Estimates of the leaf area of forage peanut for use in morphogenetic assessment

Understanding the morpho-physiological responses of forage plants is critical for successfully managing pastures; however, there is no specific method for morphogenetically assessing Arachis pintoi. The present study aimed to develop and validate mathematical models to estimate leaf area in A. pintoi to enable assessments of leaf elongation and senescence. Two experiments were performed. The first experiment used 500 A. pintoi leaves to model leaf area. Three models were used: correlation, mechanistic and empirical. A total of 336 leaflets were collected to validate the models. For the second experiment, 786 leaflet pairs were collected to test the leaf symmetry. Leaf length (L), width (W) and area (A) were measured for each leaflet in both of the experiments. The model identity test was used. The leaflet area can be estimated using the following formula:  = W ×L × 0·25 × π. Experiment 2 showed that the initial leaflet pairs were equal, as were the terminal leaflet pairs. In conclusion, the mechanistic model should be used to estimate the leaf area for A. pintoi, and only half of each leaf can be measured.     

A Method for Estimating Sago Palm (Metroxylon sagu Rottb.) Leaf Area after Trunk Formation

Abstract

It is important to measure the individual leaf area and leaf area index (LAI) of sago palm (Metroxylon sagu Rottb.) to determine the appropriate planting density and maintain populations that are highly productive with regard to starch production. However, the accurate estimation of sago leaf area from the entire leaf profile or the projecting area of the plant is not possible. Thus, we developed a method for estimating leaf area of sago palm after trunk formationby integrating the leaflet areas. All leaflets were diagrammatically converted to rectangles, each having the same area asthat of the corresponding leaflet, and these rectangles were arranged on the rachis to initiate the shape of a leaf without overlapping leaflets and gaps between their bases and between their tips. The leaf shape thus produced by the arrangement of these rectangles was represented as ellipsoidal in the apical half and as trapezoidal in the basal half. The ratiosof the estimated to the actually measured area of the apical and the basal half of the leaf were 99?107% and 94?108%, respectively. The ratio of the estimated area of the whole leaf to the measured area was 98?104%. From these results, the method for estimating the whole leaf area by converting the leaflets diagrammatically to rectangles, andcalculating the area as the sum of the ellipsoidal apical half and trapezoidal basal half, is considered to be accurate and simple.     

Estimating leaf area of warm‐season perennial legumes

Refining mathematical models may decrease labour and generate accurate estimates of leaf area in warm‐season perennial legumes. The aim of this study was to assess the use of mathematical models to determine the leaf area of four tropical forage legumes. Perennial legumes (Arachis pintoi, Stylosanthes spp., Calopogonium mucunoides and Neonotonia wightii) were collected, and an elliptical model and a corrected elliptical model were used to estimate leaf area. For comparison, linear models were also generated based on the leaflet area. The elliptical model was suitable for the initial forage peanut leaflets, while the corrected elliptical model proved suitable for estimating the area of the initial leaflets of all species as well as the terminal leaflets of forage peanut and stylo. The elliptical model could be used to estimate the area of both the initial and terminal leaflets only in stylo. Models were generated to estimate leaf area of all legumes requiring only the measurement of length and width from a single initial leaflet. In all of the studied legumes, the leaflet pairs were symmetrical, meaning the corrected elliptical model allows for the estimation of the leaflet area of each plant.     

大乌圆龙眼结果母枝单元质量与开花坐果及果实性状的关系

以大乌圆龙眼为试材,应用生物统计方法分析结果母枝单元直径、长度、复叶数、小叶数、小叶面积、总叶面积和着生角度7个自变量与穗开花总数、穗开雌花数、穗开雄花数、花穗长度、花穗宽度、花穗体积、穗坐果数、穗果重、单果重和可溶性固形物含量10个依变量的相关关系,结果表明:(1)结果母枝单元直径与穗开花总数、穗开雌花数、穗开雄花数、花穗宽度、花穗体积、穗坐果数、穗果重为显著或极显著的正单相关,与可溶性同形物含量为显著的多项式相关,对开花坐果及果实性状影响最大.(2)结果母枝单元总叶面积与穗开花总数、穗开雄花数为显著的多项式相关.(3)结果母枝长度与花穗宽度、花穗体积为显著正单相关.(4)结果母枝复叶数、小叶数、总叶面积与花穗宽度、花穗体积为显著或极显著正单相关,小叶数与穗坐果数为显著的正单相关,复叶数与单果重为显著的负相关.     

