3个薄壳山核桃品种叶片结构特征和枝条导水功能比较

Comparison on leaf structure characteristics and branch hydraulic function of three Carya illinoinensis cultivars

以在安徽省广泛栽培的薄壳山核桃〔Carya illinoinensis(Wangenh.)K.Koch〕品种‘波尼’(‘Pawnee’)、‘马罕’(‘Mahan’)和‘威斯顿’(‘Western’)为研究材料,比较3个品种叶片结构特征和枝条导水功能,并运用隶属函数值法评价其抗旱性。结果显示:总体上看,与‘马罕’相比,‘波尼’和‘威斯顿’的气孔小而密,叶脉密度较高;‘波尼’和‘威斯顿’的叶片、上表皮和下表皮较厚,明显厚于‘马罕’;‘波尼’和‘威斯顿’的叶片组织结构紧实度和比叶质量显著高于‘马罕’;‘马罕’导管直径为45.1μm,显著大于‘波尼’(42.2μm),但‘波尼’和‘威斯顿’的导管密度和导管壁加固度显著大于‘马罕’;3个薄壳山核桃品种的边材比导率差异不显著,而‘波尼’和‘威斯顿’枝条的自然状态下导水损失率分别为23.3%和22.2%,显著低于‘马罕’(32.9%);‘波尼’木材密度最大(0.49 g·cm-3),显著高于‘马罕’(0.45 g·cm-3)和‘威斯顿’(0.45 g·cm-3)。隶属函数值法分析结果表明:‘波尼’和‘威斯顿’各指标隶属函数值的均值分别为0.55和0.52,明显大于‘马罕’(0.44)。综上所述,‘波尼’和‘威斯顿’抗旱能力较‘马罕’更强,适宜在较干旱地区推广种植。

Taking widely cultivated cultivar‘Pawnee’,‘Mahan’,and‘Western’of Carya illinoinensis(Wangenh.)K.Koch in Anhui Province as research materials,the leaf structure characteristics and branch hydraulic function of the three cultivars were compared,and their drought resistance were evaluated by using subordinate function value method.The results show that compared with‘Mahan’,the stomata of‘Pawnee’and‘Western’are small,their stomatal densities are high,and their vein densities are relatively high in general;the leaf,upper epidermis,and lower epidermis of‘Pawnee’and‘Western’are relatively thick,and are evidently thicker than those of‘Mahan’;the tightness degree of leaf tissue structure and specific leaf mass of‘Pawnee’and‘Western’are significantly higher than those of‘Mahan’;the vessel diameter of‘Mahan’is 45.1μm,and is significantly greater than that of‘Pawnee’(42.2μm),but the vessel density and vessel wall reinforcement of‘Pawnee’and‘Western’are significantly greater than those of‘Mahan’;the differences among sapwood specific conductivity of the three cultivars are not significant,while the natural percentage loss of hydraulic conductivity of branches of‘Pawnee’and‘Western’are 23.3%and 22.2%,respectively,which are significantly lower than that of‘Mahan’(32.9%);the wood density of‘Pawnee’is the largest(0.49 g·cm-3),and is significantly higher than those of‘Mahan’(0.45 g·cm-3)and‘Western’(0.45 g·cm-3).The subordinate function value method analysis result shows that the subordinate function values of‘Pawnee’and‘Western’are 0.55 and 0.52 respectively,which are evidently higher than that of‘Mahan’(0.44).In conclusion,the drought resistance of‘Pawnee’and‘Western’are stronger than that of‘Mahan’,therefore,they are suitable for planting in arid areas.