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北京地区夏播小麦的生态条件及生育表现   总被引:2,自引:0,他引:2       下载免费PDF全文
本文探讨了小麦在异常种植条件下的生长发育表现,从面揭示其温光反应规律。 1982—1985年连续三年在北京地区进行的小麦夏播生态试验证明:强春性小麦品种在北京晚夏播种,能很快地顺利出苗,并能抽穗成熟。在高温和长日条件下,它们的生育进程快,植株低矮,千粒重低。在生育早期未出现低温效应,可不发生田间春化反应。此外夏播小麦在科研与生产上都具有一定意义,浮小麦和麦苗都有利用价值。  相似文献   

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不同地区春播小麦生育天数的对比试验   总被引:1,自引:0,他引:1  
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为了给西藏优质小麦生产的品种利用提供依据 ,1998~ 2 0 0 0年 ,用 7个西藏春小麦品种和 4个引进品种在拉萨进行了 3年春播试验 ;1998~ 2 0 0 1年 ,用 2个西藏冬小麦品种和 3个引进品种进行了 3年秋播试验。结果表明 ,西藏品种的蛋白质含量、湿面筋含量、沉降值明显低于引进品种。西藏品种属于弱筋小麦品种。西藏优质专用小麦生产中的品种利用途径是 :加强中筋小麦的生态育种 ;引进内地强筋小麦品种  相似文献   

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1983至1985年,在石家庄、榆林、银川、张掖进行了小麦生态研究的春播试验。这4个试点的纬度基本相同,但经度和海拔差别较大。绵阳11号属于春型小麦品种。在春播试验中,参试品种在不同地点的播种至成熟天数有明显差异。试验表明,在我国北纬38—39度之间的不同地点,海拔每升高100米,小麦生育期间的平均日均温约降低0.3℃,生育天数约增加2—3天,经度每增加1度,小麦的生育天数约减少2天。  相似文献   

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CO2浓度倍增对小麦生育性状和产量构成的影响   总被引:14,自引:0,他引:14       下载免费PDF全文
CO_2浓度倍增对小麦生育性状和产量构成的影响王修兰,徐师华,李佑祥(中国农业科学院农业气象研究所,北京,100081)THEEFFECTSOFCO_2DOUBLINGONGROWINGANDDEVELOPINGCHARACTERSANDYIELDFO...  相似文献   

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西藏小麦耐盐性鉴定及分析   总被引:2,自引:0,他引:2  
在3种不同盐胁迫浓度下对161份来源于西藏的小麦材料进行了苗期耐盐性鉴定,其中有147份西藏半野生小麦及14份密穗小麦。以普通小麦耐盐品种荼淀红麦和盐敏感品种P194341为对照。在147份西藏半野生小麦中有14份表现为耐盐,占9.5%。14份密穗小麦中没有发现耐盐材料。在这161份材料中还发现了3份对盐胁迫浓度梯度不敏感的品种。结果表明,我国特有的西藏半野生小麦中蕴藏有丰富的耐盐种质,它们可供小麦耐盐育种用做亲本。  相似文献   

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生育阶段小麦冠层的反射光谱特征及其模糊聚类的研究   总被引:2,自引:0,他引:2  
测量不同生育阶段小麦冠以反射光谱,并使用傅叶滤波及导数法信号处理技术对反射光谱进行处理,找出能最有效区分作物不同生育阶段的波长和波段,用这些波长和波段对应的反射率为指标,用模糊聚类(FCA)的方法对不同生育阶段小麦进行区分。  相似文献   

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小麦不同生育时期Cd、Cr、Pb污染监测指标体系   总被引:13,自引:0,他引:13       下载免费PDF全文
以小麦为供试材料,分别采用发芽试验、溶液培养、土柱栽培等毒理试验方法,研究了小麦萌芽期、幼苗期及成株期受重金属污染毒害的指标体系。结果表明,①小麦根伸长抑制率可作为萌芽期重金属污染评价的一项生物指标;Cd、Cr、Pb对小麦根生长的7d半效应浓度(EC50)值分别为1.39、0.20mmo.lL-1和2.75mmol.L-1,据此得到3种重金属对小麦同一性状的毒性次序为CrCdPb;此外各性状抑制率与胁迫浓度的关系可用双曲线模型y=x/(a+x/100)或指数曲线模型y=a(1-exp(-bx))较好模拟。②Cd、Cr、Pb单一污染胁迫对小麦幼苗性状的毒性次序均以影响叶面积和冠部干重为主,表明叶面积和冠部干重为幼苗期污染监测的敏感指标;重金属对除根干重外所有性状的毒性次序:CrCdPb,该毒性次序是根据引起50%抑制的临界浓度即EC50值确定的;各性状抑制率与胁迫浓度的关系可用直线模型、或双曲线模型、或指数曲线模型较好模拟。③重金属单一污染胁迫造成小麦籽粒产量下降幅度是CdCrPb;二元互作对产量影响的重要性次序为CdCrCdPbCrPb;在Cd、Cr、Pb复合污染胁迫条件下,穗数可以作为成株期重金属污染监测的首选指标。以上指标可为农田小麦重金属污染的监测和综合治理提供一些理论依据。  相似文献   

