低温胁迫对嫁接苦瓜幼苗渗透调节物质的影响

为研究低温胁迫对苦瓜嫁接苗渗透调节物质的影响，以中原共荣与苦砧 2 号 2 个南瓜品种作为砧木与翠柳2号苦瓜分别靠接的嫁接苗为试材，对照采用苦瓜自根苗，使用人工气候培养箱进行低温处理，对低温下两种不同砧木嫁接苗的冷害指数及可溶性蛋白、游离脯氨酸、可溶性总糖、葡萄糖、果糖、蔗糖含量的变化进行测定。结果显示：在低温胁迫下，嫁接苗的冷害指数极显著低于自根苗，说明嫁接可以缓解幼苗所受的低温伤害。在冷胁迫期间，可溶性蛋白、游离脯氨酸以及可溶性总糖嫁接苗显著高于自根苗；在冷胁迫前期，嫁接苗葡萄糖含量显著高于自根苗；果糖含量嫁接苗与对照差异不显著；蔗糖含量在低温胁迫过程中，嫁接苗均显著高于自根苗。苦砧 2 号在可溶性蛋白，游离脯氨酸以及可溶性糖的含量上均高于中原共荣，综合表现上苦砧 2 号的抗冷性优于中原共荣以及自根苗，说明嫁接苗在低温胁迫时能有效地提高此 3 类渗透调节物质含量，以此提高苦瓜幼苗的耐冷性，而在冷胁迫前期正向响应的可溶性糖中的主要成分是葡萄糖，蔗糖在整个耐冷胁迫期间均表现了正向作用。

Effects of Low Temperature Stress on Osmotic Solutes of Grafted Bitter Gourd Seedlings

 In order to screen cold-resistant stocks and solve the problem of poor cold resistance in bitter gourd production, the ffets of low temperature stress on the osmotic solutes of grafted seedlings of biter gourd were studied.Bitter gourd's cultivar-Chui-liu 2 was used as the scion, Pumpkin cultivar-Bitter Anvil 2 (BA) and Zhongyuan Gongrong (ZG) were used as the rootstock, the slf-rooted seedlings of biter gourd was used as the control in an artificial climate incubator at low temperature. The chilling injury index, soluble protein, free proline, soluble total sugar, glucose,fructose and sucrose content of the grafted seedlings under low temperature were measured. The results showed that under low temperature stress, the chilling injury index of the grafted seedlings was significantly lower than that of self-rooted seedlings, indicating that grafting could alleviate the cold damage LDuring cold stress, soluble protein, free proline and total soluble sugar were significantly higher than that of self-rooted seedlings. In the early stage of cold stress, the content of glucose in the grafed seedlings was significantly higher than that of slrooted sedlings. and the content of sucrose of the grafted seedlings was significantly higher than that of the control. The content of soluble protein, free proline and soluble sugar of BA were higher than that of ZG The content of soluble protein, free proline and soluble sugar of BA was higher than that of ZG The comprehensive performance of cold tolerance of BA was better than that of ZG and self-rooted seedlings, indicating that grafted seedlings in cold stress could ffectively improve the content of the three osmotic adjustment substances, thereby increasing cilling tolerance. However, the main component of soluble sugar that responded positively to cold stress was glucose, and sucrose showed a positive ffect during the whole cold-tolerant stress.