新疆阿瓦提灌区土壤盐渍化现状及特征分析     

王水献  董新光  杜卫东 《干旱地区农业研究》2006,24(5):170-175

运用统计特征值、对应分析等方法，探讨了研究新疆阿瓦提土壤含盐量、盐分化学组成及其空间分布特征。结果发现：区内有50％的土地处于中强盐渍化和盐土状态，且主要为氯化物-硫酸盐型盐渍化；在灌区内土壤盐分随灌溉和排水而呈现季节性变化，但整体上处于脱盐状态。区内土壤盐渍化是在自然和人类活动共同作用下形成的，通过节水灌溉、合理开发地下水、完善灌排系统等措施可有效地改良盐渍土。  相似文献   

桃果实发育过程中主要营养成分的动态变化及系统分析方法研究   总被引：5，自引：0，他引：5  

邓月娥  张传来  牛立元  苏成军  韩红萍 《果树学报》1998,(1)

通过对桃果实发育过程中维生素C、可溶性糖、有机酸、游离氨基酸及蛋白质含量的测定,系统分析了它们在整个生长发育过程中的动态变化。维生素C含量呈V形的变化曲线,幼果和成熟时较高,其它时期较低;可溶性糖总量随果实的生长而增加,但还原糖与非还原糖含量的变化趋势恰好相反;有机酸、游离氨基酸和蛋白质三者含量都是幼果时较高,成熟时最低。各种营养成分的变化虽然有所不同,但与果实的相对生长速度及花后天数有明显的相关关系。另外,对果实生长发育过程中营养成分的系统分析方法也进行了研究。  相似文献   

方差组分估计方法的比较   总被引：2，自引：0，他引：2  

刘增廷  张沅 《畜牧兽医学报》1989,20(4):289-294

本文通过蒙特卡罗模拟产生的八个模拟资料比较了我国常用的方差分析法(不考虑场年季效应)、Henderson方法1、Henderson方法3、最大似然法、改进最大似然法与约束最大似然法。结果表明:方差分析法估计值偏差最大,而约束最大似然法的估计值最准确。  相似文献   

黄皮疣柄牛肝菌营养成分分析   总被引：4，自引：0，他引：4  

梅文泉  董宝生  和丽忠  周茜  束继红 《中国食用菌》2005,24(1):25-26

对黄皮疣柄牛肝茵中宏量营养成分、常量及微量元素、氨基酸组成进行了较为全面的分析测定。测定结果表明：黄皮疣柄牛肝菌中蛋白质含量35.10％。脂肪1．40％。粗纤维12．53％。总糖9.33％；元素钙的含量较低为126mg／kg；氨基酸组成中谷氨酸的含量最高为3.80％。  相似文献   

The effect of leaf age on incomplete resistance of coffee to Hemileia vastatrix     

A. B. Eskes  M. Toma-Braghini 《European journal of plant pathology / European Foundation for Plant Pathology》1982,88(6):219-230

