共查询到20条相似文献，搜索用时 546 毫秒
1.
为提高喷雾干燥苹果粉的贮藏稳定性和优化贮藏条件,基于水分活度保藏理论和玻璃化转变理论,探讨了温度及添加剂对苹果粉吸附等温线和玻璃化转变温度的影响。采用静态称量法研究了苹果粉在不同温度(5、25和45℃)下的吸附等温线;采用Lewicki、GAB、Smith、Henderson和Peleg模型拟合试验数据,得到描述苹果粉水分吸附特性的数学模型;采用差示扫描量热法测定了添加β-环糊精、麦芽糊精、可溶性淀粉和玉米淀粉的苹果粉在贮藏温度40℃达到水分平衡时的玻璃化转变温度;采用Khalloufi,El-Maslouhi,Ratti方程拟合数据,探讨添加剂对苹果粉临界水分活度和临界平衡干基含水率的影响。结果表明,GAB模型为描述苹果粉水分吸附特性的适宜模型;苹果粉的平衡干基含水率随着水分活度的增加而增加,水分活度小于0.76时随着温度的升高而降低;苹果粉的玻璃化温度随平衡干基含水率的增加而降低,添加β-环糊精的苹果粉玻璃化温度较高,不易结块,有利于提高苹果粉的贮藏稳定性。研究可为苹果粉适宜干燥技术条件和贮藏条件的确立提供参考。 相似文献
2.
为了综合水分活度及玻璃化转变理论构建状态图,获得灰枣粉的较佳贮藏条件,该文采用静态称量法和差示扫描量热法测定灰枣粉的吸附特性及玻璃化转变温度。结果表明,膨化干燥灰枣粉水分吸附的平衡干基含水率随水分活度的增加而增加,水分吸附等温线呈J型,描述灰枣粉水分吸附特性的适宜模型为GAB模型（R2=0.9968）;灰枣粉的玻璃化转变温度随含水率升高而降低,湿基含水率由0.064 g/g增加到0.175 g/g时,玻璃化转变温度由29.90℃降低到?35.02℃;灰枣粉干基含水率≤0.1223 g/g、贮藏温度≤?0.062°C时其稳定性较好,研究结果为灰枣粉加工、运输等过程中的贮藏条件提供理论参考。 相似文献
3.
玉米淀粉水分吸附等温线的研究及模型建立 总被引：2，自引：0，他引：2
为了更好地指导玉米淀粉及其含物制品的干燥、储藏和包装，需要确定温度对玉米淀粉水分吸附特性的影响，及建立一个包含温度和水活度在内的新吸附等温线模型。 根据吸附原理，利用静态调整环境湿度法，测定了玉米淀粉在30℃、45℃和60℃ 3个温度不同水活度下的吸湿和解吸等温线。结果显示玉米淀粉的等温线属于Ⅱ型等温线，在一定的水活度下随着温度的升高吸附能力下降。随着水活度的增加平衡含水率增加，在整个水活度范围内吸附等温线存在一个很明显的滞后作用。用BP神经网络建立了一个新的吸附等温数学模型，分析表明BP神经网络模型不仅包含水活度和温度2个参数而且拟合程度优于其它的数学模型。 相似文献
4.
