Assessment of somaclonal variability in hop (Humulus lupulus L.) in vitro meristem cultures and clones by molecular methods     

Josef Patzak 《Euphytica》2003,131(3):343-350

In vitro meristem tissue cultures are used for production of virus-free rootstocks of hop (Humulus lupulus L.). Because use of plant tissue cultures is associated with occurrence of somaclonal variability, we assessed somaclonal variability in hop meristem in vitro cultures before and after thermotherapy by different molecular methods (RFLP, RAPD, STS, ISSR and AFLP) and compared it with existing clonal variability of Osvald's clones 31, 72 and 114. No molecular differences were observed between mother plants and in vitro mericlones by RFLP and STS analyses. Amplified molecular differences were found in RAPD and ISSR products of one from five in vitromericlones cvs. Eroica (E5) and Southern Brewer (SB2), respectively. Similarities with mother plants were 0.965 and 0.913 (JSC), respectively. Specific amplified polymorphic products were found for every mericlone and mother plant in AFLP reactions and variability of DNA sequence ranged from 0.824 to 0.993 (JSC). This variability was very similar to determined intra-clonal variability within Osvald's clones 31, 72 and 114 by AFLP analysis. Inter-clonal variability of DNA sequence was exactly higher than intra-clonal variability of DNA sequence in these clones. The molecular differences between Osvald's clone 72 normal and meristem derived were not verifiable. Thermotherapy increased frequency of molecular changes, since amplified differences were found in 14 from 20 in vitro mericlones of cv. Eroica, in 6 from 11 in vitro mericlones of cv. Yeoman and in 15 from 23 in vitro mericlones of cv. Southern Brewer by RAPD and ISSR analyses.  相似文献   

Ein Vergleich deutscher und schweizerischer Regensimulatoren nach Regenstruktur und kinetischer Energie     

Josef M. Hassel  Gerold Richter 《植物养料与土壤学杂志》1992,155(3):185-190

Comparison of German and Swiss Rainfall Simulators - Rain Structure and Kinetic Energy The drop size distributions of the investigated rain are significantly different. The rainfall simulators Swanson, Bonn, Basel and Trier culminate in the 2 - 3 mm drop diameter class (～40%) and thus simulate best the drop size distribution of natural heavy rainfall. The structure and the kinetic energy of the rains of eight rainfall simulators have been investigated. The data are compared to those registered during a thunder-shower at the research station of Mertesdorf near Trier/FRG. The results are summarized as follows:

• The impact velocity of artificial raindrops depends on the water pressure within the rainfall simulator, the initial velocity of the raindrops and the fall height. A correction factor to match the kinetic energy of natural rainfall, which is based on the percentage of deviation from the terminal velocity, can be applied only to some extend.
• With respect to various fall velocities of the artificial raindrops all tested rainfall simulators except one yield a rainfall energy between 19 and 27 J/m² per mm of rainfall.
• The actual amount of precipitation measured at the end of the rainfall experiments sometimes differs significantly from the aimed value of 60 mm/h. Due to this variation, the total rainfall energy during the experiments accumulated to 9 - 15 MJ/ha.
• This high variability depends on the used rainfall simulator. But it also demonstrates the importance of precipitation measurements on the plot during simulations in order to exactly calculate the rainfall energy.

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Effect of thinning on anatomical adaptations of Norway spruce needles     

Gebauer R  Volarík D  Urban J  Børja I  Nagy NE  Eldhuset TD  Krokene P 《Tree physiology》2011,31(10):1103-1113

Conifers and other trees are constantly adapting to changes in light conditions, water/nutrient supply and temperatures by physiological and morphological modifications of their foliage. However, the relationship between physiological processes and anatomical characteristics of foliage has been little explored in trees. In this study we evaluated needle structure and function in Norway spruce families exposed to different light conditions and transpiration regimes. We compared needle characteristics of sun-exposed and shaded current-year needles in a control plot and a thinned plot with 50% reduction in stand density. Whole-tree transpiration rates remained similar across plots, but increased transpiration of lower branches after thinning implies that sun-exposed needles in the thinned plot were subjected to higher water stress than sun-exposed needles in the control plot. In general, morphological and anatomical needle parameters increased with increasing tree height and light intensity. Needle width, needle cross-section area, needle stele area and needle flatness (the ratio of needle thickness to needle width) differed most between the upper and lower canopy. The parameters that were most sensitive to the altered needle water status of the upper canopy after thinning were needle thickness, needle flatness and percentage of stele area in needle area. These results show that studies comparing needle structure or function between tree species should consider not only tree height and light gradients, but also needle water status. Unaccounted for differences in needle water status may have contributed to the variable relationship between needle structure and irradiance that has been observed among conifers.  相似文献   

Essential role of Fkbp6 in male fertility and homologous chromosome pairing in meiosis     

Crackower MA  Kolas NK  Noguchi J  Sarao R  Kikuchi K  Kaneko H  Kobayashi E  Kawai Y  Kozieradzki I  Landers R  Mo R  Hui CC  Nieves E  Cohen PE  Osborne LR  Wada T  Kunieda T  Moens PB  Penninger JM 《Science (New York, N.Y.)》2003,300(5623):1291-1295

