井窖式移栽不同栽植深度对烤烟前期生长发育的影响

为探明井窖式移栽不同栽植深度对烟株前期生长发育的影响,在贵阳龙岗基地开展了田间试验。结果表明,移栽后35 d,烟苗生长点距井窖口6 cm处理烟株农艺性状表现最好,生物量、根系活力最高,根系发育最好,综合效应系数最大。井窖式移栽适合的栽植深度以烟苗生长点距井窖口6 cm最为适宜,有利于烟株前期地上部生长、根系发育及干物质积累。     

盐池县沙化草地土壤理化性质及酶活性研究

[目的]探讨盐池县沙化草地土壤理化性质和土壤酶活性的变化规律以及草地恢复和土壤恢复之间的关系,为草地土壤系统的恢复治理和可持续利用提供可靠的依据。[方法]对宁夏盐池县北部不同深度和不同沙化程度草地的土壤养分进行统计分析。[结果]随着沙化程度的加剧,土壤全磷、全氮、全钾、速效钾、有效磷、碱解氮、土壤酶活性、土壤水分随着土壤沙化程度的加剧而降低,土壤p H随沙化程度加剧而增大,且不同沙化程度草地之间差异显著(P0.05)。在0~60 cm土层土壤全磷、全氮、全钾、速效钾、有效磷、碱解氮、蛋白酶、磷酸酶、蔗糖酶含量随着土壤深度的增加而降低,且不同深度之间差异显著(P0.05),土壤p H、水分、过氧化氢酶含量随深度增加而增加,且不同深度之间差异显著(P0.05)。[结论]随着盐池县草地沙化程度的加剧,土壤理化性质和酶活性呈显著性下降趋势,而p H则呈现上升趋势。土壤养分和酶活性随着土壤深度的增加而降低,物理性质则随之增加,土壤表层理化性质及其酶活性对草地退化的影响最为显著。     

两种蔗糖浓度对切割取样鼠胚冷冻解冻效果的研究

小鼠晚期桑椹胚、早期囊胚和扩大囊胚，经切割取样分别采用０．３６５Ｍ和０．２５Ｍ蔗糖浓度进一步细管和分步脱除甘油解冻后体外培养发育率分别为６５．５％、４６．４％和７５．４％，两种浓度间差异显著（Ｐ＜０．０５）；分步脱除甘油解冻瑟前者差异不显著（Ｐ＞０．０５），与后者差异极显著（Ｐ＜０．０１）。     

Numerical Simulation Research on Stabilityof Dissolving Cavityfor the Low-depth-thin-layer Rock Salt

In order to extend life of salt well, avoid sinking and use the formed cavity reasonably, the factors of effecton cavity stability must be researched during the process of water mining of rock salt, so that the effective prevention measures can be put. The stability of dissolving cavity for the low depth thin layer rock salt has been researched by the ADINA non linear finite element method.The results show that the stability of dissolving cavity obviously becomes strengthened with the decrease of its height, and has a decreasing trendas with the span increase of the cavity . The effect of incidence on stability of the cavity is very little. The stability of cylindroid cavity is higher than that of converse taper cavity. The assorted model is a kind of transition shape. The influencing order of cavity stability is the ffollows, height>geometrical shape>span>incidence.     

重庆走马岭隧道岩溶及岩溶水发育特征

走马岭隧道通过方斗山背斜可溶岩地区。岩溶发育强烈。在分析隧址区地质环境的基础上，详细论述隧址区岩溶发育分布规律和特征，岩溶水补、径、排条件及化学特征，为隧道安全施工提供科学依据并提出建议。     

提高旱农地区甘草田间出苗率的试验分析

通过随机区组田间试验的方法，对如何提高甘草田间出苗率进行了研究。试验证明：甘草的田间出苗率与播种深度呈负相关，若底墒好，播后不浇水，播深2．5－3．0cm，可提高其田间出苗率；若底墒差，播后浇水，播深1．5－2．0cm，亦能提高其田间出苗率。在新垦重盐碱地播种甘草，用生长素4号和1号拌种，可分别提高田间出苗率2．9倍和2．6倍。播后3d浇水比播后16d浇水的田间出苗率提高29．5％。     

Somaclonal variation in tuber traits of potato

Summary About 13,000 somaclones of 17 cultivars and clones of potato were obtained from in vitro callus cultures and individually planted in a greenhouse, followed by tuber generations grown in the field. These plants were subjected to the multistage selection procedure commonly used in potato breeding. Over a period of five years and three field generations the tuber number, size, shape, eye depth, starch content, starch yield and tuber appearance of these somaclones were assessed and compared with that of the controls. These characters varied depending on donor genotype and trait. The frequency of variants was assessed and there were acceptable proportions of desirable abberrants and invariants among the somaclones. Depending on trait the average gain rate for all donor genotypes ranged between 0.2 and 2.3% for-deviants, between 12.2 and 15.5% for invariants and between 0.1–1.4% for +deviants. It is concluded that this technique should be used into potato breeding programmes to improve commercially important characteristics of specific cultivars and breeding clones.     

中草药浸提液在牛冻精解冻中的作用

与通用的２．９％柠檬酸钠液相比，经Ｃａｍｅｌｌｉａｓｐ浸提液解冻的牛冻精精子生存时间及活力维持时间延长，精子的生存指数、维持０．３活力的时间及受胎率显著提高。     

Seedbed Characteristics and Seeding Depth Effects on Emergence and Seedling Vigour of Upland Rice

Effects of seedbed condition and seeding depth on the emergence and seedling vigour of upland rice was studied. Regardless of aggregate size distribution, seeds sown at 2 cm depth gave the maximum emergence rate (80-90 %) which was reduced to 47 % for sowing at 5 cm depth. Seeding at 10 cm depth caused total failure in emergence. When planted at 2 cm depth, aggregate size produced considerable variation in the speed of emergence but caused no significant differences in final emergence count. For seeds sown at 5 cm depth, seedbed with aggregate size < 2 mm resulted in poor emergence (12 %) while with aggregates > 8 mm reduced emergence by 34 % compared with balanced proportion of larger, moderate and smaller aggregates. Neither the seedbed condition nor seeding depth caused significant variation in seedling height or seedling dry weight.     

朝邑内滩盐碱土成因及其改良利用

在改良利用盐碱土的各种综合措施中，设法降低并控制潜水位在临界深度以下，使土壤水分常年处于下渗为主的状态，有利于降水和灌溉对土壤淋洗脱盐，是消除土壤返盐和治理盐碱土的根本措施。