Short-statured plants revolutionized agriculture during the 1960s due to their ability to resist lodging, increased their response to fertilizers, and improved partitioning of assimilates which led to yield gains. Of more than 21 reduced-height (
Rht) genes reported in wheat, only three—
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Short-statured plants revolutionized agriculture during the 1960s due to their ability to resist lodging, increased their response to fertilizers, and improved partitioning of assimilates which led to yield gains. Of more than 21 reduced-height (
Rht) genes reported in wheat, only three—
Rht-B1b,
Rht-D1b, and
Rht8—were extensively used in wheat breeding programs. The remaining reduced height mutants have not been utilized in breeding programs due to the lack of characterization. In the present study, we determined the inheritance of
Rht18 and developed a genetic linkage map of the region containing
Rht18. The height distribution of the F
2 population was skewed towards the mutant parent, indicating that the dwarf allele (
Rht18) is semi-dominant over the tall allele (
rht18).
Rht18 was mapped on chromosome
6A between markers barc146 and cfd190 with a genetic distance of 26.2 and 17.3 cM, respectively. In addition to plant height, agronomically important traits, like awns and tiller numbers, were also studied in the bi-parental population. Although the average tiller number was very similar in both parents, the F
2 population displayed a normal distribution for tiller number with the majority of plants having phenotype similar to the parents. Transgressive segregation was observed for plant height and tiller number in F
2 population. This study enabled us to select a semi-dwarf line with superior agronomic characteristics that could be utilized in a breeding program. The identification of SSRs associated with
Rht18 may improve breeders’ effectiveness in selecting desired semi-dwarf lines for developing new wheat cultivars.
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