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1.
Nathanael R. Hauck Hisayo Yamane Ryutaro Tao Amy F. Iezzoni 《Sexual plant reproduction》2002,15(1):39-46
. Gametophytic self-incompatibility (GSI) typically "breaks down" due to polyploidy in many Solanaceous species, resulting in self-compatible (SC) tetraploid individuals. However, sour cherry (Prunus cerasus L.), a tetraploid species resulting from hybridization of the diploid sweet cherry (P. avium L.) and the tetraploid ground cherry (P. fruticosa Pall.), is an exception, consisting of both self-incompatible (SI) and SC individuals. Since sweet cherry exhibits GSI with 13 S-ribonucleases (S-RNases) identified as the stylar S-locus product, the objectives were to compare sweet and sour cherry S-allele function, S-RNase sequences and linkage map location as initial steps towards understanding the genetic basis of SI and SC in sour cherry. S-RNases from two sour cherry cultivars that were the parents of a linkage mapping population were cloned and sequenced. The sequences of two S-RNases were identical to those of sweet cherry S-RNases, whereas three other S-RNases had unique sequences. One of the S-RNases mapped to the Prunus linkage group 6, similar to its location in sweet cherry and almond, whereas two other S-RNases were linked to each other but were unlinked to any other markers. Interspecific crosses between sweet and sour cherry demonstrated that GSI exists in sour cherry and that the recognition of common S-alleles has been maintained in spite of polyploidization. It is hypothesized that self-compatibility in sour cherry is caused by the existence of non-functional S-RNases and pollen S-genes that may have arisen from natural mutations. 相似文献
2.
The impact of regional factors (such as speciation or dispersal) on the species richness in local communities (SL) has received increasing attention. A prominent method to infer the impact of regional factors is the comparison of species richness in local assemblages (SL) with the total number of species in the region (SR). Linear relations between SR and SL have been interpreted as an indication of strong regional influence and weak influence of interactions within local communities. We propose that two aspects bias the outcome of such comparisons: (1) the spatial scale of local and regional sampling, and (2) the body size of the organisms. The impact of the local area reflects the scales of ecological interactions, whereas the ratio between local and regional area reflects the inherent moment of autocorrelation. A proposed impact of body size on the relation is based on the high dispersal and high abundance of small organisms. We predict strongest linearity between SR and SL for large organisms, for large local areas (less important ecological interactions) and for sampling designs where the local habitat area covers a high proportion of the regional area (more important autocorrelation). We conducted a meta-analysis on 63 relations obtained from the literature. As predicted, the linearity of the relationship between SL and SR increased with the proportion of local to regional sampling area. In contrast, neither the body size of the organisms nor the local area itself was significantly related to the relation between SL and SR. This indicated that ecological interactions played a minor role in the shape of local to regional richness plots, which instead was mainly influenced by the sampling design. We found that the studies published so far were highly biased towards larger organisms and towards high similarity between the local and regional area. The proposed prevalence of linear relationships may thus be an artefact and plots of SL to SR are not a suitable tool with which to infer the strength of local interactions. 相似文献
3.
4.
Transpiration in response to variation in microclimate and soil moisture in southeastern deciduous forests 总被引:8,自引:0,他引:8
Responses of forests to changes in environmental conditions reflect the integrated behavior of their constituent species. We investigated sap flux-scaled transpiration responses of two species prevalent in upland eastern hardwood forests, Quercus alba in the upper canopy and Acer rubrum in the low to mid canopy, to changes in photosynthetically active radiation above the canopy (Qo), vapor pressure deficit within the canopy (D), and soil moisture depletion during an entire growing season. Water loss before bud break (presumably through the bark) increased linearly with D, reaching 8% of daily stand transpiration (EC) as measured when leaf area index was at maximum, and accounting for 5% of annual water loss. After leaves were completely expanded and when soil moisture was high, sap flux-scaled daily EC increased linearly with the daily sum of Qo. Species differences in this response were observed. Q. alba reached a maximum transpiration at low Qo, while A. rubrum showed increasing transpiration with Qo at all light levels. Daily EC increased in response to daily average D, with an asymptotic response due to the behavior of Q. alba. Transpiration of A. rubrum showed a greater response to soil moisture depletion than did that of Q. alba. When evaluated at a half-hourly scale under high Qo, mean canopy stomatal conductance (GS) of individuals decreased with D. The sensitivity of GS to D was greater in species with higher intrinsic GS. Regardless of position in the canopy, diffuse-porous species in this and an additional, more mesic stand showed higher GS and greater stomatal sensitivity to environmental variation than do ring-porous species. 相似文献
5.
