干旱胁迫下壳寡糖对玉米叶片叶绿素含量、含水量及保护酶活性的影响

摘要

以玉米为研究对象，设置壳寡糖和清水（对照）2个处理，研究了在干旱胁迫下外施壳寡糖对玉米叶片叶绿素含量、含水量及叶片保护酶（SOD、POD、CAT）活性的影响。结果表明，在干旱胁迫下，壳寡糖处理和对照均使玉米叶片中叶绿素含量表现为先上升后下降的趋势，但壳寡糖处理叶绿素含量由断水后第7天的30.7 mg/g 提高到断水后第15天的32.4 mg/g ，而对照则由断水后第7天的27.4 mg/g下降至21.4 mg/g；壳寡糖处理和对照的叶片相对含水量在断水后均呈下降趋势，但壳寡糖处理在断水第15天较对照增加16.2％，此时对照表现为萎焉（叶片含水量52.4％），壳寡糖处理则生长正常，外施壳寡糖具有减缓 SOD、POD、CAT活性下降的作用。综合分析认为，外施壳聚糖可提高玉米对干旱的抵抗能力。%In the paper,the effects of chitosan oligosaccharide on the chlorophyll content,water content and protective enzyme(SOD,POD and CAT)activities of maize were studied in drought condition.The results showed that,under drought stress,the chlorophyll content of maize leaves in both chitosan oligosaccharide treatment and CK (spraying water ) presented the trend of increase firstly and decrease afterward.The chlorophyll content in chitosan oligosaccharide treatment was 30.7 mg/g after 7 d of water stress and reached to 32.4 mg/g after 15 d of water stress,while it was 27.4 mg/g and 21.4 mg/g respectively for CK.The relative water content of maize leaves for both chitosan oligosaccharide treatment and CK showed a decrease trend,but it was 1 6.2% higher in chitosan oligosaccharide treatment than that in CK at 1 5 d after water stress.The maize leaves began to wilt for CK after 1 5 d of water stress,but it grew normally for chitosan oligosaccharide treatment.The result suggested that the external application of chitosan oligosaccharide played a role in slowing down the decrease of SOD,POD and CAT activities,and enhance the ability of drought resistance of maize.