油茶果皮解剖结构与炭疽病抗性的关系

Relationships between peel anatomy structure of Camelliaoleifera and resistance to Colletotrichum gloeosporioides

本文研究了油茶炭疽病抗性与其主要果皮结构的关系,为进一步了解油茶的抗病机制、从果皮结构角度出发选育抗病良种提供理论依据。以‘普通油茶’的不同抗感炭疽病的果实为试材,分别测定其果皮蜡质层厚度、角质层厚度、气孔大小和表皮毛密度等指标。结果表明,不同抗感炭疽病的油茶果皮的总厚度、蜡质层、角质层和薄壁组织的厚度,均以高抗类型(两个高抗类型的均值)为最大,分别为5.33×103、35.67、25.85、87.73μm,高感类型为最小,分别为2.77×103、19.33、9.67、48.33μm;随着油茶果实抗病性增强,果皮气孔开度、密度和单位气孔面积均呈现明显的下降趋势,以高感类型为最大,分别为38.58μm2、22.02个/mm2和670.50μm2,高抗类型最小,分别为12.59μm2、5.05个/mm2和82.21μm2,但气孔大小与其炭疽病抗性没有明显相关性;抗病类型的油茶果皮表皮毛长度、粗度和密度,均明显大于感病类型。油茶果皮解剖结构与炭疽病抗性关系极为密切,可以作为鉴定油茶炭疽病抗性强弱的参考指标。

The relationship between the main peel structure of Camellia oleifera and resistance to Colletotrichum gloeosporioides was studied to understand the mechanism of resistance to Co .gloeosporioides and provide a scien-tific basis for selecting resistant varieties based on Ca .oleifera peel structure.An investigation was conducted on the thickness of wax and lamina corneum,size of stoma and density of epidermal hairs of Ca .oleifera with differ-ent resistance levels to Co .gloeosporioides .The results showed that the thickness of peel,wax,lamina corneum and parenchyma of highly-resistant type were all the highest （5.33×10 ^3 μm,35.67 μm,25.85 μm,87.73 μm）, and the indexes of highly-susceptible type were the lowest （2.77×10 ^3 μm,1 9.33 μm,9.67 μm,48.33 μm）.The stomata aperture,density and unit area of stoma decreased with enhanced disease resistance in C .oleifera fruits. The indexes of highly-susceptible type were the highest （38.58 μm2 ,22.02 stomata per square millimeter,670.50μm2 ）,and the highly-resistant types were the lowest （12.59 μm2 ,5.05 stomata per square millimeter,82.21μm2 ）;the epidermal hair length,roughness and density of the resistant type were all higher than those of the sus-ceptible type.However,there was no significant difference between the size of stoma and the disease resistance. The results showed that there was an extremely close relationship between the peel structure of Ca .oleifera and anthracnose resistance,which can be a reference index to appraising anthracnose resistance of Ca .oleifera .