Dwarf mistletoe affects whole-tree water relations of Douglas fir and western larch primarily through changes in leaf to sapwood ratios 总被引:4,自引:0,他引:4
Dwarf mistletoes induce abnormal growth patterns and extreme changes in the biomass allocation of their hosts as well as directly parasitizing them for resources. Because biomass allocation can affect the resource use and efficiency of conifers, we studied the influences of dwarf mistletoe infection on above-ground biomass allocation of Douglas fir and western larch, and the consequences of such changes on whole-tree water use and water relations. Sap flow, tree water potentials, leaf:sapwood area ratios (AL:AS), leaf carbon isotope ratios, and nitrogen content were measured on Douglas fir and western larch trees with various degrees of mistletoe infection during the summer of 1996 in western Montana. Heavy dwarf mistletoe infection on Douglas fir and western larch was related to significant increases in AL:AS. Correspondingly, water transport dynamics were altered in infected trees, but responses were different for the two species. Higher AL:AS ratios in heavily infected Douglas firs were offset by increases in sapwood area-based sap flux densities (QSW) such that leaf area-based sap flux densities (QL) and predawn leaf water potentials at the end of the summer did not change significantly with mistletoe infection. Small (but statistically insignificant) decreases of QL for heavily infected Douglas firs were enough to offset increases in leaf area such that whole-tree water use was similar for uninfected and heavily infected trees. Increased AL:AS ratios of heavily infected western larch were not offset by increases of QSW. Consequently, QL was reduced, which corresponded with significant decreases of water potential at the end of the summer. Furthermore, mistletoe-infection-related changes in AL:AS as a function of tree size resulted in greater whole-tree water use for large infected larches than for large uninfected trees. Such changes may result in further depletion of limited soil water resources in mature infected stands late in the growing season. Foliage from infected trees of both species had lower water use efficiencies than non-infected trees. Our results demonstrate substantial changes of whole-tree processes related to mistletoe infection, and stress the importance of integrating whole-tree physiological and structural processes to fully understand the mechanisms by which pathogens suppress forest productivity. 相似文献
6.
K. J. Chae S. E. Oh S. T. Lee J. W. Bae In S. Kim 《Bioprocess and biosystems engineering》2000,23(3):235-243
To investigate the effect of both initially present soluble inert COD (SI) and soluble inert COD formed by microbial activities (SPM) on the effluent soluble residual COD (SR) and to determine biokinetic constants, the pure-oxygen was employed for the batch assays of biological leachate treatment. The results of this work showed that the effluent residual soluble COD was entirely composed of SI and SPM, therefore, could not be reduced below 7-10% of total influent soluble COD (ST0.inf), corresponding to the organics removal efficiency of 93-90%. The value of SI of leachate, which is associated with the types of wastewaters, was determined as approximately 7.84% of ST0.inf, and the soluble inert COD by microbial activities was assessed by means of the coefficient fPM of 0.0474. These results mean that significant amount of feed leachate COD may pass the biological system without any change. On the basis of the concept that microorganisms must satisfy their maintenance energy requirements prior to synthesizing new biomass, a set of batch assays with various ratios of ST0.inf /X0 were carried out to evaluate their effects on the excess biomass production. Decreasing the supply of substrate per unit biomass resulted in gradual decrease in the biomass yields, but, at the same time, it resulted in gradual increase in the bacteria mediated inert COD as a side effect. The optimum ratios of ST0.inf /X0 were concluded as 0.2-0.6 according to the careful consideration of both aspects on the reduction of net sludge yields and inert COD from microbial activities. 相似文献
7.
