Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD)/Jiangsu Key Laboratory of Agricultural Meteorology/School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, Jiangsu, 210044, China.
Sci Rep. 2020 Jan 31;10(1):1579. doi: 10.1038/s41598-020-58578-3.
Heat stress is one of the common agrometeorological hazards in rice production in the middle and lower reaches of the Yangtze River in China. To study the mechanism of mist spray in ameliorating heat stress injury, a field experiment was conducted at Nanjing (China) with an early and a late hybrid rice varieties (Oryza sativa L.). The mist spray treatments were conducted at the flowering period, which were at August 6-10 for early rice variety and September 1-5 for late one. Four treatments at different irrigation times (T1: 08:00; T2: 12:00; T3: 14:00; CK: no mist spray; mist spray amount of 1 L·m) were included. The temperature and humidity at the different heights of the rice canopy and the net solar radiation above the canopy were measured. The leaf senescence, chlorophyll content, photosynthetic rate and the yields of the rice were determined. The results showed that mist spray rapidly reduced the temperature and increased the relative humidity in the canopy. The cooling effect was most significant at the top of the canopy and decreased downward from the top of canopy. The duration of the temperature decrease caused by the mist spray was 2 h. Mist spray could lead to an increase in latent heat flux (LE) and a decrease in sensible heat flux (H) in the rice field. The mist spray treatments delayed the senescence of the rice leaves, increased the activity levels of the superoxide dismutase, peroxidase, catalase, and soluble protein, reduced the malondialdehyde content, increased leaf chlorophyll content, photosynthetic rate and yield. The T2 treatment showed the most significant effect against heat stress, with the yield of the two varieties increased 13.7 and 13.6% respectively. Compared with mist spray at 08:00 or 14:00, spraying at 12:00 had the strongest resistance to heat stress in rice field.
热应激是中国长江中下游地区水稻生产中常见的农业气象灾害之一。为研究雾喷缓解热应激伤害的机制，在中国南京进行了田间试验，选用早、晚两杂交稻品种（Oryza sativa L.）。雾喷处理在开花期进行，早稻品种在 8 月 6-10 日，晚稻品种在 9 月 1-5 日。共设置 4 个不同灌溉时间（T1：08:00；T2：12:00；T3：14:00；CK：无雾喷；雾喷量为 1 L·m）的处理。测量了冠层不同高度的温度和湿度以及冠层上方的净太阳辐射。测定了叶片衰老、叶绿素含量、光合速率和水稻产量。结果表明，雾喷迅速降低了冠层温度，增加了相对湿度。降温效果在冠层顶部最为显著，从顶部向下逐渐减弱。雾喷引起的温度下降持续时间为 2 小时。雾喷会导致稻田潜热通量（LE）增加，感热通量（H）减少。雾喷处理延缓了水稻叶片衰老，提高了超氧化物歧化酶、过氧化物酶、过氧化氢酶和可溶性蛋白的活性水平，降低了丙二醛含量，增加了叶片叶绿素含量、光合速率和产量。T2 处理对热应激的缓解效果最为显著，两个品种的产量分别增加了 13.7%和 13.6%。与 08:00 或 14:00 喷灌相比，12:00 喷灌对稻田的抗热应激能力最强。
