甜瓜白茎和黄绿色花冠性状的遗传研究

分别利用白茎变异甜瓜与正常绿茎甜瓜、黄绿色花冠变异甜瓜与正常金黄色花冠甜瓜进行杂交,得到对应的5个世代,并对各自5个世代中的白茎类型与绿茎类型、黄绿色花冠类型与金黄色花冠类型的分离比例进行分析和卡方检验,以验证理论值与观测值间的关系。结果表明,白茎性状在F1代中不表现,在BC1代中绿茎类型与白茎类型的分离比例为1∶1,而在F2代中二者的分离比例为3∶1;黄绿色花冠性状在5个世代中的表现与白茎性状表现一致。由此可以认定甜瓜白茎性状和黄绿色花冠性状都是由单隐性基因控制的。     

坑状浅沟侵蚀研究

坑状浅沟作为浅沟与切沟的中间过程，深入理解它对于进一步认识切沟侵蚀规律具有十分重要的意义，但是还没有见到相关的研究报道。以内蒙古高原的一个小流域为例。利用高精度的全球定位系统（GPS）测量坑状浅沟侵蚀的形态参数，探讨了坑状浅沟的相关特征，分析了坑状浅沟的坡度（S）和上有集水区面积（A）的关系（S—A）、侵蚀体积（V）和长度（L）的关系（V-L），以期能推动坑状浅沟侵蚀的研究。     

Relation between oak tree phenology and the secretion of organic matter degrading enzymes by Lactarius quietus ectomycorrhizas before and during bud break

The ectomycorrhizas (ECM) formed by Lactarius quietus, an ECM fungus specifically associated with Quercus spp., are abundant all the year long. Root and stem growth, beginning before bud break in oak, are strong carbon sinks partially fulfilled with carbohydrate reserves. We hypothesized that L. quietus contributes to providing trees with carbon at bud break through enzymatic activities before photosynthesis begins. Activities of eight secreted enzymes (xylosidase, glucuronidase, cellobiohydrolase, β-glucosidase, N-acetyl-glucosamine, leucine aminopeptidase, acid phosphatase and laccase) relevant to carbon cycling and the release of phophorus and nitrogen from soil organic matter were measured on L. quietus ECMs before, during and after the bud break. Phenological, climatic and pedoclimatic parameters were also measured. Laccase, glucuronidase, cellobiohydrolase and β-glucosidase activities proved to be significantly related to tree reactivation and climate. All these activities can help the formation of new tissues by supplying carbon. L. quietus can behave saprotrophically, using soil organic matter as substrate. This is consistent with the hypothesis that it provides the oak trees with carbon when demand is high and photoassimilates are not yet available.     

百合组培球茎尖剥取技术研究

[目的]研究百合组培球茎尖剥取技术。[方法]对不同直径大小的组培球对百合剥取茎尖的影响及不同大小的茎尖对百合脱毒效果的影响进行研究。[结果]大于0.5 cm的百合组培球适合茎尖剥取;在组培球剥取茎尖过程中,剥取0.4~0.7 mm大小的茎尖适合百合脱毒的培养。[结论]为百合种球生产提供技术支撑。     

烟杆生物质燃灰替代硫酸钾的研究

[目的]为了研究不同替代比例的烟杆生物质燃灰对烟叶质量的影响.[方法]设置1个对照和3个处理,对烟叶的农艺性状、常规化学成分与经济效益进行对比分析.[结果]不同代替比例的烟杆生物质燃灰对烟株生长有不同的影响,主要对烤烟的最大叶面积与项叶面积有较大影响;随着烟叶着生部位的降低,烟杆生物质燃灰的不同替代比例对化学成分的影响逐渐增强;其中,T3处理相比对照可以提高产值8 717.72 元/hm2.[结论]生产上,可以通过添加一定比例的生物质燃灰代替硫酸钾肥料以提高烟叶品质,充分提高生物质燃料的利用率.     

转基因大麦的gfp基因表达及染色体定位

为了深入探讨转基因的整合位置对基因表达的影响，对转绿色荧光蛋白基因（gfp）大麦的荧光表达和gfp基因的染色体位置进行了研究。结果表明，绿色荧光蛋白（gfp）在大麦的根尖和花粉中均有表达，四倍体的荧光表达强度大于二倍体，表现出基因的剂量效应。gfp基因插入到第6染色体（6H）短臂和另一染色体的短臂近末端。     

冬小麦穗—茎维管联络结构及其形成过程对幼穗生长发育的影响

本文系统研究了冬小麦穗－茎维管系统的联络特点及其形成过程，分析了其在小麦幼穗发育中所起的作用。结果表明，小麦穗部维管束主要在旗叶节与茎内维管系统联络，其次是倒二节。其联系是逐步完善的。在幼穗的护颖分化－小花分花以前，穗、茎之间缺少维管联络；到雌雄蕊分化期，穗、茎维管系统依靠原形成层束达到初步联络；药隔形成期时，这种联络已比较完善，达到筛管联结；直到四分体形成期时，穗－茎维管系统的联络才发育完善，同     

三次样条函数在树干材积测算中的应用

主要介绍了三次样条函数拟合树干曲线测定树干材积的方法。以水杉的实测资料作为算例，与常规的区分求积方法进行比较分析，结果表明：当采用2m区分段区分求积时，在不增加区分段数(不增加额外的外业工作量)情况下三次样条函数区分求积法，要好于中央断面积区分求积法，采用三次样条函数区分求积法测算树干材积能有效地提高求积精度，具有较好的应用价值。     

A method of inducing mouse embryonic stem cells cultured in vitro to differentiate into cardiomyocytes

AIM:To evaluate the method of inducing mouse embryonic stem (ES) cells in vitro to differentiate into cardiomyocytes without using any chemical reagents.METHODS:BRL conditioned medium was used to promote the growth of ES cells and maintain them in an undifferentiated state before the experiment of differentiation. Then a three-step method including ES cell culture in hanging drops and in suspending was used to induce the differentiation of ES cells. RESULTS:Rhythmically contracting cells were observed among differentiated cells, which were proved to be cardiomyocytes with electron microscope and immunocytochemistry. CONCLUSION:A simple and economical method was established to induce mouse ES cells cultured in vitro to differentiate into cardiomyocytes without using any chemical reagents.     

细胞外环境中分化抑制物对动物胚胎干细胞克隆率的影响

介绍了饲养层、条件培养基、分化抑制因子对哺乳动物胚胎干细胞分离与克隆的影响，并探讨了白血病抑制因子影响胚胎干细胞克隆的机理。