Many protocols for genetic transformation result in the regeneration of both transformed shoots and untransformed ones known as escapes. Here we describe a multiplex PCR technique for use with apple (Malus 2 domestica Borkh.), which simultaneously demonstrates the presence of both a transgene sequence and an endogenous gene using a single PCR reaction. Common transgene-specific primers were successfully used in combination with either the conserved X1 primers or with different S-allele primers. When primers matched to S-allele sequences are used during multiplex PCR, the presence of the PCR product proves that amplification occurred successfully but can also confirm the identity of the cultivar used in the experiment. This is particularly useful as a protection against mislabeling of cultivars during subculturing and other laboratory and greenhouse operations. 相似文献
8.
This study examined the effects of elevated CO2 on secondary metabolites for saplings of tropical trees. In the first experiment, nine species of trees were grown in the ground in open-top chambers in central Panama at ambient and elevated CO2 (about twice ambient). On average, leaf phenolic contents were 48% higher under elevated CO2. Biomass accumulation was not affected by CO2, but starch, total non-structural carbohydrates and C/N ratios all increased. In a second experiment with Ficus, an early successional species, and Virola, a late successional species, treatments were enriched for both CO2 and nutrients. For both species, nutrient fertilization increased plant growth and decreased leaf carbohydrates, C/N ratios and phenolic contents, as predicted by the carbon/nutrient balance hypothesis. Changes in leaf C/N levels were correlated with changes in phenolic contents for Virola (r=0.95, P<0.05), but not for Ficus. Thus, elevated CO2, particularly under conditions of low soil fertility, significantly increased phenolic content as well as the C/N ratio of leaves. The magnitude of the changes is sufficient to negatively affect herbivore growth, survival and fecundity, which should have impacts on plant/herbivore interactions. 相似文献
9.
Fernando Valladares José Chico Ismael Aranda Luis Balaguer Pierre Dizengremel Esteban Manrique Erwin Dreyer 《Trees - Structure and Function》2002,16(6):395-403
The responses of Quercus robur (oak) and Fagus sylvatica (beech) seedlings to four different light environments (full, 50%, 40% and 15% sunlight) and to a rapid increase in irradiance were explored during the summer, after 2 years of growth in a forest nursery at Nancy (France). Significant differences between the two species were found for most variables. Phenotypic plasticity for morphological variables (root-shoot ratio, leaf size, leaf weight ratio) was higher in beech than in oak, while the reverse was true for anatomical (stomatal density, epidermis thickness, exchange surface area of the palisade parenchyma) and physiological (maximum photosynthetic rate, stomatal conductance, Rubisco activity) variables. Predawn photochemical efficiency (Fv/Fm) was higher in oak than in beech in all light environments except in 15% sunlight. Fv/Fm was significantly lower in 100% sunlight than in the other light environments in beech but not in oak. Maximum photosynthetic rates (Amax) increased with increasing light availability in the two species but they were always higher in oak than in beech. Oak exhibited higher Rubisco activity than beech in full sunlight. The transfer of shade-adapted seedlings to the open caused a decrease of Fv/Fm, which was larger for beech than for oak. Transferred oak but not beech plants recovered gradually to the control Fv/Fm values. The decreased chlorophyll content and the increased non-photochemical quenching observed in high-light beech seedlings were not enough to avoid photoinhibition. The results suggest that a greater tolerance of strong irradiance is linked to an enhanced physiological plasticity (variables related to photosynthesis), while shade tolerance relies on an enhanced plasticity in light-harvesting variables (crown morphology and chlorophyll content). 相似文献
10.
