Effects of Different Irrigation Times and Nitrogen Fertilizer Application on Leaf Area Index and Grain Yield of ‘Yujiao 5'

To provide ＂more reasonable, more saving and more efficient＂ water and fertilizer application proposals, taking ‘Yujiao 5＇ as the experimental material, the effects of different irrigation times and nitrogen application treatments on the leaf area index and yield of wheat were studied using three-factor split plot method. The results showed that irrigation times, nitrogen application rate and the ratio of basa to topdressed nitrogen respectively had significant effects on the leaf area index, the yield and component factors of wheat. Under the treatment of W1（irrigation before sowing）, the leaf area index showed a positive linear correlation with nitrogen application rate; under the treatments of W2（irrigation before sowing and at jointing stage） and W3（irrigation before sowing, at jointing stage and at grain filling stages）,the leaf area index showed a positive linear correlation with nitrogen application rate at the jointing stage, booting stage and heading stage; 20 d after heading, the leaf area index showed a quadric curve relationship with nitrogen application rate at these stages, and the LAI of N3R2 was the highest. Under different irrigation times,the yield, ear number and kernels per ear showed quadric curve relationship with nitrogen application rate, 1 000-seed weight showed the trend of linear decrease with the increase of nitrogen application rate. Under the treatment combination of irrigation before sowing, at jointing stage and at grain filling stage, nitrogen application rate at 240 kg/hm^2 and the ratio of basal to topdressed nitrogen of 5：5, the grain yield（8 609.60 kg/hm^2）, ear number（688.2×104/hm^2） and kernel number per ear（37.9 grains） reached the highest value at W3N3R2, and the grain yield of W3N3R2 increased by 144.8% compared to the W1N0. In conclusion, in Eastern Henan where the rainfall is insufficient at the late growth stage of wheat, the irrigation-saving space in wheat production is relatively small, but the nitrogen-saving space is relatively large.

Basal internode elongation of rice as affected by light intensity and leaf area

Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.

Leaf Morphological and Stomatal Variations in Paper Birch Populations along Environmental Gradients in Canada

Variations in leaf morphology and stomatal characteristics have been extensively studied at both inter- and intraspecific levels although not explicitly in the context of paper birch (Betula papyrifera Marsh) populations. The birch populations might have developed the leaf variations that allowed them to adapt to a wide climatic gradient. Therefore, in this study we examined variations in the leaf morphological and stomatal characteristics of sixteen paper birch populations collected across Canada and grown in a common garden. We also examined the relationship between these leaf characteristics and the climate of the population’s origin. Significant genotypic differences were found in the leaf characteristics measured among the birch populations. Thus, we expected that the observed leaf variations may be partly explained as natural diversity in the birch due to differences in environment of origin. We noticed that along mean annual precipitation and aridity gradients, hair density on leaf adaxial surface had decreased whereas stomatal density increased significantly. Our results showed that the populations with larger leaf area and specific leaf area had higher hair density but low stomatal density. These leaf characteristics provided a structural basis in reducing water loss through leaves and increasing water use efficiency. A trade-off between stomatal area and density resulted in this study might be a strategy of the birch to balance stomatal conductance in decreased precipitation.

