土壤养分有效性测定及其方法

在提出土壤养分有效性测定概念的基础上 ,本文对各种土壤养分有效性的测定方法进行了总结 ,讨论了这些方法的测定机理、测定效果及近几年的进展。这些方法包括用于磷钾等元素测定的树脂法、用于氮测定的生物培养法和化学提取法、磷测定的氧化铁试纸法和氢氧化铁透析管法和钾的四苯硼钠法     

精密播种输种管的微机设计方法探讨

在力学分析的基础上,建立了数学模型,编制了微机程序。利用本程序设计的精密播种输种管,经台架,大土槽及田间进行排种性能试验和生产试验,均表明具有良好性能。证明该程序设计方法简单、可靠、实用。     

In-field calibration of a dielectric soil moisture meter designed for use in an access tube

Abstract. The in-field calibration of a dielectric probe to measure soil water content is described. The probe uses an access tube analogous to that of the neutron probe. The dielectric constant was measured at soil depths of 10, 20, 30, 40, 60 and 100 cm. Cores of soil were then taken from the face of pits dug 30 cm from the access tube and their soil water contents determined by oven drying. The dielectric constant values measured by the probe were calibrated against water contents from these cores. We found that sensor depth needed to be included to achieve a good calibration model that explained 72% of the variance. It is argued that depth needs to be included because of artefacts introduced during the installation of the access tube.     

外源DNA导入大豆获得一不育材料

获得不育系的途径有许多，如远缘杂交，自然变异，无性系变异等。本试验以吉林２０号大豆为受体，采用花偻管通道导入技术，导入远缘材料鹰咀豆总体ＤＮＡ，于Ｄ２代获得一不育变异株Ｄ８８０４－７，通过对该材料雌雄育性进行了一系列研究，初步认为，Ｄ８８０４－７材料为雌雄育性均不正常，自交可结少量种子，不育性可自交保持的不育材料。     

Sperm localization in the oviducts of artificially inseminated dairy cattle

Eight animals, 3 heifers and 5 primiparous cows, were artificially inseminated by intrauterine deposition of frozen-thawed semen. The insemination dose comprised 20×10⁶ or 200 × 10⁶ spermatozoa, frozen in French mini straws. Four animals were inseminated at fixed time interval (72 or 84 h) after cloprostenol injection. The remaining 4 animals were inseminated in spontaneous oestrus. Slaughter took place 2 or 12 h after insemination. After fixation the oviducts were cut into segments, which were serial-sectioned and stained. Six sections per segment were examined under the microscope for sperm recovery.The number of spermatozoa recovered from the oviducts varied considerably among animals. Recovery was poor (less than 50 spermatozoa) in 4 animals. Recovery was low when insemination took place in induced oestrus and with the lower sperm number (20×10⁶). In animals in which more than 50 spermatozoa were found the distribution varied both between animals and between oviducts within the same animal. Overall, more spermatozoa were found in the lower (UTJ, isthmus and AIJ) than in the upper (ampulla) parts of the oviducts. In 3 out of 4 animals more spermatozoa were recovered from the left than from the right oviduct. Only in 1 animal were the majority of spermatozoa found in the oviduct ipsilateral to the follicle-bearing ovary.     