Identification of self-incompatibility genotypes of almond by allele-specific PCR analysis 总被引:13,自引:0,他引:13
M. Tamura K. Ushijima H. Sassa H. Hirano R. Tao T. M. Gradziel A. M. Dandekar 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(3):344-349
In almond, gametophytic self-incompatibility is controlled by a single multiallelic locus (S-locus). In styles, the products of S-alleles are ribonucleases, the S-RNases. Cultivated almond in California have four predominant S-alleles (S
a, S
b, S
c, S
d). We previously reported the cDNA cloning of three of these alleles, namely S
b, S
c and S
d. In this paper we report the cloning and DNA sequence analysis of the S
a allele. The Sa-RNase displays approximately 55% similarity at the amino-acid level with other almond S-RNases (Sb, Sc, and Sd) and this similarity was lower than that observed among the Sb, Sc and Sd-RNases. Using the cDNA sequence, a PCR-based identification system using genomic DNA was developed for each of the S-RNase
alleles. Five almond cultivars with known self-incompatibility (SI) geno-types were analyzed. Common sequences among four
S-alleles were used to create four primers, which, when used as sets, amplify DNA bands of unique size that corresponded to
each of the four almond S-alleles; S
a (602 bp), S
b (1083 bp), S
c (221 bp) and S
d (343 bp). All PCR products obtained from genomic DNA isolated from the five almond cultivars were cloned and their DNA sequence
obtained. The nucleotide sequence of these genomic DNA fragments matched the corresponding S-allele cDNA sequence in every case. The amplified products obtained for the S
a- and S
b-alleles were both longer than that expected for the coding region, revealing the presence of an intron of 84 bp in the S
a-allele and 556 bp in the S
b-allele. Both introns are present within the site of the hypervariable region common in S-RNases from the Rosaceae family
and which may be important for S specificity. The exon portions of the genomic DNA sequences were completely consistent with the cDNA sequence of the corresponding
S-allele. A useful application of these primers would be to identify the S-genotype of progeny in a breeding program, new varieties in an almond nursery, or new grower selections at the seedling stage.
Received: 21 June 1999 / Accepted: 15 November 1999 相似文献
11.
A steady-state nonlinear feedforward controller (FFC) for measurable disturbances is designed for a continuous bioreactor, which is represented by Hammerstein type nonlinear model wherein the nonlinearity is a polynomial with input multiplicities. The manipulated variable is the feed substrate concentration (Sf) and the disturbance variable is the dilution rate (D). The productivity (Q=DP) is considered as the controlled variable. The desired value of Q=3.73 gives two values of feed substrate concentration. The nonlinearity in the gain is considered for relating output to the manipulated variable and separately for the relation between output to disturbance variable. The FFC is also designed for the overall linearized system. The performance of the FFC is evaluated on the nonlinear differential equation model. The FFC is also designed for the model based on a single nonlinear steady-state equation containing both D and Sf. This nonlinear FFC gives the best performance. The nonlinear FFC is also designed by using only linear gain for the disturbance and nonlinear gain for the manipulated variable. Similarly, nonlinear FFC is also designed by using linear gain for the manipulated variable and the nonlinear gain for the disturbance variable. The performances of these FFC schemes are compared. 相似文献
12.
Identification of Stylar RNases Associated with Gametophytic Self-Incompatibility in Almond (Prunus dulcis) 总被引:3,自引:0,他引:3
Tao Ryutaro; Yamane Hisayo; Sassa Hidenori; Mori Hitoshi; Gradziel Thomas M.; Dandekar Abhaya M.; Sugiura Akira 《Plant & cell physiology》1997,38(3):304-311
Stylar proteins of 13 almond (Prunus dulcis) cultivars withknown S-genotypes were surveyed by IEF and 2D-PAGE combinedwith immunoblot and N-terminal amino acid sequence analysesto identify S-RNases associated with gametophytic self-incompatibility(SI) in this plant species. RNase activities corresponding toSa and Sb, two of the four S-alleles tested, were identifiedby IEF and RNase activity staining. The Sa-RNase band reactedwith the anti-S4serum prepared from Japanese pear (Pyrus serotina);no reaction with the antiserum was observed with the sbRNaseband. When the sa-RNase band was excised from an IEF gel stainedfor RNase activity, subjected to SDS-PAGE, and detected by immunoblotting,it appeared that this band consisted of a single protein thatreacted with the anti-s4serum with Mr of about 28 kDa. With2D-PAGE and silver staining of the stylar extracts, all fourS-proteins could be successfully distinguished from each otherin the highly basic zone of the gel. Although Sb-, Sc-, andSdproteins had roughly the same Mr of about 30 kDa, the Sc-proteinseemed to be slightly smaller than the Sb-protein and slightlylarger than the Saprotein. In 2D-PAGE profiles as well, theSa-protein had Mr of about 28 kDa, apparently smaller than theother three proteins. A bud sport, in which one of the two S-allelesof the original cultivar is impaired, was visualized as a lossof Scprotein, which is consistent with the previous pollinationstudy. All four S-proteins reacted with the anti-S4serum, probablybecause of the differing conformations of these S-proteins inthe IEF and 2D-PAGE gels. The Sa-protein in 2D-PAGE appearedto be identical to Sa-RNase in IEF; both bad the same Mr andwere reactive with the anti-S4-serum. N-terminal amino acidsequence analysis of the four 5-proteins revealed that theywere highly homologous to each other and similar to the 5-RNasesof Malus, Pyrus, Scrophulariaceae, and Solanaceae. Taken together,RNases in the style are strongly suggested to be associatedwith the gametophytic SI of al- mond. This is the first reportidentofiying and characterizing S-RNase in almond. (Received July 11, 1996; Accepted December 26, 1996) 相似文献
13.
