不同温度对辣木种子萌发、幼苗生长及其生理特性的影响

为了探索辣木(M.oleifera Lam.)种子和幼苗对不同环境温度的适应性,设置15、20、25、30、35、40℃等不同温度处理,研究不同温度条件对辣木种子萌发、幼苗生长及生理指标的影响。结果表明:辣木种子发芽的最适温度为25℃,幼苗生长的最适温度为30℃,温度过高或过低都会抑制辣木种子的萌发和幼苗的生长。一定程度的高温和低温胁迫会使辣木种子的发芽势、发芽率、发芽指数等发芽指标以及幼苗的苗高、茎粗、根长、鲜质量增量、壮苗指数等生长指标显著下降。高、低温胁迫还会使辣木幼苗叶片的MDA含量、相对电导率、可溶性糖、SOD活性、POD活性显著增加,使叶绿素相对含量、φ_(Po_、RC/ABS、P_(TR)、P_(ET)、PI_(ABS)显著下降。

Effects of Different Temperature Treatments on Seed Germination,Seedling Growth and Physiological Characteristics of M.oleifera Lam.

In order to understand the effects of different temperature treatments on seed germination and seedling growth of M.oleifera Lam.,the dynamic indices of its seed germination and seedling growth at 15,20,25,30,35,40 ℃ temperature were observed.The results showed that the optimum temperature for seed germination and seedling growth was 25 ℃ and 30 ℃,the seed germination and seedling growth could be inhibited by too high or too low temperature treatments.A certain degree of high temperature and low temperature stress decreased seed germination rate,germination power and germination index,decreased stem diameter,seedling length,root length and fresh mass increment of the seedling.Under high temperature or low temperature stress,the MDA content,relative electric conductivity,soluble sugar content,SOD activity and POD activity of the seedling increased significantly,while the relative chlorophyll content,φPo,RC/ABS,PTR,PET and PIABS dropped significantly.