Stem Population and Tissue Replacement of <i>Urochloa</i>in Different Phenological Stages

The objective of the present investigation was to evaluate the Urochloa Insurgent, Piata and Signal grasses by varying the phenology in the attributes: stem population dynamics, tissue replacement, leaf:stem relation and weight per stem. The data were analyzed using a completely randomized block design with arrangement in divided plots and four replications, the procedure used was PROC GLM from SAS. The Signal grass presented higher stem density with an average of 450 m?2 stems, while the meadow with Insurgent grass registered the lowest stem density throughout the investigation, with an average of 320 m-2 stems;furthermore, in this treatment, the stem density tended to increase slowly over time (P = 0.05). The Insurgente and signal grasses showed rapid leaf elongation from day 21 of regrowth with 123 and 104 cm stem?1, while in Piata the accelerated leaf elongation was on day 14 with 113 cm stem?1 where it remained active its growth until day 56 (P > 0.05). As the regrowth age was increasing, the population dynamics of stems and weight per stem were increasing;in Insurgent and signal the leaf elongation and net growth increased to a maximum point to start declining;however, in Piata grass was increasing without decreasing. The trend of the leaf:stem relation was decreasing as the test progressed and senescence increased from day 21 of regrowth.

Effects of sulfur dioxide on growth， gas exchange rate and leaf sulfur content of massion pine seedlings

The effects of sulfur dioxide(SO_2) on the dry weight growth gas exchange rate and leaf sulfur content of massion pine(Pinus massoniana Lamb. )were investigated. The results obtained in this study show that the dry weight growth and net photosynthetic rate of masson pine seedlings are reduced by exposure to SO_2 at ≥100 ppb. From these results,one of the main causes in the dieback of masson pine forest reported in Chongqing,China may be relatively high concentrations of atmospheric SO_2 in the relevant area.

Interactive Effects of Drought Stress and Phytohormones or Polyamines on Growth and Yield of Two M(<i>Zea maize</i>L) Genotypes

Two maize genotypes (Nefertiti and Bashaier) were picked up from nine maize genotypes during the early vegetative growth (25 days) to be cultivated in open field upon the crop yield under the different drought stress levels (90,70,50,30) or under the interaction effect of drought stress and phytohormones or polyamines. According to the data of growth criteria, the maize genotype Nefertiti was found to be the most drought sensitive genotype, while the genotype Bashaier was found to be the most drought resistant genotype. Additionally while the photosynthetic pigments remained more or less unchanged in genotype Bashaier, their biosynthesis destroyed earlier in the drought sensitive genotype (Nefertiti). Also while the genotype Bashaier absorbed and accumulated a sufficient amount of mono and divalent cations (K+, Ca++ and Mg++), the genotype Nefertiti did not. Accordingly while the genotype Bashaier gave a crop yield up to 50% field capacity, the genotype Nefertiti gave a crop yield only up to 70% field capacity and failed to give a crop yield beyond this level. The interaction effect of drought stress and phytohormones and polyamines improved the all above characteristics. Interestingly each of these activators considerably improved the production of crop yield only in genotype Bashaier specially polyamines they produced more than 60% field capacity and at the level of 30% field capacity (the level which did not give crop yield in this genotype). However, phytohormones in generally did not make an important effect on the crop yield in genotype Nefertiti although they improved the dry matter production during the vegetative stages. Such situation seemed to be complicated and borne many questions to be studied in the future.

Evaluation of Sweet Sorghum as a Feedstock by Multiple Harvests for Sustainable Bioenergy Production

Sweet sorghum has become an important feedstock for bioethanol production. Total sugar yield and multiple harvests can directly affect ethanol production cost. Little is known about stem traits and multiple harvests that contribute to sugar yield in sweet sorghum. Stem traits were evaluated from 25 sweet and grain sorghum accessions. Stems were harvested twice at the soft-dough stage and the stems were pressed with a hydraulic press. Sugars in the stem juice were quantified by high performance liquid chromatography. Sweet sorghum produced five times more fresh stem weight and dry stem mass (830 gand164 g) than grain sorghum (150 gand27g). Sweet sorghum produced a much higher volume of juice and higher yield of sugars (366 ml and42 g) per stem than grain sorghum (70 ml and4 g). Significant variability in fresh stem weight (72 - 1837 g), juice volume (31 - 753 ml), sugar yield (3 - 81 g), dry stem mass (14 - 383 g), and sugar yield/dry stem mass ratio (0.11 - 0.53) per stem was detected among sweet sorghum accessions. Stem sugar yield was significantly correlated with stem fresh weight and juice volume. Sorghum was harvested twice within one growing season resulting in some sweet sorghum accessions producing double amount of sugars. Sweet sorghum produced three times more dry mass weight (bagasse) than fermentable sugar weight. To reduce feedstock cost, methods have to be developed for efficiently utilizing bagasse. Our results showed high fresh stem weight, high ratio of sugar yield to dry stem mass, and double harvests are prime traits to boost sugar yield. Sweet sorghum may be suitable for multiple harvests in certain regions of theU.S.TheU.S.sweet sorghum collection needs to be screened for acces- sions that can be harvested twice with an extended feedstock-production season and used as a feedstock for sustainable and renewable bioenergy production.

