糜子叶片表皮蜡质的组分及晶体结构分析

在植物的生长发育中，植物表皮蜡质能够保护植物免受外来生物和非生物胁迫的侵害。本研究选取榆黍1号、雁黍7号、陇糜8号、晋黍9号和宁糜10号5个糜子品种材料，利用气相色谱(GC)技术对不同品种及不同生长发育时期糜子叶片的表皮蜡质成分进行分析从而了解糜子叶片表皮蜡质的组成，并对不同品种糜子蜡质晶体结构进行扫描电镜观察。结果表明，不同糜子品种叶片表皮蜡质含量不同，高蜡品种榆黍1号蜡质总含量是低蜡品种宁糜10号的1.4倍。不同糜子品种蜡质组成成分相同，均以碳链长度分布范围为C₂₂-C₃₅的烷烃、初级醇、萜类物质等20种化合物为主。初级醇是糜子叶片表皮蜡质的主要组成成分，占蜡质总含量的67.46%；其中C₃₂醇含量最高，占初级醇含量的82.73%。糜子不同生长发育时期蜡质组成比较相似，均含有初级醇、烷烃及萜类物质；且蜡质总量随生长发育时间的延长不断增加。扫描电镜观察表明，叶片表皮蜡质晶体结构为片状和少量球状。

Analysis of cuticular wax components and crystal structures on the leaves of broomcorn millet

During plant growth and development, cuticular wax can protect plants from exotic biotic and abiotic stresses. In order to understand the cuticular wax composition and crystal structure at different growth and development stages of broomcorn millet, we used five varieties of broomcorn millet (Yushu 1, Yanshu 7, Longmi 8, Jinshu 9, and Ningmi 10) as materials to analyze the cuticular wax components by gas chromatography (GC), and observed the structure of cuticular wax crystal by scanning electron microscope. Finally, the total wax content of high wax variety, Yushu 1, was 1.4 times that of low wax variety Ningmi 10. Twenty compounds including alkanes, primary alcohols, and triterpenoids were identified by GC-MS, and the carbon chain length of these components were ranged from C₂₂-C₃₅. The content of primary alcohols was the highest in broomcorn millet leaves accounting for 67.46% of the total and the main compound was C₃₂ alcohol, which accounted for 82.73% of primary alcohols. The wax components of broomcorn millet were similar at different growth stages, which contained primary alcohols, alkanes, and triterpenoids, and the total amount of wax increased with the growth. Based on the observation using scanning electron microscope, the wax crystal structures with platelets generally existed in the leaves of broomcorn millet.