INVESTIGADORES
TOSTO Daniela Sandra
artículos
Título:
? Population Genetics Structure of Glyphosate-Resistant Johnsongrass (Sorghum halepense L. Pers) does not support a single origin of the Resistance
Autor/es:
FERNÁNDEZ, L; DE HARO, L; DISTÉFANO, A.J; CAROLINA MARTÍNEZ; LIA, VERÓNICA; OLEA,I; PAPA, JUAN CARLOS; ESTEBAN HOPP; DANIELA TOSTO
Revista:
TRENDS IN ECOLOGY AND EVOLUTION - TREE
Editorial:
ELSEVIER SCIENCE LONDON
Referencias:
Lugar: Londres; Año: 2013 vol. 3 p. 3388 - 3400
ISSN:
0169-5347
Resumen:
Single sequence repeats (SSR) developed for Sorghum bicolor were used to characterize
the genetic distance of 46 different Sorghum halepense (Johnsongrass)
accessions from Argentina some of which have evolved toward glyphosate resistance.
Since Johnsongrass is an allotetraploid and only one subgenome is
homologous to cultivated sorghum, some SSR loci amplified up to two alleles
while others (presumably more conserved loci) amplified up to four alleles.
Twelve SSR providing information of 24 loci representative of Johnsongrass
genome were selected for genetic distance characterization. All of them were
highly polymorphic, which was evidenced by the number of different alleles
found in the samples studied, in some of them up to 20. UPGMA and Mantel
analysis showed that Johnsongrass glyphosate-resistant accessions that belong to
different geographic regions do not share similar genetic backgrounds. In
contrast, they show closer similarity to their neighboring susceptible counterparts.
Discriminant Analysis of Principal Components using the clusters identified
by K-means support the lack of a clear pattern of association among
samples and resistance status or province of origin. Consequently, these results
do not support a single genetic origin of glyphosate resistance. Nucleotide
sequencing of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) encoding
gene from glyphosate-resistant and susceptible accessions collected from
different geographic origins showed that none presented expected mutations in
aminoacid positions 101 and 106 which are diagnostic of target-site resistance
mechanism.