Abstract
The introgression of
Reduced height
(
Rht
)-
B1b
and
Rht
-
D1b
into bread wheat (
Triticum aestivum
) varieties beginning in the 1960s led to improved lodging resistance and yield, providing a major contribution to the ‘green revolution’. Although wheat
Rht
-
1
and surrounding sequence is available, the genetic composition of this region has not been examined in a homoeologous series. To determine this, three
Rht
-
1
-containing bacterial artificial chromosome (BAC) sequences derived from the A, B, and D genomes of the bread wheat variety Chinese Spring (CS) were fully assembled and analyzed. This revealed that
Rht
-
1
and two upstream genes were highly conserved among the homoeologs. In contrast, transposable elements (TEs) were not conserved among homoeologs with the exception of intronic miniature inverted-repeat TEs (MITEs). In relation to the
Triticum urartu
ancestral line, CS-A genic sequences were highly conserved and several colinear TEs were present. Comparative analysis of the CS wheat BAC sequences with assembled
Poaceae
genomes showed gene synteny and amino acid sequences were well preserved. Further 5′ and 3′ of the wheat BAC sequences, a high degree of gene colinearity is present among the assembled
Poaceae
genomes. In the 20 kb of sequence flanking
Rht
-
1
, five conserved non-coding sequences (CNSs) were present among the CS wheat homoeologs and among all the
Poaceae
members examined.
Rht
-
A1
was mapped to the long arm of chromosome 4 and three closely flanking genetic markers were identified. The tools developed herein will enable detailed studies of
Rht
-
1
and linked genes that affect abiotic and biotic stress response in wheat.