电导法测定鲜食葡萄的抗寒性

以1年生葡萄休眠枝条为试材,应用电导法研究了7个鲜食葡萄品种在不同低温下细胞膜透性的变化,配合Logistic方程求出拐点值,测定冰冻半致死温度(LT50)。结果表明,低温处理下,鲜食葡萄组织电解质渗出率增加呈S形曲线增长,在-15℃～-25℃之间随着温度的下降,葡萄组织电解质渗出率有一急剧升高的敏感区域;葡萄LT50在-13.9℃～-19.72℃之间;品种京秀、矢富罗莎抗冻性最强,美人指抗冻性最弱;提出了以电解质渗出率40.0%～52.0%相对应的拐点温度为枝条组织的临界致死温度。

Study on cold tolerance of table grape cultivars by measuring the conductivity

In order to investigate the semi-lethal temperature(LT50)for grapevine, the changes of cell membrane permeability at different low temperature were studied with 1-year dormant branches collected from 7 table grape cultivars. The temperature of breakpoint was obtained on the basis of conductivity and Logistic equation. The results showed that leakage ratio of electrolyte increased like "S" curve concomitant with a decrease of temperature. It was a sensitive area where leakage ratio of electrolyte increased sharply when the temperatures decreased from -15 ℃ to-25 ℃. The semi-lethal temperature for grapevine was thus defined from -13.9 ℃ to -19.72 ℃.Among the cultivars the Jingxiu and Yatcmi Rosa had the strongest cold tolerance and Manicure Finger the weakest. It is suggested that the temperature with 40.0% to 52.0% of leakage ratio of electrolyte is the lethal temperature of branch tissue.