蒙古绵羊胚胎胚中轴的形成

蒙古绵羊胚胎胚中轴的形成,对各器官系统的发生起着定向发育的作用。原条最初发生于交配后12天23时47分。从胚盘后结开始外胚层表面的中线加厚並向前延伸形成原条。随后,原结、原沟、原窝、头突及神经板相继出现。原条是胚中轴发生的基础。交配后13时5分,原窝底部的头突向前延伸形成管索管。交配后14天15时,脊索在内外胚层间形成空心的脊索管。脊索管的底部与内胚层融合。进而消失开口于卵黄囊,形成临时性的神经肠管。脊索是胚胎椎柱形成的中轴。胚胎的第1对体节,发生于交配后15天3时20分。交配后15天15时35分为3对体节(图1),交配后16天14时3分,已出现6对体节(图2)。此时,体节两侧的间中胚层及侧扳分界清楚。胚内体腔仅见于前肠两侧。体节的发生是胚胎的骨骼、肌肉、及尿殖系统等对称发育的基础。早期的神经扳,大约发生于交配后14天2时20分。当胎胚发育到16天14时3分,神经沟两侧的神经皱逐渐在背中线吻合,形成神经管。神经管是胚体未来中抠神经系统的原基。交配后14天5时至16天14时5分,绒毛膜呈长囊状,长约35cm。卵黄管呈细长的管状,长约30cm。羊膜随胚体发育,比胚体稍宽大。尿囊呈半月形囊,发生于胚胎的后肠。     

肺癌腔内后装治疗方法改进的研究

对７０例肺癌患者随机分为两组，用改进麻醉及插管方法与常规方法作了对经研究，结果表明：在改进法组中，患者剧烈咳嗽，支气管痉挛和咯血等并发症明显减少，并对两组并发症的治疗作了讨论。     

介导玉米DNA的水稻高秆变异株AFLP分析

用AFLP分子标记技术,对花粉管介导玉米总DNA获得的2个高秆水稻变异植株C(HN28)和D(HN31)进行分析,揭示水稻变异植株和亲本间在DNA水平的差异,为进一步研究变异机制提供数据。首先对64对AFLP选扩引物进行筛选,优选出11对选扩引物,它们均能够在2个变异植株中扩增出较多清晰的DNA差异带。对变异植株和对照中的DNA图谱进行分析,结果显示,变异植株C、D、受体水稻B与阳性对照玉米A之间的DNA图谱相似率分别为38.30%、38.58%和32.99%,水稻变异植株C、D和受体水稻B的DNA图谱相似率分别为90.04%和85.84%,说明变异植株与受体水稻基因组DNA存在显著差异,变异植株与阳性对照玉米基因组DNA相似率明显高于受体水稻。变异植株C检测到12条与对照玉米一致的目的带,变异植株D检测到11条与对照玉米一致的目的带。说明变异植株C、D基因组中可能存在有玉米DNA片段,变异性状的差异可能是介导玉米DNA引起。     

怀地黄脱毒试管苗生根移栽技术的研究

怀地黄为传统大宗中药材,为探究其脱毒试管苗生根移栽的最佳条件,提高移栽成活率,以怀地黄脱毒试管苗85-5为材料,探索了不同因子对地黄试管苗管内和管外生根的影响以及适宜于试管苗移栽的基质配比。结果表明:管内生根最适的PP333质量浓度为0.10mg/L,此时试管苗的根数达到28条,株高为4.0cm;接种密度为6个/瓶时,株高、叶片数、根数、根长都达到了较为理想的状态,根数达38条,株高为3.3cm;接种部位为顶芽时根数较多,达到38条,株高达到3.5cm,与侧芽相比有显著性差异;管外生根NAA生根效果明显优于IBA,2种激素最适浓度和处理时间分别为:NAA 50mg/L处理60min,苗存活率100%,生根率90%;IBA 50mg/L处理15min,苗的存活率95%,生根率85%;移栽基质的最适质量比例为草炭土∶蛭石=1∶2。     

大花香水月季的授粉率及花粉管生长途径

 研究大花香水月季雌蕊群的授粉率及花粉管生长途径,为其育种应用及资源保护提供依据。显微观察统计大花香水月季花期雌蕊群的授粉效率,荧光显微观察花粉管生长途径。结果表明：花朵萼片平行伸展后120h,柱头授粉率接近100%,单柱头花粉量达最大值为（84.20±5.8）粒;自萼片自然伸展48h时柱头上少量萌发,72h后花粉管伸长至花柱中下部,90h后观察到有花粉管进入子房。大花香水月季单花雄蕊（129±20）枚,雌蕊（30±5）枚,开放持续5～7d;花粉自萌发至花粉管进入胚珠需要30～40h。