红光与远红光比值对温室切花菊形态指标、叶面积及干物质分配的影响

以切花菊品种‘神马’(Chrysanthemum morifolium Ramat ‘Jinba’)为试材,于2010-2011年设计不同红光(R: (660 ±10) nm)与远红光(FR: (730±10)nm)比值(R/FR分别为0.5、2.5、4.5、6.5)的LED灯照射处理,研究不同R/FR值对温室切花菊形态指标、叶面积形成及干物质分配的影响。结果显示R/FR=2.5处理的植株叶片数、株高、茎粗、花径、叶面积及总干重均为各个处理中最高,R/FR=0.5处理的节间最长。所有R/FR处理的单株地上干物质重量与光质处理天数呈指数-线性模型。随处理天数的增加不同R/FR值处理菊花植株地上部分及地下部分干物质分配指数差异均不显著,叶片和花的干物质分配指数随处理天数的增加分别呈降低和升高的趋势,茎干物质分配指数则呈现先升高后降低的趋势,R/FR=2.5处理下,菊花叶片干物质分配指数和花干物质分配指数最高,而茎干物质分配指数却为最低;R/FR=6.5处理茎干物质分配指数最高,叶片干物质分配指数最低;0.5处理花朵干物质分配指数最低,说明远红光比例增加能够促进干物质向茎中分配,R/FR=2.5处理利于干物质向花朵中分配。     

基于光温的温室多杆切花菊干物质生产与分配的预测模型

根据菊花生长对光温的反应,设计不同品种、不同单株主杆数、不同定植密度和不同定植日期的试验,构建了以生理辐热积(Physiological product of thermal effectiveness and PAR,PTEP)为尺度的温室多杆切花菊的干物质生产与分配预测模型,并用与建模相独立的试验数据对模型进行了检验.结果表明:随单位面积杆数增加,切花菊的单位面积地上干物质产量增加,单枝切花鲜重减少.所建模型对温室多杆切花菊的单株叶干重、茎干重、花干重和地上部分鲜重的预测值与实际观测值基于1:1线的决定系数(R2)分别为:0.96、 0.95、0.82和0.97,回归估计标准误(RMSE)分别为:0.863、1.005、0.201和10.190g ·株-1.模型模拟精度较高,可为温室切花菊栽培密度和保留杆数的优化调控提供理论依据.     

基于叶干质量比的杉木比叶面积估算模型的构建

随着叶片功能性状研究的不断深入, 通过简单易测量的叶片指标, 同时探究植物生活史权衡对策和估算林分生产力的研究需求日益增长, 例如叶干质量比(LDMC)和比叶面积(SLA)的相互转换。杉木(Cunninghamia lanceolata)是亚热带重要的常绿针叶树种, 基于LDMC对杉木SLA进行估算, 能够为核算SLA提供途径, 为机理解释和生产估算构建连接途径, 为小区域到大尺度、精算到估算搭建桥梁。该研究在湖南会同和河南信阳两个杉木生长区, 对处于不同小生境(坡向、坡位和冠层深度)以及不同生活史(林龄和叶龄)的叶片进行抽样和采集, 通过测得不同叶龄的单叶LDMC和SLA, 初步探究在不同因子下两个性状值的分布差异, 进一步基于LDMC构建SLA估算模型并讨论以叶龄为差分因子对模型的影响。结果表明: 1)杉木SLA平均值为(103.15 ± 69.54) cm ²·g ^-1, LDMC为0.39 ± 0.11; 2)杉木LDMC和SLA可用非线性模型进行估算, 模型符合估算要求; 3)其中一年生叶的拟合效果最好, 老叶(大于二年生叶)的拟合优度较低, 老叶较低的SLA (52.28-75.74 cm ²·g ^-1)可能暗示LDMC的变化保持相对独立性。该研究基于杉木LDMC的SLA估算模型可信且有效, 且不同叶龄对LDMC和SLA的影响可能预示着杉木叶片的响应敏感性和生活史权衡策略。     

不同沙丘生境主要植物比叶面积和叶干物质含量的比较

研究了生长在不同沙丘生境中 (流动沙丘 ,半固定沙丘和固定沙丘 ) 2 0个植物种 (10个 1年生植物种和 10个多年生植物种 )的比叶面积 (SL A)和叶干物质含量 (L DMC)的变化 ,并且分析了各个沙丘生境的土壤养分特征。结果表明 ,各个植物种的平均 SL A和 L DMC在植物种之间差异显著 ;多数在两种或 3种沙丘生境均有分布的植物其 SL A在不同沙丘生境之间差异显著 ,但是仅有 6个植物种的 L DMC在不同沙丘生境之间表现出差异 (p<0 .0 5 )。与许多研究结果类似 ,1年生植物的 SL A显著大于多年生植物的 SL A,而且两者之间 L DMC存在一定的差异。 1年生植物 SL A和 L DMC之间相关性不显著 ,但多年生植物SL A和 L DMC之间呈显著负相关。综合所有 2 0个植物种可以发现 ,SL A增大时 ,L DMC有下降的趋势     

