Molecular detection of QTL controlling plant height components in a doubled haploid barley population.

Yield losses caused by lodging in barley can be partially controlled by reducing plant height. In order to understand dwarfing mechanisms and efficiently use new dwarf germplasms for a breeding program, it is important to identify QTL of plant height components. QTL analysis was performed for seven plant height component traits using a DH population of 122 lines derived from the cross of Huaai 11 x Huadamai 6. Composite interval mapping procedures detected 20 QTL, which were mapped onto chromosomes 2H, 3H, 5H, 6H, and 7H. Eleven QTL were detected in 3 years and four QTL were detected in 2 years. QTL controlling all seven plant height component traits were found near the dwarfing gene btwd1 on chromosome 7H. These QTL accounted for 27.19 to 59.73% of phenotypic variation in seven plant height component traits. Positive transgressive segregation was found for all traits. Some of the QTL identified in this study will be useful for understanding the dwarfing mechanism and for developing new dwarf varieties using marker-assisted selection.