The influence of leaf age on incomplete resistance to race II of coffee leaf rust (Hemileia vastatrix), which is the most common race in Brazil, was tested in the greenhouse and in the field. Three stages of leaf age were distinguished: young leaves which had just fully expanded and still had a shiny appearance on the day of inoculation, adult leaves of 1 to 4 months old, and old leaves of 6 to 12 months old which were formed in the foregoing growing season.The effect of leaf age varied with the coffee genotype. With the susceptibleCoffea arabica cvs Mundo Novo and Catuai no important effect of leaf age on latency period and reaction type was observed. Lesion density, depending on inoculation method, was affected to some extent, older leaves showing lower values. With genotypes of theC. canephora cv. Kouillou, which varied in level of incomplete resistance, adult leaves appeared to be more resistant than young and old leaves. This adult leaf resistance was expressed mainly by a lower lesion density, but also by a longer latency period and a lower reaction type.Within the hybrid populations Icatu and Catimor, genotypes with race-specific incomplete resistance were tested and others of unknown specificity. Resistance was expressed mainly by a low reaction type. Generally, resistance decreased with increasing leaf age, which was occasionally associated with a complete change in reaction type. Contrary to cv. Kouillou, in Icatu and Catimor no higher susceptibility of young leaves than of adult leaves was observed.The incomplete resistance to race I of the differential CIFC H152/3, heterozygous for S_H4, was also better expressed in young leaves, older ones becoming gradually more susceptible.It is concluded that for screening incomplete resistance to coffee leaf rust leaves of different ages should be tested.Samenvatting Het effect van bladleeftijd op incomplete resistentie van koffie tegen fysio II van koffieroest (Hemileia vastatrix), het algemeen voorkomende fysio in Brazilië, werd getoetst in de kas en in het veld. Drie stadia in de bladleeftijd werden onderscheiden: jong blad dat net volgroeid was en nog glansde op de dag van inoculatie, volwassen blad van 1 tot 4 maanden oud en oud blad van 6 tot 12 maanden oud dat gevormd was in het voorafgaande groeiseizoen.Het effect van bladleeftijd varieërde met het koffiegenotype. Bij de vatbareCoffea arabica rassen Mundo Novo en Catuai werd geen belangrijke invloed waargenomen van bladleeftijd op latentieperiode en reactietype. Lesiedichtheid werd, afhankelijk van de inoculatiemethode, wel enigszins beïnvloed. Bij vijf genotypen van hetC. canephora ras Kouillou, die varieerden in niveau van incomplete resistentie, bleek volwassen blad veelal resistenter dan jong en oud blad. Deze resistentie uitte zich voornamelijk door een lagere lesiedichtheid maar ook door een langere latente periode en een lager reactietype.Van de hybride populaties Icatu en Catimor werden enkele genotypen met fysiospecifieke incomplete resistentie getoets alsmede genotypen waarvan de specificiteit van de resistentie onbekend was. Verschillen in resistentie uitten zich voornamelijk door verschillen in reactietype. Over het algemeen nam de resistentie af bij toenemende bladouderdom. Anders dan bij de cv. Kouillou werd bij Icatu en Catimor geen grotere vatbaarheid van jong ten opzichte van volwassen blad waargenomen. Bij sommige genotypen kwam resistantie zelfs alleen maar tot uiting in het jonge blad, terwijl het volwassen blad normaal vatbaar was. Een soortgelijk effect van bladleeftijd werd waargenomen bij inoculatie van de koffiedifferentieel CIFC H153/3, die heterozygoot is voor het resistentiegen S_H4, met het incompatibele fysio I.Er wordt geconcludeerd dat voor het bepalen van incomplete resistentie tegen koffieroest bladeren van verschillende ouderdom getoetst dienen te worden.  相似文献   

葡萄种间杂交香味成分的遗传研究   总被引：7，自引：2，他引：7  

李记明  贺普超 《园艺学报》2002,29(1):9-12

 利用气相色谱—质谱—计算机联用系统(GC2MS2CS) 对两个葡萄种间杂交的亲本及其后代的香味成分进行了研究。结果表明: 葡萄种间杂交时, 甲基丙烯醇、二甲基丁烯醇、沉香醇、甲酸异戊酯、2 ,4 - 二甲基己烷等香味成分具有1∶1、1∶3、1∶9 的分离比例, 表现出了质量性状的遗传特征; 而二甲基丁烷、四氢呋喃、1 - 甲氧基丙酮、丁内酯、苯乙醇等香味成分呈现多基因控制数量性状的遗传趋势。  相似文献   

Use of a test day model for dairy goat milk yield across lactations in Germany.   总被引：1，自引：0，他引：1  

B Zumbach  S Tsuruta  I Misztal  K J Peters 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2008,125(3):160-167

Breeding value prediction for dairy goats in Germany is still based on herd mate comparison within breeding society. The objective of this study was to estimate genetic parameters for milk yield based on a test day model. For the analysis 35,308, 30,551 and 23,640 test day records from lactations 1, 2 and 3 from 5079, 4118 and 3132 animals, respectively, were used. The data between 1987 and 2003 were obtained from six German breeding societies. The multiple trait (lactations 1, 2 and 3) repeatability model (RPT) included the fixed effects of breeding society-breed-herd-year, litter size, lambing season, and days in milk of third-order Legendre polynomials nested within herd-year, and the random effects of animal additive and permanent environment. The three-trait random regression model (RR) also included the random regressions based on second-order Legendre polynomials for animal additive and permanent environmental effects. Heritability estimates in RPT were 0.27 +/- 0.02, 0.20 +/- 0.02 and 0.37 +/- 0.02 for the first, second and third lactation, respectively. The genetic correlation between the first and second lactation was 0.69, between the second and third lactation 0.79, and between the first and third lactation 0.45. Heritability estimates from the RR in the first and second lactations decreased from the beginning to the end of the lactation, with average values of 0.28 and 0.27, respectively. Estimates in the third lactation showed a maximum in the middle of lactation, averaging 0.37. Genetic correlations between the first and second lactation averaged 0.64, between the second and third lactation 0.72, and between the first and third lactation 0.46. Despite the small data set and restricted relationship structure the estimates were reasonable with the exception of estimates from the third lactation, which seemed inflated. RR could be used for genetic evaluation of dairy goats in Germany.  相似文献   