Leaf Positions of Potato Suitable for Determination of Nitrogen Content with a SPAD Meter

Abstract

Hand-held SPAD meter can be used to evaluate the leaf nitrogen status of potato. For practical use, it is necessary to select a proper compound leaf, a proper leaflet within compound leaf and position of leaflet suitable for measurement. Therefore, field experiments were conducted in northern China in 2009 and 2010. The SPAD values, plant growth, N uptake of potato plants at tuber initiation and tuber bulking stages under different N supply levels, and final tuber yields were examined. The criteria for determining the most suitable leaf, leaflet and position within a leaflet are that the SPAD values show less variation at a given N supply level, and show a more sensitive response to different nitrogen levels. Our results showed that the coefficients of variance of SPAD values ranged from 8.7 to 25.9% with a leaf N concentration range of 2.1 to 3.8 gN 100 g-¹ at tuber initiation stage, and 7.2 to 21.6% with leaf N concentration range of 0.96 to 1.26gN 100 g-¹ at the tuber bulking stage. The SPAD values of the 4th compound leaf from apex were more stable and more sensitive to the nitrogen level than those of other leaves, suggesting that the 4th compound leaf is suitable for estimating the leaf N status using a SPAD meter. Within a compound leaf, the SPAD value of the top leaflet was more sensitivethan the other leaflets to nitrogen supply, whereas it was less stable, making it difficult to chose the leaflet for measurement. However, the top leaflet emerges and expands much earlier than the side leaflets, and should be better for SPAD value measurement. The SPAD measurements at the top point of the top leaflet of the 4th leaf demonstrated both less variation and higher sensitivity to nitrogen supply. Therefore, we conclude that the top point of the top leaflet of the 4th compound leaf is the best position for potato N status diagnosis using a SPAD meter.     

大豆叶调位运动的研究——Ⅰ.大豆叶运动与叶面受光

本研究通过盆栽试验于大豆R_5时期,在晴天(f)和阴天(c)条件下,对大豆叶运动与叶面受光的研究结果表明,大豆各方位的叶数(％),晴天时,西和西南高于东和东北;阴天时,东西水平线以南各方位叶数(％)大致相近。还看出,不论晴阴天时,东西水平线以南高于以北。大豆叶片倾斜方向,主、副倾角,晴天时的叶数(％)正向>负向;阴天时,相反。大豆叶片倾斜角度,主、副倾角,晴天时,正向>负向,阴天时,相反。大豆叶面受光,晴天群体光照强度处于20～30KLx,阴天4～6KLx,多数未达光饱和状态。从叶片分布方位,叶片倾斜方向、角度和叶面受光关系看,在晴天时,由于太阳高度和位置变化,直射光多,主、副倾角正向角度大。为充分利用光能,大豆叶由东南向西南作调位运动。本研究进一步证实了叶枕中钾的含量增高时对叶片直立和扭曲起调节作用。     

Regional variation in leaf form and other characters of solanum tuberosum Group Andigena

Summary Study of seedling progenies grown at Edinburgh showed that the terminal leaflet becomes an increasingly important part of the leaf as one proceeds northwards from Southern Bolivia to Colombia, the frequencies of lateral leaflets, interjected leaflets, and secondary leaflets consequently declining. Actual leaf length, and the breadth of the terminal leaflet, are least in South-Central Peru, and increase towards the extremities of the geographical range. Flowering in the seedling year was most frequent in progenies from South-Central Peru. while low-dormancy of tubers was most frequent in those from Ecuador, these characters not showing clear geographical trends.     

