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1.
2.
Cross-compatibility relationships in almond are controlled by a gametophytically expressed incompatibility system partly mediated by stylar RNases, of which 29 have been reported. To resolve possible synonyms and to provide data for phylogenetic analysis, 21 almond S-RNase alleles were cloned and sequenced from SP (signal peptide region) or C1 (first conserved region) to C5, except for the S 29 allele, which could be cloned only from SP to C1. Nineteen sequences (S 4 , S 6 , S 11 S 22 , S 25 S 29 ) were potentially new whereas S 10 and S 24 had previously been published but with different labels. The sequences for S 16 and S 17 were identical to that for S 1 , published previously; likewise, S 15 was identical to S 5 . In addition, S 4 and S 20 were identical, as were S 13 and S 19 . A revised version of the standard table of almond incompatibility genotypes is presented. Several alleles had AT or GA tandem repeats in their introns. Sequences of the 23 distinct newly cloned or already published alleles were aligned. Sliding windows analysis of Ka/Ks identified regions where positive selection may operate; in contrast to the Maloideae, most of the region from the beginning of C3 to the beginning of RC4 appeared not to be under positive selection. Phylogenetic analysis indicated four pairs of alleles had ‘bootstrap’ support > 80%: S 5 /S 10 , S 4 /S 8, S 11 /S 24 , and S 3 /S 6 . Various motifs up to 19 residues long occurred in at least two alleles, and their distributions were consistent with intragenic recombination, as were separate phylogenetic analyses of the 5′ and 3′ sections. Sequence comparison of phylogenetically related alleles indicated the significance of the region between RC4 and C5 in defining specificity.An erratum to this article can be found at  相似文献   

3.
This paper presents the mitotic chromosome numbers of 18 species of Bromeliaceae. The diploid number 2n = 50 was observed in Aechmea comata, A. caudata, A. correia‐araujoi, A. recurvata, A. marauensis, A. bicolor, A. pineliana, Hohenbergia catingae, H. blanchetti, Alcantarea imperialis, Al. nahoumi, Neoregelia tenebrosa, Nidularium lyman‐smithii, N. scheremetiewii, N. innocentii var. innocentii, and N. innocentii × Neoregelia johannis hybrid, whereas 2n = 34 was observed in Cryptanthus maritimus and C. warren‐loosei. All of the determinations presented in this study are previously unpublished, except A. comata and H. catingae. These results confirm x = 25 as the basic number for the family and x = 17 as a secondary basic number probably generated by decreasing dysploidy. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 189–193.  相似文献   

4.
 For the angiosperm dominants of northern California’s mixed evergreen forests, this study compares the display of photosynthetic tissue within leaves and along branches, and examines the correspondence between these morphological attributes and the known environmental tolerances of these species. Measurements were made on both sun and shade saplings of six species: Arbutus m e n z i e s i i (Ericaceae), C h r y s o l e p i s c h r y s o p h y l l a (Fagaceae), L i t h o c a r p u s d e n s i f l o r u s (Fagaceae), Quercus c h r y s o l e p i s (Fagaceae), Quercus w i s l i z e n i i (Fagaceae), and Umbellularia c a l i f o r n i c a (Lauraceae). All species had sclerophyllous leaves with thick epidermal walls, but species differed in leaf specific weight, thickness of mesophyll tissues and in the presence of a hypodermis, crystals, secretory idioblasts, epicuticular deposits, and trichomes. The leaves of Arbutus were 2 – 5 times larger than those of C h r y s o l e p i s, L i t h o c a r p u s and Umbellularia and 4 – 10 times larger than those of both Quercus species. Together with differences in branch architecture, these leaf traits divide the species into groups corresponding to environmental tolerances. Shade-tolerant C h r y s o l e p i s, L i t h o c a r p u s, and Umbellularia had longer leaf lifespans and less palisade tissue, leaf area, and crown mass per volume than the intermediate to intolerant Arbutus and Quercus. Having smaller leaves, Quercus branches had more branch mass per leaf area and per palisade volume than other species, whereas Arbutus had less than other species. These differences in display of photosynthetic tissue should contribute to greater growth for Quercus relative to the other species under high light and limited water, for Arbutus under high light and water availability, and for C h r y s o l e p i s, L i t h o c a r p u s, and Umbellularia under limiting light levels. Accepted: 22 March 1996  相似文献   