三江源区适宜的小黑麦和饲用豌豆混播比例及施肥方法

【目的】三江源区地处青藏高原,是中国母亲河的发源地,也是牦牛等典型牲畜的重要草场。探索适宜的施肥方法和牧草作物混播比例,旨在提高牧草产量,减轻生态重要地区天然草场的放牧压力。【方法】于2022年在三江源地区进行了小黑麦和饲用豌豆的田间试验,试验材料为小黑麦品种‘青饲麦1号’和饲用豌豆品种‘青建1号’。设置3个施肥处理:不施肥(A_(1))、单施氮肥(尿素75 kg/hm^(2),A_(2))、氮磷配合施用(尿素75 kg/hm^(2)和过磷酸钙300 kg/hm^(2),A3);每个施肥处理下,分别设小黑麦和豌豆混合播种比例70∶30(B1)、50∶50(B_(2))和30∶70(B_3)。在豌豆盛花期刈割前,调查小黑麦和饲用豌豆株高、叶片形态指标(面积、周长、长度、宽度),及生物量和营养品质。【结果】与不施肥处理A_(1)相比,施肥处理(A_(2)和A_3)显著提高了牧草的鲜重和干重、蛋白质产量以及两种作物的株高和叶面积。A_(2)和A_3处理在上述指标上没有显著差异,但A_3处理叶宽的增幅显著高于A_(2)。A_(2)和A_3处理对两种牧草粗蛋白、可溶性糖、中性和酸性洗涤纤维含量均无显著影响,但A_(2)处理增加了粗脂肪含量。小黑麦和饲用豌豆的播种比例对两种作物的鲜重、干重、蛋白质产量和株高没有显著影响,但降低小黑麦播种比例增加了饲草粗脂肪和可溶性糖含量,显著降低了中性与酸性洗涤纤维含量。播种比例与施肥有显著的交互作用,A_3B_(1)的牧草鲜重和干重最高,分别比其他处理高36.09%~180.08%和62.27%~281.59%,叶面积和蛋白质、可溶性糖含量也最高。A_3B_(1)处理的小黑麦叶片周长比A_(1)B_(1)、A_(1)B_(2)和A1B3处理分别高15.76%、40.29%和54.51%,饲用豌豆叶面积比A1B1、A1B2和A1B3处理分别提高20.31%、14.06%和64.65%,饲草中性洗涤纤维含量分别比A1B1、A1B2和A1B3处理增加了7.15%、27.14%和17.89%。【结论】氮磷配施可显著提高牧草生产性能、叶片形态和牧草质量。小黑麦和饲用豌豆按70∶30的比例混合播种,牧草生产性能、叶片形态和质量均优于其他处理。因此,在高寒地区,建议推广小黑麦和饲用豌豆按70∶30的比例混合播种,并配施氮、磷肥。

Changes of Leaf Morphological, Anatomical Structure and Carbon Isotope Ratio with the Height of the Wangtian Tree (Parashorea chinensis) in Xishuangbanna, China

Leaf morphological and anatomical structure and carbon isotope ratio （δ^13C） change with increasing tree height. To determine how tree height affects leaf characteristics, we measured the leaf area, specific leaf mass （ratio of leaf mass to leaf area [LMA]）, thickness of the total leaf, cuticle, epidermis, palisade and sponge mesophyll, stomata traits and δ^13C at different heights of Parashorea chinensis with methods of light and scanning electron microscopy （SEM） and isotope-ratio mass spectrometry. The correlation and stepwise regression between tree height and leaf structure traits were carried out with SPSS software. The results showed that leaf structures and δ^13C differed significantly along the tree height gradient. The leaf area, thickness of sponge mesophyll and size of stomata decreased with increasing height, whereas the thickness of lamina, palisade mesophyll, epidermis, and cuticle, ratios of palisade to spongy thickness, density of stomata and vascular bundles, LMA and δ^13C increased with tree height. Tree height showed a significant relationship with all leaf indices and the most significant relationship was with epidermis thickness, leaf area, cuticle thickness, δ^13C. The δ^13C value showed a significantly positive relationship with LMA （R = 0.934）. Our results supported the hypothesis that the leaf structures exhibited more xeromorphic characteristics with the increasing gradient of tree height.

Competition-density effect of tree organs in Acacia auriculiformis stands

The competition-density (C-D) effects for mean mass for tree, stem, branch and leaf were analyzed in Acacia auriculiformis stands. Mean tree mass-density and mean organ mass-density were well explained by the C-D equation of tree and the C-D equation of tree organ, respectively. An equation describing the relationship between mean leaf area u and density was formulated that fit the u-data well. The relationship between mean tree mass w and the ratio of each organ to mean tree mass (wo/ w) was examined. With increasing w, the stem mass ratio wS/w increased, whereas the branch mass ratio wB/w and the leaf mass ratio wL/w decreased. The yield difference between the lowest-density stand and the high-density stand became greater with stand growth. However, the yield of the mid-density stand was slightly lower than the yield of the high-density stand during the experimental period. To produce the most desirable combination of demanding individual-tree size and relative high stem yield, the mid-density is recommended as proper planting density for future management of A. auriculiformis stands.