华杂6号叶面积简易测定方法

研究了在直播条件下，华杂6号的叶长、叶宽、长宽乘积与叶面积，单叶面积与整株叶面积的关系。结果表明，华杂6号的单片叶面积与叶长、叶宽、长宽乘积都呈幂函数关系，但单片叶面积与长宽乘积关系最密切，其次是叶宽，最后是叶长。单株叶面积与单片叶面积呈一元线性函数关系，但相关性最好的叶片所处叶位，随绿叶数的增加而降低。     

荔枝树冠长势的几种测量方法对比

选择长势稍有差异的两组糯米糍(Nuomici)荔枝树，探索测量荔枝(Litchi chinensis Sonn)树冠长势的简单和精确的方法，分别测量他们的末次秋梢枝条长度、枝条粗度、复叶数、小叶数、小叶长度、小叶宽度、叶片厚度、叶脉粗度、叶片鲜重、自然干燥叶片的重量、烘干至恒重的叶片重量等。结果表明：在两组长势稍有差异的同一个荔枝品种中，他们的枝条长度、枝条粗度、复叶数、小叶数、小叶长度、小叶宽度、叶片厚度、叶脉粗度等数据没有统计学上的显著差异，但叶片鲜重、自然干燥叶片的重量、烘干至恒重的叶片重量则差异显著。作者认为：通过测量叶片鲜重来定量判定荔枝果树树冠长势的方法是既简单又精确的办法之一。     

橄榄种质资源叶片表型性状多样性分析

对农业部福州橄榄种质资源圃中80份橄榄种质资源叶片12个表型性状进行了调查分析.结果表明:这一群体橄榄种质资源的嫩叶颜色、成熟叶颜色、叶面光泽度、叶片形状、叶尖形状、叶基形状、小叶数、复叶主轴长度、小叶叶柄长度、小叶长度、小叶宽度、叶形指数等表型性状均存在丰富的多样性;不同来源地橄榄种质资源叶片表型性状差异明显.主成分分析结果表明,叶片形状、叶形指数、嫩叶颜色、成熟叶颜色、小叶数是叶片表型性状多样性构成的主导因子.     

越冬前冬小麦主茎叶片几何参数模型研究

为了定量分析冬小麦越冬前叶片主要几何参数与器官生物量及比叶重的关系,以小麦品种济麦22、泰农18和鲁原502为材料,于2013-2014和2014-2015年冬小麦生长季内开展了品种和施氮试验,通过分析越冬前叶长和叶宽与器官生物量和比叶重之间的定量关系,以及叶弦角和叶切角与比叶重之间的关系,构建了冬小麦越冬前叶片几何参数模型。经独立试验资料检验,冬小麦越冬前叶片主要几何参数叶长、最大叶宽、叶切角和叶弦角实测值与模拟值的RMSE、平均绝对误差（d_a）、平均相对误差（d_ap）和R分别为1.453 cm (n=46)、1.136 cm、11.997%和0.916;0.093 cm (n=46)、0.073 cm、13.396%和0.837;23.906°(n=46)、16.059°、52.153%和0.556;23.706°(n=46)、19.818°、53.966%和0.787,均达极显著水平（P<0.001）,说明实测值与模拟值的吻合程度较好。所建模型可较好地模拟不同品种、不同施氮水平下冬小麦越冬前叶片主要几何参数。     

巴西香蕉叶面积与叶片形态特征关系的定量分析

采用“3414”设计方案进行田间实验,在实验观测的基础上,建立了中肥不同生育期巴西香蕉叶面积与叶长、叶宽及长宽乘积之间的定量关系,结果表明：不同生育期,巴西香蕉叶面积与叶长、叶宽及长宽乘积最佳模型Y=ax+b,具体关系如下：在营养生长期中,叶面积与叶长、叶宽及长宽乘积间定量关系分别为：A=-2 162+54.957 L、A=-2 202.687+123.919 W、A=-76.014+0.767 P;孕蕾期及抽蕾期,叶面积与叶长、叶宽及长宽乘积间定量关系分别为：A=-6 969+90.584 L、A=-6     

Natural variation and morpho-physiological traits associated with water-soluble carbohydrate concentration in wheat under different nitrogen levels