为提高燕麦片的贮藏稳定性和优化贮藏条件,基于水分活度保藏理论和玻璃化转变理论,探讨了不同添加剂对燕麦片吸附等温线和玻璃化转变温度的影响。采用静态称量法研究了纯燕麦片(PO)、添加纯燕麦片总固形物质量10%麦芽糊精(PO-10%MD)、10%乳清分离蛋白(PO-10%WPI)和5%麦芽糊精+5%乳清分离蛋白(PO-5%MD-5%WPI)等4种燕麦片在不同温度(15、25和35℃)下的吸附等温线。采用GAB和BET模型拟合试验数据,得到描述燕麦片水分吸附特性的数学模型。采用差示扫描量热法测定了PO、PO-10%MD、PO-10%WPI和PO-5%MD-5%WPI的玻璃化转变温度(glass transition temperature,Tg),采用Gordon-Taylor方程拟合Tg数据,探讨添加剂对燕麦片临界水分活度(critical water activity,CWA)和临界干基含水率(critical water content,CWC)的影响。结果表明,燕麦片的水分吸附等温线呈S型,GAB模型为描述燕麦片水分吸附特性的适宜模型。燕麦片的平衡干基含水率随着水分活度的增加而增加,随着温度的升高而降低。燕麦片的Tg随着湿基含水率的增加而降低,添加麦芽糊精和乳清分离蛋白显著提高了燕麦片的Tg。温度25℃时,PO、PO-10%MD、PO-10%WPI和PO-5%MD-5%WPI的CWC和CWA分别为0.054 g/g、0.126;0.060 g/g、0.175;0.056 g/g、0.138和0.056 g/g、0.139。因此,添加总固形物质量10%麦芽糊精能显著增加纯燕麦片的CWC和CWA,从而提高燕麦片的贮藏稳定性。研究结果为燕麦片适宜包装材料的筛选和适宜贮藏条件的确立提供参考。 相似文献
5.
热风干制温度对枣果微观组织结构的影响 总被引：3，自引：2，他引：1
为了研究热风干制温度对枣果微观组织结构的影响,该试验选用不同温度(35、40、45、50、55℃)热风干制枣果,利用石蜡切片、显微成像技术获得了热风干制过程中不同含水率条件下果肉细胞、空腔等结构参数的分布曲线,借助分布曲线的偏度、峰度(以鲜枣为参照)描述了微观结构参数在热风干制过程中的变化趋势,并建立了微观结构参数(果肉细胞、空腔横截面的面积比、周长比及当量直径比)与宏观干燥参数(水分比)的拟合方程。结果表明,利用微观结构参数分布曲线的偏度、峰度可较好地描述不同温度干制过程中细胞、空腔整体的变化趋势;干制过程中随着含水率的降低,果肉细胞、空腔结构参数的变化趋势均不具有一致性或连续性;不同温度相比之下,低温、高温干制过程对果肉细胞形态的改变均有较大影响,且高温(55℃)条件影响更大;不同温度热风干制过程中,由果肉细胞结构改变所引起的空腔塌缩和扩增同时存在,高温(55℃)条件对空腔的扩增、塌缩影响较大。果肉细胞,空腔结构参数比与水分比之间关系可用非线性模型描述(R2≥0.7283,Std≤25.1682%),模型可预测在不同温度热风干制过程中细胞、空腔随含水率的变化情况,研究结果可为热风干制新工艺的开发提供参考。 相似文献
6.
以平衡吸附法研究了菲和萘在塿土上的吸附行为,考察了初始浓度、温度、pH、离子强度和CaCO3对塿土吸附菲和萘的影响,Henry方程、Freundlich方程和deBoer-Zwikker极化方程被用来拟和吸附等温线。结果表明,菲和萘在塿土上的吸附等温线为非线性,Freundlich方程最符合其吸附行为。菲和萘在塿土上的吸附量随温度升高而降低,其吸附是一个放热过程;吸附自由能小于零,表明吸附过程是自发的;熵变值也小于零,说明焓变是吸附过程的驱动力。随着pH增加,塿土对菲和萘的吸附量下降;而随着离子强度增加,塿土对菲和萘的吸附量增加。CaCO对菲和萘的吸附等温线也为非线性,其对塿土吸附菲和萘具有较大的贡献。 相似文献
7.
