An examination of zinc uptake patterns by cultivars of sorghum and maize : Differences amongst hybrids and their parents

Abstract

Zinc absorption and transport patterns were examined in sorghum and maize hybrids and their parent cultivars with a view to observe, if any, and relate the differences amongst them meaningfully to traits like hybrid vigor. Short term uptake by excised roots or intact seedlings, from different concentrations of ZnCl₂ or ZnEDDHA and also, time course from 50 μM ZnCl₂, were measured. The results showed significant differences in the Zn absorption patterns by excised roots of sorghum cultivars. The rate of Zn transport to shoot in CSH‐8 was found to be higher than in others. The amount of Zn transported from ZnEDDHA was also more than that from ZnCl₂ in all sorghum cultivars. Furthermore, significant hybrid vigor was observed in Zn transport from ZnEDDHA for the two hybrids CSH‐7 and CSH‐8. The resemblance of absorption and transport patterns of Zn in CSH‐8 to those of 36‐A strongly suggests that the trait is inherited from the female parent.

No heterosis was observed in the absorption and transport of Zn in maize hybrids. However, a linear and an exponential isotherms for Zn transport in Ganga‐5 and Ganga‐2 hybrids indicates some hybrid vigor.

Key words:

• Zn absorption
• transport
• sorgum
• maize
• hybrid vigor