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1.
长序榆是我国二级重点保护的濒危植物,对研究榆属、榆科植物的系统发生有重要意义,并且具有潜在的经济价值。研究长序榆的生境特点,对该种的引种、科学保护有重大意义,通过对分布在我国的长序榆近两年的踏查发现,长序榆主要集中在我国的安徽、浙江、江西和福建等省,长序榆生境已经严重片段化,自然干扰和人为干扰是造成其濒临灭绝的主要原因。长序榆多分布在海拔600—900 m的阳坡或半阳坡上,其中最大的种群分布在浙江开化和遂昌,分布区的特殊地势使其成为长序榆的冰期避难所。对18项生物学、生态学指标的主成分分析结果表明,影响长序榆生存的主要环境因子是:光照、土壤养分、坡向和海拔。对浙江松阳、江西武宁和福建南平数量极少的种群需优先进行迁地保护,积极引种栽培;而对于安徽歙县、浙江临安、开化和遂昌等大种群分布区,应该扩大核心保护区面积,避免人为破坏。  相似文献   
2.
小麦-中间偃麦草双体异附加系的选育和鉴定   总被引:1,自引:0,他引:1  
在小麦-中间偃麦草59个杂交后代种质系中,筛选出6个小麦-中间偃麦草双体异附加系(line0605,line0607,line0609,line0610,line0611,line0625),并对其进行了形态学、白粉病抗性、细胞学和RAPD鉴定。形态学结果表明:6个双体异附加系农艺性状较好地结合了双亲的优良特点;细胞学结果表明:6个双体异附加系具有高度的细胞学稳定性,花粉母细胞减数分裂中期Ⅰ(PMCMI)的染色体构型为2n=22Ⅱ;RAPD分析表明:在供试的209个随机引物中有5个引物分别能在6个异附加系中稳定地扩增出不同的特异带型,可以作为各个异附加系所附加染色体的特异分子标记;白粉病抗性鉴定结果表明:line0605表现免疫,line0610和line0625表现高抗,line0607表现中抗,line0609和line0611表现中感。  相似文献   
3.
张耿  王赞  关宁  王学敏  李源  高洪文 《遗传》2007,29(10):1263-1270
根据小麦液泡膜Na /H 逆转运蛋白基因TaNHX1的全长序列设计引物,通过RT-PCR直接扩增的方法从中间偃麦草(Elytrigia intermedia)中克隆到了TaNHX1的同源基因,命名为TiNHX1(Acession Numeber:EF409418).TiNHX1最大开放阅读框为1 641 bp,编码含有546个氨基酸残基、分子量为59.8 kDa的蛋白,预测等电点8.0.TiNHX1含有38个碱性氨基酸,36个酸性氨基酸,256个疏水氨基酸及129个极性氨基酸.二级结构预测表明该蛋白含约44%的a-螺旋、21%的p-折叠、4%的p-转角和29%的不规则卷曲.亲疏水性分析显示,TiNHX1含有12个连续的疏水片断,其中10个可能构成穿膜螺旋.序列分析显示,TiNHX1与小麦(Triticum aestivum)、长穗偃麦草(Elytrigia elongate)、水稻(Oryza sativa)、小盐芥(Thellungiella halophila)、拟南芥(Arabidopsis thaliana)等植物的液泡膜Na /H 逆向转运蛋白高度同源,序列相似性分别为97%、96%、85%、68%、67%.序列比对结果以及进化树分析均表明TiNHX1应为定位于中间偃麦草液胞膜上的Na /H 逆向转运蛋白.  相似文献   
4.
Morris, C. J. O. R.; Morris, P.: Separation methods in biochemistry. London, Sir Isaac Pitman & Sons Ltd., 1964, 887 S., 155 Abb., Leinen, £ 5, 15 s. Reviewed by H. Wolffgang.