5.
 Forty three S tester lines of Brassica oleracea were characterized using DNA and protein gel-blotting analyses. DNA gel-blot analysis of HindIII-digested genomic DNA with class-I and class-II SLG probes revealed that 40 lines could be classified as class-I S haplotypes while three lines could be classified as class-II S haplotypes. The band patterns in the S tester lines were highly polymorphic. Although the S tester lines typically showed two bands corresponding to SLG and SRK in the analysis with the class-I SLG probe, only one band was observed in the S 24 homozygote. This band was identified as SRK, suggesting that this haplotype has no class-I SLG band. In the analysis using the class-II SLG probe, one plant yielded a different band pattern from the known class-II haplotypes, S 2 , S 5 and S 15 . Unexpectedly, this plant was reciprocally cross-incompatible with the S 2 haplotype. Therefore, it was designated as S 2-b . We found an S 13 haplotype having a restriction fragment length polymorphism different from that of the S 13 homozygotes of the S tester line. These findings indicate that S homozygous lines with the same S specificity do not necessarily show the same band pattern in the DNA gel-blot analysis. Soluble stigma proteins of 32 S homozygotes were separated by isoelectric focusing and detected using anti-S 22 SLG antiserum. S haplotype-specific bands were detected in 27 S homozygotes but not in five S homozygotes, including the S 24 homozygote. This is consistent with the observation that the S 24 haplotype had no SLG band. Received: 13 July 1998 / Accepted: 29 September 1998  相似文献   

6.
Proceeding from three previously derived expressions for the intensity of nitrification in soil as a function of time (logΣN=K.logt+q), as a function of incubation moisture (logΣN=A.pF i+B), as a function of initial moisture (logΣN=C.pF v+D), it was shown that the nitrification intensity as a function of time and of moisture can be expressed by the bilinear function log ΣN=a.pF i.logT+b.pF i+c.logt+d; as a function of time and of initial moisture by the bilinear function logΣ=N=a.pF v.logt+b.pF v+c.logt+d; as a function of initial and incubation moisture by the bilinear function log ΣN=a.pF ipF v+b.pF i+c.pF v+d. The intensity of nitrification as a function of time, incubation moisture and initial moisture may be expressed by the multilinear function log ΣN=a.pF i.pF v.logt+b.pF i.pF v+c.pF i.logt+d.pF v.logt+e .pF i+f.pF v=g.logt+h. This function is valid for all the incubation moistures lying between pF i 3.0 and 4.0 and for all initial moistures between 3.5 and 5.9 provided that the incubation temperature remains constant.  相似文献   

7.
The palynological characterisation of 157 honey samples from three northwest regions of Argentina (Prepuna, Yungas and Chaco) are presented to determine their botanical origin and species associations to be able to define their geographic origin. Samples were harvested during 2003–2011 and processed by means of melissopalynological conventional techniques. One-hundred and nine pollen types were identified. Representative pollen types with a frequency of occurrence greater than 50% in descending order of importance are: Salix humboldtiana, Allophylus edulis, Baccharis, Solanaceae, Eucalyptus, Schinus, Brassicaceae, Papilionoideae, Celtis, Scutia/Condalia-type and Parapiptadenia excelsa. The most important monofloral honeys are from the following: Salix humboldtiana, Scutia/Condalia-type, Allophylus edulis, Baccharis, Blepharocalyx salicifolius, Gleditsia amorphoides, Myrtaceae, Sicyos, Ziziphus mistol, Schinopsis-type, Agonandra excelsa, Anadenathera colubrina, Mimosa, all of them native species, and among introduced species are Eucalyptus, Citrus and Tithonia. Three apicultural zones and their corresponding pollen association indicators were determined: Zone I, Prepuna: Arquita trichocarpa, Prosopis ferox, Schinus areira, Baccharis, Buddleja and Mutisieae; Zone II, Yungas: Myrtaceae, Parapiptadenia excelsa, Baccharis, Salix humboldtiana, Allophylus edulis, Scutia/Condalia-type and Zanthoxylum coco; Zone III, transitional area Yungas-Chaco: Prosopis, Salix humboldtiana, Schinus, Anadenanthera colubrina and Allophylus edulis.  相似文献   

