Narrow-sense heritability estimates for root traits and Monosporascus cannonballus tolerance in melon (Cucumis melo) by parent-offspring regression

The goal of this investigation was to determine the narrow-sense heritability estimates for several melon (Cucumis melo) root traits and tolerance to Monosporascus cannonballus. Control and inoculated greenhouse-grown root systems were analyzed with Rhizo Pro 3.8 software. Progeny means were regressed onto parent means to produce estimates of narrow-sense heritability (h(2)) for root length traits, root area and vine length. Performance of inoculated roots as a percentage of control roots was used to estimate h(2) for disease tolerance. Estimates of h(2) for root lengths and area were high. Estimates of h(2) for M. cannonballus tolerance were highest (1.0+) for total root length and root surface area. Heterosis was observed and was the likely cause of inflated h(2) estimates and transgressive variation. Selection for improved root systems and disease tolerance should be successful due to the additive genetic variation observed.