用油菜素内酯(BR)对水稻进行浸种处理或幼苗喷雾,可促进幼苗在低生长温度下的生长,其株高、干物重,成苗率和叶片叶绿素含量均较对照明显增加。但幼苗在较高的生长温度下,处理组与对照组之间无显著差异。同时还发现,经BR处理的幼苗在低温下生长,其组织的电导率下降、膜酯不饱和脂肪酸中的亚麻酸含量及脂肪酸不饱和指数有所提高,幼苗可溶性糖含量也增加。这种变化与BR处理后水稻幼苗耐冷性的提高有关。 Brassinolide (BR) soaking rice seedlings or spraying seedlings could promote seedling growth at low growth temperature, and its plant height, dry matter weight, seedling emergence rate and chlorophyll content of leaves were significantly increased compared with the control. However, there was no significant difference between the treatment group and the control group at higher growth temperature. At the same time, it was also found that the growth of BR-treated seedlings at low temperature decreased the electrical conductivity of the tissue, increased the content of linolenic acid and fatty acid unsaturation in unsaturated fatty acid esters, and increased the soluble sugar content of seedlings. This change is related to the improvement of cold tolerance of rice seedlings after BR treatment.