空气相对湿度对高温下番茄幼苗营养物质含量及干物质分配的影响

Effect of Air Humidity on Nutrient Content and Dry Matter Distribution of Tomato Seedlings under High Temperature

以番茄品种"金粉五号"为试材,于2016年4-9月在南京信息工程大学利用人工气候箱进行试验,设置温度为41℃(昼温)/18℃(夜温),空气相对湿度(白天)分别设置为50%、70%和90%(正负误差控制在5个百分点),并以28℃/18℃、45%~55%为对照处理(CK),测定不同处理对植株各器官营养物质及干物质分配的影响。结果表明:(1)高温条件下,番茄幼苗各器官的可溶性糖和游离氨基酸含量均显著高于正常温湿度条件下(CK),而蛋白质含量则显著低于CK(P<0.05);从不同空气湿度处理来看,增加湿度至70%以上时幼苗各器官可溶性糖含量降低,且湿度越高其含量越低,处理间差异显著(P<0.05);而游离氨基酸和可溶性蛋白含量表现为,随着空气相对湿度的增大,番茄幼苗各器官的游离氨基酸和可溶性蛋白含量明显上升。(2)高温条件下番茄幼苗叶片干物质分配比例增加,茎秆和根系干物质分配比例均降低,且湿度越低,其分配比例与CK差距越大,在50%湿度处理下,幼苗茎秆和根系干物质分配比例显著降低(P<0.05),对植株生长极为不利。(3)在高温胁迫解除后,70%和90%湿度处理的幼苗有更高的恢复能力,在恢复处理的第12天植株营养物质含量和干物质分配比例基本恢复至CK水平。说明41℃高温环境中增加空气湿度至70%以上有效提高了番茄植株的耐热性和胁迫解除后的恢复能力。

Took tomato variety of ‘Jinfen5＇ as material, the experiment was conducted in Venlo greenhouse of Nanjing University of Information Science and Technology from April to September in 2016. The temperature was maintained at 41℃/18℃（day/night）, the humidity（daytime） was set at 50%, 70%, and 90%（±5 percent points）, and 28℃/18 ℃and 45%-55% was took as control（CK）, to determine the effects of different treatments on the distribution of nutrients and dry matter in different organs of plants. The results showed that the contents of soluble sugar and free amino acids in different organs of tomato seedlings were significantly higher than those under normal temperature and humidity conditions（CK） at high temperature, but the protein content was significantly lower than CK（P〈0.05）.When the humidity was increased to above 70%, the content of soluble sugar in various organs of tomato seedlings decreased, and the higher the humidity was, the lower the content of soluble sugar was in different air humidity treatments, the differences of treatments were obvious（P〈0.05）. The contents of free amino acids and soluble proteins in different organs of tomato seedlings were as follows, the higher the air humidity, the higher the contents of free amino acids and soluble proteins. The proportion of dry matter in tomato seedling leaves increased, the proportion of dry matter in stems and roots decreased at high temperature, and the lower the humidity, the greater the difference with CK. The proportion of dry matter in stems and roots decreased significantly（P〈0.05）, it was extremely unfavorable to plant growth under 50% humidity. After the high temperature stress was relieved, 70% and 90% of humidity treated tomatoes had higher recovery ability, and the ratio of nutrient and dry matter allocation of plants returned to CK level on the 12 th day during recovery. The results indicated that increasing air humidity to more than 70% can effectively improve the heat resistance and resilience after the high temperature stress on tomato.