Meiosis is a critical stage of gametogenesis in which alignment and synapsis of chromosomal pairs occur, allowing for the recombination of maternal and paternal genomes. Here we show that FK506 binding protein (Fkbp6) localizes to meiotic chromosome cores and regions of homologous chromosome synapsis. Targeted inactivation of Fkbp6 in mice results in aspermic males and the absence of normal pachytene spermatocytes. Moreover, we identified the deletion of Fkbp6 exon 8 as the causative mutation in spontaneously male sterile as/as mutant rats. Loss of Fkbp6 results in abnormal pairing and misalignments between homologous chromosomes, nonhomologous partner switches, and autosynapsis of X chromosome cores in meiotic spermatocytes. Fertility and meiosis are normal in Fkbp6 mutant females. Thus, Fkbp6 is a component of the synaptonemal complex essential for sex-specific fertility and for the fidelity of homologous chromosome pairing in meiosis.  相似文献   

Genetic diversity in sweetpotato [Ipomoea batatas (L.) Lam.] in relationship to geographic sources as assessed with RAPD markers     

Simon Templar Gichuki  Maria Berenyi  Dapeng Zhang  Michael Hermann  Josef Schmidt  Josef Glössl  Kornel Burg 《Genetic Resources and Crop Evolution》2003,50(4):429-437

Available evidence shows that sweetpotato originated from either Central or South American lowlands with subsequent dispersal to North America, Europe, Africa, Asia and the pacific islands. A total of 71 polymorphic RAPD molecular markers were used to assess the genetic relationships amongst 74 sweetpotato varieties originating from a total of 23 sweetpotato producing countries within six geographical regions, namely, South America, Central America/Caribbean, United States of America (USA), East Africa, Asia and Oceania. An Analysis of Molecular Variance (AMOVA) indicated that 93.4% of the total variance was due to the differences between genotypes within regions. The difference between regions was significant (P < 0.001) but only contributed 6.6% to the variance. Genetic distance (PhiST) calculated with AMOVA and multidimensional scaling (MDS) revealed that the South American and the Central American/Caribbean genotypes formed two separate clusters. East African varieties, which have unique characteristics from other traditional varieties, were distinct from other traditional varieties from South America and Oceania. These results support the reported hypothesis of the origin and dispersal of the sweetpotato and indicate that the primary centre of diversity probably has two distinct genepools. It is proposed that the dispersal of the sweetpotato from its origin may have mainly involved varieties from Central America/Caribbean as opposed to varieties from South America. There is an indication that new genepools may be evolving in Africa and Asia due to hybridisation and adaptation to the local environments.  相似文献   

Microbiological characterization of the structures built by earthworms and ants in an agricultural field     

José A. Amador  Josef H. Görres 《Soil biology & biochemistry》2007,39(8):2070-2077

The genesis and architecture of the structures built by ants and earthworms differ markedly, suggesting that—in addition to having different physical and chemical properties—the resident microbial community should also have unique properties. We characterized the inorganic N, biomass C, C mineralization rate, and functional diversity of the microbial communities of earthworm casts, earthworm burrow soil, ant mounds, and bulk soil from an agricultural field. Mound soil was most enriched in inorganic N and had the lowest pH, moisture content, and C mineralization rate. Functional diversity was evaluated by determining the ability of microorganisms to grow on 31 substrates using Biolog^®EcoPlates in combination with a most probable number (MPN) approach. Casts had MPNs that were one to two orders of magnitude higher than burrow, mound and bulk soil for most substrates. Casts also had the highest MPNs for particular substrate guilds relative to bulk soil, followed by mound and burrow soil. Indices of substrate diversity and evenness were highest for casts, followed by burrow, mound, and bulk soil. Differences in the type of habitat provided by the structures built by ants and earthworms result in the differential distribution of nutrients, microbial activity, and metabolic diversity of soils within an agricultural field that affect soil fertility and quality.  相似文献   

Solar UV measurements with Robertson–Berger type instruments: influence of the detector’s internal humidity status     

Martin Huber  Mario Blumthaler  Josef Schreder   《Agricultural and Forest Meteorology》2003,120(1-4):39

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Fenbendazole. I. Structure-activity relationships     

Heinz Loewe  Josef Urbanietz 《Pest management science》1977,8(5):544-549

Substitution of alkyl benzimidazol-2-ylcarbamates by phenoxy- or phenylthio-groups in the 5-position results in an increase in anthelmintic activity. The biological spectrum is altered by substitution of the phenyl ring. A sulphonic ester substituent in the 5-position of the benzimidazole nucleus also increases anthelmintic activity.  相似文献   

Cryopreservation of isolated mouse germinal vesicles     

Kren R  Fulka J  Fulka H 《The Journal of reproduction and development》2005,51(2):289-292

The storage of unfertilized oocytes, either immature, maturing or mature, is still unsatisfactory. Here we describe an approach in which germinal vesicles isolated as karyoplasts from immature oocytes are vitrified by open the pulled straws (OPS) method in evacuated porcine zonae pellucidae. After thawing, their survival was almost absolute. Moreover, when thawed GV-karyoplasts were fused to immature oocyte cytoplasts the maturation of reconstructed cells resulted in the production of secondary oocytes--metaphase II.  相似文献   

Protein characters in species hybrids of the genus phaseolus studied by means of serological methods     

Eva Klozová  Josef Kloz 《Plant foods for human nutrition (Dordrecht, Netherlands)》1966,13(1-4):75-77

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