How <i>Betula ermanii</i>Maintains a Positive Carbon Balance at the Individual Leaf Level at High Elevations

Generally, plant species with shorter leaf longevity maintain a positive carbon balance by decreasing leaf mass per area (LMA) and increasing photosynthesis. However, plants at high elevations need to increase LMA against environmental stresses. Therefore, plants need to increase both LMA and photosynthesis at high elevations. To examine how deciduous plants maintain a positive carbon balance at high elevations, photosynthesis and related leaf traits for deciduous broad-leaved tree Betula ermanii were measured at three elevations. LMA was greater at middle and high elevations than at low elevation. Leaf δ13C was greater at higher elevations, and positively correlated with LMA, indicating greater long-term deficiency of CO2 in leaves at higher elevations. However, the Ci/Ca ratio at photosynthetic measurement was not low at high elevations. Nitrogen content per leaf mass and stomatal conductance were greater at higher elevations. Photosynthetic rates and photosynthetic nitrogen use efficiency (PNUE) did not differ among the three elevations. Photosynthetic rate showed a strong positive correlation with stomatal conductance on a leaf area basis (R2 = 0.83, P < 0.001). Therefore, this study suggests B. ermanii compensates the deficiency of CO2 in leaves at high elevation by increasing stomatal conductance, and maintains photosynthesis and PNUE at high elevation as much as at low elevation.

去叶方式对皖南烟区烟叶等级结构和品质的影响

为了明确去叶数量和去叶时间对烤烟等级结构、经济效益和烟叶品质的影响,以云烟87为试验材料,设置去叶数量和去叶时间2个因素,对烤后烟叶的正/副组烟叶重量比、等级结构、化学指标及感官质量等方面进行分析。结果表明:打顶前7 d去除3~4片下部叶,其副组烟比例比打顶当天、打顶后7 d处理的显著降低,且烟叶产量、产值显著增加,同时烟叶感官质量也得到提升。打顶当天去除4片下部叶处理,中部叶覆盖的叶位范围最广(第6~17叶位),烤后烟中部叶比例最高(44.05%),等级结构最合理。打顶后7 d去除4片下部叶处理的上部叶比例最高(38.94%),中部叶比例最低(28.70%),等级结构最差。综合分析,打顶前7 d去除3片下部叶处理的中部叶比例高(40.02%),副组烟比例低(20.45%),各部位烟叶感官品质较好,产量、产值最高,是最合理的去叶方式。

基于胸高处边材面积、胸径和冠基部直径的杉木单木叶生物量预测模型

【目的】基于多个变量分别构建杉木单木叶生物量预测模型,并选择出预测效果最佳的模型,为杉木叶生物量的精准预测提供参考。【方法】以21块不同林龄样地共63株解析木为例,分别基于胸高处边材面积、胸径和冠基部直径3个变量,考虑其他与叶生物量相关的单木和林分因子,以样地为随机效应因子构建非线性混合模型,采用指数函数、幂函数和常数加幂函数消除数据间的异方差性。根据模型评价指标赤池信息准则(AIC)、贝叶斯信息准则(BIC)和对数似然值(Log Likelihood)选择最佳模型,并对不同参数的混合模型进行似然比检验。采用留一交叉验证法,计算模型决定系数(R^(2))、总相对误差(TRE)和平均绝对误差(MAE),对模型预测效果进行检验。【结果】基于3个变量以幂函数为异方差结构构建的混合模型效果最好,混合模型均优于基础模型,且基于冠基部直径构建的模型预测效果最佳。【结论】以基于冠基部直径构建的非线性混合效应模型(模型16)作为预测杉木单木叶生物量的最佳模型,符合管道模型理论。各变量均具有一定生物学和统计学意义,野外调查较易获取(非破坏性)。模型具有一定实用性,且预测精度较高(R2=0.8051)。本研究结果可为其他树种构建单木叶生物量模型提供参考。

