基于PEG胁迫的美丽异木棉等园林景观树种抗旱性评价

Drought Resistance Evaluation of Ceiba speciosa and Other Landscape Tree Species Based on PEG Stress

为探究水分胁迫对南方常用园林景观树种生理特性的影响,文章以美丽异木棉Ceiba speciosa等27种南方常用园林树种为材料,采用PEG水分胁迫模拟干旱处理,设置轻度、中度、重度3种胁迫方式,测定其相对电导率、相对含水量以及相对水分亏缺生理指标,进行抗旱性评价。结果表明,随着干旱胁迫程度的增加,27个树种叶片相对电导率值呈增加趋势;在轻度胁迫下,不同处理时间间无显著差异,而27个树种间差异达到极显著(P<0.01);中度胁迫下,27个树种间差异达到极显著(P<0.01),不同处理时间间达到显著(P<0.05);当胁迫程度达到重度时,树种间和不同处理间均达到极显著差异(P<0.01)。选取相对含水量和相对水分亏缺指标,采用模糊隶属函数值法综合评价了27个树种的抗旱性。在园林植物耐旱、节水配置中可以优选穗花棋盘脚Barringtonia racemosa、蓝花楹Jacaranda mimosifolia、黄槐Cassia surattensis、红花荷Rhodoleia championii、蓝花风铃木Tabebuia impetiginosa、杜鹃红山茶Camellia azalea、深山含笑Michelia maudiae、本地木棉Bombax malabaricum、美花红千层Callistemon citrinus、澳洲火焰木Brachychiton acerifolius等树种。

In order to explore the effect of water stress on physiological characteristics of landscape tree species in South China,drought resistance was evaluated.Twenty seven landscape tree species in South China,such as Ceiba speciosa,were used to simulate drought treatment under PEG water stress.Three stress modes,namely mild,moderate and severe,were set up to measure the relative electrical conductivity,relative water content and relative water deficit physiological indexes.The results showed that the relative electrical conductivity of 27 tree species increased with the increase of stress degree.Under mild stress,there was no significant difference among different treatment time,but the difference among 27 tree species reached extremely significant.Under moderate stress,the difference between 27 tree species reached extremely significant(P<0.01),and reached significant between different treatment time(P<0.05).When the stress degree reached severe stress,the difference was significant.There were significant differences among tree species and different treatments.According to the relative water content and relative water deficit,the drought resistance of 27 tree species was comprehensively evaluated by fuzzy membership function value method.In the drought resistant and water-saving configuration of garden plants,we can select some tree species,such as Barringtonia racemosa、Jacaranda mimosifolia、Cassia surattensis、Rhodoleia championii、Tabebuia impetiginosa、Camellia azalea、Michelia maudiae、Bombax malabaricum、Callistemon citrinus and Brachychiton acerifolius.