The multiple steady states in an isothermal, constant-density CSTR involving two-substrates, enzyme- catalyzed reactions is determined by a zero eigenvalue analysis. The hysteresis and bistability occurs for a certain range of the rate constant of product formation from a ternary complex, kES1S2MP+E. A two-parameter (kES1S2MP+E, k0MS1) bifurcation diagram for several different values of flow rate kS1̂ is also presented. It shows that, to maintain the existence of the steady state multiplicity under a fixed flow rate, the larger the rate constant kES1S2MP+E is, the larger the feed concentration of a substrate is required and the wider the range of that exists. To maintain the existence of the steady state multiplicity for a lower flow rate, it is required to reduce the feed concentration of substrates. 相似文献
14.
The effect of elevated carbon dioxide and ozone on leaf- and branch-level photosynthesis and potential plant-level carbon gain in aspen 总被引:7,自引:0,他引:7
Asko Noormets Evan P. McDonald Richard E. Dickson Eric L. Kruger Anu Sôber J. Isebrands David F. Karnosky 《Trees - Structure and Function》2001,15(5):262-270
Two aspen (Populus tremuloides Michx.) clones, differing in O3 tolerance, were grown in a free-air CO2 enrichment (FACE) facility near Rhinelander, Wisconsin, and exposed to ambient air, elevated CO2, elevated O3 and elevated CO2+O3. Leaf instantaneous light-saturated photosynthesis (PS) and leaf areas (A) were measured for all leaves of the current terminal, upper (current year) and the current-year increment of lower (1-year-old) lateral branches. An average, representative branch was chosen from each branch class. In addition, the average photosynthetic rate was estimated for the short-shoot leaves. A summing approach was used to estimate potential whole-plant C gain. The results of this method indicated that treatment differences were more pronounced at the plant- than at the leaf- or branch-level, because minor effects within modules accrued in scaling to plant level. The whole-plant response in C gain was determined by the counteracting changes in PS and A. For example, in the O3-sensitive clone (259), inhibition of PS in elevated O3 (at both ambient and elevated CO2) was partially ameliorated by an increase in total A. For the O3-tolerant clone (216), on the other hand, stimulation of photosynthetic rates in elevated CO2 was nullified by decreased total A. 相似文献
15.