不同有机无机氮配比对南阳烟区土壤碳氮及烤烟上部叶质量的影响

为探究不同有机肥与无机肥比配对南阳烟区烟草上部叶品质、改善土壤碳氮结构的作用,以烤烟品种云烟87为试验材料,以沼渣和芝麻饼肥为有机氮源,根据有机氮∶无机氮的不同配比设置6个处理[T1(0∶10,纯化肥)、T2(1∶9)、T3(2∶8)、T4(3∶7)、T5(4∶6)、T6(5∶5)],对相应的烟叶和土壤样品进行检测分析。结果表明,与T1处理相比,施用沼渣有机肥和芝麻饼肥处理的烟草叶片大小、单叶重、钾氯比、淀粉含量、产值、香气总量等均显著提升,其中T4处理烟叶的叶长、叶宽、钾离子含量、淀粉含量、均价、产值、香气总量分别较T1处理提升了9.23%、10.49%、21.79%、31.91%、21.31%、26.57%、19.92%。与T1处理相比,施用有机肥处理的土壤有机碳含量、土壤碳氮比及微生物量碳、氮含量均明显提高。在南阳烟区按照有机氮∶无机氮配比为3∶7施用沼渣有机肥和芝麻饼肥能够有效提升烟草上部叶质量、耐熟性及成熟度,并改善土壤碳氮比。

甘肃中部干旱半干旱区小黑麦饲用价值评价

为研究甘肃中部干旱半干旱地区小黑麦的饲用价值,筛选最适种植品种,对从中国农业科学院作物科学研究所引进的11个小黑麦新品系进行了连续2 a的品比试验,鉴定其田间农艺性状、鲜草产量、干草产量、茎叶比等差异。结果表明,3297、5全50鲜草产量分别为68.25、67.05 t/hm^(2),较对照品种中饲3241分别增产7.70%、4.81%;干草产量分别为23.55、22.80 t/hm^(2),较对照品种中饲3241分别增产5.64%、2.25%;茎叶比分别为1.78、1.87,饲草可利用价值高。综合评价认为,3297、5全50以开花盛期获取鲜干草为佳。

Effects of leaf age,elevation and light conditions on photosynthesis and leaf traits in saplings of two evergreen conifers,Abies veitchii and A.mariesii

Aims Subalpine coniferous species are distributed over a wide range of elevations in which they must contend with stressful conditions,such as high elevations and extended periods of darkness.Two evergreen coniferous species,Abies veitchii and Abies mariesii,dominate at low and high elevations,respectively,in the subalpine zone,central Japan.The aim of this study is to examine the effects of leaf age,elevation and light conditions on photosynthetic rates through changes in morphological and physiological leaf traits in the two species.Methods We here examined effects of leaf age,elevation and light conditions on photosynthesis,and leaf traits in A.veitchii and A.mariesii.Saplings of the two conifers were sampled in the understory and canopy gaps at their lower(1600 m)and upper(2300 m)distribution limits.Important Findings The two species showed similar responses to leaf age and different responses to elevation and light conditions in photosynthesis and leaf traits.The maximum photosynthetic rate of A.veitchii is correlated negatively with leaf mass per area(LMA)and non-structural carbohydrate(NSC)concentration.LMA increased at high elevations in the two species,whereas NSC concentrations increased only in A.veitchii.Therefore,the maximum photosynthetic rate of A.veitchii decreased at high elevations.Furthermore,maximum photosynthetic rates correlate positively with nitrogen concentration in both species.In the understory,leaf nitrogen concentrations decreased and increased in A.veitchii and A.mariesii,respectively.LMA decreased and the chlorophyll-to-nitrogen ratio increased in understory conditions only for A.mariesii,suggesting it has a higher light-capture efficiency in dark conditions than does A.veitchii.This study concluded that A.mariesii has more shade-tolerant photosynthetic and leaf traits and its photosynthetic rate is less affected by elevation compared with A.veitchii,allowing A.mariesii to survive in the understory and to dominate at high elevations.

