春季—冻融交替时期9种落叶及半常绿小灌木抗寒性综合评价

在春季—冻融交替时期,以北京地区迎春、金叶女贞、小花溲疏等9种落叶及半常绿小灌木一年生枝条为试材,通过人工模拟降温,测定其在4~-20℃低温胁迫下的6个生理响应指标,并对各指标进行相关性分析。结果表明,相对电导率、半致死温度、游离-脯氨酸含量和相对含水量这4个生理指标可作为9种小灌木抗寒性的评价指标。利用主成分分析、隶属函数法进行抗寒性综合评价,发现9种小灌木的抗寒性强弱顺序为:小花溲疏紫叶小檗太平花红王子锦带迎春连翘金叶女贞棣棠金山绣线菊。通过聚类分析可将9种小灌木分为3类,小花溲疏和紫叶小檗归为一类,其抗寒性相对较好;太平花、红王子锦带、迎春和连翘聚成一组,抗寒性一般;金叶女贞、棣棠和金山绣线菊聚在一起,抗寒性相对较差。

Comprehensive Evaluation on Cold Resistance of Nine Kinds of Deciduous and Semi-evergreen Dwarf Shrubs from the Freeze to Melt Period in Spring

During the alternation from the freeze to melt period in spring, annual shoots from nine kinds of deciduous and semi-evergreen dwarf shrubs in Beijing, including Jasminum nudiflorum, Ligustrum vicaryi, and Deutzia parviflora, were used to measure six physiological response indices to low temperatures from 4℃ to -20℃ through an artificially-simulated cooling process. Based on correlation analysis among the six physiological indices, relative conductivity, semi-lethal temperature, free proline content and relative water content could be used to evaluate cold resistance. Using principal component analysis and subordinate functions to assess cold resistance comprehensively, the order of all nine dwarf shrubs was: Deutzia parviflora > Berberis thunbergii var. atropurpurea>Philadelphus pekinensis>Weigela florida ‘Red Prince’>Jasminum nudiflorum>Forsythia suspensa > Ligustrum vicaryi>Kerria japonica>Spiraea bumalda ‘Gold Mound’. According to cluster analysis, the nine dwarf shrubs could be divided into three groups. Among them, Deutzia parviflora and Berberis thunbergii var. atropurpurea could be classified as a class that had relatively higher cold resistance. Philadelphus pekinensis, Weigela florida ‘Red Prince’, Jasminum nudiflorum and Forsythia suspensa were categorized with medium cold resistance, and Ligustrum vicaryi, Kerria japonica, and Spiraea bumalda ‘Gold Mound’ were classified with relatively low cold resistance.