Bodensystematik und Bodenklassifikation Teil I: Grundbegriffe

Soil systematics and classification systems Part I: Fundamentals Soil‐ordering systems are primarily based and developed on one of two underlying principles: They are either categorized according to soil‐forming processes, or the formation of categories develops by chosen parameters. This perspective has already been established in the literature, though it is often confusing as many terms are defined and applied differently. In this contribution, the various definitions of systematics, classification, taxonomy, and identification will be clearly differentiated and summarized. The core of our work is to clearly define and contrast three terms: systematics, classification, and identification. Systematics is the fundamental scientific and deductive ordering of objects into systematic units. The purpose of this approach is to organize the entire spectrum of knowledge within a discipline into a transparent and manageable form. Classification, in direct contrast to systematics, is goal‐oriented and an inductive ordering of objects. Thus, the ordering scheme consists of classes which are clearly parameterized. Identification is the ordering of new objects into an already existing systematics or classification system. Close attention is paid to both the differences and the similarities between a systematics and a classification system, especially pertaining to their practical applications. The identification requires that the category‐forming characteristics can be measured (e.g., for soil systematics, these are the soil‐forming processes and factors). Currently, it is unfortunately not feasible to objectively quantify most soil‐forming processes. Thus, most attempts at categorizing soils by systematics are hypothetical and highly subjective in nature. The resulting identification derived from the soil systematics approach is open to questions and contestable, since a graded measuring system does not yet exist to verify these determinations. In contrast, a soil‐classification system does allow an objective soil‐profile identification, although such systems are conceived pragmatically and designed for a practical purpose (e.g., not scientifically based on process intensities). Unfortunately, such a classification system cannot be applied as a universal scientific categorization system due to this method of conception. Both categorization approaches are required in soil science in order to satisfy both the practical and the scientific aspects of the field. However, substantial research must be done to complete and verify systematics. The only viable short‐term solution is through the development of a graded classification system where the categories of the system are directly derived from the current systematics approach. In the long run both the exact investigation and the detailed modeling of the soil‐forming processes are inevitable.     

用遥感图象进行土壤侵蚀系列制图的方法与实践

按照制定的土壤侵蚀图成图系列，根据黄土丘陵沟壑区的特点，以地形结构特征图为主要控制，按地形一植被条件（或土地利用）一致性原则圈定图斑，用多层逐步判别归类法确定土壤侵蚀的相对等级，再运用试错迭代法并参照各小流域的实测土壤侵蚀资料把土壤侵蚀分级图转化为定量的土壤侵蚀强度图，完成了洪水沟流域的侵蚀等级的地面绝对定标，得到反映各侵蚀因子综合作用的且有充分的地面侵蚀实测数据支持的士壤侵蚀强度分布图。     

水稻早衰突变体els-R7954的遗传分析和初步定位

为了深入研究水稻早衰机理,找到有效消除和延缓植株早衰的方法,本研究通过350Gy60Co-γ射线辐照水稻浙恢7954干种子,获得1份特异性水稻早衰突变体。观察该突变体生物学性状,发现苗期生长正常,分蘖末期叶片出现早衰现象,灌浆期整个植株枯黄,早衰现象非常明显,将其暂名为elsR7954(early leaf senescence)。遗传分析和基因定位发现,els-R7954受单隐性核基因控制,位于第2染色体SSR标记RM530和RM3774之间,距RM530约5.0c M。为进一步克隆该基因,丰富叶片早衰的分子机制奠定了一定基础,也为研究水稻早衰,最终提高产量和品质提供可能。     

一个水稻类感干尖线虫卷叶突变体的遗传分析与基因定位

筛选和鉴定水稻卷叶突变体是研究叶片形态建成机理的前提.本研究利用甲基磺酸乙酯对常规粳稻秀水09进行诱变,获得了一个稳定遗传的类感干尖线虫卷叶突变体(nematode infestation mimic rolling leaf mutant,nir).与野生型相比,nir全生育期叶尖卷曲、枯萎,表型与干尖线虫侵染症状相似.此外,突变体植株矮小,叶片表面较光滑,有效分蘖数少.采用nir与秀水09杂交的F2群体进行遗传分析,结果表明nir的类感干尖线虫卷叶性状受一对隐性核基因控制.利用nir与籼稻93-11杂交获得的F2群体,采用分子标记技术将目的基因最终定位在水稻第二染色体2 ～ 88w和2～82w之间,遗传距离为1.1 cM,物理距离245 kb.研究结果表明,nir很可能是一个尚未报道的新基因,进一步克隆nir基因有可能揭示与现有报道的卷叶基因不同的卷叶调控机理,为筛选理想株型、培育高产水稻品种提供理论基础和供试材料.     

