外源物质处理对大果榉扦插苗抗寒性的影响

Effects ofExogenous Substance Treatment on Cold Resistance of Cutting Seedlings of Zelkova sinica

以1年生大果榉扦插苗为试验材料,探讨喷施不同浓度多效唑(PP_(333))与CaCl_(2)对其抗寒性的影响。结果表明,在试验温度范围内,与对照相比,喷施此2种外源物质均可不同程度降低大果榉叶片的相对电导率和MDA含量,延缓光合色素和可溶性蛋白含量的降解;大果榉幼苗冻害级别与相对电导率、MDA含量呈极显著正相关,与光合色素和可溶性蛋白含量呈极显著负相关。隶属函数法对不同处理大果榉抗寒性的评价结果与自然越冬后冻害级别的统计结果相一致,外源物质种类及其使用浓度对大果榉幼苗抗寒性影响的大小依次为20 mmol/L CaCl_(2)>25 mmol/L CaCl_(2)>0.15%PP_(333)>0.1%PP_(333),20 mmol/L CaCl_(2)提高抗寒效果最优。

In order to explore the effects of different concentrations of PP_(333)and CaCl_(2) on the cold resistance of Zelkova sinica,the annual cutting seedlings were used as materials.The results showed that in the range of experimental temperature,the two exogenous substances could reduce the relative conductivity and MDA content in the leaves,and delay the degradation of photosynthetic pigment and soluble protein content,compared with the control.The freezing damage grade of the seedlings was positively related to relative conductivity and MDA content,negatively related to photosynthetic pigment and soluble protein content.By the membership function method,the comprehensive evaluation of the cold resistance of Z.sinica with different treatments was consistent with the results of freezing damage grade after natural overwintering.The influence of the types and the concentrations of exogenous substances on the cold resistance of Z.sinica,from strong to weak was in the order of 20 mmol/L CaCl_(2)>25 mmol/L CaCl_(2)>0.15%PP_(333)>0.1%PP_(333).And 20 mmol/L CaCl_(2) was the optimal treatment to improve the cold resistance of Z.sinica.