基于叶片解剖结构的山核桃品种的抗旱性评价

Drought resistances analysis of different Carya cathayensis based on leaves structure analysis

【目的】基于叶片解剖结构对5个山核桃品种进行抗旱性评价,为山核桃生态栽培提供理论依据。【方法】以5个山核桃品种的3年生嫁接苗成熟叶片为材料制作切片,通过扫描电子显微镜(型号:Tecnai G220 TWIN)下观测计算叶片厚度、上表皮厚度、下表皮厚度和栅栏组织厚度等11项叶片抗旱的相关解剖结构特征参数,采用单因素方差分析方法,对山核桃各品种间11个指标的差异开展比较分析,运用相关性分析评价关联度,通过隶属函数法综合评价5个山核桃品种的抗旱性。【结果】5个山核桃品种的11项抗旱性指标存在较大差异,叶片厚度73.14~114.85μm、上表皮厚度5.56~8.76μm、下表皮厚度4.74~6.18μm、栅栏组织厚度48.77~57.14μm、海绵组织厚度27.80~52.71μm、结构紧密度0.49~0.86、结构疏松度0.37~0.46、栅海比0.96~1.83、叶脉厚度204.20~281.70μm、气孔密度389.83~1012.09个·mm^(-2)、气孔长度15.24~23.13μm,变异系数分别为18.11%、20.75%、6.00%、24.87%、26.12%、9.48%、26.77%、11.32%、43.85%、17.75%、18.11%。相关性分析结果显示,叶片厚度与海绵组织厚度、结构紧密度呈极显著正相关。聚类分析结果表明,11项叶片指标分成4类,栅栏组织厚度、结构紧密度、结构疏松度与栅海比在各类别中相关指数最大,为山核桃品种抗旱性的关键指标;通过隶属函数分析,山核桃抗旱性:宁国山核桃3号>宁国山核桃4号>宁国山核桃5号>宁国山核桃1号>宁国山核桃2号。【结论】叶片解剖结构能够较好地反映山核桃的抗旱特性,可以作为评价山核桃品种抗旱能力的指标,其中宁国山核桃3号抗旱能力较强,适宜在干旱区域栽植。

【Objective】The drought resistance of 5 cultivars of Carya Cathayensis were evaluated based on leaf anatomical structure to provide basis for the Ecological cultivation.【Method】The mature leaves of 3-year-old grafted seedlings of 5 C.cathayensis were obtained and 11 drought structural indexes including leaf thickness,upper epidermis thickness,lower epidermis thickness and palisade tissue thickness were compared under transmission electron microscope(Tecnai G 220 TWIN)by convectional paraffin sectioning method.Single factor ANOVA was used to investigate the differences of 11 drought indexes,correlation analysis was used to judge the correlation degree among indexes,and principal component analysis was used to screen main indexes affecting drought resistance.Finally,drought resistances of 5 cultivars of C.Cathayensis were evaluated by fuzzy mathematics membership function method.【Result】There were differences among 11 drought structural indexes of 5 cultivars of C.Cathayensis and the amplitudes of leaf thickness,upper epidermis thickness,lower epidermis thickness,palisade tissue thickness,sponge tissue thickness,structural tightness,structural porosity,palisade to sea ratio,leaf vein thickness,stomatal density and stomatal length were 73.14-114.85μm,5.56-8.76μm,4.74-6.18μm,48.77-57.14μm,27.80-52.71μm,0.49-0.86,0.37-0.46,0.96-1.83,204.20-281.70μm,389.83-1012.09 per·mm^(-2)and 15.24-23.13 um,respectively.The coefficients of variation were 18.11%,20.75%,6.00%,24.87%,26.12%,9.48%,26.77%,11.32%,43.85%,17.75%and 18.11%,respectively.According to the results of correlation analysis,leaf thickness had an extremely significant positive correlation with spongy tissue thickness and respectively tissue structure tightness.Through cluster analysis,11 indicators were divided into 4 categories,and indicators with the largest correlation coefficients were thickness of palisade tissue thickness,respectively tissue structure tightness,looseness of leaf spongy tissue and palisade tissue and spongy tissue ratio.Using membership function method,the drought resistance of the 5 cultivars of C.Cathayensis were in the order of Ningguoshanhetao 3>Ningguoshanhetao 4>Ningguoshanhetao 5>Ningguoshanhetao1>Ningguoshanhetao 2.【Conclusion】The anatomical structure of leaves can reflect the drought resistance of C.cathayensis and can be used as an index to evaluate the drought resistance of C.Cathayensis.Among 5 cultivars of C.Cathayensis,the cultivars with the strongest drought-resistance was‘Ningguoshanhetao 3’,and it was suitable for planting in arid area.