低温胁迫对直播早稻出苗及幼苗生长的影响

Effects of low temperature stress on seedling emergence and seedling growth of direct-seeding early rice

为探究直播早稻从播种至苗期生长受低温胁迫的反应,以中嘉早17为试验材料,研究低温及处理时间对不同催芽程度和不同日龄秧苗形态和生理指标的影响。结果表明,种子催芽程度为破胸的较芽谷(芽半长)的种子更耐低温。在温度10℃以下处理2 d以上时,随着处理温度降低和处理时间延长,催芽程度为芽谷的较破胸的种子出苗率下降更显著;秧龄越小耐低温能力越强,当温度降至6℃时,幼苗基本停止生长。受低温胁迫的影响,地上部丙二醛(MDA)含量随秧龄的增加而逐渐增加,且温度越低变化越明显;脯氨酸含量随秧龄增加逐渐减少,秧龄越小含量越高。说明低温胁迫条件下,催芽程度为芽谷的较破胸的种子对低温更敏感,大秧龄较小秧龄更敏感,可为进一步指导双季早稻直播生产提供参考依据。

In order to explore the effect of low temperature stress from sowing to seedling growth of early rice. With Zhongjiazao17 as material,the effects of low temperature and treatment time on the morphological and physiological indexes of germination and seedling were studied. The results showed that the breaking rice seed was more resistant to low temperature than the bud（bud half length）. When the treatment temperature was below 10℃and the treatment days was more than 2 days,the seedling emergence rate of the bud decreased more significantly than the breaking rice seed with the temperature decreased and the time prolonged. The younger seedling,the stronger the cold tolerance ability,when the temperature dropped to 6℃,seedlings would basically stop growing.Under the influence of low temperature,the MDA content of plant on the ground increased gradually with the increase of seedling age,the lower the temperature,the more obvious change. The proline content decreased gradually with the increase of seedling age,seedling age was smaller,the higher the content of proline. Therefore,under the condition of low temperature stress,germination degree of the bud was more sensitive to low temperature,the large seedling age was more sensitive to the small seedling age. This paper would provide reference for guidance to the direct seeding production of double season early rice.