Figure 1.

Aerial roots produced on different maize accessions secrete mucilage and support biological nitrogen fixation. (A) Aerial roots formed on the stem of maize accessions Ames 19897 that produce 1,5 mL of mucilage are longer and thicker than those produced in common maize variety PHP02 (25 µL). (B) There is a correlation between root diameter, volume of mucilage produced, and the ability to support nitrogen fixation. Aerial roots from 22 distinct maize accessions showed variable diameters. Those with larger diameters tended to secret more mucilage, showing higher nitrogenase activity (nmol of ethylene per hour per mL of mucilage). The Blue to red color scale indicates the nmole/ethylene/mL/h.