秋石斛‘三亚阳光’中苗低温胁迫生理响应研究及耐寒指标筛选

对秋石斛’三亚阳光’中苗进行15、10和5℃胁迫处理,测定各处理样品的电导率、可溶性蛋白、可溶性糖、游离脯氨酸、丙二醛、叶绿素含量、恢复生长之后的落叶率等耐寒生理指标,分析这些耐寒指标在胁迫下的变化规律,筛选出有效的耐寒评价生理指标。结果表明,电导率及可溶性蛋白、可溶性糖、游离脯氨酸、丙二醛含量和落叶率均随着处理温度的降低和处理时间的延长呈现上升趋势,而叶绿素含量则呈现逐渐下降的趋势。相关性分析发现,可溶性糖、游离脯氨酸、丙二醛、叶绿素含量和落叶率都与半致死温度有极显著的相关性,表明可溶性糖、游离脯氨酸、丙二醛、叶绿素含量和落叶率可作为秋石斛’三亚阳光’耐寒性综合评价的有效评价指标。研究结果可以为秋石斛种质资源的耐寒性评价提供了理论依据和技术方法。

Physiological Response of Low Temperature Stress and Screening of Cold-resistant Assessment Indicators of Middle Age Plantlets Dendrbium Sonia Hiasakul

In order to select effective cold-resistant physiological indexes and provide reference for cold tolerance evaluation of germplasm resources of Dendrobium hybrid, the middle age plantlets Dendrbium ’Sonia Hiasakul’ were subjected to low temperature stress at 15, 10 and 5 ℃, respectively. And then the electrical conductivity, soluble protein, soluble sugar, free proline, Malondialdehyde(MDA), chlorophyll content and the rate of defoliation after regrowth were measured, the change rule of the cold-resistance indexes under low temperature stress was analyzed, and the effective cold-resistance evaluation indexes were selected through correlation analysis. The results showed that the electrical conductivity, soluble protein, soluble sugar, free proline, MDA content and defoliation rate were increased with the decrease of treatment temperature. It was indicated that the content of soluble sugar, free extension of treatment time,however, the content of chlorophyll was decreased gradually. The correlation analysis showed that soluble sugar, free proline, Malondialdehyde, chlorophyll content and defoliation rate were significantly correlated with the semi-lethal temperature. Proline, malondialdehyde, chlorophyll and defoliation rate could be used as the effective indexes for the comprehensive assessment of cold tolerance of Dendrbium ’Sonia Hiasakul’. The results could provide a theoretical basis and technical method for the comprehensive assessment of cold tolerance of Dendrobium hybrid.