低温胁迫下黄瓜嫁接苗和自根苗内源激素的变化

Changes of Hormone in Grafted and Non grafted Cncumber Seedlings Under Low Temperature Stress

以黄瓜自根苗为对照, 研究了以黑籽南瓜为砧木的‘长春密刺’黄瓜嫁接苗在5 ℃低温胁迫下ABA、GA1 + 3 和IAA 含量的变化。结果表明; 低温胁迫下嫁接苗叶片、根系和伤流液中ABA、IAA 含量高于自根苗, GA1 + 3 含量低于自根苗; 较高的ABA 水平和较低的GA1 + 3 水平及较高的ABA/GA1 + 3 比值是嫁接苗抗冷的内在原因。

Grafted and non grafted seedlings were treated at 5℃for 1,2,3,4 and 5d,and then ABA and GA 1+3 contents in leaves and roots were determined.ABA contents in leaves and roots were slightly lower in grafted seedlings than those of non grafted seedlings at normal temperature.But,ABA content increased more rapidly in grafted seedlings than in non grafted ones under low temperature tress.ABA content in xylem exudate of grafted seedlings was lower than that of non grafted ones in non treated seedlings.However,after being treated at 5℃ for 2d,ABA content in exudate increased greatly in grafted seedlings while decreased obviously in non grafted seedlings.On the contrary,GA 1+3 content in leaves and roots of grafted seedlings were lower than that of non grafted ones regardless of low temperature stress or not.High ABA and high ABA/GA value was very important to regulate chilling tolerance of grafted cucumber seedlings.