• 研究报告 •

### 越冬期低温胁迫对黄淮地区不同品种小麦的影响

1. 1中国气象局/河南省农业气象保障与应用技术重点实验室， 郑州 450003；2中国农业大学资源与环境学院， 北京 100193）
• 出版日期:2021-08-10 发布日期:2021-08-16

### Effects of freezing stress on different varieties of wheat during overwinter period in Huang-Huai area.

YU Wei-dong1,2*, WU Lu2, FENG Li-ping2, HU Cheng-da1

1. (1Key Laboratory of Agrometeorological Ensuring and Applied Technique, China Meteorological Administration/Henan Province, Zhengzhou 450003, China; 2College of Resources and Environment, China Agricultural University, Beijing 100193, China).
• Online:2021-08-10 Published:2021-08-16

Abstract: Freezing injury is one of the common agrometeorological disasters in winter wheat production. The risk of winter wheat freezing injury during overwintering was not reduced with the increased winter temperature under climate warming. In this study, field acclimated seedlings and freezing chamber process were combined in a controlled freezing experiment for one day treatment. Three winter wheat cultivars were used in this experiment, including winterness wheat (Nong 211, ND), semiwinterness wheat (Zheng 366, ZM) and weakspring wheat (Yan 4110, YZ). The treatment temperature for ND and ZM was -8, -9, -10, -12 and -15 ℃, while the temperature for YZ was -6, -9, -10, -12 and -15 ℃. The results showed that no plants were killed in ND when temperature was above -15 ℃, while 58.3%–66.7% and 100% of plants were killed in ZM and YZ when temperature was between -15 ℃ and -12 ℃, respectively. Relative stem loss rate of ND and YZ significantly increased at -10 ℃, while that of ZM significantly increased at -9 ℃. When relative stem loss rate reached 50%, the critical temperature was -14.6 ℃ (ND), -11.3 ℃ (ZM) and -10.0 ℃ (YZ). The relative stem loss rate could thus be used as an index to identify the freezing tolerance of winter wheat in Huang-Huai area. Compared with the control, dry matter weight of each plant in the milk stage was significantly reduced due to low temperature stress below -12 ℃. However, the low temperature stress did not affect the net photosynthetic rate of leaves in the flowering stage. Moreover, grain yield of the three cultivars decreased under low temperature stress, while the yield loss rate increased with the decreased temperature. The yield loss rate and relative stem loss rate were ND < ZM < YZ at the same low temperature. Furthermore, the results of yield loss indicated that the decrease of spike number per unit area was the leading cause for the final yield reduction.