Neuman, M.: Vade-mecum des antibiotiques et agents chimiothérapiques anti-infectieun. Paris, Librairie Maloine G. Doin et Cie Editeurs, 1962, 410 S., 8 Abb.; 15 Tab., Karton. 40,00 NF. Reviewed by Thren.

Umbreit, W. W.: Modern microbiology. San Francisco und London, W. H. Freeman and Company, 1962, 507 S., 307 Abb., Leinen, 48 s. Reviewed by H. J. Müller.

Gold, V.: pH-Measurements. Their theory and practice. London, Methuen & Co. Ltd., 1963, 125 S., 11 Abb., Leinen, 10 s 6 d. Reviewed by H. Wolffgang.

Horsfall, J. G. (Ed.): Annual review of phytopathology. Vol. 1, Palo Alto, Annual Reviews, Inc., 1963, 469 S., 6 Abb., Leinen, 9,00 $. Reviewed by M. Schmiedeknecht.

Rubin, B. A.; Artsikhovskaya, Ye. V.: Biochemistry and physiology of plant immunity. Oxford, Pergamon Press, 1963, IX und 358 S., 68 Abb., Leinen, £ 5. Reviewed by H. Wolffgang.

Nord, F. F. (Ed.): Advances in Enzymology. Vol. 24, New York und London, Interscience Publishers a division of John Wiley & Sons, 1962, 572 S., 23 Abb., Leinen, 120 s. Reviewed by H. Wolffgang.

Nord, F. F. (Ed.): Advances in Enzymology. Vol. 25, New York und London, Interscience Publishers a division of John Wiley & Sons, 1963, 565 S., 56 Abb., Leinen, 115 s. Reviewed by H. Wolffgang.

Forbes, J.: A laboratory manual for histology. 2. Aufl., New York, Fordham University Press, 1961, 132 S., 3 Abb., brosch., 3,00 $. Reviewed by J. H. Scharf.

Guaoliumi, P.: Las Plagas de la Caña de Azucar en Venezuela. Bd. 1 und 2, Maracay/Yenezuela, Ministerio de Agricultura y Cria Centro de Investigaciones Agronoinicas, 1962, 850 S., 212 Abb., 14 ganzs. Farbtafeln, brosch., 8,00 $. Reviewed by G. Fröhlich.

Clifton, C. E. (Ed.): Annual review of microbiology. Vol. 17, Palo Alto, Annual Reviews, Inc., 1963, 628 S., 19 Abb., Leinen, 9,00 $. Reviewed by K. Naumann.

