This subset identifies Manganese efficient (germplasm that is tolerant to Mn deficiency) materials.

In the field, as with Fe deficiency, Mn deficiency can be induced on calcareous soils or after heavy applications of lime. Mn deficiency shows up as patches of pale, floppy wheat in an otherwise green healthy crop; symptoms may be worse in compacted areas, such as wheel tracks.

Chloroplasts in plants are most sensitive to Mn deficiency, which results in pale plants and is, to some degree, similar to iron (Fe) and magnesium (Mg) deficiencies. However, symptoms of Mn deficiency can be quite characteristic. In wheat, symptoms appear first in new leaves, which become pale and limp in contrast to the old leaves.