8.
Thirty‐six genotypes, including 15 cultivars and 10 breeding lines of Trifolium subterraneum, a single genotype of each of seven other species of Trifolium (viz. Trifolium dasyurum, Trifolium glanduliferum, Trifolium incarnatum, Trifolium michelanium, Trifolium purpureum, Trifolium spumosum and Trifolium vesiculosum), Biserrula pelecinus, Hedysarum coronarium, Ornithopus compressus and Ornithopus sativus were screened under controlled environmental conditions for resistance to root disease caused by the most pathogenic race of Phytophthora clandestina occurring in Australia, namely race 177. This is the first time any of these genera/species other than T.subterraneum has ever been screened for its response to P. clandestina. The root disease caused by P.clandestina is the first report of susceptibility to this pathogen for the seven other species of Trifolium and also for B.pelecinus, H.coronarium and O.sativus. Within T.subterraneum, a very high level of resistance was identified in cvs Denmark, Junee and Meteora [scores ≤1.5 (0–5 scale where 0 = no disease) across two separate screening tests] and in the breeding lines SL027 and SM023 (scores ≤1.3 across two separate screening tests). Six of the seven other species of Trifolium (viz. T.dasyurum, T.glanduliferum, T.incarnatum, T.michelanium, T.purpureum and T.spumosum) showed a high level of resistance (scores ≤0.8 across two separate screening tests), while T.vesiculosum showed a disease score of ≤1.2 across both screening tests. O.compressus showed no disease in either test, and O.sativus showed a disease score of ≤0.7 across both screening tests. H.coronarium was susceptible with a disease score of ≤2.8 across two separate screening tests, while B.pelecinus was highly susceptible with disease scores of 3.5 and 4.6 in these tests. The high levels of resistance identified against P.clandestina are useful sources of resistance that can be exploited commercially, either directly to minimise damage from this disease or as parents in breeding programs to develop cultivars within the genera/species tested with improved resistance to this highly pathogenic race of P.clandestina.  相似文献   

9.
The ability to assimilate D-glucose and D-xylose was studied in 21 yeast species of the following genera: Candida, Kluyveromyces, Pachysolen, Pichia, and Torulopsis. All the cultures fermented D-glucose with the formation of ethanol. During the assimilation of D-xylose, ethanol was produced by P. stipitis and C. shehatae, whereas xylitol was produced by C. didensiae, C. intermediae, C. parapsilosis, C. silvanorum, C. tropicalis, K. fragilis, K. marxianus, P. guillermondii, and T. molishiama. The yeast P. tannophilus produced comparable amounts of both alcohols. The possible use of xylose-assimilating yeasts for the production of xy-litol and ethanol is discussed.  相似文献   

10.
Antagonistic capability of Trichoderma harzianum was improved through UV-irradiation. Four different type of mutants, T. harzianum - Ma (Th-Ma), T. harzianum - Mb(Th-Mb), T. harzianum - Mc (Th-Mc), T. harzianum - Md (Th-Md) of T. harzianum and the parent strain (Th-P) were selected for further studies. Th-Ma and Th-Mb showed more antagonistic capability against Macrophomina phaseolina than its parent strain Th-P in dual culture. Biochemical analysis of these four mutants and the parent strain showed that Th-Ma releases higher level of two lytic enzymes i.e. chitinases and cellulases and Th-Mb produces more β-1,3-glucanase activity than the parent strain. Culture filtrate of Th-Ma also showed antifungal properties. Study of the competitive saprophytic ability (CSA) of these four mutants and the parent strain were also made. Th-Ma exhibited higher CSA than the parental isolate while Th-Md had less CSA than all other mutants and the parent strain of T. harzianum.  相似文献   

11.
Double-stranded synthetic polydeoxynucleotides of the general form poly[d(GnCn)] · poly[d(GnCn)], poly[d(GnC)] · poly[d(GCn)], and poly[d(AnTn)] · poly[d(AnTn)] have been synthesized. When n = 4 or larger, the CD spectra of polymers of the form poly[d(GnCn)] · poly[d(GnCn)] or poly[d(GnC)] · poly[d(GCn)] closely resemble the spectrum of poly[dG] · poly[dC], suggesting that a string of four continguous guanosine residues is sufficient to induce a conformation resembling that of the polypurine · polypyrimidine. With polymers of the form poly[d(AnTn)] · poly[d(AnTn)], however, the CD spectrum only gradually approaches that of poly[dA] · poly[dT].  相似文献   

