不同测定方法下叶片穿透力与叶片功能性状之间的关系

Relationship Between Leaf Force-to-punch and Leaf Functional Traits under Different Measurement Methods

为探究不同校准方法和不同穿刺针直径作用下叶片穿透力测定结果是否存在差异,以及该结果与叶片功能性状之间的关系,选取了30种双子叶植物,分别测定其2.0、1.0、0.5 mm穿刺针直径下的穿透力、撕裂力和叶片的功能性状等指标。结果表明:(1)叶片穿透力在3种不同穿刺针直径作用下差异显著(P<0.05),其在以周长校准方法下,同一物种在穿刺针直径0.5与1.0 mm的差异显著性占所有物种之比为76%、0.5 mm与2.0 mm为76%、1.0 mm与2.0 mm为33%(P<0.05);而同样在以横截面积校准下则为66%、56%、30%(P<0.05)。(2)不同校准方法下3种穿刺针直径之间的叶片穿透力在同一生活型中差异不显著,而在草本分别与灌木和乔木等不同生活型中差异显著(P<0.05),同时0.5 mm直径针的穿透力均大于1.0 mm和2.0 mm。(3)叶片穿透力与叶片角质层厚度、叶片厚度、撕裂力呈显著正相关(P<0.05),与比叶面积呈显著负相关(P<0.05),且以针周长校准的穿透力与叶片功能性状的相关性强于以横截面积校准的穿透力,而不同直径穿刺针作用下的叶片穿透力与叶片性状间的关系无显著差异。因此,穿刺针直径和校准方法的不同对叶片穿透力测定结果均产生差异,不同穿刺针直径测定的差异不会影响穿透机械力与叶片功能性状的相关关系,而不同校准方法测定的差异会影响穿透机械力与叶片功能性状相关关系的强弱。综上所述,在叶片穿透力测试中,选取合适的校准方法和穿刺针直径有利于提高数据的规范化和准确性,在此建议在两种校准方法下首先选用以针周长校准的方法,在3种穿刺针直径中选用0.5 mm测量叶面积小、叶脉密度大且较薄的叶片,对于叶面积大、叶脉密度大且较硬的叶片则选用2.0 mm。

In order to investigate whether there were differences in the results of leaf force-to-punch under different calibration methods and different puncture needle diameters,and the relationship between the results and leaf functional traits,30 dicotyledonous species were selected to determine the punching force and the tearing force of the leaves and the functional traits of leaves under three puncture needle diameters of 2.0,1.0 and 0.5 mm,respectively.The results showed that:(1)the leaf force-to-punch differed significantly(P<0.05)among the three different puncture needle diameters,for the same species when the method calibrated by perimeter,the difference between 0.5 mm and 1.0 mm was 76%,between 0.5 mm and 2.0 mm was 76%,and between 1.0 mm and 2.0 mm was 33%(P<0.05);however,when calibrated by cross-sectional area,the difference was 66%,56%and 30%(P<0.05)respectively.(2)There was no significant difference in leaf force to punch between the three puncture needle diameters under different calibration methods in the same life form,but there was significant differences(P<0.05)between herbs and different life form such as shrubs and trees,respectively,while the leaf force-to-punch of 0.5 mm diameter needles was greater than that of 1 and 2 mm needles.(3)Leaf force to punch was significantly positively correlated with leaf cuticle thickness,leaf thickness,and leaf tearing force(P<0.05),and negatively correlated with specific leaf area(P<0.05),and the correlation between punching force calibrated by needle circumference and leaf functional traits was stronger than that calibrated by cross-sectional area,whereas there was no significant difference in the correlation between leaf force to punch and leaf traits under the action of different diameters of puncture needles.Therefore,differences in both needle diameter and calibration methods produced differences in the results of leaf force to punch measurements.Differences in needle diameters did not affect the correlation between mechanical punching force and leaf functional traits,whereas differences in calibration methods affected the strength of the correlation between mechanical punching force and leaf functional traits.In conclusion,in the leaf force to punch research,selecting the appropriate calibration method and puncture needle diameter was conducive to improving the standardization and accuracy of the data,it was recommended that the two calibration methods based on the needle perimeter should be selected first,and among the three types of puncture needle diameter,0.5 mm was selected to measure with small leaf area and dense and thin veins,and 2.0 mm was selected to measure with large leaf area and,dense and stiff veins.