Specific leaf area estimation model building based on leaf dry matter content of Cunninghamia lanceolata

随着叶片功能性状研究的不断深入, 通过简单易测量的叶片指标, 同时探究植物生活史权衡对策和估算林分生产力的研究需求日益增长, 例如叶干质量比(LDMC)和比叶面积(SLA)的相互转换。杉木(Cunninghamia lanceolata)是亚热带重要的常绿针叶树种, 基于LDMC对杉木SLA进行估算, 能够为核算SLA提供途径, 为机理解释和生产估算构建连接途径, 为小区域到大尺度、精算到估算搭建桥梁。该研究在湖南会同和河南信阳两个杉木生长区, 对处于不同小生境(坡向、坡位和冠层深度)以及不同生活史(林龄和叶龄)的叶片进行抽样和采集, 通过测得不同叶龄的单叶LDMC和SLA, 初步探究在不同因子下两个性状值的分布差异, 进一步基于LDMC构建SLA估算模型并讨论以叶龄为差分因子对模型的影响。结果表明: 1)杉木SLA平均值为(103.15 ± 69.54) cm ²·g ^-1, LDMC为0.39 ± 0.11; 2)杉木LDMC和SLA可用非线性模型进行估算, 模型符合估算要求; 3)其中一年生叶的拟合效果最好, 老叶(大于二年生叶)的拟合优度较低, 老叶较低的SLA (52.28-75.74 cm ²·g ^-1)可能暗示LDMC的变化保持相对独立性。该研究基于杉木LDMC的SLA估算模型可信且有效, 且不同叶龄对LDMC和SLA的影响可能预示着杉木叶片的响应敏感性和生活史权衡策略。     

Specific leaf area and dry matter content estimate thickness in laminar leaves

BACKGROUND AND AIMS: Leaf thickness plays an important role in leaf and plant functioning, and relates to a species' strategy of resource acquisition and use. As such, it has been widely used for screening purposes in crop science and community ecology. However, since its measurement is not straightforward, a number of estimates have been proposed. Here, the validity of the (SLA x LDMC)(-1) product is tested to estimate leaf thickness, where SLA is the specific leaf area (leaf area/dry mass) and LDMC is the leaf dry matter content (leaf dry mass/fresh mass). SLA and LDMC are two leaf traits that are both more easily measurable and often reported in the literature. METHODS: The relationship between leaf thickness (LT) and (SLA x LDMC)(-1) was tested in two analyses of covariance using 11 datasets (three original and eight published) for a total number of 1039 data points, corresponding to a wide range of growth forms growing in contrasted environments in four continents. KEY RESULTS AND CONCLUSIONS: The overall slope and intercept of the relationship were not significantly different from one and zero, respectively, and the residual standard error was 0.11. Only two of the eight datasets displayed a significant difference in the intercepts, and the only significant difference among the most represented growth forms was for trees. LT can therefore be estimated by (SLA x LDMC)(-1), allowing leaf thickness to be derived from easily and widely measured leaf traits.     

油菜地上部干物质分配与产量形成模拟模型

利用油菜器官生长与发育进程及环境因子之间的定量关系,构建了基于分配指数的油菜地上部器官干物质分配动态模拟模型.各器官干物质分配指数随着生理发育时间而变化,基因型、播期、氮素及水分水平影响各器官干物质在地上部分配的大小.其中,氮素营养水平对绿色叶片干物质分配影响最大,氮素营养水平越高,绿色叶片分配指数越大;播期影响角果分配指数,晚播的角果分配指数高于早播.模型引入氮素营养指数、水分及播期影响因子来定量油菜各器官在实际生产条件下的分配强度,同时考虑了品种遗传特性的影响.通过不同品种氮肥处理试验建立模型,利用不同品种播期试验资料对模型进行了初步检验,表明模型具有较好的预测性和适用性.     

大麦叶面积指数模拟模型

准确模拟叶面积指数是作物生长模拟模型预测作物生长和产量的关键.本文通过系统分析扬州和武汉地区不同大麦品种高产群体叶面积指数变化动态,建立了大麦群体的叶面积指数模拟模型.大麦叶面积指数是品种叶面积指数扩展的遗传参数和气温日较差、日照时数、辐射量等气候因子及水肥丰缺因子的函数.孕穗抽穗期最大叶面积指数与该期最适叶面积指数是不同的概念,二者之间存在着极显著差异.利用扬州、南京和昆明地区不同品种的播期试验及氮肥试验资料对模型进行了检验,结果表明,模型对大麦叶面积指数的模拟效果较好,模拟值与观测值吻合度高,根均方差RMSE介于0.742～2.865,平均值为1.348.对模拟值与观测值进行y=x的线性回归分析,相关系数R²介于0.511～0.954,均呈极显著正相关.     

