Twice-split phosphorus application alleviates low-temperature impacts on wheat by improved spikelet development and setting
Hui Ping Xu, Kuo-yang HOU, Hao Fang, Qianqian Liu, Qiu Jue Wu, Feifei Lin, Rui Deng, Lin-jie ZHANG, Xiang Chen, Jincai Li
Abstract
With the intensification of climate change, extreme low temperature incidents have become more frequent and severe. In the Huang-Huai-Hai wheat growing area of China, the late spring coldness occurred at the jointing-booting stage (anther interval stage) has resulted in significant yield losses of winter wheat. As an attempt to develop an economical, feasible and efficient cultivation technique for improving the low temperature (LT) resistance of wheat, here we explored the effects of twice-split application of phosphorus on wheat antioxidant characteristics and carbon-nitrogen metabolism physiology under LT treatment at the anther interval stage using Yannong 19 as the experimental material. The treatments consisted of traditional phosphorus application and twice-split application of phosphorus, followed by a -4°C LT treatment and natural temperature (NT) control at the anther interval stage. Our analyses showed that, compared with traditional application, twice-split application of phosphorus increased the net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of leaves, and reduced the intercellular carbon dioxide concentration (Ci). The activity of carbon metabolism-nitrogen metabolism enzymes in the young wheat spikes were also increased by the twice-split application, which promoted the accumulation of soluble sugar (SSC), sucrose (SUC), soluble protein (SP) and proline (Pro) in young wheat spike, and reduced the toxicity of malondialdehyde (MDA). Due to the improved organic nutrition for reproductive development, the young wheat spikes exhibited enhanced LT resistance, which reduced the sterile spikelet number (SSN) per spike by 11.8%, and increased the spikelet setting rate (SSR) and final yield by 6.0 and 8.4% compared with that of traditional application, respectively. The positive effects of split phosphorus application became more pronounced when the LT treatment was prolonged.