稻叶表皮蜡质提取方法及含量的比较

以水稻成熟叶片为材料,用氯仿和正己烷两种溶剂,采用常温法、加热法和常温加热结合法提取稻叶表皮蜡质.结果表明,氯仿作溶剂的提取效果好于正己烷,常温加热结合法提取表皮蜡质含量最高,加热法居中,常温法最低.扫描电镜观察结果表明,采用常温加热结合法,用两种溶剂都能将叶表皮蜡质完全提取干净;采用加热法,用氯仿为溶剂能将叶表皮蜡质提取干净,而用正己烷为溶剂,叶片表皮蜡质还有少量呈不规则的小粒状残存;用常温法则两种溶剂都不能将稻叶表皮蜡质提取干净.提取时间对蜡质提取效果有明显影响,高温下(氯仿60℃或正己烷67℃)提取超过30 s,导致细胞内脂溶性成分渗出.综合蜡质含量和扫描电镜分析的结果,以氯仿为溶剂、60℃30 s提取是有效且简单易行的稻叶表皮蜡质提取方法.

On comparison of extraction methods of epicuticular wax and content of rice leaves

Extraction of epicuticular wax on rice leaves are studied comparatively with solution CHCl3 and solution n-hexane with room-temperature method,high-temperature method and room-high-temperature combinative method.Calculation of the total wax contents shows that wax contents with room-high-temperature combinative method are higher than those of room-temperature method and high-temperature method.The wax contents are higher with solution CHCl3 than that with solution n-hexane.The microstructure observed by electronic scanning microscope shows that epicuticular wax is completely extracted with room-high-temperature combinative method with both solution CHCl3 and solution n-hexane and using high-temperature method with solution CHCl3,whereas the epicuticular wax could not be extracted completely with room-temperature method with either solution CHCl3 or solution n-hexane.Extraction time is found significantly affecting the extracted wax contents and quality.Under high temperature,extraction time longer than 30 s leads to leaking out of intracellular fat soluble components into the wax extracts.Combining the results of wax contents and microstructures,high-temperature method with solution CHCl3 is the most effective and simplest wax extraction method.