Ramschandran, G. N. (Ed.): Aspects of protein structure. Proceedings of a symposium held in Madras 14–18 January 1963 and organized by the University of Madras. London und New York, Academic Press, 1963, 380 S., 130 Abb., Leinen, 84 s. Reviewed by P. Hermann.  相似文献   
5.
Background and Aims Clonal plants can plastically modify their traits in response to competition, but little is known regarding the spatio-temporal scale at which a competitive neighbourhood determines the variability in species traits. This study tests the hypothesis that the local neighbourhood can be expected to influence the processes that are involved in competition tolerance and avoidance, and that this effect depends on organ lifespan.Methods Fragments of the rhizomatous Elytrigia repens (Poaceae) were sampled in 2012 in experimental plant communities that varied in species identity and abundance. These communities had been cultivated since 2009 in mesocosms in a common garden. Fragment performance, shoot and clonal traits were measured, and the effects of past and present local neighbourhoods of five different radius sizes (5–25 cm) were examined. Past and present local neighbourhood compositions were assessed in 2011 and 2012, respectively.Key Results Most of the measured traits of E. repens responded to the local neighbourhood (5–10 cm radius), with an additional effect of the larger neighbourhood (20–25 cm radius) on ramet height, leaf dry matter content, maximal internode length and specific rhizome mass. Contrary to the expectation of the hypothesis, the temporal influence was not due to the organ lifespan. Indeed, five of the eight traits studied responded to both the past and present neighbourhoods. With the exception of specific rhizome mass, all trait responses were explained by the abundance of specific species.Conclusions This study demonstrates that the traits of a single clonal individual can respond to different competitive environments in space and time. The results thus contribute to the understanding of competition mechanisms.  相似文献   
6.
7.
For a study of local adaptations in the Alpine leaf beetle, Oreina elongata, we developed six microsatellite loci and screened them in 305 individuals from 13 populations. All markers were polymorphic with three to 15 alleles per locus. Average observed and expected heterozygosity values were 0.14 and 0.62, respectively. Four markers showed heterozygote deficiency and deviated significantly from Hardy–Weinberg expectations, indicating the presence of null alleles.  相似文献   
8.
Elytrigia atherica is a tall clonal grass species typical of higher salt marshes, but is gradually invading to the lower marshes. At young successional stages of a salt marsh, E. atherica is found sparsely dispersed in small groups of ramets. These patches increase in size and ramet density over time, eventually forming extensive swards as succession proceeds. This study investigates the change in the clonal diversity of E. atherica stands during colonization as a result of its reproductive strategy. Clonal diversities of differently sized patches of E. atherica were investigated on two lower salt-marsh sites of different age, 25 years and 35 years, respectively. Microsatellite fingerprint patterns were used to determine genet identities and to estimate relatedness and genetic differentiation between the sites, between patches within sites and within patches. The majority of the patches on both sites contained more than one genet. On the older site, the clonal diversity was higher than on the younger site. However, the clonal diversity tended to decrease with increasing patch size. Low genetic differentiation was found between the two sites, indicating habitat differentiation, whereas differentiation between patches within sites was high. It is reasoned that different environmental conditions could have resulted in different clonal structures: On an older marsh, the increase of successful seedling recruitment, due to more suitable environmental conditions, leads to an increase in clonal diversity. Over time, with increasing ramet density, intraspecific competition is likely to increase, resulting in a decrease of clonal diversity.  相似文献   
9.
We investigate an organism that closely resembles the nonphotosynthetic dinoflagellate “Gymnodinium elongatum” Hope 1954 using EM and molecular methods. Cells are 20–35 μm long, 10 μm wide, biconical, transparent, and have a faint broad girdle. Thecal plates are thin but present (plate formula Po Pi CP 3′ 1–2A 5″ 3C 6S 4? 3″″). With the exception of one feature, the presence of three antapical plates, the amphiesmal arrangement of this species is consistent with that of the order Peridiniales, family Podolampaceae; it is not at all consistent with the characteristics of the genus Gymnodinium. On the basis of these ultrastructural findings, we establish a new genus, Lessardia, and a new species, Lessardia elongata Saldarriaga et Taylor. Molecular phylogenetic analyses were performed using the small subunit rRNA genes of L. elongata as well as Roscoffia capitata, a member of a genus of uncertain systematic position that has been postulated to be related to the Podolampaceae. These analyses place Lessardia and Roscoffia as sister lineages within the so‐called GPP complex. Thecal plate arrangements led us to expand the family Podolampaceae to include the genus Lessardia and, in combination with new molecular results, to propose a close relationship between the Podolampaceae and Roscoffia. Within this lineage, Lessardia and Roscoffia appear to have retained a number of ancestral characters: Roscoffia still has a well‐developed cingulum, a feature absent in all members of the Podolampaceae, and Lessardia has more than one antapical plate, a character reminiscent of some members of the family Protoperidiniaceae.  相似文献   
10.
长薄鳅胚胎发育的观察   总被引:11,自引:2,他引:9  
1999年5月,作者首次通过人工繁殖获得长薄鳅的受精卵,并对其胚胎发育特征进行了连续的观察。卵膜无粘性,吸水后卵周间隙明显膨胀扩大,卵膜径3.67-4.00 mm,平均3.79mm,属漂流性卵。胚胎发育可分为26个时期,初孵仔鱼长5.0mm左右,通体透明无色素。  相似文献   
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