| 摘要: | The effects of CO₂ enrichment on the in vitro growth and acclimatization of Protea cynaroides L. plantlets were investigated. Three CO₂ enrichment concentrations were used: 0 (control), 1000, 5000, and 10000 μmol．mol⁻¹. Plantlets in the control treatment were cultured on half-strength Murashige and Skoog (MS) medium supplemented with sucrose, whereas those enriched with different CO₂ concentrations were grown on sucrose-free MS medium. Compared with the control, significant improvements were observed in the growth of plantlets enriched with CO₂ irrespective of the concentration. Plantlets enriched with 5000 μmol·mol⁻¹ CO₂ produced the highest number of leaves and the largest leaf area. In addition, the photosynthetic ability of plantlets enriched with CO₂ was enhanced, which resulted in significant increases in shoot growth and dry matter accumulation. In particular, the shoot dry weight of plantlets cultured in 5000μmol·mol⁻¹CO₂ and 10000μmol·mol⁻¹CO₂ were, respectively, 2.1 and 4.2 times higher than those without CO₂ enrichment. During acclimatization, the survival percentage, rooting percentage, and leaf number of plantlets grown in elevated CO₂ were, respectively, up to 4.5, 1.8, and 2.7 times higher than plantlets without CO₂ enrichment. The improvements in survival percentage and ex vitro growth of these plantlets were the result of their enhanced photosynthetic ability in vitro, which resulted in the production of high-quality plantlets. Significant improvements in the overall growth of P. cynaroides plantlets were achieved through the use of photoautotrophic micropropagation with CO₂ enrichment. |
