不同砧木材料嫁接冬瓜苗期氮营养特性综合评价

评价冬瓜砧木的氮素营养效率,解决冬瓜氮肥施用过量的问题。以‘铁柱168’为接穗,获得11种嫁接苗,以自根苗为对照,分别在低氮（0.5 mmol/L）和正常氮（14.0 mmol/L）水平下进行水培试验,测定11种砧木材料的嫁接冬瓜苗期的植株干物量、氮含量和氮素累积量等指标。通过主成分分析计算嫁接苗与自根苗在正常氮和低氮水平下的氮效率综合值,并由聚类分析将砧木材料进行氮素营养效率的划分。结果表明,除正常氮水平下的根干物量小于低氮水平外,植株氮含量、氮积累量、茎干物量、叶干物量、地上部干物量和整株干物量均大于低氮水平;氮积累量和干物量为氮效率评价的最主要指标,其中正常氮水平下主要与茎、叶的干物量和氮积累量有关,低氮水平下主要与根、茎、叶干物量及其氮积累量有关;正常氮水平下,黑杆为氮高效型,‘京欣砧1号’和‘301’为氮低效型,‘海砧1号’‘冬砧1号’‘黄砧1号’‘雪藤木’‘铠甲’‘果砧2号’‘京欣砧2号’和‘京欣砧5号’为氮中效型;低氮水平下,‘京欣砧1号’为氮高效型,‘黄砧1号’和‘铠甲’为氮低效型,‘海砧1号’‘冬砧1号’‘雪藤木’‘301’‘黑杆’‘果砧2号’‘京欣砧2号’和‘京欣砧5号’为氮中效型。当前“一控两减三基本”的背景下,推荐选用‘京欣砧1号’作为冬瓜的嫁接砧木。

Comprehensive Evaluation of Nitrogen Nutrition Characteristics of Wax Gourd Grafted with Different Stock materials at Seedling Stage

Wax gourd is an important melon crop in China, but applying excessive nitrogen fertilizer is very common in wax gourd production. In order to solve the problem of excessive application of nitrogen fertilizer in wax gourd, it is necessary to evaluate and screen the wax gourd rootstocks with high nitrogen utilization. Eleven grafted seedlings, ‘Tiezhu168’ as the scion and 11 materials as the stock, were studied. ‘Tiezhu168’ self-rooted seedling were used as the controls. The grafted and self-rooted seedlings were treated with low nitrogen (0.5 mmol/L) and normal nitrogen (14.0 mmol/L) by hydroponic experiments. The dry matter content, nitrogen content and nitrogen accumulation of the treatment were determined during the seedling stage. Principal component analysis was used to calculate the comprehensive value of nitrogen efficiency of grafted seedlings and self-rooted seedlings at normal nitrogen and low nitrogen levels, and the rootstock materials were divided into three kinds of nitrogen nutrition efficiency by cluster analysis. The root dry matter under the normal nitrogen level was less than that of the low nitrogen, but the plant nitrogen content, nitrogen accumulation, stem matter, leaf dry matter, above ground dry matter and whole plant dry matter were all bigger than that of the low nitrogen. Nitrogen accumulation and dry matter were the most important indicators for the evaluation of nitrogen efficiency. Under the normal nitrogen level, they were mainly related to the dry matter and nitrogen accumulation of stems and leaves. Under the low nitrogen level, nitrogen efficiency was related to the dry matter and the amount of nitrogen accumulation of root, stem, leaf. Under the normal nitrogen level, Heigan was the high nitrogen efficiency type, Jingxinzhen No.1 and 301 were low nitrogen efficiency types, Haizhen No.1, Dongzhen No.1, Huangzhen No.1, Xuetengmu, Kaijia, Guozhen No.2, Jingxinzhen No.1 and Jingxinzhen No.5 were the nitrogen intermediate-efficiency type. Under low nitrogen level, Jingxinzhen No.1 was the nitrogen high-efficiency type, Huangzhen No.1 and Kaijia were the nitrogen low-efficiency type, Haizhen No.1, Dongzhen No.1, Xuetengmu, 301, Heigan, Guozhen No.2, Jingxinzhen No.2 and Jingxinzhen No.5 were the nitrogen intermediate-efficiency type. Under the background of “one control, two reduction and three basic”, Jingxinzhen No.1 is recommended as the grafting rootstock of wax gourd, but still need further validation of field trials.