低温胁迫对甜瓜嫁接苗和自根苗生长及生理特性的影响

摘要

以4种白籽南瓜为砧木，以甜宝甜瓜为接穗，对嫁接苗和自根苗进行15℃/5℃（昼/夜）连续5 d低温处理，统计嫁接苗成活率，并进行生长指标及抗冷相关生理指标的测定。结果表明，低温胁迫后嫁接苗株高、茎粗、地上部鲜质量、根鲜质量的相对生长量均高于自根苗，根系活力、可溶性糖含量、脯氨酸（Pro）含量、超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性、过氧化氢酶（CAT）活性亦不同程度高于自根苗，而丙二醛（MDA）含量则显著低于自根苗。嫁接显著提高了甜瓜的耐冷性，低温胁迫后甜砧嫁接苗的生长指标以及抗冷相关生理指标几乎全部优于其他3种砧木嫁接苗及自根苗，更适合在甜瓜耐低温生产中推广应用。%Taking 4 species of white seed pumpkin as rootstock and ‘Tianbao’ melon as scion,this study treated the root-stocks and own root melon seedlings with low temperature (15 ℃/5 ℃,day/night,for 5 days);counted the survival rate of grafting and tested the growth and physiological indexes related to low temperature stress. The results indicated that after low temperature stress plant height,stem diameter,shoot FW and root FW of grafting seedlings were higher than that of own root melon seedlings;and the root activity,soluble sugar content,proline (Pro) content,SOD activity,POD activity,CAT activity of grafting seedlings were also higher than that of own root melon seedlings,by different degree. While the MDA content was remarkably lower than that of own root melon seedlings. It was concluded that grafting significantly improved the chilling tolerance of melon;and low temperature stress made the growth index and physiological index related to chilling resistance of ‘Tianzhen’ grafted seedlings all better than that of the other 3 rootstocks and own root melon seedlings. Therefore,‘Tianzhen’ is suitable to be popularized and applied in low temperature production of melon.