12.
The possible modes of binding for methyl-α-d-mannopyranoside, methyl-β-d-mannopyranoside, 2-O-methyl-α-d-mannopyranoside, methyl-2-O-methyl-α-d-mannopyranoside and methyl-α-d-N-acetylmannosamine to concanavalin A have been investigated using theoretical methods. All these sugars, except methyl-α-d-N-acetylmannosamine, reach the active site of concanavalin A with a highly restricted number of binding orientations. Present investigations suggest that the failure of methyl-α-d-N-acetylmannosamine to bind to concanavalin A is not so much due to steric factors as to repulsive electrostatic interactions. Methyl-2-O-methyl-α-d-mannopyranoside can bind to concanavalin A in one mode whereas the other sugars can bind in more than one mode. The high potency of methyl-α-d-mannopyranoside over methyl-β-d-mannopyranoside is mainly due to the possibility of hydrophobic interactions of the α-methoxy group with Leu(99) or Tyr(100) and also due to the possibility of formation of better and more hydrogen bonds with the protein. A comparison of these data with those for the d-glucopyranosides suggests that the change of the hydroxyl at the C-2 atom from equatorial to axial orientation increases the stereochemically allowed region as well as the possible binding modes. From these studies it is also suggested that the overall shape of the oligosaccharides rather than the terminal or internal mannose alone affects the binding potency of saccharides to concanavalin A.  相似文献   

13.
The reversible hydrolysis of maltose to glucose by immobilized glucoamylase entrapped in spherical solid particles is studied theoretically. For this purpose a known kinetic model taking into account these reversible reactions and the competitive synthesis of iso-maltose was adopted. The mass transfer limitations in the bulk liquid and in the pores of the particles containing the enzyme are considered, using Fick's law. On the basis of mathematical modelling the optimum conditions for biocatalyst performance are established. An appropriate combination of particle size and initial substrate concentration may lead to reduction of undesirable mass transfer resistance and therefore product inhibition and to an improved selectivity of the biocatalyst with respect of glucose formation.List of Symbols C i kmoles/m3 current concentration ofi-th component along the radius - C oi kmoles/m3 bulk concentration ofi-th component - C i * kmoles/m3 concentrations ofi-th component on the pellet surface - D si ,D i m2/s internal and molecular diffusion coefficient ofi-th component - W M kmoles/m3·s reaction rate of maltose hydrolysis - W IM kmoles/m3·s reaction rate of iso-maltose formation - W G kmoles/m3·s reaction rate of glucose production - R 0 m pellet radius - r m current radius of the pellet - t s time coordinate - r 0 ratio of the time step to the square of the radial coordinate - Re Reynolds number =w·R/v - Sc Schmidt number =v/D - Bi Biot number = R/D - A j ,B, C j coefficients in the system of linear equations, Eq. (8) - X i dimensionless degree of transformation - NR number of independent reactions - N number of division sections of the pellet radius - G kmoles/m3 concentration of glucose - M kmoles/m3 concentration of maltose - IM kmoles/m3 concentration of isomaltose - K m kmoles/m3 Michaelis constant - V max kmoles/m3·s maximum reaction rate in Eq. (6) - K i kmoles/m3 inhibition constant - K 1eq ,K 2eq equilibrium constants in Eq. (6) - , h steps along the time and radial coordinate in the pellet - m/s mass transfer coefficient - dimensionless radius of the pellet - computation accuracy Indices i number of reaction component - j index along the radius of the pellet - k index along the time coordinate This work was accomplished with thanks to the financial support of the Bulgarian National Fund for Scientific Investigations —Grant No. MU-1-BE/93.  相似文献   

14.
Desmids from 12 freshwater resources in the northern part of Thailand were investigated during 2002 to 2003. A total of 91 taxa were found. They belonged to 17 genera: Actinotaenium, Spirotaenia, Netrium, Gonatozygon, Pleurotaenium, Closterium, Euastrum, Micrasterias, Cosmarium, Cosmocladium, Stuarastrum, Staurodesmus, Xanthidium, Teilingia, Spondylosium, Hyalotheca and Desmidium. The water qualities in all the water resources were classified as oligotrophic to meso-eutrophic by trophic status. The taxa that could possibly be used as bioindicators of trophic state were Staurastrum gutwinskii, Spondylosium pandurifoemae, Cosmarium capitulum, C. mediosrobiculatum var. egranutum, S. tortum, Closterium gracile var. elongatum, C. kuetzingii and Closterium dianae var. dianae. The most frequently found taxa were Staurastrum limneticum var. burmense, S. tetracerum var. tetraerum, Pleurotaenium trabecula, Closterium ehrenbergii var. ehrenbergii and C. kuetzingii. The rare taxa in this study were Actinotaenium sp. Spirotaenia condensata, Pleurotaenium burmense var. dacchense and Micrasterias apiculata. Forty-one taxa of desmids were identified as new records for Thailand. Presented at the 6th Meeting of the Asian Pacific Society of Applied Phycology, Manila, Philippines.  相似文献   

