1College of Life Sciences, Nankai University, Tianjin 300071, China.
2Tianjin Academy of Agricultural Sciences, Tianjin 300192, China
3Department of Plant Nutrition, China Agricultural University, Beijing 100094, China.
*Correspondence author: E-mail: ruanweibin@nankai.edu.cn.
Based on our previous study, the Fraction III (one of 4 fractions which separated from the 95% ethanol extracts of sesame seed cakes), was further separated into 23 portions by a gradient of CHCl3 – MeOH (9:0.5, V/V). The tenth portion consisted of palimitc acid, oleic acid and octadecanoic acid, identified by GC-MS. To evaluate the effect of palimitic acid and oleic acid on the cucumber plant growth and the mechanism of their action, a series of potted experiments were conducted in greenhouse. The results showed that application of palmitic and oleic acids to sick soil significantly increased the dry weight and chlorophyll content of cucumber. However, the cucumber shoot Na content was decreased, because lower amount of Na was transferred to the shoot. Furthermore, the antagonistic effects of oleic acid under salt stress, were confirmed in hydroponics culture. The analysis of the soil microbial populations at harvest indicated that the activity of fungi, bacteria and actinomycetes were markedly promoted, especially bacteria (P 0.001). The results suggested that the fatty acids probably have potential substance to improve the soil borne diseases occurring either in the greenhouses or orchards.
Cucumber, oleic acid, palmitic acid, sesame seed cake, soil sickness