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不同小麦进化材料生育后期光合特性和产量   总被引:12,自引:0,他引:12       下载免费PDF全文
以二倍体野生一粒小麦(Triticum boeoticum)、栽培一粒小麦(T. monococcum)、节节麦(Aegilops tauschii)和黑麦(Secale cereale)、四倍体野生二粒小麦(T. dicoccoides)、栽培二粒小麦(T. dicoccum)、硬粒小麦(T. durum)、六倍体普通小麦(T. aestivum)‘扬麦9号’和‘扬麦158’及八倍体小黑麦(Triticale)为材料,采用盆栽试验研究了不同小麦进化材料生育后期旗叶光合特性的演变及产量的差异。结果表明,与六倍体普通小麦和八倍体小黑麦相比,二倍体和四倍体材料在开花前具有较高的光合速率(Pn)、气孔导度(Gs)、最大光能转换效率(Fv/Fm)和实际光化学效率(ΦPSⅡ)。开花以后,二倍体和四倍体材料受非气孔因素的影响,光合能力下降较快;除黑麦外,旗叶光合速率在开花10 d后都低于普通小麦和小黑麦,胞间CO2浓度(Ci)迅速增加,Fv/FmΦPSⅡ和叶绿素含量快速下降。二倍体和四倍体材料开花前单株总叶面积和旗叶叶面积较大,花后下降迅速,功能期短;单株穗数也较多,但穗粒数、千粒重、产量和收获指数却显著低于普通小麦。因此,小麦长期进化过程中,普通小麦花后较高的光合能力及较长的光合持续期是提高千粒重,进而提高产量的重要生理基础。  相似文献   

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The style of wheat divides into 2 branches, separated from its base and covered with a large number of slender stigmatic branches. The stigma is of dry type. The style is solid. There is no transmitting tissue differentiated in the style. Young stylar cells appear polygonal in transverse sections and elongated in longitudinal sections with an increase in length of the cells from periphery towards center. In transverse sections, mature stylar cells look extremely irregular. They are contorted and mosaicked with one another. During their development, stylar cells elongated vigorously with intrusive growth. The wall of stylar cells is thin, except at the corners where cells connect, that slight thickening of the cell wall occurs. Stylar cells start vacuolation at the earlier stages and gradually become highly vacuolated, but still remain rich in organelles, such as mitochondria, endoplasmic reticulum, dictyosomes and chloroplasts, the amount of which varied with the development stages of the style. Stigmatic branches are differentiated from the stylar epidermal cells, composed of 4 files of cells which link end to end with one another. Not long before anthesis, wall material in the intercellular corners becomes loose and porous. After pollination, pollen tubes grow along the intercellular spaces among the 4 files of cells in the stigmatic branches and then enter the style. Pollen tubes may pass through any intercellular corner throughout the 2 branches of the style, except for the lateral-outer portion which is composed of larger stylar cells. Eventually, pollen tubes enter the ovary.  相似文献   

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The conservation of biological diversity concerns the management of the development process, not only at the national but also at the global level. Individual countries have made their development choices independently but relatedly, too often following the precise form of the choices of other countries preceding them in the development process. Development via imitation is pursuing the form, rather than the substance of a successful development strategy. Countries should instead be developing upon a base of assets that provides them with a relatively unique set of goods and services to place upon global markets. When the first countries developed, this criterion indicated that they should convert their countries to new forms of production; when the last countries are developing, relatively unique goods and services flow from their lands as they stand. What is required is the development of global institutions that encourage countries to see that their best development opportunities lie down these alternative development pathways, based upon their already-existing but relatively unique national assets.  相似文献   

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Size variation in African apes (Gorilla gorilla [gorilla], Pan paniscus [pygmy chimpanzee], and Pan troglodytes [“common” chimpanzee]) is substantial, both within and between species. We investigate the possible evolutionary significance of this variation through an analysis of the ontogeny of size variation in this group. In addition, we highlight possible areas of future endocrinological research, and evaluate recently proposed alternative models that attempt to account for ontogenetic variation in apes. The present study shows that intergeneric variation in size is largely a consequence of differences among species in the rate of body weight growth. Interspecific size variation in Pan is a product of both rate and duration differences in growth. The ontogenetic bases of sexual dimorphism vary in this group. Dimorphism is largely a result of sex differences in the duration of body weight growth in gorillas and pygmy chimpanzees, but results from differences in the rate of growth in common chimpanzees. Ontogenetic analyses largely confirm earlier interpretations, but with better data and methods. The great degree of ontogenetic variation within and among these species, especially in the timing and magnitude of “pubertal” growth spurts, implies that studies of endocrine growth control in African apes could be a productive line of future research. We also suggest that ontogenetic variation can be understood with respect to ecological risks. Growth rates seem to be negatively correlated with ecological risk in African apes, suggesting links between ontogenetic patterns and social and ecological variables. High growth rates in gorillas compared to Pan are most consistent with this model. Variation between chimpanzees and pygmy chimpanzees (especially females) also seem to fit predictions of this model. © 1996 Wiley-Liss, Inc.  相似文献   

