Abstract:

【Objective】 The objective of the experiment is to screen heat-tolerant variants in Gerbera hybrida with Shenzhen 5 (S5) as material. 【Method】 Heat tolerant lines EH and H10 were obtained by in vitro screening with treatments of EMS and intermittent high temperature. After rooting, the regenerated plants were transferred to field. The growth and some physiological and biochemical changes of leaf, the yield and quality of cut flower under natural high temperature environment were determined. 【Result】 Compared with the control, the leaf area of H10 was larger and chlorophyll content was higher. In July and August, the hottest months of the year in Zhuhai, the flower yield of H10 increased by 55.67% and 53.27% and flower diameter increased by 5.57% and 5.70%, scape length increased by 10.35% and 11.77%, respectively, and the anthocyanin content of H10 petals was also obviously higher than that of the control. Moreover, H10 showed higher membrane stability with lower permeability, higher proline content and increased activities of superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX). Nevertheless, EH had no significant improvement in the characters of plant growth, flower yield and quality under natural high temperature conditions. 【Conclusion】 H10 would be an excellent heat-tolerant variant of G. hybrida from the field identification and determination of physiological and biochemical changes.

Key words: Gerbera hybrida, heat tolerance, in vitro screening, field identification