Hunan Provincial Key Laboratory of Crop Sterility Mechanism and Sterile Germplasm Resources Innovation, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China.
Biol Res. 2020 Feb 18;53(1):8. doi: 10.1186/s40659-020-00276-5.
Rice is the staple food of many people around the world. However, most rice varieties, especially widely grown indica varieties and hybrids, are sensitive to cold stress. In order to provide a basis for the utilization of a common wild rice (CWR, Oryza rufipogon Griff.) named 'Chaling' CWR in cold-tolerant rice breeding and deepen the understanding of rice cold tolerance, the cold tolerance of ratoon 'Chaling' CWR was studied under the stress of the natural low temperature in winter in Changsha, Hunan province, China, especially under the stress of abnormal natural low temperature in Changsha in 2008, taking other ratoon CWR accessions and ratoon cultivated rice phenotypes as control.
The results showed that ratoon 'Chaling' CWR can safely overwinter under the natural conditions in Changsha (28° 22' N), Hunan province, China, which is a further and colder northern place than its habitat, even if it suffers a long-term low temperature stress with ice and snow. In 2008, an extremely cold winter appeared in Changsha, i.e., the average daily mean temperature of 22 consecutive days from January 13 to February 3 was - 1.0 °C, and the extreme low temperature was - 4.7 °C. After subjected to this long-term cold stress, the overwinter survival rate of ratoon 'Chaling' CWR was 100%, equals to that of ratoon 'Dongxiang' CWR which is northernmost distribution in the word among wild rice populations, higher than those of ratoon 'Fusui' CWR, ratoon 'Jiangyong' CWR, and ratoon 'Liujiang' CWR (63.55-83.5%) as well as those of ratoon 'Hainan' CWR, ratoon 'Hepu' CWR, and all the ratoon cultivated rice phenotypes including 3 japonica ones, 3 javanica ones, and 5 indica ones (0.0%).
The results indicate that ratoon 'Chaling' CWR possesses strong cold tolerance and certain freezing tolerance.
水稻是世界上许多人的主食。然而，大多数水稻品种，特别是广泛种植的籼稻品种和杂交种，对冷胁迫敏感。为了为耐寒水稻育种中利用一种名为“茶陵”普通野生稻（CWR，Oryza rufipogon Griff.）提供依据，并加深对水稻耐寒性的理解，本研究在自然低温胁迫下，对轮作‘茶陵’CWR 的耐寒性进行了研究，特别是在 2008 年长沙异常自然低温胁迫下，以其他轮作 CWR 材料和轮作栽培稻表型为对照。
结果表明，轮作‘茶陵’CWR 可以在湖南省长沙市（28°22'N）的自然条件下安全越冬，这是比其栖息地更北、更冷的地方，即使遭受长期冰雪低温胁迫也是如此。2008 年，长沙出现了一个极寒的冬天，即从 1 月 13 日到 2 月 3 日的 22 天内，平均日平均气温为-1.0°C，极端最低气温为-4.7°C。在经历了这种长期的寒冷胁迫后，轮作‘茶陵’CWR 的越冬存活率为 100%，与野生稻种群中分布最北的轮作‘东乡’CWR 相同，高于轮作‘富绥’CWR、轮作‘江永’CWR 和轮作‘柳江’CWR（63.55-83.5%）以及轮作‘海南’CWR、轮作‘合浦’CWR 和所有轮作栽培稻表型（包括 3 个粳稻、3 个爪哇稻和 5 个籼稻）（0.0%）。
结果表明，轮作‘茶陵’CWR 具有较强的耐寒性和一定的抗冻性。
