Zinc‐stress response in some sorghum hybrids and parent cultivars: Significance of pH reduction and recovery from chlorosis

Abstract

Zinc deficiency was induced in two sorghum hybrids and their parent cultivars by growing them in complete nutrient medium for 30 days and then transferring to minus zinc medium at pH 6.4. The onset of Zn chlorosis and recovery as well as the change in the pH of the nutrient medium under Zn‐stress conditions were recorded. It was found that chlorotic symptoms due to Zn deficiency appeared after 2 days of stress and persisted for a long period in the cultivars, 36‐A and 168, while the hybrid CSH‐7 (36‐A X 168) recovered from chlorosis after 12 days. The hybrid CSH‐8 (36‐A X PD‐3) was chlorotic after 2 days, but recovered after 15 days.

A significant hybrid vigor was observed for Zn‐stress tolerance in the hybrid CSH‐7 and CSH‐8.

Key words:

• Zn‐stress response
• sorghum cultivars
• hybrid vigor