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81.
场地特征是场地传达出来的信息,包括空间上的自然特征和时间上的人文特征。通过分析大同"桐城怡景"景观,探讨场地特征对于设计的重要意义,并为该场地找寻出合适的设计语言。  相似文献   
82.
犬冠状病毒的分离鉴定及其纤突蛋白基因的克隆与序列比较   总被引:10,自引:0,他引:10  
以犬胎原代细胞,采用同步接种、带毒传代和添加新细胞的方法,从1例腹泻犬脾脏和1例临床健康犬肠内容物中分离出2株犬冠状病毒(CCVYS1,CCV CI1)。该2株病毒可使CRFK细胞出现典型的细胞融合病变,与从美国引进的CCVNL-18参考株形成的细胞病变相似;电镜负染和超薄切片观察,分离毒株细胞培养物中均含有典型的冠状病毒粒子,并形成胞浆内包涵体;经理化学、生物学鉴定,濉有CCV的特性;间接免疫荧  相似文献   
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84.
M. O. Nassi    E. Ruffa    G. Me    G. Lepori  L. Radicati 《Plant Breeding》2003,122(6):532-535
Prunus domestica L., P. insititia L., P. salicina Lindl. and P. cerasifera Ehrh. are the most important species included in the plum group. Many ‘cultivars’ have an undefined origin and share very similar morpho‐phenological characteristics that make their identification difficult. This is the case of ‘Ramasin’, a group of Piedmontese genotypes whose fruits are small, ellipsoidal and very tasty. They are commonly considered as P. domestica varieties, even though on the basis of some morphological characteristics they are similar to other species such as P. insititia. In order to study the origin of this group, the DNA of 25 genotypes of ‘Ramasin’, and that of some ‘cultivars’ of P. domestica, P. insititia, P. cerasifera, P. salicina and two selections of P. spinosa L. was examined. The PCR‐RAPDs method (Random Amplified Polymorphic DNA amplified by Polymerase Chain Reaction) was used and all 69 primers that were tested generated more or less polymorphic bands. From the results of these analyses it can be supposed that the ‘Ramasin’ plums are a single genetically heterogeneous group. Moreover it can probably be assumed that ‘Ramasin’ arose from crosses between P. domestica and P. insititia.  相似文献   
85.
Amplified fragment length polymorphism (AFLP) analysis is a rapid and efficient method for producing DNA fingerprints and molecular characterization. Our objectives were to: estimate genetic similarities (GS), marker indices, and polymorphic information contents (PICs) for AFLP markers in almond cultivars; assess the genetic diversity of almond cultivars and wild species, using GS estimated from AFLP fingerprints and molecular characterization; and facilitate the use of markers in inter-specific introgression and cultivar improvement. The genetic diversity of 45 almond cultivars from Iran, Europe, and America, were studied assaying 19 primer combinations. In addition, several agronomic traits were evaluated, including flowering and maturity times, self-incompatibility, and kernel and fruit properties. Out of the 813 polymerase chain reaction fragments that were scored, 781 (96.23%) were polymorphic. GS ranged from 0.5 to 0.96, marker indices ranged from 51.37 to 78.79, and PICs ranged from 0.56 to 0.86. Results allowed the unique molecular identification of all assayed genotypes. However, the correlation between genetic similarity clustering as based on AFLP and clustering for agronomic traits was low. Cluster analysis based on AFLP data clearly differentiated the genotypes and wild species according to their origin and pedigree, whereas, cluster analysis based on agronomic data differentiated according the pomological characterization. Our results showed the great genetic diversity of the almond cultivars and their interest for almond breeding.  相似文献   
86.
刘祝玲  韩胜芳  肖凯 《作物学报》2007,33(2):327-332
以拟南芥AtNHX1 cDNA 片段作为探针,筛查水稻盐胁迫植株叶片cDNA 文库,获得与AtNHX1同源的水稻新型液泡Na+/H+逆向转运蛋白基因(OsANT1)。序列分析表明,OsANT1 全长cDNA为2 178 bp,包括一个长度为1 608 bp的完整开放阅读框,编码535个氨基酸残基。在DNA水平上,OsANT1基因含有15个外显子和14个内含子,长度为4 835 bp。OsANT1含有12个跨膜域,系统进化树分析结果表明,与来自拟南芥、水稻、小麦、玉米、大麦、马蔺和芦苇等的Na+/H+逆向转运蛋白高度同源。盐胁迫条件下,OsANT1的表达具有盐分诱导特征,且随着胁迫的增大而增加。表明该基因可能在水稻抵御盐分胁迫的过程中具有一定作用。  相似文献   
87.
TCTP(translationally controlled tumor protein)是许多动物肿瘤细胞中存在的一类较丰富的蛋白(Yenofsky et al.1983),目前为止,有关TCTP的确切功能还不是很清楚,推测TCTP可能是属于对热较为稳定的钙结合蛋白(Kim et al.,2000),能够结合微管蛋白(Gachet et al.,1999),诱导细胞内的信号传递(MacDonald et al.,1995),同时细胞增殖有关(Bohm et al.,1989)。  相似文献   
88.
以高粱(S.BICOLOR)为母本、旱稻(O.SATIVA)为父本进行属间杂交,F1出现双亲没有的短芒和黄色柱头新性状,并能在F2、F3及BC1稳定遗传。F3在株高、穗长、穗型、分蘖性等性状上仍疯狂分离,并出现父本白色籽粒单株。BC1在株高、分蘖二性状上接近父本,回交效应非常明显,T测定无差异,并出现多子房新性状。高梁与旱稻杂交及回交,能创造变异,产生新性状,对创造矮秆、优质、多子房新种质十分有效。然而,二者杂交后代主体性状仍似母本,只表现父本少数性状,属于部分遗传物质导入。  相似文献   
89.
90.
All the accessions (35) of white lupin (Lupinus albus L.) landraces collected from northwest Iberian plateau and maintained at the Spanish germplasm collection (CRF of INIA), were studied with the general objective of assessing the biodiversity of these landraces and to ascertain their value as genetic resources for the development of germplasm adapted to the areas where they were collected with long and chilly winters. The characterization study comprised 51 qualitative and 50 quantitative characters. Quantitative parameters were analyzed by Principal Components Analysis (PCA). The 2-dimensional plot (49.3% of cumulative variability) formed a main group of accessions and 4 outliers (#1, #9, #27 and #28) separated in the first PC. The characters with a higher contribution to the first PC were inflorescence length, leaf petiole length and leaf central foliole area. The presence of alkaloids, the percentage of plants killed by soil borne fungal diseases, the phenology, the yield per plant and yield components were also assessed. Twenty six accessions (the main group in the PCA plot) showed high homogeneity, with the following highlights: bitterness, indeterminate growth habit, early ripeness and spring sowing with the exception of #18, in which seeding date is unknown and it had a later phenology. By contrast accessions #9 and #27 were bitter of autumn sowing with determinate growing habit and they had the longest values of primary inflorescence length and a later phenology when they were sown in spring. Average values for yield and yield components showed a broad range of variation between accessions. The main yield component was the number of pods per plant. Accession #22 had the highest mean seed mass, although this had not significant influence in yield. Accession #17 showed the highest yield and #1 the lowest. This last also had the lowest values of inflorescence length, leaf petiole length and leaf central foliole area. No significant differences of resistance to soil-borne fungi were found between accessions. The year had a significant effect in the phenology, yield and yield components except for number of seeds per pod. The studied material might be of interest for the development of spring sowing germplasm adapted to north Iberian peninsula.  相似文献   
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