Shoot Biomass Assessments of the Marine Phanerogam Zostera marina for Two Methods of Data Gathering

In order to compare to data gathering methods for shoot biomass assessments of Zostera marina, we compare two allometric models each one representing a data gathering method, one at leaf level and the other in aggregated form. The first allometric model presented leaf dry weight in terms of leaf length as . The second model is expressed as a several-variables version of the allometric Equation (1) dry weight of each leaf in a given shoot can be considered to be a random variable therefore shoot biomass ws can be represented in the form Both models presented similar determination coefficients values of 0.85 and 0.87 respectively. We found no significant differences between parameters α (p = 0.11) and β (p = 0.50) fitted for each model, showing that both equations conduced to the same result. Moreover, both fitted models presented high Concordance Correlation Coefficients of reproducibility () (0.92 and 0.91). We concluded that for shoot weight assessments if larger samples and faster data processing is required then should model of Equation (2) be used. On the other hand, we proposed model of Equation (1) if data at leaf level is required for other endeavors.

烟叶和烟梗颗粒溶出速率及性质研究

为探究烟叶和烟梗颗粒溶出效果及性质,实现烟叶和烟梗颗粒在造纸法再造烟叶加工过程中有效物质的最大保留,本文通过考察溶出条件对烟叶和烟梗颗粒溶出效果的影响,对比两者在溶出前后组分、热重、致香成分等方面的差异。结果表明:在40~80目、0~10 min、20~40℃、添加比例低的条件下,颗粒溶出速率最快;溶出后烟叶和烟梗颗粒的水溶性糖、总植物碱、氯等组分呈下降趋势,且随着溶出时间的延长而降低,各组分溶出量有一定差异;溶出前后的烟叶和烟梗颗粒分别经历了4个和5个温度范围接近的失重阶段,烟叶的第Ⅱ阶段的温度范围大致包含了烟梗颗粒的第Ⅱ、Ⅲ两个阶段,且每个阶段的残余质量低于烟梗,烟梗组分及热解过程比烟叶更为复杂;在溶出前后的烟叶和烟梗颗粒中分别检出69种和71种致香成分,且烟叶颗粒中的致香物质总量较高,其组分含量由多到少分别为酮类,醛类、醇类、杂环类、酸类、酯类、酚类,且每类致香成分溶出的速率有所不同。

吉林省不同年代大豆品种某些株型性状的演变

对吉林省1923年以来生产上主推的9个大豆品种的产量、叶面积、叶面积指数(LAI)、叶柄长度、茎直径和比叶重(SLW)等参数的研究表明:大豆产量、叶面积、叶面积指数(LAI)、茎直径和比叶重(SLW)随着年代的增加而增加;老品种的冠层结构呈伞型,新品种的冠层结构呈宝塔型;大豆产量与单株叶面积、叶面积指数(LAI)和茎直径呈显著相关(P≤0.05),株型可以作为大豆高产、高光效育种的重要依据。

北柴胡生长发育规律的研究

在不同试验区对引种野生北柴胡的物候期及各器官生长发育规律进行了调查研究。结果表明:北柴胡个体发育可划分营养生长期和生殖生长期;物候期为返青期、苗期、抽茎拔节期、孕蕾期、开花期、座果期、果熟期、枯萎期;年生育期为180～200d;植株呈单茎或丛生,株高65～90 cm,总叶面积随株高的增高而增加,盛花期株叶面积最大,叶面积指数最高;开花特性为有限花序,无限分枝型植株,其根长、根重在开花盛期和座果初期后呈快速增长;根长在土壤结冻前基本趋于最大;而根重增长至10月上中旬基本趋于最大,以后呈直线下降趋势。

