A quantitative trait locus for reduced culm internode length in barley segregates as a Mendelian gene.

Yield losses caused by lodging in cereals can be partially controlled by reducing plant height. A progeny of recombinant inbred lines from a cross of two Japanese barley varieties was used to study the inheritance of culm and culm internode lengths. An unexpected QTL for reduced culm length (qCUL), which affected mainly the length of the third and fourth culm internodes, was contributed by 'Kanto Nakate Gold'. This QTL was also associated with reduced lodging in two experiments. A near-isogenic line (culm length 62.9-73.4 cm) in an 'Azumamugi' background, carrying a chromosome segment containing the qCUL allele from Kanto Nakate Gold, was significantly shorter than its recurrent parent (82.9-89.4 cm). The F(2) generation from the next backcross segregated for plant height in a Mendelian monogenic ratio. The qCUL locus was shown to be tightly linked (1.2 cM) with the codominant STS marker ABG608.