不同模拟增雨下白刺比叶面积和叶干物质含量的比较

以荒漠生态系统典型植物白刺(Nitraria tangutorum)为研究对象,根据内蒙古磴口多年平均降水量和植物生长规律,设计两个增雨时段(生长季前期与生长季后期),每个增雨时段设置两个增雨梯度(72.5mm/a(50%)、145mm/a(100%)),对天然白刺灌丛进行增雨实验,研究了不同模拟增雨处理下2012年与2013年生长季白刺叶片的比叶面积(SLA)与叶干物质含量(LDMC)的变化。结果表明,增雨处理可以增加白刺叶片的SLA及LDMC,同时期增雨100%处理对SLA及LDMC的影响大于50%处理,但同时期增雨的两个处理之间无显著差异;白刺叶片SLA在生长季前期对水分响应明显,LDMC则在生长季后期对水分反应敏感;相同增雨处理,2012年白刺叶片SLA及LDMC的净增加值高于2013年;SLA与LDMC在2012年呈显著负相关,在2013年虽呈负相关,但相关性不显著。在未来降雨增加的背景下,荒漠植物白刺叶片SLA与LDMC对增雨具有较强的协调适应能力,在不同生长季节可以通过改变不同的叶片性状来适应环境变化。     

基于源库生长单位的温室番茄干物质生产-分配模拟

为了量化研究温室番茄果穗间干物质的分配,提高温室番茄栽培的效益,采用源库生长单位的测定方法,将经典的单叶同化物生产模型与GreenLab模型相结合,构建了干物质向源库生长单位内茎节、叶片、果实分配的动态模型,利用越冬茬、早春茬和春夏茬温室番茄各器官的干物质测定数据对模型进行了验证.结果表明:所构建的模型模拟结果与实测结果吻合性较好,不同茬口同化物生产模拟值与实测值的回归方程斜率为0.93,R~2为0.92;源库生长单位内茎节、叶片、果实以及根系的模拟值与实测值间回归方程斜率在0.85～0.89之间,其相对误差(R_e)均值分别为5.3%、5.6%、8.1%和3.6%,说明模型的模拟准确度较高,可为不同茬口温室番茄栽培管理提供理论依据和决策支持.     

基于辐热积法模拟烤烟叶面积与烟叶干物质产量

烟叶叶面积增长与干物质累积是烤烟产量形成的主要部分,对品质的形成也有影响。本研究根据气温和光照对烤烟叶片生长和干物质累积的影响,基于辐热积理论建立了适用于不同烟区的烤烟叶面积模型和干物质累积模型,分别使用独立的试验数据建模及对模型进行检验,再通过多年次烟叶干重试验数据对模型进行检验。结果表明,与传统的预测方法相比,用辐热积模型获得的叶面积模拟值与实测值间1:1线的决定系数（R2）和RMSE值为0.9634和0.1653 m2/株,预测精度比SLA法和GDD法分别提高了93%和82%。模型对叶干重模拟的RMSE值为27.1 g/m2,用历年玉溪试验数据检验的RE值为24.5%,说明模型的拟合度和可靠性较好。本研究所建立的模型能够利用气温、日照等常规气象观测数据,动态预测烤烟叶面积增长和干物质累积,且模型参数少,符合度好,实用性强,可以为烤烟生产中的产量预测提供理论依据和决策支持。     

温室番茄干物质分配与产量的模拟分析

根据试验资料及温室番茄(Lycopersicon esculentum)作物的生长特性,构建了基于分配指数(Partitioning index,PI)和收获指数(Harvest index,HI)与辐热积(Product of thermal effectiveness and PAR,TEP)关系的番茄干物质分配和产量预测的数学模型,并利用不同品种、基质和地点的试验资料对模型进行检验.模型对番茄地上部分干重、根系干重、茎干重、叶片干重和果干重的预测结果与1∶1直线之间的决定系数(Coefficient of determination,R²)分别为0.95、0.57、0.82、0.79和0.93;统计回归标准误差(Root mean squared error,RMSE)分别为647.0、78.1、279.0、496.9和381.8 kg·hm^-2;对产量的预测结果与1∶1直线之间的R²和RMSE分别为0.88和5 828.5 kg·hm^-2;不仅预测精度较高,且参数少、用户易于获取,为温室番茄模型应用于温室番茄生产的优化管理奠定了基础.     