改性磁性荔枝皮对水及果汁中砷的吸附效果及动力学分析 总被引：2，自引：2，他引：0
为探索安全高效实用的果汁类食品砷吸附材料,以天然植物副产物荔枝皮为材料,通过共沉法制备砷吸附材料磁性荔枝皮(magnetic litchi peel,MLP),采用电感耦合等离子体质谱法测定砷含量,以砷清除率为判断指标,研究了MLP对三价砷和五价砷吸附效果及机理。结果表明:改性MLP表面含有粉末状的Fe3O4,与未改性荔枝皮相比部分官能团增加,表面粗糙、更加凹凸不平,结构疏松,微孔数量增加,有利于吸附作用的进行,在砷浓度为0.20 mg/L水溶液中三价砷和五价砷吸附率为88%和90%,对苹果汁中的三价砷和五价砷吸附率为83%和93%;MLP对三价砷和五价砷溶液吸附等温线符合Langmuir等温线模型,拟合决定系数R2均大于0.99,为单分子层吸附,在298 K条件下饱和吸附量三价砷为0.181 mg/g,五价砷为0.225 mg/g;MLP对砷溶液吸附动力学可以通过准二级吸附动力学模型描述,R2均高于0.99;MLP对三价砷和五价砷的吸附过程中吉布斯自由能小于0,吸附反应是自发进行的,焓变小于0,MLP对两种价态砷的吸附都是放热反应。研究结果可为改性荔枝皮在果汁类食品中砷脱除方法和工艺的应用提供理论与数据参考。 相似文献
8.
为考察大孔吸附树脂对蜂蜜中羟甲基糠醛(HMF)的吸附可行性，该文采用静态吸附法研究了LSA-800B型大孔树脂对HMF吸附过程的热力学性质。结果表明，在298，308，318 K和研究的浓度范围内，蜂蜜中的HMF在LSA-800B型树脂上的吸附等温线均符合Freundlich等温吸附方程，Freundlich吸附等温线和等量吸附焓表明LSA-800B型树脂对蜂蜜中HMF吸附是放热过程。吸附自由能ΔG＜0表明吸附的自发性，吸附熵变ΔS＜0说明吸附质分子在吸附树脂表面上的运动比在溶液中受到更大的限制。 相似文献
9.
温度与水分状况对作物叶片水分能态的影响 总被引：2，自引：0，他引：2
在实验室条件下试验研究不同温度与水分胁迫对小麦和玉米幼苗叶水势及渗透势的影响结果表明，在一定温度时随土壤水势的降低，叶水势呈下降趋势；相同土壤水势条件下随温度升高，叶水势呈下降趋势。温度和水分状况对叶片渗透势的影响与叶水势不同，随温度升高和水分胁迫的加剧，叶片渗透势则呈先降后升趋势。通过对作物叶水势和渗透势变化幅度的比较，说明小麦的渗透调节能力和抗旱性能均大于玉米。对植物叶片水分水偏摩尔自由能（ΔG）、焓（ΔS）、熵（ΔH）计算与分析，初步从能量的观点证实作物在27℃左右温度时生长最佳。 相似文献
10.
萘在土壤上的吸附行为及温度影响的研究 总被引：2，自引：0，他引：2
采用批量平衡法研究了多环芳烃萘在塿土耕层土、塿土粘化层土、塿土古土壤、黄壤、紫色土和石灰土上的吸附行为,比较了不同吸附模型方程对实验数据的拟合情况,并探讨了温度对萘在土壤上吸附行为的影响机理及吸附热力学特征。Henry模型、Freundlich模型和deBoer-Zwikker极化模型均能较好地拟合萘的吸附等温线;45℃下的吸附等温线明显地高于25℃的吸附等温线,表现出随温度升高吸附量增大的趋势。Freundlich模型的吸附容量参数Kf和deBoer-Zwikker模型的起始吸附势ε0在两个温度下有极显著的差异;但Freundlich模型的n参数表征了土壤颗粒表面的性质,对温度变化不敏感。在25℃条件下,萘在土壤有机碳上的分配可能是吸附的主要机制,但随着温度增加,吸附机制变得复杂。土壤对萘的吸附是一吸热反应,整个吸附体系中熵增是吸附作用进行的主要驱动力。 相似文献
11.
【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。 相似文献
12.
Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing. 相似文献
13.
《中国生态农业学报》2014,(8)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
14.
M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. 相似文献
15.
Grete Skrede Berit Karoline Martinsen Anne-Berit Wold Stein-Erik Birkeland Kjersti Aaby 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):193-208
Abstract A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species. 相似文献
16.
《Communications in Soil Science and Plant Analysis》2012,43(7):865-877
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils. 相似文献
17.
Y. Bashan J. J. Bustillos L. A. Leyva J.-P. Hernandez M. Bacilio 《Biology and Fertility of Soils》2006,42(4):279-285
Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several
photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene.
