不同遮光程度对玉米叶片结构的影响

The Effect of Different Shading Degrees on Maize Leave Structure

为了研究玉米多样性种植增产、抗病的可能机制,以不同遮光处理玉米植株时玉米叶片为实验材料,用光学显微镜对玉米叶片表皮细胞密度、表皮细胞长宽及大小、上、下表皮厚度和叶片厚度进行测量研究。结果表明,玉米叶片表皮细胞密度、上表皮厚度、下表皮厚度和叶片厚度的变化趋势为:未遮光处理时(对照)的最大,其次是遮光后透光率为30%,而透光率为10%时的最小。玉米叶片表皮细胞长度、宽度和面积以透光率10%时最大,透光率为30%的次之,而未遮光处理的最小。由此看出,随着透光率的增加,上、下表皮厚度和叶片厚度显著增加,由于植物病原真菌侵染时是通过直接穿透植物叶片表皮实现的,因此叶片的这种解剖结构变化可能是作物影响病菌侵染过程,减轻病害发生程度的机制之一。同时还观察到表皮细胞长度、宽度和单个表皮细胞面积均显著减少,而表皮细胞密度增加,从而导致单位叶面积的细胞数目增多,细胞总表面积增加,光合膜面积增大,有利于叶片整体光合效率的提高。

The aim was to study the mechanism of increasing yield and resistance of maize.Maize leaves at different shading degrees were used as the experimental materials,leaves epidermal cell density,epidermal cell length,width and size,the thickness of adaxial and lower epidermis,leaf thickness were observed by an optical microscope.The results showed that the trend of some maize leaves structure characteristic index including maize leaf epidermal cell density,the thickness of the upper epidermis,lower epidermis thickness and blade thickness,which were as following：the control〉30% transmittance〉10% transmittance;however,other index including epidermal cell length,width and area,which were as following：10% light transmission〉 30% transmittance〉control.This could be seen to increase with luminousness,the upper and lower epidermis thickness and a significant increase in leaf thickness.It mgiht reduce the extent of the plant disease occurrence caused by pathogen.At the same time,the cell length,width,and a single cell area of epidermal cell were significantly reduced,epidermal cell density increased.The number of cells per unit leaf area,total cell surface area and photosynthetic membrane area were increased.So,the overall favorable leaf photosynthetic efficiency was promoted.