles (NA) per marker ranged from 2 to 9, with an average of 4.23. The average genic diversity (H) over all SSR loci for the 18 genotypes was 0.524, ranging from 0.105 to 0.815. Positive correlations were found between H at each locus, NA, the allele size range and the maximum number of repeats. Venezuelan cultivars showed lower H (mean = 0.37) and NA (total = 124, mean = 2.58) than the whole sample. UPGMA-cluster-analysis based on genetic distance coefficients clearly separated all the genotypes, and showed that the Venezuelan rice varieties are closely related. Molecular identification of 7 Venezuelan cultivars could be done with 9 primers pairs which produced 10 genotype-specific-alleles. Although the genetic diversity was low, SSRs proved to be an efficient tool in assessing the genetic diversity of rice genotypes. Implications of the low genetic diversity detected and relatedness of Venezuelan cultivars are discussed.

Supported by UNESCO / MIRCEN network