INVESTIGADORES
LIJAVETZKY diego Claudio
artículos
Título:
Genetic and physical characterization of grain texture-related loci in diploid wheat
Autor/es:
TRANQUILLI, G; LIJAVETZKY, D; MUZZI, G; DUBCOVSKY, J
Revista:
MOLECULAR AND GENERAL GENETICS
Referencias:
Año: 1999 vol. 262 p. 846 - 850
ISSN:
0026-8925
Resumen:
Endosperm texture, i.e. the hardness or softness of the grain, is an
important quality criterion in cereals because it determines many grain
end-use properties. Grain softness is the dominant trait and is mainly
controlled by the Ha locus on the short arm of chromosome 5D in
hexaploid bread wheat. Genes for puroindoline a (Pina-D1), puroindoline
b (Pinb-D1), and grain softness related protein (Gsp-D1) have been
shown to be linked to the Ha locus in different mapping populations and
have been associated with the expression of grain softness. The study
of the linkage relationships among these genes has been limited by the
low level of polymorphism in the D genome of hexaploid Triticum
aestivum. In the present study, a highly polymorphic Triticum
monococcum mapping population was used to analyze linkage relationships
among these three genes. Gsp-Am1 and Pina-Am1 were found to be
completely linked and lie 0.14 cM distal to Pinb-Am1 in the distal
region of the short arm of chromosome 5Am. The tight genetic linkage
among these three genes was paralleled by their physical proximity
within a single 105-kb clone isolated from a T. monococcum bacterial
artificial chromosome (BAC) library. A restriction map of this BAC
clone showed that Pina-Am1 is located between Pinb-Am1 and Gsp-Am1.
Partial sequences of the T. monococcum genes showed a high degree of
similarity with their T. aestivum counterparts (> or =94%).
Marker-assisted selection strategies based on the tight linkage among
Ha-related genes are discussed.