不同生态环境下水稻基因型产量形成与源库特性的比较研究

以日本和IRRI的9个水稻品种为材料,分别以武香粳9号和两优培九为对照,在江苏南京和云南丽江研究了不同水稻基因型干物质积累与源库形成特征及其在不同生态环境下的差异.结果表明,生态环境对水稻产量和干物质积累量影响显著.高产水稻品种积累了高额干物质量,且干物质生产优势在中后期.高产品种的总颖花量、LAI及群体生长速率(CGR)都较高.稻谷产量随干物质积累总量的增加而提高,与齐穗后干物质积累量、总颖花量和LAI呈极显著正相关,与粒叶比呈显著正相关.与云南丽江点相比,群体LAI、单位面积颖花量和抽穗后干物质积累量少及生长速率(CGR)低是南京点稻谷产量低的关键因素.

树高对马占相思整树水分利用的效应

利用Granier热消散探针,于2004年观测了华南丘陵坡地常见绿化先锋树种马占相思(22年生)的树干液流,同时监测林冠上方的光合有效辐射、气温、相对湿度和0～30cm的土壤体积含水量.结合树木的形态特征、液流密度和简化的Whitehead&Jarvis公式,分别计算了整树蒸腾、冠层气孔导度和叶面积/边材面积比值,分析了树高对整树蒸腾、冠层气孔导度和叶面积/边材面积比值的影响.结果表明:土壤水分充足时,马占相思整树蒸腾随树高呈二次多项式增加(P<0.01),冠层气孔导度日变化均呈"单峰"格型;在所有光合有效辐射范围内,高树的参比冠层气孔导度和冠层气孔导度对水汽压亏缺的敏感性均高于矮树;叶面积/边材面积比值为(1.837±0.048)m2·cm-2,并与树高呈幂函数关系.随着树木高度的增加,马占相思没有发生明显的水力限制和补偿.

高粒叶比小麦群体生理基础研究进展

粒叶比是衡量源库关系是否协调的一种数量化表示方法,被作为筛选高产品种的综合指标。本文主要从生长发育时期、叶面积和茎蘖等的生长变化动态、衰老期间冠层叶片的生理特性、叶绿素含量和光合强度等方面对高粒叶比小麦群体进行了综述,分析了高粒叶比小麦群体的光合特性以及干物质积累的分配动态,认为粒叶比高的群体,其经济系数较高,具有较高的增产潜力。

新疆若干杏品种叶、枝和果实品质与叶面积的相关分析

对8个新疆杏品种的叶片主脉长度、新梢长度、果实重量、可溶性固形物与叶面积之间进行了相关性分析。所有供试品种的叶片主脉长度与叶面积之间呈非线性幂函数回归关系,新梢长度与叶面积之间呈线性回归关系,相关(指)系数在0.01水平下都达到极显著水平,二者与叶面积之间皆呈极显著正相关;多数品种的叶果比,与平均单果重呈显著正相关,而与果实可溶性固形物的相关性不显著。就叶果比的大小对杏树的产量和果实品质的影响进行了讨论。