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Recent studies of interactions between the brain and immune system cells, as well as reports of bioeffects from artificial electromagnetic sources too weak to exert thermal effects, suggest that biophysical communication may exist between them not explained by electrochemical action. We report here that a human donor's endogenous electric fields protect his lymphocyte viability in vitro. The endogenous fields of a healthy male donor were introduced into a cell culture via a gold wire for 7 h overnight and the cells' viability compared by trypan blue exclusion, with nonexposed cells cultured similarly. Cells exposed to their donor's endogenous fields remained significantly more viable compared with unexposed cells. However, when cells were exposed to the endogenous fields of a nondonor, viability was no different from that of unexposed controls. We conclude that endogenous electric fields, observed in all living organisms, perform a previously unsuspected but important role in cellular immune system surveillance.  相似文献   

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以野生狼牙委陵菜(Potentilla cryptotaeniae Maxim.)为试材,从种子萌发特性、个体发育节律、开花传粉习性等方面,对其生物学及生长发育规律进行了研究。结果表明:狼牙委陵菜种子萌发的最适温度为30℃/20℃,对光需求敏感。幼苗属子叶出土型,发芽后第9d露出第一片真叶,20d出现第二片真叶,40d子叶开始出现脱落。一年生实生苗的叶片数、叶长和冠幅呈“慢-快-慢”的变化规律,当年10月下旬进入枯萎期。花黄色,花径9—15mm,单花开放时间4—6d,单株开放时间40~60d。狼牙委陵菜传粉方式主要为虫媒授粉。通过以上研究,初步了解了狼牙委陵菜的生物学特性,为丰富其基础研究资料,进一步为杂交育种等工作提供了可靠的数据。  相似文献   

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F1代西藏小型猪早期生长发育特点   总被引:7,自引:0,他引:7  
目的研究西藏小型猪早期生长发育的规律。方法对本基地F1代西藏小型猪的体重、体长、胸围、体高、体温、呼吸频率、心率及血液生理生化指标进行了测定。结果西藏小型猪体型小,生长性能稳定,生长速度与原产地西藏小型猪基本一致;西藏小型猪的体温、呼吸次数和心率与原产地西藏小型猪相近,且雌雄之间差异不显著(P>0.05);F1代雌雄间除嗜碱性粒细胞、单核细胞数和尿素氮外其他指标也基本一致,大部分指标与人接近。结论由于西藏小型猪体型小、生长性能稳定,血液生理生化值与人类相近,因而是理想的医学研究用实验动物。  相似文献   

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温度对蜘蛛个体发育的影响   总被引:8,自引:0,他引:8  
赵敬钊 《蛛形学报》2001,10(1):58-64
从我国农田常见20种蜘蛛的温度实验材料和中找出,温度对蜘蛛胚胎期、幼蛛历期、幼蛛存活率、产卵前期、世代历期、成蛛寿命、幼蛛蜕皮次数和蜘蛛抗逆能力影响的一般规律和种间的差异。进而把蜘蛛分为不抗高温、中抗高温和高抗高温三种类型。为保护利用和人工大量饲养蜘蛛提供依据。  相似文献   

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对罗汉果组培苗生育周期、生长发育习性以及生态适应性进行观测,结果表明:年全生育期为240~260d,定植当年即可正常开花结实。根系与块茎有两个增长高峰期,分别为开花结果期(7月上、中旬)、枯苗期(11月上旬~12月上旬);茎蔓在定植20d内生长较缓慢,之后逐步加快,其中主蔓和一级侧蔓构成植株空间骨架结构,二级侧蔓和三级侧蔓为主要结果蔓;开花座果盛期在7月下旬至8月中旬,花、果着生位置以二级侧蔓的6~15节和三级侧蔓的3~18节为主,点花授粉宜在雌雄花开放的当天上午进行,果实的生长膨大约在座果后的30d内完成,但果实发育成熟约需80d。生长发育的适温为22~28℃,其中旬温25~28℃时对花果生育最为适宜;生长过程中应保持土壤湿润和80%以上的空气湿度;全生育期对氮和钾的吸收量较大,但在生殖生长期,尤其在结果盛期与果实发育期,对磷、钾的需求增加。  相似文献   

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