平欧杂种榛'达维'叶面积与叶片特征值的相关回归分析

为获得平欧杂种榛叶面积简便、快捷的测定方法,分别于2011年7月和2012年7月,从6年生平欧杂种榛'达维'树上采集发育枝中段成熟叶片,以透明方格法和线性回归法测定叶面积结果表明:叶长、叶宽、叶长与叶宽乘积、叶长平方、叶宽平方与叶面积均呈正相关,其中以叶长与叶宽乘积与叶面积的复相关系数最高;以叶片特征值为因变量,以叶面积(Y)为应变量,采用逐步回归分析建立了叶面积二元回归方程,其中叶长(X_1)、叶长平方(X_1~2)和叶宽平方(X_2~2)是二元线性回归方程的3个自变量;通过对一元线性回归方程和二元线性回归方程的检验分析比较,确立了二元线性回归方程Y=67.248-13.917X_1+0.951 X_1~2+0.548X_2~2为平欧杂种榛'达维'叶面积回归方程。     

金光杏梅叶面积回归测算研究

以金光杏梅成熟叶片为试材,研究了叶长、叶宽与叶面积的关系.结果表明:叶长、叶宽与叶面积均呈正相关关系.叶长、叶宽与叶面积之间的相关系数分别为0.7084、0.8546,叶长和叶宽与叶面积的复相关系数为0.9868,在0.01水平下均达到了极显著水平.在此基础上建立了叶长(x1)、叶宽(x2)、叶长和叶宽与叶面积(y)之间的回归方程y=61.4140x1-2 480.6、y=28.7600x2-0.8546、y=17.6276x1+41.2594x2-1 078.4906,3个回归方程均可用于测算金光杏梅的叶面积,其中以叶长和叶宽与叶面积的二元回归方程测算结果更为精确.在具体应用中,可根据所要求的精确度进行选择.     

节瓜叶面积回归方程的比较

采用回归的方法 ,对 11个节瓜品种 (品系 )建立了叶面积与叶长、叶宽和两者乘积的线性回归和幂函数回归方程。结果表明 ,各节瓜品种叶面积与相应指标呈极显著回归关系 ,通过比较选择确定一元线性回归和幂函数回归方程较为适用于叶面积的估算 ,同时还得出了各品种通用的回归方程。     

枇杷叶面积测定方法的研究

本试验用方格法、鲜重法、纸重法、光电面积仪法、求积仪法、面积对叶长直线回归估测法、面积对叶宽直线回归估测法、面积对叶长宽积的直线回归估测法和面积对长宽积的系数直接回归估测法等九种方法，测定了白梨、解放钟、霞钟和太城四号四个枇杷品种的叶面积，其中以光电面积仪法测定的数据为标准叶面积（其测定的相对误差小于1％）。经方差分析证明，九种方法所测面积无显著差异，均可应用，而其中的直线回归法和系数法操作简便，不必摘叶。故本文给出的回归方程和系数有一定的实用价值。     

银杏叶面积和果实鲜重非破坏性测定方法研究

以扬州大学园艺与植物保护学院果园中的银杏核用主栽品种‘佛指’为材料,定期取其叶片和果实,进行叶片的叶长、叶宽、叶面积和果实的果长、果径、果重之间的回归分析。结果表明:叶面积模型为:y=0.0004×(LL×LW)2+0.6367×LL×LW-0.3395,R2=0.9868,RMSE=1.247;果实鲜重模型为:y=0.0382×(FL×FD)2+1.1663×FL×FD-1.0251,R2=0.9674,RMSE=0.4536。通过对该模型的验证,发现这2个模型能准确地依据叶长、叶宽和果长、果径的资料来模拟银杏叶面积和果实鲜重。     

两种紫薇属植物叶片形态及面积估算模型

以中国特有树种云南紫薇和外来树种大花紫薇成熟叶片为试材,采用图像处理法测算各样叶叶长(L)、叶宽(W)、叶周长(LW)和叶面积(LA),利用不同类型的线性或非线性回归方程对2个树种单叶叶面积进行拟合,研究了云南紫薇和大花紫薇叶片形态特征及单叶叶面积估算模型,以期为树种生态功能评价提供参考依据。结果表明：云南紫薇与大花紫薇成熟叶片的叶长(L)、叶宽(W)、叶周长(LW)和叶面积(LA)均存在显著差异,种内也存在不同程度变异;云南紫薇单叶面积拟合度最高的单变量回归模型是LA=4.254+0.305LW+0.051LW²和LA=6.200+0.063LW²(R²=0.932),多变量回归模型是LA=0.547L+0.449W(R²=0.884);大花紫薇单叶面积拟合度最高的单变量回归模型是LA=2.261W^1.898(R²=0.834),多变量回归模型是LA=0.204L+0.371W+0.442LW(R²=0.907)。由此可知,云南紫薇...     

