低温弱光逆境对西葫芦幼苗生理指标的影响研究

The Effects of Low Temperature and Iight Stress on Physiological Characteristics of Pumpkin Seedlings

以西葫芦品种早青一代为试材，研究了不同低温弱光组合及低温弱光持续时间对西葫芦幼苗生长指标的影响。结果表明，低温弱光对西葫芦幼苗生长有明显的抑制作用。在昼温20～25℃、夜温10～15℃条件下，光照强度从250μmol／（m^2·s）避渐减弱到150μmol／（m^2·s）、50μmol／（m^2·s）时，西葫芦幼苗的株高、茎粗、叶面积、地上部鲜重、干物质积累量下降，根系活力减弱，但随着时间的延长，株高、茎粗和总叶面积增加，根系活力避渐提高；在昼温15℃、夜温5℃条件下，随着光照强度的减弱，西葫芦幼苗的株高、茎粗、叶面积、地上部鲜（干）重下降，根系鲜（干）重和根冠比提高，随着处理时间的延长，根系活力下降。

Pumpkin（Cucubita pepo L.）seedlings were exposed under different low temperature-light regimes to investigate the responses of physiological characteristics. The results indicated that height, stem diameter, the area of total leaves, fresh weight of the parts above ＆ under the ground, root-top ratio （R/T）, root activity and dry matter accumulation of pumpkin seedlings decreased as the stress degree increased or the time prolonged. However, the inhibitions of 15℃/5℃, 250 μmol/m^2·s are significantly several than that under the other temperature and light level, Fresh and dry weight of root ＆ root-top ratio （R/T） increased, but height, stem diameter, the area of total leaves and root activity decreased.