不同施氮量对蓖麻产量和生物及营养性状的影响

为确定绿洲灌溉区蓖麻栽培的最佳施氮量,采用田间试验方法,对不同施氮量下蓖麻产量和生物、营养性状的变化规律进行了研究。结果表明:(1)通过数据拟合得出:蓖麻种植的最佳施氮量为195kg·hm-2,预计最高产量为8×103 kg·hm-2;(2)蓖麻株高、茎粗和穗数等生物性状总体上随施氮量提高逐渐增大,而主穗长、主穗种仁数、百粒重及产量均随施氮量增加呈现出抛物线变化趋势,其中产量峰值出现在施氮量200kg·hm-2时,其余指标均在施氮量150kg·hm-2时达到最高值;(3)在花果期,增加氮肥施用量能够促进蓖麻对氮素和钾素的积累,磷素积累量随施氮量增加呈抛物线上升的趋势,峰值出现在施氮量150kg·hm-2时;(4)施氮量与叶片氮素、磷素含量表现出明显的相关性。蓖麻在灌浆期对钾素的需求很高,叶片钾素大量转移到穗部。

冬小麦产量形成的干物质模式

针对徐淮地区冬小麦的生长情况，建立了冬小麦总生物量与气象条件综合因子逐日蒸发量的增长模式，并在引进三种群生态模型基础上，结合穗茎叶之间关系，研制出穗茎叶干物质相互作用模式。用数学方法研究了冬小麦干物质形成的规律。

冬小麦不同灌浆时期穗和叶茎鞘对粒重的贡献

为了揭示冬小麦穗和叶茎鞘在不同灌浆时期对粒重的贡献,于2011-2012年度,在大田条件下,选用河南省大面积推广的6个冬小麦品种,进行穗遮光和去叶+茎鞘遮光处理,研究了冬小麦不同灌浆时期的干物质积累转运量和粒重,分析了穗和叶茎鞘对粒重的贡献率。结果表明,穗遮光和去叶+茎鞘遮光显著影响冬小麦茎鞘干物质转运量、转运率以及其对穗粒重的贡献率。穗和叶茎鞘对冬小麦粒重的贡献率总体表现为灌浆前期低、中后期高;在灌浆中期穗对粒重的贡献优于叶茎鞘,而在灌浆前期和后期呈相反规律,且其影响效应因品种而异;整个灌浆期穗对单粒重和穗粒重的平均贡献率分别为30.31%和34.64%,叶茎鞘分别为32.87%和35.95%。穗对粒重贡献的关键时期为灌浆中期,筛选和培育灌浆中期穗对粒重贡献率高的品种有利于提高冬小麦粒重。

不同生育期水稻干物质量与产量的关系研究

为明确不同生育期的干物重对粤晶丝苗2号、粤农丝苗、合美占3个水稻(Oryza sativa L.)品种的产量及产量构成因素的影响,设置了早造和晚造两次不同氮肥梯度随机区组栽培试验。结果表明,叶片干物质的分配比例在拔节孕穗期时最高,且其随着生育进程逐渐降低,在乳熟期达到最低值;茎干物质的分配比例在乳熟期降至最低;齐穗期的穗干物质分配比例不到20%,而乳熟期的穗干物质量将近占总干物质量的43%;早造和晚造水稻的结实率差异极显著,总干重差异显著,而穗数、每穗粒数、千粒重、产量差异不显著;齐穗期以后,结实率和千粒重均与干物重呈负相关,而叶干重与穗数呈显著正相关,且相关性较大,茎干重与各产量性状密切相关,总干重与产量呈正相关。水稻干物重是决定高产的重要因素。

高粱不同品种茎、叶形态生理指标比较研究

对8个高粱杂交种的茎、叶的形态生理指标进行比较。以7050A、9198亲本系组配的杂交种茎粗系数较大,抗倒伏性强,利于稳产。高粱单株叶面积生长呈"S"形曲线发展。单株和群体叶面积发展经历了四个时期:指数增长期、直线增长期、稳定期和下降期。抽穗开花期,叶面积达到最大值。

弱光下黄瓜苗期性状的遗传分析

以 6份黄瓜自交系为试材 ,采用完全双列杂交设计GriffingⅡ配制 15个组合 ,亲本自交留种。研究了弱光下黄瓜苗期茎粗、下胚轴长、比下胚轴长、叶面积、比叶面积、子叶面积、地上部鲜重、全株干重等 8个性状的遗传规律。只有下胚轴长和比下胚轴长这 2个性状的遗传符合加性 显性遗传。所测 8个性状的狭义遗传力均较低 ,其遗传以非加性效应为主。

气象条件和栽培因素对高产小麦生长发育的影响研究

研究了不同年份的温、光、水对高产小麦生长发育的影响,探明了影响小麦冻害、最高群体及穗数、穗粒数和千粒重的主要气象因子与次要因子;提出了最佳播期、适期上限、适期下限播种的冬前主茎叶龄数;确定了冬前不同主茎叶龄数与播种期、播种量的关系;明确了在中、上等土壤肥力条件下公顷产量为7 500.0～9 000.0 kg的施肥量,氮肥基施、冬前和拔节期追施的比例;制定了冬前肥水的积温指标和拔节肥水的生物学指标。研究成果可作为黄淮海地区小麦高产栽培的参考。

