壳聚糖处理对苜蓿幼苗抗旱性的影响

Effects Chitosan Treatment on Drought Resistance of Alfalfa Seedlings

[目的]初步探讨壳聚糖处理对干旱胁迫下苜蓿幼苗抗旱性的影响。[方法]选取饱满度一致的紫花苜蓿种子，置于培养箱（25℃）中培养，待长出3～4片真叶后分装于培养皿，分别用0．1％、0．3％、0．5％、0．7％的壳聚糖喷涂处理，以喷蒸馏水为对照，研究不同浓度的壳聚糖处理对苜蓿幼苗抗旱性的影响。[结果]干旱胁迫下，壳聚糖处理后苜蓿幼苗的脯氨酸含量上升幅度比对照组的缓慢，其中以0．5％处理上升幅度最慢；各处理组苜蓿幼苗POD活性上升幅度明显大于对照组，其上升幅度依次为0．5％〉0．7％〉0．3％〉0．1％，并在断水后第9天时达到最高值后缓慢下降。[结论]壳聚糖处理苜蓿幼苗能调节干旱胁迫下其脯氨酸积累速率，提高和维持其POD活性，从而增强其抗旱性。壳聚糖处理的适宜浓度为0．5％。

[ Objective] The study aimed to preliminarily discuss the effect of ehitosan treatment on the drought resistance of alfalfa seedlings under drought stress. [ Method] The alfalfa seeds with uniform plumpness were cultured in incubator at 25℃. When 3 - 4 true leaves were gown out and put on the culture dishes they were sprayed by 0.1% ,0.3 %, 0.5 %,0.7 % chitosan, with spraying the distilled water as CK, so as to study the effect of chitosan treatment with.different concn, on the drought resistance of alfalfa seedlings. [ Result ] Under drought stress, compared with the control group, the proline content of alfalfa seedlings treated by chitosan with different conch.was increased slowly and its increasing in treatment group with 0.5% chitosan was slowest. POD activity of alfalfa seedlings in alfalfa seedlings treatments was raised obviously fast than that in the control group,with their increasing extent in different eoncn, treatments in order being 0.5 % 〉 0.7% 〉 0.3 % 〉 0.1%, and POD activity of alfalfa seedlings in treatment groups was decreased slowly after reaching the peak value at the 9 th d under stopping water. [Conclusion] Treating alfalfa seedling by chitosan could regulate the ratio of praline accumulation, maintain and enhance the POD activity in alfalfa seedling under drought stress, thus increasing its drought resistance. The optimum concn, of chitosan for treating alfalfa seedlings was 0.5%.