15.
Higher‐level relationships within Aedini, the largest tribe of Culicidae, are explored using morphological characters of eggs, fourth‐instar larvae, pupae, and adult females and males. In total, 172 characters were examined for 119 exemplar species representing the existing 12 genera and 56 subgenera recognized within the tribe. The data for immature and adult stages were analysed separately and in combination using equal (EW) and implied weighting (IW). Since the classification of Aedini is based mainly on adult morphology, we first tested whether adult data alone would support the existing classification. Overall, the results of these analyses did not reflect the generic classification of the tribe. The tribe as a whole was portrayed as a polyphyletic assemblage of Aedes and Ochlerotatus within which eight (EW) or seven (IW) other genera were embedded. Strict consensus trees (SCTs) derived from analyses of the immature stages data were almost completely unresolved. Combining the adult and immature stages data resulted in fewer most parsimonious cladograms (MPCs) and a more resolved SCT than was found when either of the two data subsets was analysed separately. However, the recovered relationships were still unsatisfactory. Except for the additional recovery of Armigeres as a monophyletic genus, the groups recovered in the EW analysis of the combined data were those found in the EW analysis of adult data. The IW analysis of the total data yielded eight MPCs consisting of three sets of two mutually exclusive topologies that occurred in all possible combinations. We carefully studied the different hypotheses of character transformation responsible for each of the alternative patterns of relationship but were unable to select one of the eight MPCs as a preferred cladogram. Overall, the relationships within the SCT of the eight MPCs were a significant improvement over those found by equal weighting. Aedini and all existing genera except Ochlerotatus and Aedes were recovered as monophyletic. Ochlerotatus formed a polyphyletic assemblage basal to Aedes. This group included Haemagogus and Psorophora, and also Opifex in a sister‐group relationship with Oc. (Not.) chathamicus. Aedes was polyphyletic relative to seven other genera, Armigeres, Ayurakitia, Eretmapodites, Heizmannia, Udaya, Verrallina and Zeugnomyia. With the exception of Ae. (Aedimorphus), Oc. (Finlaya), Oc. (Ochlerotatus) and Oc. (Protomacleaya), all subgenera with two or more species included in the analysis were recovered as monophyletic. Rather than leave the generic classification of Aedini in its current chaotic state, we decided a reasonable and conservative compromise classification would be to recognize as genera those groups that are ‘weighting independent’, i.e. those that are common to the results of both the EW and IW analyses of the total data. The SCT of these combined analyses resulted in a topology of 29 clades, each comprising between two and nine taxa, and 30 taxa (including Mansonia) in an unresolved basal polytomy. In addition to ten genera (Armigeres, Ayurakitia, Eretmapodites, Haemagogus, Heizmannia, Opifex, Psorophora, Udaya, Verrallina and Zeugnomyia), generic status is proposed for the following: (i) 32 existing subgenera of Aedes and Ochlerotatus, including nine monobasic subgenera within the basal polytomy, i.e. Ae. (Belkinius), Ae. (Fredwardsius), Ae. (Indusius), Ae. (Isoaedes), Ae. (Leptosomatomyia), Oc. (Abraedes), Oc. (Aztecaedes), Oc. (Gymnometopa) and Oc. (Kompia); (ii) three small subgenera within the basal polytomy that are undoubtedly monophyletic, i.e. Ae. (Huaedes), Ae. (Skusea) and Oc. (Levua), and (iii) another 20 subgenera that fall within the resolved part of the SCT, i.e. Ae. (Aedes), Ae. (Alanstonea), Ae. (Albuginosus), Ae. (Bothaella), Ae. (Christophersiomyia), Ae. (Diceromyia), Ae. (Edwardsaedes), Ae. (Lorrainea), Ae. (Neomelaniconion), Ae. (Paraedes), Ae. (Pseudarmigeres), Ae. (Scutomyia), Ae. (Stegomyia), Oc. (Geoskusea), Oc. (Halaedes), Oc. (Howardina), Oc. (Kenknightia), Oc. (Mucidus), Oc. (Rhinoskusea) and Oc. (Zavortinkius). A clade consisting of Oc. (Fin.) kochi, Oc. (Fin.) poicilius and relatives is raised to generic rank as Finlaya, and Downsiomyia Vargas is reinstated from synonymy with Finlaya as the generic name for the clade comprising Oc. (Fin.) leonis, Oc. (Fin.) niveus and their relatives. Three other species of Finlaya?Oc. (Fin.) chrysolineatus, Oc. (Fin.) geniculatus and Oc. (Fin.) macfarlanei? fall within the basal polytomy and are treated as Oc. (Finlaya) incertae sedis. Ochlerotatus (Ochlerotatus) is divided into three lineages, two of which, Oc. (Och.) atropalpus and Oc. (Och.) muelleri, are part of the basal polytomy. The remaining seven taxa of Oc. (Ochlerotatus) analysed, including the type species, form a reasonably well‐supported group that is regarded as Ochlerotatus s.s. Ochlerotatus (Rusticoidus) is retained as a subgenus within Ochlerotatus s.s. Ochlerotatus (Nothoskusea) is recognized as a subgenus of Opifex based on two unique features that support their sister‐group relationship. A new genus, Tanakaius gen. nov. , is proposed for Oc. (Fin.) togoi and the related species Oc. (Fin.) savoryi. The taxonomic status and generic placement of all currently valid species of Aedini are listed in an appendix. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 142 , 289?368.  相似文献   