朱砂根盆花果实数量指标一元线性回归方程的建立

为探索朱砂根盆花果实结果枝数、结果量、果实直径之间的关系,通过对武平县钦福花场绿叶型的朱砂根盆花进行抽样调查,调查内容包括结果枝数、结果量、果实直径3项指标,并在R语言程序中,利用函数hist()、plot()、cor()、cor.test()、lm()、Summary()、predict()及相关命令对调查结果进行直方图分析、散点图分析、相关分析及t检验、回归分析及t检验、一元线性方程预测。结果:3项指标呈近正态分布,并存在线性相关关系;结果枝数、结果量的相关系数为0.6106085,结果枝数与果实直径的相关系数-0.2811521,结果量与果实直径的相关系数-0.4104362,均通过t检验;结果枝数与结果量的一元线性回归方程为y=-283.04+62.83x,结果枝数与果实直径一元线性回归方程为:y=9.42124-0.06184x,结果量与果实直径的一元线性回归方程为y=9.023579-0.0008772x,均过t检验;一元线性回归方程预测结果与实际调查值相符或相近。     

木菠萝叶面积无损伤测定方法研究

运用SPSS13．0,建立了以各种叶形的木菠萝实际面积、叶长、叶宽为测算指标的叶面积计算回归模型。结果表明,木菠萝叶面积（LA）与叶长（L）、叶宽（w）呈极显著回归关系。通过比较择优,模型LA=-23．644＋1．899w＋3．491L＋0．023LW＋0．545w。适用于所有叶形木菠萝的叶面积估算。通过对该叶形回归模型的使用,可实现木菠萝叶面积的活体快速估测。     

'野酿2号'与'桂葡6号'叶面积回归分析

为了找到快速测量‘野酿2号’与‘桂葡6号’叶面积的办法,本研究以这两种葡萄叶片为研究对象,通过方格纸法测算准确的叶面积,将主脉长、斜长1、斜长2、叶宽等24个叶片参数与实测叶面积进行回归分析。研究结果表明:两种葡萄的(主脉长+斜长1)×叶宽、(主脉长+斜长1+斜长2)×叶宽与其实测叶面积的相关系数均最大;且‘野酿2号’以(主脉长+斜长1)×叶宽为叶片参数的线性方程LA=12.349+0.452[(L+L_1)W]得出的预测叶面积与其实测叶面积无显著性差异,‘桂葡6号’以(主脉长+斜长1+斜长2)×宽为叶片参数的幂函数LA=0.379[(L+L_1+L_2)W]~(0.974)得出的预测叶面积与其实测叶面积无显著性差异。     

番茄叶面积与干物质重量的相关性研究

本文研究了两个番茄品种(“白果”,“丽泰”)在营养生长阶段,植株地上部分千重、叶干重与叶面积的相关性。结果表明:叶面积与叶干重比值(两品种平均)基本不变;植株地上部分干重、叶干重与叶面积均呈极显著正相关,其相关系数分别为R=0.9845和R=0.9967,提出了用植株地上部分干重和叶干重估测叶面积的一元线性回归方程式。     

Estimating leaf area of plantain

The area of leaves of plantain (Musa acuminata × Musa balbisiana) was traced on graph paper. Then the length (L) and the maximum width (W) were measured. A known leaf area from each leaf was taken and both the sample and the remaining leaf blades were dried and weighed. Using known leaf area and their dry weights, the leaf area of each whole leaf was determined. From the regression equation, a coefficient for estimating the true leaf area from the L × W measurements was determined to be 0.8 (approx.) which was statistically significant (P = 0.05).Using a mathematical method (independent of the first method), the coefficient for estimating the true leaf area of plantain was found to be 0.7854. A significant correlation (r, 0.001 = 0.73) was also found between the area traced on graph paper and that determined using the coefficient 0.8 (L × W).     

