低温胁迫及恢复对杏树品种雌蕊生长发育的影响

以抗寒品种‘围选1号’和冷敏感品种‘龙王帽’的雌蕊为试验材料,利用LED人工气候箱对杏树枝条进行低温处理,研究低温胁迫和恢复处理对‘围选1号’和‘龙王帽’雌蕊表型、解剖结构和生理指标(相对电导率、丙二醛(MDA)质量摩尔浓度、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性)的影响。结果表明:‘围选1号’和‘龙王帽’雌蕊的相对电导率随温度的降低呈上升的趋势且与抗寒性呈负相关关系,‘围选1号’和‘龙王帽’雌蕊的低温半致死温度(LT50)分别为-3.44℃和-2.30℃。相较于‘围选1号’,‘龙王帽’出现的裂隙较多且裂隙在较高温度时就会出现;‘龙王帽’和‘围选1号’雌蕊的褐化率和MDA质量摩尔浓度随温度的降低呈上升的趋势,与其抗寒性呈负相关关系;CAT和POD活性呈先上升后下降的趋势,与杏树雌蕊的抗寒性呈正相关关系。恢复过程中‘围选1号’的MDA质量摩尔浓度较‘龙王帽’低,POD和CAT活性较高,表明‘围选1号’恢复能力较强;另外,相较于低温胁迫,恢复过程的MDA质量摩尔浓度较低,POD和CAT活性较高,表明温度的恢复使雌蕊的膜损伤有所减缓。

Response of Pistils in Two Contrasting Apricot (Prunus armeniaca L.)Cultivars to Low Temperature Stress and Recovery

Pistils in two contrasting apricot cultivars with different cold tolerance(Longwangmao and Weixuan 1) were used as experimental materials, phenotypic, anatomical and physiological index(relative conductivity, molar concentration of MDA, CAT and POD activities) in pistils were studied by using LED artificial climate box under low temperature stress and recovery. With the decrease of temperature, the relative conductivity of Longwangmao and Weixuan 1 pistils increased and showed a negative correlation with cold tolerance. The semi-lethal temperatures in Longwangmao and Weixuan 1 pistils were-2.30 ℃ and-3.44 ℃, respectively. The rate of freezing injury and molar concentration of MDA increased in two apricot cultivars with the decrease of temperature, which showed a negative correlation with cold tolerance. POD and CAT activities were increased and then decreased, which were positively correlated with the cold tolerance of apricot pistils. Under recovery, molar concentration of MDA, POD and CAT activities in Weixuan 1 were lower than those in Longwangmao, indicating that the recovery ability of Weixuan 1 was stronger. Furthermore, pistils had lower molar concentration of MDA, as well as higher POD and CAT activities under recovery compared to low temperature stress, indicating that the recovery of temperature slowed down the membrane damage in pistils.