低温对苦菜种子萌发及幼苗生长的影响

Effects of Low Temperature on Seed Germination and Seedling Growth of Sonchus oleraceus L.

以苦菜种子为材料,研究低温梯度对苦菜种子萌发和幼苗生长的影响。在各处理温度下逐日记录发芽数,计算苦菜的发芽势、发芽率和发芽指数;测量苦菜幼苗株高、幼苗根长、苗鲜质量、根鲜质量、苗干质量和根干质量。结果表明,随着温度的降低,苦菜种子的发芽势,发芽率以及发芽指数均明显下降;同时苦菜幼苗株高和幼苗根长也降低,且在4℃温度条件下的每个指标与对照组相比均差异显著,表明低温降低了苦菜的发芽速率、抑制了幼苗生长;根的相对值总是高于苗的相对值,而且无论是低温下还是常温下,苦菜种子的根干鲜比均高于苗干鲜比,说明苗比根对低温更敏感。

With the Sonchus oleraceus L. seed as materials, the effects of low temperature on seed germination and seedling growth were studied. The number of germination was recording at each processing temperature, then calculated the germination energy, germination percentage, germination index, seedling height, root length, seedling fresh quality, root fresh quality, dry seedling quality and dry root quality. The results showed that with the decrease of temperature, the germination energy, germination percentage, germination index decreased significantly, at the same time, seedling height and root length reduced, every indicators were significantly different from the control group at 4 ℃, indicated low temperature inhibited the germination rate and seedling growth. The relative value of the root was always higher than seedling, whether it was low temperature or normal temperature, the root dry fresh ratio was higher than that of seedling, demonstrated seedlings were more sensitive to low temperature.