Taking 1/2Hoagland solution as basic culture solution, effects of 1,2, 3, 4, 6, 8 and 10 g · L-1 NaCl stress on some growth and physiological-biochemical indexes of Iris lactea Pall. var.chinensis (Fisch.) Koidz. seedling were researched by hydroponic culture method. The results show that with rising of NaCl concentration, height and root length, dry weights of above-ground part, root and whole plant of Ⅰ. lactea var. chinensis seedling decrease gradually, but height and dry weights of aboveground part and whole plant are significantly higher than those of the control under 1 g · L-1 NaCl stress.With rising of NaCl concentration and prolonging of stress time, relative conductivity and MDA content in leaf of Ⅰ. lactea var. chinensis seedling appear the trend of increasing gradually. In which, relative conductivity increases slightly but has no significant difference with that of the control under 1-4 g · L-1 NaCl stress for 7 or 14 d, and also, MDA content has no significant difference with that of the control under 1-8 g · L-1 NsCl stress for 7 d. Contents of chlorophyll and proline and SOD activity in leaf appear the trend of increasing firstly and then decreasing, and these indexes reach the highest values under NaCl stress for 14 or 21 d. With rising of NaCl concentration, proline content and SOD activity increase continuously and generally are significantly higher than those of the control. Chlorophyll content appears the trend of increasing under low concentration and decreasing under high concentration with rising of NaCl concentration, in which, that is the highest of treatment groups with 3 and 4 g · L-1 NaCl. Soluble protein content of every group under NaCl stress is not significantly different with that of the control at the 7th or 14th day, but that appears the trend of increasing under low concentration and decreasing under high concentration at the 21st day with rising of NaCl concentration, while that decreases gradually at the 28th day with rising of NaCl concentration. Overall, NaCl stress with low concentration and short time has an un-obvious inhibition effect or even a slight promotion effect on growth and metabolism of Ⅰ. lactea var. chinensis seedling, while the inhibition effect of NaCl stress with high concentration and long time is obvious. As survival of all treated seedlings after the experiment finished, and combining with determination results of growth and physiological-biochemical indexes, it is preliminarily concluded that Ⅰ. lactea var. chinensis has a stronger resistance to NaCl stress.%采用水培法,以1/2Hoagland溶液为基础培养液,研究了1、2、3、4、6、8和10 g·L-1NaCl胁迫处理对马蔺[Iris lactea Pall.var.chinensis(Fisch.)Koidz.]幼苗部分生长和生理生化指标的影响.结果显示:随NaCl质量浓度的提高,马蔺幼苗的株高和根长、地上部分和根及全株干质量逐渐减小,但在1 g·L-1NaCl胁迫条件下,株高和地上部分及全株干质量均显著高于对照.随NaCl质量浓度的提高和胁迫时间的延长,马蔺幼苗叶片的相对电导率和丙二醛(MDA)含量总体上呈逐渐升高的趋势;其中,用1～4 g·L-1NaCl胁迫处理7或14 d,相对电导率有小幅增加但与对照差异不显著;用1～8 g·L-1NaCl胁迫处理7 d,MDA含量与对照差异不显著.叶片叶绿素和脯氨酸含量以及超氧化物歧化酶(SOD)活性则随胁迫时间的延长呈先升后降的趋势,在胁迫的14或21 d各指标达到最高值.随NaCl质量浓度的提高,脯氨酸含量和SOD活性均不断增加且总体上显著高于对照;叶绿素含量则随NaCl质量浓度的提高出现低浓度升高、高浓度降低的趋势,其中3和4 g·L-1NaCl胁迫处理组叶绿素含量最高;各处理组的可溶性蛋白质含量在处理的第7大或第14天与对照无显著差异,第21天则随NaCl质量浓度的提高呈低浓度升高、高浓度降低的趋势,而第28天则随NaCl质量浓度的提高逐渐降低.总体上看,低质量浓度和短时间的NaCl胁迫对马蔺生长和代谢的抑制作用不明显甚至略有促进作用,而高质量浓度和长时间的NaCl胁迫则具有明显的抑制作用.在实验结束后全部供试植株均存活,结合生长和生理生化指标的测定结果,初步判定马蔺对NaCl胁迫具有较强的耐性.
展开▼
