Optimized nitrogen fertilizer application mode increased culms lignin accumulation and lodging resistance in culms of winter wheat

The present study used both winter wheat cultivars Jimai 22 (lodging-resistant cultivar) and Yannong 19 (lodging-susceptible cultivar) to investigate the effect of optimized nitrogen fertilizer application on lignin accumulation, its related enzyme activities in the basal second internode, and the breaking strength and culm lodging resistance index (CLRI) in winter wheat. Results showed that optimized nitrogen fertilizer application rates significantly increased the phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL) and peroxidase (POD) activities as well as lignin accumulation, the breaking strength and CLRI. Lignin accumulation and CLRI could be significantly increased by shifting nitrogen from base to topdressing under identical nitrogen application rates. Lignin accumulation, PAL, TAL and POD activities, the breaking strength and CLRI were significantly increased by an appropriate increase of the booting fertilizer proportion (DC 4.1) when identical base and topdressing ratios. These results suggested that the nitrogen fertilizer application rate of 202.5 kg hm−2 with the ratio of 4:4:2 for base (DC 0.0), elongation (DC 3.0) and booting stage (DC 4.1) significantly increased the lodging resistance of winter wheat in Xuhuai district.