川西北高寒地区6个燕麦品种生长特性的比较分析

为筛选适宜在川西北地区种植的优良燕麦(Avena sativa)品种,对国内外6个燕麦品种(青海444、青引1号、林纳、定燕2号、讴歌、莫妮卡)的生育期、株高、茎粗、产草量、鲜干比、茎叶穗构成及营养成分(粗蛋白、粗脂肪、粗灰分、酸性洗涤纤维、中性洗涤纤维)进行了品比试验。结果表明,除定燕2号外,其余5个燕麦品种均能完成生育期,其中青海444和青引1号生育期最短,分别为130和133d。供试燕麦的株高在81.53~90.54cm,品种间没有显著差异(P>0.05)。莫妮卡的茎粗最大,为4.35mm;青引1号最小,为3.32mm。林纳干草产量最高,达到10 448.52kg·hm-2;而青引1号最低,仅8 554.81kg·hm-2。青海444和青引1号鲜干比显著低于其他品种(P<0.05)。林纳的叶和穗重量占总干物质量的比例最高。林纳粗蛋白含量最高,为7.82%;定燕2号最低,为5.83%。青引1号粗脂肪含量最高,为2.93%;讴歌最低,为2.48%。粗灰分、酸性洗涤纤维和中性洗涤纤维含量最高的品种是青海444,分别为4.60%、35.57%和63.27%;含量最低的定燕2号则分别为3.76%、32.00%和54.47%。综合评价分析结果表明,品种林纳和莫妮卡最适宜在该区域推广种植。

模拟增温增雨对典型草原优势种羊草功能性状的影响

全球气候变化情景下,植物功能属性对于揭示植物对环境变化的响应和适应规律至关重要。本研究以内蒙古典型草原优势种羊草(Leymus chinensis)为研究对象,通过开顶式生长室(open top chamber,OTC)人工模拟增温和降雨,量化分析了羊草植物功能性状对增温和增雨处理的响应。得到以下结果:1)单因素方差分析表明,增温增水和增温处理都显著增加了羊草植物株高、茎鲜质量和茎干质量,对其余指标没有显著影响;增水处理对羊草所有指标都没有显著影响(P>0.05)。2)双因素方差分析结果显示,增温增水对植物的功能性状不存在明显的交互作用(P>0.05)。3)各处理下,叶片干物质含量与比叶面积呈负相关关系。在内蒙古典型草原,未来气候暖湿化对羊草的生长在一定程度上起促进作用。

超吨粮田中玉米植株性状与穗粒重的关系

对粮、粮、豆立体多熟种植超吨粮田生产中，玉米地上１～４节茎粗、棒三叶、穗位以上叶面积、棒三叶和穗位以上叶质重、株型和穗型指数等１５个性状因子与穗粒数和穗粒重之间的关系进行了相关和回归分析。结果表明，这１５个性状均与其穗粒数和穗粒重呈极显著正相关。其中计算了第４节茎粗、穗位叶、穗位以上叶面积、穗位以上叶质重和穗型指数扩大单位量级后的增产效果。与此同时，通过逐步回归建立了穗粒数和穗粒重的逐步回归模式，其间二者共同性状因子是第４节茎粗、棒三叶面积、穗位以上叶质重和穗型指数，可视为二式的主导制约因子。

海岛棉盛铃期不同节位光合源叶比叶重变异的比较

在 9个零式果枝海岛棉品种的盛铃期测定了 8～ 1 9节位主茎叶、苞叶、混生有限短果枝叶的比叶重 ,并作显著性检测和相关分析。结果表明 :各品种各节位的比叶重 (SLW ,g·m-2 )混生限短果枝叶 (79.42 ) >主茎叶 (75 .2 4) >苞叶(5 0 .0 8) ;各节位源叶SLW呈现自下而上、由内向外而递增的动态分布规律 ;所测源叶SLW在供试品种间和节位间存在极显著的差异性 ;1 0～ 1 9节位叶片的SLW、1 0～ 1 2、1 4～ 1 6节位苞叶的SLW分别与各节位相应的叶片、苞叶SLW平均值呈显著正相关 ;

几种因素对烤烟不同部位抗拉力的影响

在四川省泸州市古蔺县烟草科技示范园开展田间试验,研究几种因素对烤烟不同部位抗拉力值的影响。结果表明,鲜叶重、茎叶夹角、叶长、含水率等与抗拉力值存在二次多项式关系。在一定范围内,烤烟不同部位抗拉力值随鲜叶重增加、叶片长度增加、茎叶夹角增大而增大;超过一定范围后,烤烟不同部位抗拉力值随鲜叶重增加、叶片长度增加、茎叶夹角增大而减小。