水稻苗期耐冷性的QTL定位分析

为水稻苗期耐冷性QTL定位克隆研究提供实验素材,以213个IR24/Asominori重组自交家系(RIL)为作图群体,并以141个SSR标记构建的分子连锁图谱为基础,结合苗期低温处理后亲本和213个RILs的苗期死苗率,运用QTL IciMapping 4.0软件进行水稻苗期耐冷性QTL检测及其遗传效应分析。结果表明:在第6、第11和第12染色体上检测到3个苗期耐冷性QTL,分别命名为qCTS-6、qCTS-11和qCTS-12。这3个QTL的LOD值分别为3.194 3、4.688 2和3.797,对应表型变异的解释率分别为5.662 7%、8.549 6%和12.787 7%,且抗性等位基因均来自苗期耐冷亲本Asominori。     

一个简便的适合于分析油菜中SSR位点的检测体系

介绍一个DNA用量少、灵敏度高、重复性好和快速简便的适合于分析油菜中SSR位点的检测体系，该体系对于其它作物的SSR标记分析也有一定的参考价值。     

Interpretation and Compilation of Landsat TM Imagery for Land-use and Site Classification Mapping in the Korqin Sandy Lands, NE China

For the purpose of of forestation, planning and development in the Three-North Region, a series of 6 Landsat TM scenesfrom 1996 to 1997 were used to classify land-use conditions in the whole Korqin Sandy Lands at eastern part of Inner Mongolia, China, with an area of about 430×306 square kilometers. Later on, Site classiflcation was made and mapped for the 4 southern sandy counties. The annotation symbol for each agglomeration of site condition is comprised of six parts: land unit, land use pattern, soil texture, under ground water table, top-soil existence, wind erosion or salinisation condition. Field expedition and soil file augering help information extraction from the satellite imagery. The products include a land-use classiflcation map at scale 1/200,000 of the whole Korqin Sandy Lands, and a collection of site classiflcation maps at scale of 1/50,000, consisting of 135 pieces (42.8 cm×30.8 cm each). Electronic version of the maps is in raster form.     

Identification and Gene Mapping of Completely Dominant Earliness in Rice

The completely dominant earliness was identified in a genic male-sterile and early maturing indica line 6442S-7. F1 progenies from 6442S-7 crossed with thirteen various types of medium- or latematuring varieties, shared the same heading date as 6442S-7. The segregation of heading date in the F2 and B1F1 populations showed that the earliness of 6442S-7 is mainly controlled by two dominant major genes. The local linkage map of one dominant earliness gene harbored in 6442S-7 was constructed with F2 population and four kinds of molecular marker techniques. The results showed that the gene was located between a RFLPmarker C515 and a RAPD marker OPI 11. 557 on the terminal region of short arm of rice chromosome 3,10.9cM and 1.5 cM from C515 and OPI11. 557, respectively. The genetic distances from the target gene to twoSSR markers, RM22 and RM231, and one AFLP marker, PT671, were 3.0, 6.7 and 12.4 cM, respectively. This gene, being identified and mapped first, is designated tentatively as Ef-cd (t). As a new genetic resource of completely dominant earliness, 6442S-7 has splendid future in rice improvement.     

求解一类B可微方程的阻尼牛顿法：祝贺肖伊莘教授八十寿辰

本文研究由非线性映射双障碍问题导出的一类Ｂ可微函数的性质，并证明了在一定条件下求解相应非线性方程组的阻尼牛顿法具有全局收敛性。     

玉米籽粒突变体dek101的表型分析和精细定位

As the storage organ of maize, kernel development and accumulation of storage production directly determines maize yield and quality. In this study, a stable defective kernel mutant, named as defective kernel 101 (dek101), was identified during the development of double haploid (DH) lines in maize. The dek101 kernels displayed severely shrunk kernel appearance, significantly reduced kernel weight, lethal embryo, defective endosperm and were incapable of germinating. The dek101 showed obvious developmental abnormalities at 12 days after pollination (DAP). The fresh weight, dry weight and volume of the kernels were no longer increased after 21 DAP. Scanning electron microscopy (SEM) observation revealed that the starch granules of dek101 were significantly smaller compared with wild-type kernels. Genetic analysis demonstrated that the mutant trait was controlled by a recessive single gene. Using 441 F₂ individuals and 1648 F₃ individuals, dek101 was narrowed down to a genomic region of about 300 kb between the InDel marker IDP2182 and IDP4600 on chromosome 1, which contains five predicted genes. These results laid the foundation for mining functional genes related to maize kernel development and deciphering the mechanism of grain development.