16.
The Family Thelastomidae (Thelastomatoidea; Oxyurida; Nematoda) is revised, genera are diagnosed and a complete list of species is given. The following genera, normally classified in the family, are not included: Linstowiella Basir is considered a member of the Pharyngodonidae and perhaps a synonym of Pharyngodon Diesing; Klossinema Lal is considered a synonym of Cephalobellus Cobb; Schubartnema Kloss is considered a taxonomic chimaera, the male corresponding to Carnoya Gilson and the female probably to Binema Basir. Two new species are proposed: Gryllophila bainae and G. klossae for material assigned to G. skrjabini (Sergiev) by Bain (1965) and Kloss (1959) respectively. The following new synonyms are proposed: Blattellicola Basir and Blatellicoloides Farooqui synonyms of Blatticola Schwenck; Basiriella Ahmed & Jabin synonym of Blattophila Cobb; Leidynema (Basiria) Farooqui synonym of Cranifera Kloss; Posterovulva Van Waerebeke synonym of Desmicola Basir; Oryctophila Van Waerebeke synonym of Johnstonia Basir; Panaesthiana Kloss synonym of Leidynemella Chitwood & Chitwood; Psilocephala Rao synonym of Cameronia Basir; Welchiella Gupta & Kaur synonym of Hammerschmidtiella Chitwood. The following new combinations are proposed: Blattophila basiri for Basiriella basiri Ahmed & Jabin, leaving Blattophila basiri Farooqui pre-occupied (and renamed B. farooquii); Cameronia psilocephala and C. aspiculata for Psilocephala psilocephala Rao and P. aspiculata Farooqui respectively; Corydiella mamba (Van Waerebeke) for Thelastoma mamba; Desmicola moramangi for Posterovulva moramangi Van Waerebeke; Johnstonia morondovae for Oryctophila morondovae; Leidynemella sphaeropoei for Oxyuris sphaeropoei Parona; Thelastoma aurangabadense, T. indica (preoccupied), T. mackenziei, T. thapari, T. unicoloris and T. welchi for Schwenkiella aurangabadense Farooqui, S. indica Rao & Rao, Suifunema mackenziei Zervos, Bulhoesia thapari Singh & Singh, Cephalobellus unicoloris Van Waerebeke and Schwenkiella welchi Farooqui, respectively.  相似文献   

17.
Five mutants of Escherichia coli K12 (lam 24, lam 25, lam 26, lam 27 and lam 646) that block head formation of λ are described. In vitro complementation tests and electron microscopy demonstrated that in these bacteria phage tails were produced normally, whereas head formation was abnormal, aberrant head-related structures being produced. In lysates prepared from lam 24, lam 25 and lam 26, monsters and empty heads without tail were the predominant structures, whereas in lysates from lam 27 and lam 646, petit λ and empty heads were the most common structures. The five lam mutations were located in two regions on the bacterial chromosome; lam 24, lam 25 and lam 26 were near the dnaB gene and lam 27 and lam 646 near the lac gene. It was suggested that the former three mutants are new isolates that belong to GroE mutants, whereas the latter two comprise a new group of mutants. Analyses of phage mutants (ov mutants) that overcome the interference by the lam 646 mutation revealed that this mutation blocks normal expression of the gene E of λ.  相似文献   