5种绿化树种叶片比叶重、光合色素含量和δ^(13)C的开度与方位差异

受太阳活动的影响,树冠不同方位以及内外部的叶片接受到的光照存在差异,造成温度、湿度等小气候因子也存在差异。叶片的形态解剖结构和生理特性等会对外界环境条件的改变发生响应。为了更好地了解树木生长的局部小环境条件差异对树木生长的影响,该文选择国槐(Sophora japonica)、悬铃木(Platanus orientalis)、银杏(Ginkgo biloba)、榕树(Ficus mi-crocarpa)和黄葛榕(F.lacor)5种冠幅较大的树种,通过测定树冠内外部及4个方位上的比叶重(leaf mass per area,LMA)、叶绿素a(chlorophyll a,Chl a)、叶绿素b(chlorophyll b,Chl b)及类胡萝卜素(carotenoid,Car)的含量及碳稳定同位素比率(carbon isotope ratio,δ13C)等指标,研究叶片形态、生理指标等随树冠开度的变化以及方位差异。结果表明,叶片LMA和δ13C均随树冠开度增加而增大,光合色素含量则相反;叶片LMA和δ13C的方位变化则是南向>西向>北向>东向,与叶片所接受到的光强变化规律一致,而光合色素含量的方位差异较复杂、且因树种而异,总的来说,以受光最弱的东向含量最高。上述结果表明,树冠外围和南向、西向的叶片由于接受到的光能较多、温度高、相对湿度小等,其叶片会增大单位面积的重量、减小气孔开度和光合色素含量,从而减少对光能的吸收,也使光合作用降低、δ13C增大,而不同方位光照对光合色素含量的影响机制较为复杂,这些都表明了叶片对周围小气候的形态和生理上的适应。

吉林省过去47年来水稻品种遗传改良过程中叶片光合指标的变化

2006-2007年对吉林省1958年至2005年间育成的25个粳稻品种产量特性及叶片光合生理指标进行了比较。结果表明,粳稻品种产量随育成年代呈线性增加。由1958年的6671.9kg/hm2增加至2005年的11853.2kg/hm2,平均每年增加110.2kg/hm2,年增幅为1.65%。收获指数、成熟期和粒叶比随育成年代推延而增加且与产量呈显著正相关。随着品种产量的增加,单叶净光合速率显著增加且与产量呈正相关,光合速率增加主要是由于品种表观叶肉导度随育成年代推延而显著增加所致。同时,胞间CO2浓度/大气CO2浓度比值呈下降趋势,说明现代品种的光合作用存在一定的气孔限制作用。现代品种叶片的蒸腾速率的增幅大于光合速率的增幅,导致水分利用效率下降。因此,在未来水稻品种选育中,筛选高光合种质资源的同时要兼顾品种的水分利用特性。

春小麦源库特性及其关系的研究(Ⅱ)——群体库源比及其与产量的关系

为了给春小麦高产栽培提供理论依据,通过试验对两个春小麦品种在不同密度、施肥量处理下群体库源比值(粒叶比)在产量形成中的作用和相互关系进行了系统的研究。结果表明,在不同处理条件下,春小麦的经济系数均随密度和施P量的增加而降低;随施N量的增加,永良4号经济系数表现出降低的趋势,但内麦19呈增加趋势。经济系数高,经济产量均相对较高。粒叶比随密度、施N量、施P量的增加而降低,但在叶面积相近的情况下,粒叶比高的产量高。因此,在合理的栽培技术措施下,实现源、库的协调是小麦获得高产的生理基础。叶片单位面积负荷量(粒数/叶)与叶片单位面积有效生产量(粒重/叶)呈极显著正相关。在适宜的群体叶面积指数范围内,采取优化栽培措施,争取形成较多的结实粒数(库容),并提高粒重(库的充实度),是实现高产的有效途径。

葡萄幼苗对弱光环境的形态和生长反应

以京玉葡萄 (VitisvineferaL cv Jingyu)幼苗为材料 ,用遮阳网营造弱光环境 ,研究了葡萄幼苗在弱光环境中的形态和生长反应。京玉葡萄幼苗的相对生长速率、根生物量比、根冠比和总生物量随遮荫程度的加深而降低 ;叶生物量比、支持结构生物量比、株高、比茎长、总叶面积、叶面积率和比叶面积增加。这些结果表明葡萄幼苗的形态和生长反应对弱光环境具有生态适应性 ,弱光环境下葡萄幼苗的比茎长和株高增加有利于葡萄尽快到达有利的光环境 。