Stem water-soluble carbohydrates (WSCs) are important plant traits influencing grain yields in wheat. However, the traits regulating WSCs storage, particularly under different nitrogen (N) levels are poorly addressed. This study investigated 35 morpho-physiological traits associated with the variation in WSC concentration (WSCc) in the main stem of eight wheat genotypes including two primitive genotypes under three N levels (0, 100, and 200 kg N ha⁻¹). 28 traits were significantly, positively or negatively, correlated with the WSCc in all N levels, and 22 of them were consistent across N levels. Majority of the traits were positively correlated with WSCc suggesting that multiple traits regulate WSCc in wheat plants. However, few traits such as root:shoot ratio (RS_R), stem nitrogen (S_N), leaf nitrogen (L_N), nitrogen per unit leaf area (N_LA), total vegetative mass (V_MASS), cellulose (C_L), and hemicellulose (H_C), were negatively correlated with WSCc. This suggests that plant N concentration was an important selective force driving WSCc in wheat. Indeed, a percent increase in leaf N concentration resulted in 28% lower WSCc. Direct selection estimated that higher V_MASS, flag-leaf width (FL_W), but lower RS_R was adaptive and resulted in higher WSCc in low N level. In contrast, lower V_MASS and FL_W were adaptive and resulted in higher WSCc in high N level. Higher cellulose and hemicellulose were associated with lower WSCc suggesting that a reduced carbon flux to stem structural compounds may improve WSCc in wheat plants. Together, these results demonstrate that a specific suit of trait changes that evolve under N-specific selection increase main stem WSCc but the adaptive value of these changes varies among traits and N levels.     

澳洲坚果种质资源叶片形态性状观测分析

为鉴别与利用澳洲坚果种质资源,以湛江地区栽培的25份澳洲坚果种质为试验材料,调查研究叶片的14个表型性状,并对部分性状进行遗传变异与相关性分析。结果表明：供试澳洲坚果资源的叶片表型性状（叶序、嫩叶颜色、叶片形状、叶尖形状、叶基形状、叶缘形状、叶缘刺多少、叶面状态、嫩叶黄化、叶面积、叶长、叶宽、叶形指数、叶柄长度）具有明显的变异性。其中,叶片5个数量性状的变异系数为13.47%~25.19%,变异幅度以叶面积最大、叶片长度最小;各数量性状数据分布均为偏正态分布,偏度大小范围为-0.20~1.33。相关性分析结果表明,叶面积与叶形指数均与叶片长度及其宽度间存在极显著的相关性,而叶柄长度与叶面积、叶片长度、叶片宽度及叶形指数之间的相关性均不显著。因此,澳洲坚果种质资源的叶片表型性状显示出较为丰富的遗传多样性,部分数量性状之间存在较为密切的关系。并且,运用石蜡切片法,对澳洲坚果叶片的解剖结构特征进行了初步观测。     

花生胚小叶外植体再生影响因素研究简报

胚小叶外植体再生是进行花生外源基因遗传转化的重要途径之一。研究表明,品种对花生胚小叶外植体再生有较大影响,BA／NAA比值与愈伤组织诱导、芽再生数量及速度关系密切,发芽势强的花生品种宜用低BA／NAA比值的MS培养基,发芽势弱的品种则宜用高BA／NAA比值MS培养基。     

基于无人机RGB影像的小麦叶面积指数与产量估算研究

为探讨基于无人机RGB影像实现对小麦叶面积指数(leaf area index, LAI)和产量估算的可行性,设置不同生态点、品种和氮素处理的小麦田间试验,应用大疆精灵4 Pro无人机获取小麦拔节期、抽穗期、扬花期和灌浆期4个主要生育时期的RGB高时空分辨率影像,并同测定小麦LAI。采用相关性分析筛选出不同生育时期对LAI敏感的光谱与纹理特征集,并借助随机森林(random forest, RF)、偏最小二乘回归法(partial least squares regression, PLSR)、BP神经网络(back propagation neural network, BPNN)和支持向量机(support vector machine, SVM)分析方法,筛选出小麦不同生育时期最优的LAI估测模型。基于不同生育时期的光谱与纹理特征以及时期特征集,进一步建立产量预测模型,并在不同生态点验证叶面积估算模型与产量预测模型的普适性。结果表明,基于RF的LAI估测模型的验证精度最高,4个生育时期的均方根误差(root mean square error, RMSE)分别为2.26、1.44...     