18.
Analysis of the rnc locus of Coxiella burnetii   总被引:4,自引:0,他引:4  
A 3.2 kb EcoRI genomic DNA fragment of Coxiella burnetii was isolated by virtue of Its ability to suppress mucoidy in Eschertchia coli. Nucleotide sequence analysis revealed the presence of the genes homologous to rnc, era and recO of E. coli. Suppression of capsule synthesis, measured by β-galactosidase expression in Ion cps-lac fusion strains of E. coli, is caused by gene-dosage effects of the plasmid-borne rnc genes of either C. burnetii or E. coli. The rnc gene of C. burnetii complemented rn– E. coli hosts for lambda plaque morphology and stimulation of lambda N gene expression. We also demonstrated heterologous complementation of an E coli strain defective for the expression of Era, an essential protein in E. coli, using the plasmid-borne C. burnetii era. Under the control of the bacteriophage lambda PL promoter, this 3.2 kb EcoRI DNA fragment directed the synthesis in E. coli of three proteins with approximate molecular masses of 35,27 and 25 kDa. Antibodies against purified E. coli Era protein cross-reacted with the 35 kDa protein of C. burnetii on Western blots.  相似文献   

19.
Macrolycus is a genus of net‐winged beetles with 69 species distributed in the eastern Palearctic and northernmost part of the Oriental region. The first molecular phylogeny of Macrolycus was produced using an rrnL + tRNA‐Leu + nad1 mtDNA fragment. The major lineages and species limits were identified with morphology and molecular data. We propose that Cerceros is a subgenus of Macrolycus to enable identification of all adult specimens in the genus without DNA sequencing. Two species groups are proposed in Macrolycus s. str. and six in Cerceros. Additionally, twelve Macrolycus species are newly described from China: M. aquilinus, M. baihualingensis, M. bicolor, M. guangxiensis, M. jianfenglingensis, M. kuatunensis, M. lizipingensis, M. parvus, M. phoeniceus, M. rhodoneurus, M. rosaceus and M. sichuanensis. Macrolycus holzschuhi is proposed to be a junior subjective synonym of M. jeanvoinei. The highest diversity of Macrolycus is found in southern China. The species from the main islands of Japan are placed in two species groups: M. excellens is a sister to remaining species of the M. murzini group and the M. flabellatus group is a monophylum of closely related species in a sister position to the M. bicolor group.  相似文献   

20.
The antifungal activities of volatile phase effects of essential oils from Origanum onites, O. syriacum, O. minutiflorum, O. vulgare, O, marjorana, Thymus vulgaris, T. serpyllum, Rosmarinus officinalis, Salvia officinalis and Micromeria fruticosa were evaluated for their ability to inhibit growth of three vegetative compatibility groups (VCGs) of Verticillium dahliae. Carvacrol was the main component of O. onites, O. minutiflorum and O. vulgare essential oils, while γ-terpinene was the main component of O. syriacum. P-cymene and thymol were the dominant component of T. vulgaris and T. serpyllum. β- thujone and l-camphor were the main component of S. officinalis. Polegone and isomenthone were the dominant components of M. fruticosa essential oil. Based on the in vitro test, the degree of fungistatical effects can be ranked in the following order of inhibition: O. syriacum = O. onites = O. minutiflorum = O. vulgare = T. vulgaris > T. serpyllum > M. fruticosa > S. officinalis = O. marjorana > R. officinalis. The essential oils of S. officinalis, O. marjorana and R. officinalis displayed moderate antifungal activity, that increased with increasing concentrations. Among the VCGs, VCG2A and VCG4B were found to be highly sensitive to the essential oils. The essential oils of O. syriacum, O. onites, O. minutiflorum, O. vulgare and T. vulgaris were the most efficacious, demonstrating strong antifungal activity against all of the tested VCGs of V. dahliae at relatively low concentrations and they could find practical application as natural fungicides in the prevention and protection of plants from V. dahliae infections.  相似文献   

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