This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments
for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference
in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless
of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots.
Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production
or the positive response of the plants towards A. brasilense Cd inoculation. 相似文献
18.
Dhritiman Ghosh Velusamy Srinivasan Olli H. Tuovinen Aaron Peacock Mark Radosevich 《Soil biology & biochemistry》2009,41(6):1331-1334
We examined the community composition of microbes that colonized atrazine-containing beads buried in agricultural soils that differed in atrazine treatment history. Bacterial abundance was 5-40-fold greater in atrazine-fortified beads. In beads containing 20 mg atrazine kg−1 buried in soil with a history of atrazine application (conditioned soil), the abundance of Actinobacteria increased approximately 80-fold whereas in control soil, Actinobacteria were enriched only 10-fold and the gamma-Proteobacteria and Planctomycetes increased by 60- and 25-fold, respectively. The gamma-Proteobacteria were enriched by 120- and 230-fold in beads containing 200 mg atrazine kg−1 in conditioned and control soil, respectively. The results demonstrate that BioSep® beads are a suitable matrix for recruiting a diverse subset of the bacterial community involved in atrazine degradation. 相似文献
19.
Pilar García Juan-Vicente Monte Carlos Casanova Consuelo Soler 《Genetic Resources and Crop Evolution》2002,49(1):103-109
Arbitrary oligonucleotides were used as primers to amplifygenomic DNA of 48 wild Spanish populations of Agropyroncristatum, Elymus hispanicus,E. caninus,E. repens,Thinopyrum curvifolium, Th.junceum and Th.intermedium. Genetic diversity was analysedusing nineteen primers. The number of amplified products ranged from8 to 18 per primer and a total of 240 markers were scored. Differentlevels of intraspecific genetic diversity were found, the allogamousspecies E. repens andTh. intermedium being themost variable. Jaccard's similarity coefficients for internalmeasure within and between populations were used to produce a clusterdiagram. The results demonstrate differences in the degree ofsimilarity between taxonomic units. Interpopulational variability andinterspecific genomic relationships of these species arediscussed. 相似文献
20.
The effects of three commonly used fungicides on the colonization and sporulation by a mixture of three arbuscular mycorrhizal (AM) fungi consisting of Glomus etunicatum (Becker & Gerd.), Glomus mosseae (Nicol. & Gerd.) Gerd. & Trappe, and Gigaspora rosea (Nicol. & Schenck) in symbiosis with pea plants and the resulting response of the host-plant were examined. Benomyl, PCNB, and captan were applied as soil drenches at a rate of 20 mg active ingredient kg-1 soil 2 weeks after transplanting pea seedlings in a silty clay-loam soil containing the mixed inocula of AM fungi (AM plants). Effects of fungicides were compared to untreated plants that were inoculated with fungi (AM control). The effect of mycorrhizal inoculation on plant growth was also examined by including nonmycorrhizal, non-fungicide-treated plants (non-AM control). Fungicides or inoculation with AM fungi had only a small effect on the final shoot weights of pea plants, but had greater effects on root length and seed yield. AM control plants had higher seed yields and lower root lengths than the corresponding non-AM plants, and the fungicide-treated AM plants had intermediate yields and root lengths. Seed N and P contents were likewise highest in AM control plants, lowest in non-AM plants, and intermediate in fungicide-treated AM plants. All three fungicides depressed the proportion (%) of root length colonized by AM fungi, but these differences did not translate to reductions in the total root length that was colonized, since roots were longer in the fungicide-treated AM plants. Pea plants apparently compensated for the reduction in AM-fungal metabolism due to fungicides by increasing root growth. Fungicides affected the population of the three fungi as determined by sporulation at the final harvest. Captan significantly reduced the number, relative abundance, and relative volume of G. rosea spores in the final population relative to the controls. The relative volume of G. etunicatum spores was greater in all the fungicide-treated soils, while G. mosseae relative volumes were only greater in the captan-treated soil. These findings show that fungicides can alter the species composition of an AM-fungal community. The results also show that AM fungi can increase seed yield without enhancing the vegetative shoot growth of host plants. 相似文献