PEG浸种对低温弱光下辣椒幼苗叶片部分生理指标的影响

Effects of Seed Soaking with PEG on Physiology Indexes in Leaves of Pepper Seedlings under Low Temperature and Poor Light

以湘研1号辣椒为试材,用25%聚乙二醇(PEG)溶液处理种子,研究了在低温弱光胁迫下PEG处理对辣椒幼苗与抗冷性有关的部分生理指标的影响。结果表明:在15℃/5℃(昼/夜)低温,100μmol.m-2.s-1弱光下,辣椒幼苗地上部干质量、地下部干质量、株高、茎粗均降低;辣椒幼苗叶片细胞膜透性、丙二醛(MDA)和脯氨酸(Pro)含量升高,并随低温弱光处理时间的延长而增加;超氧化物歧化酶(SOD)和过氧化物酶(POD)活性呈现先升高后降低的趋势;可溶性蛋白含量呈逐渐下降趋势。PEG浸种处理可使辣椒幼苗地上部干质量、地下部干质量、株高、茎粗和叶片SOD、POD活性、可溶性蛋白含量的下降幅度均较低温弱光对照显著减缓,细胞膜透性、MDA与Pro含量的增加幅度均较低温弱光对照显著降低,表明PEG浸种处理能够提高辣椒幼苗对低温弱光的适应能力。

The changes of some physiological indexes were investigated in seedling leaves of‘Xiangyan No. 1 ＇ pepper under low temperature and poor light stress with 25 % concentration of polyethylene glycol （PEG） solution seed soaking. Significant increases in membrane permeability, malondialdehyde （MDA） and proline （Pro） contents, decreases in soluble protein and dry weight of aboveground, dry weight of underground, plant height and stem diameter were observed in leaves of pepper seedlings under low temperature and poor light 15℃/5℃ （day/night） , 100μLmol·m^-2·s^-1 The SOD and POD activities increased and arrived at highest value on the 4th day, then decreased in leaves of pepper under low temperature and poor light stress. Compared to the control, the increment in membrane permeability, MDA and Pro contents were smaller, and the reducement in activities of SOD and POD, contents in soluble protein, dry weight of aboveground, dry weight of underground, plant height and stem diameter were smaller in leaves of pepper under low temperature and poor light stress with PEG seed-soaking. These results suggested that PEG seed-soaking could increase the resistance ability to low temperature and poor light stress of pepper seedlings.