Influence of climate-driven shifts in biomass allocation on water transport and storage in ponderosa pine 总被引:12,自引:0,他引:12
Conifers decrease the amount of biomass apportioned to leaves relative to sapwood in response to increasing atmospheric evaporative demand. We determined how these climate-driven shifts in allocation affect the aboveground water relations of ponderosa pine growing in contrasting arid (desert) and humid (montane) climates. To support higher transpiration rates, a low leaf:sapwood area ratio (AL/AS) in desert versus montane trees could increase leaf-specific hydraulic conductance (KL). Alternatively, a high sapwood volume:leaf area ratio in the desert environment may increase the contribution of stored water to transpiration. Transpiration and hydraulic conductance were determined by measuring sap flow (JS) and shoot water potential during the summer (June-July) and fall (August-September). The daily contribution of stored water to transpiration was determined using the lag between the beginning of transpiration from the crown at sunrise and JS. In the summer, mean maximum JS was 31.80LJ.74 and 24.34Dž.05 g m-2 s-1 for desert and montane trees (a 30.6% difference), respectively. In the fall, JS was 25.33NJ.52 and 16.36dž.64 g m-2 s-1 in desert and montane trees (a 54.8% difference), respectively. JS was significantly higher in desert relative to montane trees during summer and fall (P<0.05). Predawn and midday shoot water potential and sapwood relative water content did not differ between environments. Desert trees had a 129% higher KL than montane trees in the summer (2.41᎒-5 versus 1.05᎒-5 kg m-2 s-1 MPa-1, P<0.001) and a 162% higher KL in the fall (1.97᎒-5 versus 0.75᎒-5 kg m-2 s-1 MPa-1, P<0.001). Canopy conductance decreased with D in all trees at all measurement periods (P<0.05). Maximum gC was 3.91 times higher in desert relative to montane trees averaged over the summer and fall. Water storage capacity accounted for 11 kg (11%) and 10.6 kg (17%) of daily transpiration in the summer and fall, respectively, and did not differ between desert and montane trees. By preventing xylem tensions from reaching levels that cause xylem cavitation, high KL in desert ponderosa pine may facilitate its avoidance. Thus, the primary benefit of low leaf:sapwood allocation in progressively arid environments is to increase KL and not to increase the contribution of stored water to transpiration. 相似文献
16.
We tested the hypothesis that hydraulic conductance per unit leaf surface area of plant shoots (KSL) determines the maximum diurnal stomatal conductance (gL) that can be reached by plants growing in the field. A second hypothesis was tested that some xylem cavitation cannot be avoided by transpiring plants and might act as a signal for regulating gL. Eleven woody species were studied, differing from each other with respect to taxonomy, wood anatomy and leaf habit. Maximum diurnal gL, transpiration rate (EL), pre-dawn and minimum diurnal leaf water potential (Opd and Omin, respectively) were measured in the field. The critical O level at which stem cavitation was triggered (Ocav) was measured on detached branches, using the acoustic method. A high-pressure flow meter was used to measure maximum KSL of 1-year-old shoots. Both gL and EL were positively related to KSL. The whole-plant hydraulic conductance per unit leaf area (KWL) of all the species studied, calculated as the ratio of EL to (O (=Opd-Omin) was closely related to KSL. In every case, Omin (ranging between -0.85 and -1.35 MPa in the different species) dropped to the Ocav range or was <Ocav (ranging between -0.71 and -1.23 MPa), thus suggesting that some cavitation-induced embolism could not be avoided. The possibility is discussed that some cavitation-induced reduction in KSL is the signal for stomatal closure preventing runaway embolism. The lack of correlation of gL to Ocav is discussed in terms of the inconsistency of Ocav as an indicator of the vulnerability of plants to cavitation. No differences in hydraulic traits were observed between evergreen and deciduous species. 相似文献
17.