动物免疫增效剂黄芪多糖化学组分及其结构分析   总被引：6，自引：1，他引：5  

李宏全  赵万国  吕小虎 《中兽医医药杂志》2008,27(5):5-9

应用微波辅助提取技术从内蒙古黄芪的干燥根中获得黄芪多糖（Astraglus Polysaccharides,APS）;确定中性蛋白酶与APS质量比为1：200,50℃水浴酶解2h为脱除APS中蛋白质的最佳条件;除蛋白后的APS过DEAE-cellulose 52柱、透析袋和Sephadex G-100柱纯化,经醇沉、真空干燥后,高效凝胶过滤色谱法（HPGPC）测得其分子量（Mw）为1．1×10^4Da,纯度为97．16％;以1-苯基-3-甲基-5-吡唑啉酮（PMP）为衍生剂,经柱前衍生化HPLC分析。确证APS的单糖组成为Rha、Glc、GalA和Ara,其摩尔比为1．19：72．01：5．85：20．95;红外光谱、^13C核磁共振和^1H核磁共振技术确定本实验所得APS其主链由葡萄糖以α-型糖苷键连接而成,前期实验证实其具有增强机体免疫功能和抗氧化作用。  相似文献   

封育对云南退化山地草甸植物种类及盖度的影响   总被引：4，自引：2，他引：2  

殷振华  毕玉芬  李世玉 《草业科学》2008,25(12):18-22

对云南退化的山地草甸进行了为期3年的禁牧封育,并对其进行监测,研究了禁牧封育对退化山地草甸的改良作用。结果表明,禁牧封育对恢复退化山地草甸物种丰富度和草地盖度有明显的效果。禁牧封育后草地植物的盖度明显提高,植物种类增加很快,植物组成发生了显著变化。经过3年的封育,植物种类由27种增加到57种,是封育前的2倍多,封育第4年,植物物种基本稳定。封育措施有效恢复了不同退化程度山地草甸的物种丰富度和草地盖度,遏制了草地退化,是治理南方草地退化的有效途径。  相似文献   

Effects of transient subsurface waterlogging on root growth, plant biomass and yield of chickpea     

J.A. Palta  A. Ganjeali  K.H.M. Siddique 《Agricultural Water Management》2010,97(10):1469-1476

Root growth and proliferation are important for achieving the yield potential of chickpea in soils prone to waterlogging. Root growth characteristics and seed yield of the desi cultivar Rupali and the kabuli cultivar Almaz that differ in seed size and early vigour were investigated under well-drained and transiently-waterlogged conditions in glass-walled root boxes in a controlled-temperature glasshouse. Rooting parameters and detailed measurements of root growth and proliferation were made at 2-day intervals using a root mapping technique and by sampling the roots from the soil 14 days after the transient waterlogging ended. Although the roots of the kabuli cultivar Almaz had greater dry matter and length than the desi cultivar Rupali, the subsurface waterlogging promptly stopped the root growth of both genotypes. Root dry matter in both types of chickpea was reduced by two-thirds, 14 days after the cessation of the 12-day waterlogging treatment. The reduction resulted from an inhibition in root growth and proliferation, which led to a lower root length density down the soil profile, particularly in the top 0.6 m of the waterlogged plants. While root length and root dry matter was higher in the kabuli cultivar Almaz than in the desi cultivar Rupali after waterlogging, they were not associated with a greater above-ground dry matter or seed yield at maturity. The transient waterlogging reduced the seed yield by 54% in the kabuli cultivar Almaz and by 44% in the desi cultivar Rupali. The reduction in seed yield in the kabuli cultivar Almaz resulted from 50% decline in the number of seeds per pod while in the desi cultivar Rupali it was a consequence of less pods and seeds per pod. Subsurface waterlogging changed the rooting pattern in chickpea, inhibiting root branching and the growth of the tap root and severely reducing the growth of root branches. The release from the waterlogging induced the production of new roots rather than regrowth of existing roots.  相似文献