黄瓜嫁接苗抗冷特性研究

Study on Low Temperature Tolerance in Grafted Cucumber Seedlings

研究了以黑籽南瓜为砧木的长春密刺黄瓜嫁接苗的低温致死温度和对５℃低温胁迫的反应。结果表明，黄瓜嫁接苗叶片与根系致死温度均显著低于自根苗。５℃低温胁迫４天，嫁接苗叶片与根系电解质泄漏率均低于５０％，幼苗移至常温下尚能恢复；而对照幼苗叶片与根系电解质泄漏率均超过５０％，移至常温下不能恢复。在５℃低温胁迫下，嫁接苗叶片相对含水量、叶绿素含量、呼吸强度和气孔阻力均显著高于自根苗，而叶片蒸腾强度和根系琥珀酸脱氢酶活性均低于自根苗，但根系琥珀酸脱氢酶活性较自根苗稳定。嫁接苗叶片较强的保水力和较高的能量代谢水平是较自根苗抗冷的重要原因。

Lethal temperature and physiological effect of low temperature stress at 5℃ (1d,2d,3d and 4d) in the grafted cucumber seedlings (GS) and the own root cucumber seedlings (OS) were studied. Rootstock and scion were figleaf gourd ( Cucurbita ficifolia Bouche) and cucumber ( Cucumis sativus L. ) cv. Chang Chun Mi Ci. respectively. The results showed that lethal temperature of both leaves and roots of GS were lower than that of OS. Electrolytic leakage (%) of both leaves and roots of GS was lower than 50% respectively under 5℃ for 4d, however, that of OS was greater than 50%. Relative water content, chlorophyll content,respiratory intensity and stomatal resistance in GS leaves were higher than those in OS leaves. Transpiratory intensity in leaves and succinic dehydrogenase activity in root of GS were lower than those of OS under 5℃. However, succinic dehydrogenase activity in roots of GS was more stable than that in roots of OS under the low temperature stress.