Chinese Bulletin of Botany ›› 2018, Vol. 53 ›› Issue (4): 519-527.DOI: 10.11983/CBB18007

• TECHNIQUES AND METHODS • Previous Articles     Next Articles

An Efficient Nutrient Solution System to Study Symbiotic Nitrogen Fixation in Soybean

Ai Wenqin1, Jiang Hanyuan1, Li Xinxin2, Liao Hong2,*()   

  1. 1College of Resources and Environment, South China Agricultural University, Guangzhou 510642, China
    2Root Biology Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China
  • Received:2018-01-09 Accepted:2018-02-12 Online:2018-07-01 Published:2018-09-11
  • Contact: Liao Hong
  • About author:† These authors contributed equally to this paper

Abstract: To establish a nutrient solution system for soybean cultivation with effective nodulation and relatively high yield, we first evaluated the effect of nitrogen (N) content and rhizobia inoculation on soybean growth, yield and biological nitrogen fixation (BNF). Too high or too low N supply affected soybean growth, yield and N2 fixation capacity. Also, the required optimal N level was much higher for plant growth than that of BNF. Furthermore, the highest nitrogenase activity in soybean occurred before the first stage of reproduction (R1 stage). Thus, the enzyme activity could facilitate nodule formation and N2 fixation with a lower N supply before the R1 stage and a higher N supply afterward to promote plant growth and yield in soybean. A second experiment was conducted to optimize N supply (i.e., low N supply before R1 and medium N supply at the beginning of R1). As compared with continuously supplied high N, the optimal scheme promoted BNF with more and larger nodules with higher nitrogenase activity and also maintained a good growth performance with higher 100 grain weight and about sustained 80% of soybean yield. These results provide a reference for nutrient receipt for soybean BNF study as well as soybean production for high yield and nutrient efficiency.

Key words: soybean, nodule, biological nitrogen fixation, nutrient solution, yield