Flooding tolerance in interspecific introgression lines in Zea

Nicaraguan teosinte Zea nicaraguensis, a species found in frequently flooded areas, is useful germplasm for breeding flooding-tolerant maize. Mano and Omori select flooding-tolerant lines using a library of introgression lines (ILs), each containing a chromosome segment from Z. nicaraguensis in the maize (Z. mays) inbred Mi29. The most flooding-tolerant line they identify contains a Z. nicaraguensis chromosome segment on the long arm of chromosome 4, suggesting the presence of a major quantitative trait locus (QTL) in that region. There is no significant relationship between the capacity to form constitutive aerenchyma and flooding tolerance in the ILs, indicating the presence of other factors related to flooding tolerance under reducing soil conditions.