摘要
【目的】探究低温胁迫下2种火龙果植株的耐寒性差异及机理。【方法】以‘白水晶’和‘台湾6号’火龙果植株为材料,设置适温(30℃/24℃)、冷害(15℃/8℃)、冻害(4℃/-2℃)3个温度梯度,分析火龙果植株的冷害指数、抗氧化系统及脂肪酸组分等的变化情况。【结果】低温胁迫使2种火龙果植株的冷害指数均升高,且在冻害下升高幅度更大;冷害和冻害下,‘白水晶’的冷害指数均低于‘台湾6号’。低温诱导2种火龙果植株的抗氧化酶活性显著升高,而‘白水晶’抗氧化酶活性升高幅度始终高于‘台湾6号’;同时,‘白水晶’植株ROS积累量、MDA含量和REC增幅更低。2种火龙果植株的不饱和脂肪酸相对含量及UFA/SFA随温度降低而降低;其中‘白水晶’植株的降幅较小。【结论】低温胁迫使2种火龙果植株均受冻,其中‘白水晶’的耐寒性强于‘台湾6号’。在冷害和冻害下,‘白水晶’植株保持较高的抗氧化酶活性和ROS清除能力,减轻膜脂过氧化伤害,提高脂肪酸不饱和度是其耐寒性较强的主要原因。结果可为亚热带地区火龙果植株的抗寒栽培提供一定的理论依据。
【Objective】The objective of this study was to explore the mechanisms of cold tolerance in two varieties of pitaya under low-temperature stress.【Method】'Baishuijing'and'Taiwan No.6'pitayas were used as materials to analyze changes in the chilling injury index(CI),antioxidant systems,and fatty acid composition across three temperature gradients:optimal(30℃/24℃),chilling(15℃/8℃),and freezing(4℃/-2℃).【Result】The CI of both pitaya varieties increased under low-temperature stress,with higher levels observed under freezing conditions.Under chilling and freezing conditions,the CI of'Baishuijing'was consistently lower than that of'Taiwan No.6'.The activity of antioxidant enzymes in both pitaya plants significantly increased in response to low temperatures,with'Baishuijing'consistently showing higher activity than'Taiwan No.6'.Additionally,'Baishuijing'exhibited lower accumulation of reactive oxygen species(ROS),lower increases in malondialdehyde(MDA)content,and reduced electrolyte leakage(REC).The relative content of unsaturated fatty acids and the ratio of unsaturated to saturated fatty acids(UFA/SFA)in both pitaya plants decreased with temperature reduction,but this decline was less pronounced in'Baishuijing'.【Conclusion】Both pitaya varieties were susceptible to freezing under low-temperature stress,but‘Baishuijing’demonstrated stronger cold tolerance than'Taiwan No.6'.'Baishuijing'maintained higher antioxidant enzyme activity and ROS scavenging capacity,reduced membrane lipid peroxidation damage,and enhanced fatty acid unsaturation under chilling and freezing conditions,which are the main reasons for its enhanced cold tolerance.These findings provide a theoretical basis for the cold-resistant cultivation of pitaya in subtropical regions.
作者
王晓莉
罗弦
王楚侨
徐嘉宁
WANG Xiaoli;LUO Xian;WANG Chuqiao;XU Jianing(College of Horticulture,Sichuan Agricultural University,Chengdu 611130,China)
出处
《四川农业大学学报》
CSCD
北大核心
2024年第2期339-345,共7页
Journal of Sichuan Agricultural University
基金
四川省衔接推进乡村振兴科技项目(2022ZHXC0097)
四川农业大学专业建设支持计划(2221998084)。
关键词
低温胁迫
火龙果
耐寒性
抗氧化系统
脂肪酸
low temperature stress
pitaya plants
cold resistance
antioxidant system
fatty acid