Patterns in specific leaf area and the structure of a temperate heath community

Relationships between the distribution and specific leaf area (SLA: leaf area per unit dry mass) of six heath (Ericaceae) species were investigated along an environmental gradient between peat bogs and conifer forest in British Columbia, Canada. I asked whether patterns in SLA could help to identify the processes shaping plant distributional patterns. Specifically, I assessed whether (i) species’ distributions across the environmental gradient are correlated with SLA (ii) relationships between plant distributional patterns and SLA are similar among bogs with different shrub species (iii) intraspecific patterns in SLA parallel interspecific relationships between distributions and SLA, and (iv) intraspecific patterns are environmentally determined. Results showed that distributional patterns were often correlated with SLA; species with lower SLA were more abundant towards the centre of bogs, while species with higher SLA were more abundant in forest. Intraspecific patterns in SLA paralleled distributional patterns across the gradient; individuals located towards the centre of bogs had lower SLA than those growing in forest. A transplantation experiment showed that plants typically altered their SLA according to local environmental conditions. However, one bog showed no relationship between species’ distributions and SLA. This bog lacked the two species with lowest SLA, which typically occurred at the centre of other bogs. In their absence, species with higher SLA that typically occurred in forest increased in abundance towards the centre of the bog, where they obtained lower values of SLA. Therefore, while distributional patterns were often closely associated with SLA, plasticity in SLA was associated with increased breadth of species’ distributions across the gradient. Overall results indicate SLA may serve as a useful proxy for a range of life history traits to help elucidate the processes structuring plant communities.     

Specific leaf area and leaf dry matter content as alternative predictors of plant strategies

A key element of most recently proposed plant strategy schemes is an axis of resource capture, usage and availability. In the search for a simple, robust plant trait (or traits) that will allow plants to be located on this axis, specific leaf area is one of the leading contenders. Using a large new unpublished database, we examine the variability of specific leaf area and other leaf traits, the relationships between them, and their ability to predict position on the resource use axis. Specific leaf area is found to suffer from a number of drawbacks; it is both very variable between replicates and much influenced by leaf thickness. Leaf dry-matter content (sometimes referred to as tissue density) is much less variable, largely independent of leaf thickness and a better predictor of location on an axis of resource capture, usage and availability. However, it is not clear how useful dry matter content will be outside northwest Europe, and in particular in dry climates with many succulents.     

The scaling of leaf area and mass: the cost of light interception increases with leaf size

For leaves, the light-capturing surface area per unit dry mass investment (specific leaf area, SLA) is a key trait from physiological, ecological and biophysical perspectives. To address whether SLA declines with leaf size, as hypothesized due to increasing costs of support in larger leaves, we compiled data on intraspecific variation in leaf dry mass (LM) and leaf surface area (LA) for 6334 leaves of 157 species. We used the power function LM=alpha LAbeta to test whether, within each species, large leaves deploy less surface area per unit dry mass than small leaves. Comparing scaling exponents (beta) showed that more species had a statistically significant decrease in SLA as leaf size increased (61) than the opposite (7) and the average beta was significantly greater than 1 (betamean=1.10, 95% CI 1.08-1.13). However, scaling exponents varied markedly from the few species that decreased to the many that increased SLA disproportionately fast as leaf size increased. This variation was unrelated to growth form, ecosystem of origin or climate. The average within-species tendency found here (allometric decrease of SLA with leaf size, averaging 13%) is in accord with concurrent findings on global-scale trends among species, although the substantial scatter around the central tendency suggests that the leaf size dependency does not obligately shape SLA. Nonetheless, the generally greater mass per unit leaf area of larger than smaller leaves directly translates into a greater cost to build and maintain a unit of leaf area, which, all else being equal, should constrain the maximum leaf size displayed.     

Partitioning of dry mass and leaf area within plants of three species grown at elevated CO2

1. We tested the hypothesis that the net partitioning of dry mass and dry mass:area relationships is unaltered when plants are grown at elevated atmospheric CO₂ concentrations.
2. The total dry mass of Dactylis glomerata, Bellis perennis and Trifolium repens was higher for plants in 700 compared to 350 μmol CO₂ mol^–1 when grown hydroponically in controlled-environment cabinets.
3. Shoot:root ratios were higher and leaf area ratios and specific leaf areas lower in all species grown at elevated CO₂. Leaf mass ratio was higher in plants of B. perennis and D. glomerata grown at elevated CO₂.
4. Whilst these data suggest that CO₂ alters the net partitioning of dry mass and dry mass:leaf area relationships, allometric comparisons of the components of dry mass and leaf area suggest at most a small effect of CO₂. CO₂ changed only two of a total of 12 allometric coefficients we calculated for the three species: ν relating shoot to root dry mass was higher in D. glomerata , whilst ν relating leaf area to total dry mass was lower in T. repens .
5. CO₂ alone has very little effect on partitioning when the size of the plant is taken into account.