柚单株产量影响因素的相关分析

通过对影响柚单株产量的十个因子的简单相关分析、通过分析，并应用逐步回归法剔出与单株产量相关不显著的因子得到最优多元回归方程，认为影响梁平柚单株产量的主要因子有花杂数、果数、座果率、每果叶面积和单果重。树高／冠径、干周、树冠体积、叶面积系数、总枝数与单株产量相关不显著。     

叶用莴苣叶面积测定方法的研究

叶面积大小是决定植物光合作用产物量的重要因素。为了得到一种快速、准确、灵活测定蔬菜叶面积的方法，本试 验以叶用莴苣为例，运用Image J 图像处理软件进行植株叶面积的测定，然后与传统测定方法方格计数法与纸样称重法的测 定结果进行比较验证。结果表明：方格计数法、纸样称重法与Image J 图像处理3 种方法测定结果之间不存在显著性差异； 通过方程线性回归分析发现，3 种方法之间的相关系数均在0.99 以上。由此可见Image J 图像处理软件可准确地应用于叶用 莴苣叶面积测定。     

茄子幼苗叶面积速测方法

应用相关与回归分析方法，对春播长茄品种（Ｆ１）幼苗叶面积的测定结果表明，茄子幼苗叶长、叶宽与单株叶面积之间存在极显著的正相关，第４叶位单叶面积与单株叶面积间的相关最为密切，因而以其回归方程作为茄子苗叶面积的无破坏性速测方法是简便可行的。     

Evaluation of four methods for estimating leaf area of isolated trees

The accurate modeling of the physiological and functional processes of urban forests requires information on the leaf area of urban tree species. Several non-destructive, indirect leaf area sampling methods have shown good performance for homogenous canopies. These methods have not been evaluated for use in urban settings where trees are typically isolated and measurement may be complicated by proximity to residential areas, buildings, signs, and other infrastructure elements. We evaluated the accuracy, precision, efficiency and other practical considerations associated with four methods of estimating the leaf area of open-grown deciduous trees in urban forests. The methods included color digital image processing (CD), the LAI-2000 Plant Canopy Analyzer, the CI-100 Digital Plant Canopy Imager, and a logarithmic regression equation. Regression coefficients, adjusted R², and confidence intervals were used to determine the best method when using true leaf area of 25 Platanus x acerifolia Willd. and 25 Platanus racemosa Nutt. as an independent variable. Practical considerations included ease of data collection and processing and costs associated with each method. The CD method and LAI-2000 estimates showed good correlation with true leaf area (R² 0.71); however, only the CD method produced estimates within 25 percent of mean true leaf area and met additional requirements for accuracy, precision, and efficient use in urban settings.     

A simple method for non-destructive estimation of total shoot leaf area in tree fruit crops

Leaf area is a commonly used measurement in many horticultural research experiments, but is generally destructive, requiring leaves to be removed for measurement. Leaf removal precludes repeated measures and disrupts carbohydrate assimilation and translocation, which is another frequent parameter of interest. Numerous methods have been devised for estimating leaf area of individual leaves in situ. These methods generally involve measuring leaf parameters such as length and width and using those as variables in an equation describing a relationship between those variables and leaf area specifically developed for each species. However, these methods are typically highly labor intensive when scaling to the level of the shoot because they require each leaf to be measured individually. Here we report on a method that makes use of a regression relationship for non-destructively estimating whole shoot leaf area, but only involves measuring the length of the longest leaf on the shoot and multiplying it by the number of leaves on the shoot. The method has been tested on 14 diverse fruit and nut tree cultivars. Deciduous and evergreen species with both simple and compound leaves were included. For 13 out of 14 cultivars, coefficients of determination (r²) between actual measured leaf area and estimated leaf area were equal to or greater than 0.80. The model was validated for shoot leaf area of different trees in different years for four of the cultivars. The relationship developed for these cultivars appears to be broadly applicable to other tree species and will be a simple and useful tool for research requiring accurate non-destructive estimates of shoot leaf area.     

六种兜兰属植物的叶面积和叶幅与开花的关系

测定了硬叶兜兰、杏黄兜兰、麻栗坡兜兰、长瓣兜兰、红旗兜兰及根茎兜兰6种兜兰的开花植株和非开花植株的叶片数、叶面积、叶幅及花器官大小等形态性状,利用Logistic模型分析了叶片数、叶面积及叶幅与开花与否的关系。结果表明:6种兜兰个体是否开花与叶面积和叶幅都有极显著的相关性,经回归方程计算,硬叶兜兰、杏黄兜兰、麻栗坡兜兰、长瓣兜兰、红旗兜兰及根茎兜兰开花的叶面积阈值(P=50%)需要达到48.88、75.55、141.75、243.42、49.02、151.94cm~2;而叶幅阈值则要达到15.87、15.76、21.51、36.85、17.99、39.06cm,表明兜兰属植物植株个体的叶面积或叶幅要达到一定大小才可以进入生殖生长。利用叶面积大小及叶幅与开花显著相关的指标,可以判定兜兰植株是否完成幼年期进入成熟期。此外,杏黄兜兰、麻栗坡兜兰、长瓣兜兰的开花与否与叶片数也有显著的相关性,叶片数也可以成为指示是否可能开花的指标。