Abstract

Bananas that are biologically tolerant of excess water will complement the current costly engineering solution of surface or deep drainage systems. Banana roots are sensitive to low oxygen (O₂) content, a consequence of waterlogging (WL). Identifying root characters that favor reduced physical resistance to gas diffusion (Rρ, s cm^-3) may improve tolerance of banana roots to waterlogging. In this study, response of root growth and root characters influencing Rρ such as root porosity and thickness under waterlogging were measured. Root length under WL was significantly reduced by about 48% compared with well-drained control. Regardless of root type, treatment and sampling time, trend in root thickness was the same, in the order of Saba (BBB)>Tindok (ABB)≥Latundan (AAB)>Lakatan (AA)>Quarenta dias (QD) (AA). Root diameter was highly associated with the B genome and ploidy. All of the five cultivars had >10% porosity even in well-drained condition. When waterlogged, QD (AA) had significantly reduced Rρ along the root length whereas, the thicker roots of Saba and Latundan reduced Rρ only at the base.