Molecular marker analysis of heading date Hd1 locus in Egyptian rice varieties
Nine molecular markers derived from the heading date QTL Hd1 DNA sequence for cultivated rice were used to study the heading date allelic diversity of the cultivated Egyptian rice varieties. The results showed that among the nine simple sequence repeats (SSR) and sequence tagged-sites (STS) markers used, one SSR marker, Hd1AGC, amplified three polymerase chain reaction (PCR) fragments (alleles) of various sizes (441, 490, and 620 bp) in all rice varieties, while the rest of the markers amplified only one
non-polymorphic PCR fragment. The study also exhibited that Hd1AGC amplified a unique PCR fragment (620 bp) linked to early heading date in Giza 177 and Sakha 103.
Key words: Flowering time, simple sequence repeats, Oryza sativa L., heading date, sequence tagged-sites.