Chinese Journal of Agrometeorology ›› 2019, Vol. 40 ›› Issue (08): 512-522.doi: 10.3969/j.issn.1000-6362.2019.08.004

Previous Articles     Next Articles

Low Temperature and Low Irradiation Affected the Metabolism of Low-Molecular- Weight Organic Acids and Nutrients Uptake in Tomato Seedling Root

LI Yu-shan, LI Ping, YANG Zai-qiang, WANG Fu   

  1. 1.Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing 210044, China; 2.Meteorological Service Center of Jiangxi, Nanchang 330096; 3.Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing 210044
  • Online:2019-08-20 Published:2019-08-01

Abstract:

Combined low temperature and low irradiation(LTLI) conditions seriously affect the yield and quality of tomato, the present study aimed to clarify the underlying mechanisms through investigating the changes of organic acids metabolism and nutrients uptake in tomato root. A pot experiment in artificially controlled environments was conducted to study the dynamic changes of root activity, nitrogen(N), phosphorus(P), and potassium(K) uptake by the root, dry weights of the root and shoot, and the secretion of low-molecular-weight organic acids(LMWOAs) by the root, under different LTLI conditions (maximum/minimum temperature: 12/2℃, 14/4℃, 16/6℃, 18/8℃; weak irradiation: 200, 400μmol·m-2·s-1). Results showed that the LTLI strongly inhibited the root activity, net absorption of N, P and K, and dry weights of the root and shoot, and the effects were enhanced with the decrease of temperature. Under the condition of 12/2℃ and 200μmol·m?2·s?1, the root activities were 7.70%-22.1% of the control, net absorption of N, P and K in the root were 3.75%-18.1%, 1.28%-27.1%, and 19.1%-35.5% of the control, respectively, dry weights of the root and shoot were 23.4%-55.9% and 42.6%-66.5% of the control, respectively. The LTLI also inhibited the secretion of LMWOAs and increased the soil pH, oxalic acid was the main acid which decreased most obviously. This study indicates that the inhibition of the LTLI on the growth of tomato seedling was related to the decrease of root activity, secretion of oxalic acid, and the nutrients uptake. Therefore, suitable application of oxalic acid or complex fertilizer (including N, P, K) at the initial stage of the LTLI occurrence, may enhance the resistance ability of tomato seedling to the LTLI.

Key words: Low temperature low irradiation, Tomato, Root activity, Soil nutrient, Organic acid