吉林省大豆品种遗传改良过程中叶片性状的演变

以吉林省1923-2005年育成的30个大豆（Glycine max）品种为材料,通过2005和2006两年田间试验在R2﹑R4和R6期对叶部性状演化及其与产量的关系进行研究。结果表明,产量随育成年代呈线性增加,根据回归方程计算,产量从1923年的1197.80kg&;#8226;hm-2增加到2005年的2305.545 kg&;#8226;hm-2,82年来增加了1107.73kg&;#8226;hm-2,平均每年增加14.60kg&;#8226;hm-2;单株叶面积﹑单株叶片数目﹑长宽比和叶面积指数（LAI）随着育成年代的增加而增加,小叶面积随着育成年代的增加而降低;新品种的单株叶面积在生殖生长期均大于老品种,尤其在后期有较长的绿叶期;通过相关分析表明,产量与单株叶面积﹑叶面积指数均达到显著水平（P≤0.05）,在R2和R4期与单株叶片数目到显著水平（P≤0.05）,说明在遗传改良过程中叶部性状与产量关系密切,在品种选育和高产栽培过程中可以考虑作为选择的依据。     

多遥感光谱指标结合进行大田冬小麦叶片叶绿素含量估测研究

为解决大田冬小麦叶片叶绿素含量估测模型精度低、通用性弱的问题,在获取冬小麦拔节期和抽穗期冠层红光波段反射率(BR_red)和近红外波段反射率(BR_nir)的基础上,计算归一化差值植被指数(NDVI)、差值植被指数(DVI)、比值植被指数(RVI)、土壤调节植被指数(SAVI)、改进型比值植被指数(MSR)、重归一化植被指数(RDVI)、II型增强植被指数(EVI2)和非线性植被指数(NLI)等8个植被指数。经统计分析,选择与叶片叶绿素含量(SPAD值)相关性较好的5个遥感光谱指标(NDVI、MSR、NLI、BR_red和RVI)作为输入变量,建立了冬小麦叶片叶绿素含量的BP神经网络估测模型(WWLCC_BP),并对估测模型进行精度验证。结果表明,WWLCC_BP估测模型在拔节期估测的决定系数(r²)为0.84,均方根误差(RMSE)为5.39,平均相对误差(ARE)为9.87%。抽穗期的估测效果与拔节期较为一致。将WWLCC_BP和高分六号影像...     

Simulating growth,development, and yield of tillering pearl millet: I. Leaf area profiles on main shoots and tillers

Pearl millet (Pennisteum americanum L.) is an essential crop in farming systems of the dry areas of the semi-arid tropics and its tillering habit is an important adaptive feature. This is the first paper in a series aiming at developing and validating a pearl millet simulation model that recognises tillers as functional entities, analogous to intercrops. The objective of this paper is to quantify the effects of total leaf number per axis (TLN), cultivar, plant density and axis number on parameters that are used to simulate potential leaf area per plant. Four cultivars with different phenology and tillering habit were grown under well-watered and well-fertilised conditions at two locations in India, covering a range of daylengths and plant densities. For selected plants, the area of fully expanded leaves was measured non-destructively. A bell-shaped function adequately described the relationship between individual leaf area and leaf position on an axis. Its shape was determined by the position (X₀) and area (Y₀) of the largest leaf and by the breadth and skewness of the leaf area profile curve. TLN affected all four parameters, although the association with Y₀ was weak. Cultivar only affected Y₀, suggesting that parameterising new cultivars is straightforward. The observed density effect confirmed that competition for light between axes started during stem elongation. The results highlighted the consistent differences between leaf area profiles of main shoots and tillers. For a high-tillering crop like pearl millet, modelling leaf area dynamics through individual leaves is justified, as this approach can potentially deal with cultivar and environmental effects on tillering.     

大豆苗期叶片形态对烯效唑干拌种的响应

利用Laser Area Meter CI-203在大豆三叶期探究大豆不同复叶的形态对烯效唑干拌种的响应.结果表明:不同复叶的叶柄长度、叶长和叶宽对烯效唑的敏感程度存在差异,且各复叶指标的变化与烯效唑拌种浓度变化的相关性均达到极显著水平.烯效唑拌种处理后第1复叶的叶柄长、叶长和叶宽度受到抑制,叶面积减小,第2、3复叶的叶柄长、叶长和叶宽的伸长得到促进,叶面积增加.烯效唑干拌种适宜范围为6～12 mg·kg~(-1)时,利于大豆苗期叶片形态发展,其中以9 mg·kg~(-1)拌种浓度最适宜.