Abstract
Rht8 is widely used in dry environments such as Mediterranean regions where
it increases plant adaptability. Variation at the Gatersleben wheat
microsatellite Xgwm261 locus, whose 192-bp allele closely linked to the
dwarfing gene Rht8, on chromosome 2D within 0.6 cM, was used to screen thirty
Egyptian bread wheat genotypes released from (1947-2004) to assess the
variation at this locus. There were three microsatellite allelic variants
based on size. Screening of this wheat collection showed that the three
alleles Xgwm261-165, Xgwm261-174 and Xgwm261-192 bp were the most frequent.
The highest allele frequency was observed for a Xgwm261-165 bp fragment
(65.52%) followed by a Xgwm261-174 bp fragment (24.14%). However, the allele
frequency of a Xgwm261-192 bp fragment among these wheat genotypes was
10.34%. The percentage distribution of dwarfing alleles for the
microsatellite locus Xgwm261 in the Egyptian wheat breeding programs was 30,
20, 20 and 30% for the wheat breeding program Giza, Sakha, Gemmiza and Sids,
respectively. PIC for Xgwm261 was 0.527. Genetic heritage of Egyptian
genotypes at the microsatellite locus Xgwm261 is consequence of new parental
components usage, carriers short plant and early maturity attributes and
consequent selection progeny with these traits in breeding programs. The
present study will be helpful in characterization Egyptian wheat genotypes,
as well as in accurate selection of parents for wheat breeding program in
Egypt.
nema