Tranel J Wassom J Jeschke R Rayburn L 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,105(5):674-679
The genus Amaranthus includes several important monoecious and dioecious weed species, and several populations of these species have developed resistance to herbicides. These species are closely related and two or more species often coexist in agricultural settings. Collectively, these attributes raise the concern that herbicide resistance might transfer from one weedy Amaranthus species to another. We performed research to determine if a dominant allele encoding a herbicide-insensitive form of acetolactate synthase (ALS) could be transferred from a monoecious species, A. hybridus, to a dioecious species, A. rudis. Numerous F1 hybrids were obtained from controlled crosses in a greenhouse between A. rudis and herbicide-resistant A. hybridus, and most (85%) of these hybrids were herbicide-resistant. Molecular analysis of the ALS gene was used to verify that herbicide-resistant hybrids contained both an A. rudis and an A. hybridus ALS allele. Although hybrids had greatly reduced fertility, 42 BC1 plants were obtained by backcrossing 33 hybrids with male A. rudis. Fertility was greatly restored in BC1 progeny, and numerous BC2 progeny were obtained from a second backcross to A. rudis. The herbicide-resistance allele from A. hybridus was transmitted to 50% of the BC1 progeny. The resistance allele was subsequently transmitted to and conferred herbicide resistance in 39 of 110 plants analyzed from four BC2 families. Parental species, hybrids, and BC2 progeny were compared for 2C nuclear DNA contents. The mean hybrid 2C nuclear DNA content, 1.27 pg, was equal to the average between A. rudis and A. hybridus, which had 2C DNA contents of 1.42 and 1.12 pg, respectively. The mean 2C DNA content of BC2 plants, 1.40 pg, was significantly (! < 0.01) less than that of the recurring A. rudis parent and indicated that BC2 plants were not polyploid. This report demonstrates that herbicide resistance can be acquired by A. rudis through a hybridization event with A. hybridus. 相似文献
18.
The mixing behaviour of the liquid phase in concentric-tube airlift bioreactors of different scale (RIMP: VL=0.070 m3; RIS-1: VL=2.50 m3; RIS-2: VL=5.20 m3) in terms of mixing time was investigated. This mixing parameter was determined from the output curves to an initial Dirac pulse, using the classical tracer response technique, and analyzed in relation to process and geometrical parameters, such as: gas superficial velocity, xSGR; top clearance, hS; bottom clearance, hB, and ratio of the resistances at downcomer entrance, Ad/AR. A correlation between the mixing time and the specified operating and geometrical parameters was developed, which was particularized for two flow regimes: bubbly and transition (xSGRА.08 m/s) and churn turbulent flow (xSGR> 0.08 m/s) respectively. The correlation was applied in bioreactors of different scale with a maximum error of ᆲ%. 相似文献
19.
Self-incompatibility in the genus Prunus is controlled by two genes at the S-locus, S-RNase and SFB. Both genes exhibit the high polymorphism and high sequence diversity characteristic of plant self-incompatibility systems.
Deduced polypeptide sequences of three myrobalan and three domestic plum S-RNases showed over 97% identity with S-RNases from other Prunus species, including almond, sweet cherry, Japanese apricot and Japanese plum. The second intron, which is generally highly
polymorphic between alleles was also remarkably well conserved within these S-allele pairs. Degenerate consensus primers were developed and used to amplify and sequence the co-adapted polymorphic SFB alleles. Sequence comparisons also indicated high degrees of polypeptide sequence identity between three myrobalan and the
three domestic plum SFB alleles and the corresponding Prunus SFB alleles. We discuss these trans-specific allele identities in terms of S-allele function, evolution of new allele specificities and Prunus taxonomy and speciation.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
El-Mezawy A Dreyer F Jacobs G Jung C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,105(1):100-105
Sugar beet (Beta vulgaris L.) is a biennial species. Shoot elongation (bolting) starts after a period of low temperature. The dominant allele of locus B causes early bolting without cold treatment. This allele is abundant in wild beets whereas cultivated beets carry the recessive allele. Fifteen AFLP markers, tightly linked to the bolting locus, have been identified using bulked segregant analysis. The F2-population consisted of 2,134 individuals derived after selfing a single F1-plant (Bb). In a first step, a linkage map was established with 249 markers based on 775 F2-individuals with a coverage of 822.3 cM. The loci are dispersed over nine linkage groups corresponding to the haploid chromosome number of Beta species. Seventeen marker loci were placed at a distance less than 3.2 cM around the bolting gene. In a second step, four of those markers most closely linked to B were mapped with the entire F2-population. Two of the markers were mapped flanking the B gene at distances of 0.14 and 0.23 cM. The other two markers were mapped at a distance of 0.5 cM from the gene. The tight linkage could be verified by testing 88 unrelated plants from a breeding program. The closely linked markers will enable breeders to select for the non-bolting character without laborious test crossings. Moreover, these markers are being used for map-based cloning of the bolting gene. 相似文献