菊芋营养器官解剖结构及其与抗旱性的关系

为了探讨菊芋适应干旱环境的解剖特征,分析菊芋植株营养器官解剖结构与抗旱性的关系,本研究采用石蜡切片和光学显微技术,对2个菊芋品种的根、地上茎、匍匐茎、叶的解剖结构进行了观察比较与参数测定。结果表明:‘青芋1号’与‘青芋2号’的根、地上茎、匍匐茎及叶的解剖结构均存在显著差异。与‘青芋2号’相比,‘青芋1号’根的表皮、皮层厚度分别显著减小35.21%、49.06%,内皮层、韧皮层厚度、韧皮部和木质部所占的比例分别是‘青芋2号’的1.23倍、1.33倍、1.34倍、1.57倍;‘青芋1号’地上茎和匍匐茎表皮的厚度分别是‘青芋2号’的1.18倍和1.38倍;在叶片的解剖结构上,‘青芋1号’的叶片厚度、上表皮、下表皮、栅栏组织厚度分别显著高于‘青芋2号’71.63μm、1.57μm、2.48μm、19.25μm。综合分析说明,‘青芋1号’通过根部表皮、皮层厚度的减小,内皮层、韧皮部的增厚及韧皮部和木质部所占比例的增加来响应干旱胁迫;通过地上茎和匍匐茎表皮厚度的增加,抵御水分流失;通过叶片、上表皮、下表皮的增厚及其内部栅栏组织的增多,利于水分的储存,从而适应干旱环境。本研究结果为菊芋抗旱性品种的鉴定提供解剖学依据。

Anatomical Structure of Nutrient Organs of Helianthus tuberosus L.and Its Relationship with Drought Resistance

In order to analyze the relationship between the anatomical structure of nutrient organs and drought resistance,the structure characteristics of Jerusalem artichoke(Helianthus tuberosus L.)were studied under arid environment.Through paraffin section and optical microscopy technology,the anatomical structures of root,overground stem,stolon and leaf in two Jerusalem artichoke varieties were observed.The results showed that the anatomical structure of root,overground stem,stolon and leaf in'Qingyu1'and'Qingyu2'were significantly different.Compared with'Qingyu2',epidermis thickness and cortex thickness of the root in'Qingyu1'significantly decreased by 35.21%and 49.06%.Endodermis thickness,phloem thickness and the proportion of the phloem and xylem of'Qingyu1'were 1.23 times,1.33 times,1.34 times and 1.57 times of'Qingyu2'.Epidermis thickness of the overground stem and stolon of'Qingyu1'were 1.18 times and 1.38 times of'Qingyu2'.The leaf,upper epidermis,lower epidermis and palisade tissue of'Qingyu1'were 71.63μm,1.57μm,2.48μm,19.25μm thicker than that of'Qingyu2'.The comprehensive analysis shows that the root of'Qingyu1'adapt to drought by reducing epidermis thickness and cortex thickness,increasing endodermis thickness and phloem thickness,as well as enlarging the proportion of phloem and xylem.The overground stem and stolon prevented water loss by thick epidermis.The leaf relied on thicker leaf,upper epidermis,lower epidermis and palisade tissue to store water and react against drought stress.The result provides anatomical basis for the identification of drought-resistant varieties in Jerusalem artichoke.