渗透胁迫对菜用大黄组培苗生长及生理特性的影响

以菜用大黄(Rheum rhaponticum L.)组培苗为材料,比较不同浓度的聚乙二醇PEG6000(分别为0、10、30、50、70 g/L)对其生长和生理特性的影响,主要测定了生长势、形态指标(苗高、鲜重)、生理指标(可溶性蛋白、脯氨酸、丙二醛含量及过氧化氢酶、过氧化物酶活性)的变化。结果表明,随着聚乙二醇浓度增加和培养时间的延长,菜用大黄组培苗出现萎蔫、玻璃化等现象;苗高和鲜重逐渐降低;可溶性蛋白含量先升后降,脯氨酸含量急速增长后缓慢下降,丙二醛含量、过氧化物酶和过氧化氢酶活性不断上升。说明菜用大黄对适度的聚乙二醇渗透胁迫有一定的抗性,但高浓度聚乙二醇胁迫会对其造成严重伤害。

Effects of Osmotic Stress on the Growth and Physiological Characteristics of Culinary Rhubarb Tissue Culture Seedling

The effects of different concentration of PEG-6000 (0, 10, 30, 50, 70 g∕L, respectively) on the growth and physiological and biochemical characteristics of culinary rhubarb (Rheum rhaponticum L.) tissue culture seedling were studied. The changes of morphological index, plant height, fresh weight, soluble protein, proline, MDA content and the activity of catalase (CAT) and peroxidase (POD) were determined. The results showed that with the increase of PEG concentration and prolonging of incubation time, the phenomenon of wilting and vitrification appeared; while seedling height and fresh weight decreased gradually; soluble protein increased first and then decreased; the proline content increased rapidly and decreased slowly afterwards; the content of MDA, activity of POD and CAT increased continuously. It was indicated that culinary rhubarb had some adaptability to moderate osmotic stress; but the PEG osmotic stress with high concentration might lead to severe damage on culinary rhubarb.