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1.
Summary In this communication four species each ofHelicomyces Linder andHelicosporium Nees are reported.Helicomyces hyderabadense, Helicosporium indicum andH. nizamabadense are reported as new species.Helicomyces fuscopes Linder,H. lilliputeus Moore andHelicosporium Neesii Moore are first records to India.  相似文献   

2.
The hypothesis ofHenriques andFernandes that several Iberian species ofNarcissus (Amaryllidaceae) are tristylous is reconsidered. Contrary to the opinion ofBateman and most subsequent authors, we believe that the available evidence indicates that some populations ofN. triandrus andN. fernandesii, at least, are tristylous; other populations ofN. triandrus are distylous.Hugonia cf.penicillanthemum (Linaceae) from new Caledonia is distylous, but it remains possible that other species ofHugonia are tristylous. The disputed occurrence of heterostyly in S. African species ofBauhinia (Leguminosae),Cleome (Capparaceae) andAneilema (Commelinaceae), and inAgelaea (Connaraceae) is discussed.  相似文献   

3.
The formation of sperm cells has been examined ultrastructurally in the tricellular pollen grains ofGalium mollugo L. (Rubiaceae).Trichodiadema setuliferum Schwantes (Aizoaceae), andAvena sativa L. (Poaceae). After detachement from the intine the generative cell of all three species lies free within the vegetative cytoplasm. The two sperm cells are built inTrichodiadema andAvena by a single separating wall, while inGalium mollugo two independent walls are formed. However, both mechanisms separate the two male gametes completely.  相似文献   

4.
    
Summary On the basis of electron micrographs of the egg cell ofPteridium aquilinum Mühlethaler andBell (1962) have recently cast doubt upon the generally accepted theory of the continuity of the plastids. They assert that the nucleus forms plastids and mitochondriade novo after the latter have been broken down and eliminated.Mühlethaler andBell mistakenly believe that these findings agree most closely with the genetical results ofBaur, Correns, Renner and others concerning a maternal inheritance of the plastids. In the present paper it is shown that the findings inOenothera can be understood only on the basis of a continuity of the plastids.  相似文献   

5.
V. Labeyrie 《BioControl》1959,4(1):43-46
Summary The Braconid,Chelonus contractus Nees, egg endoparasite ofPhthorimea ocellatella Boyd, in S.E. of France, presents only females in his progeny. Its breeding is easy with the help of the small wax moth:Gnorimoschema operculella Zell. The mass breeding is inspired from method that we established for the production ofMacrocentrus ancylivorus Roh.   相似文献   

6.
Intergeneric crosses were made between representatives of the genomically-defined generaElymus, Agropyron, Elytrigia, Pseudoroegneria, andThinopyrum. The genomic constitution ofElytrigia repens, the type species ofElytrigia, is shown to be SSH, a genomic combination otherwise found only inElymus. The S genome ofPseudoroegneria has almost always a dominant influence on the morphology of the taxa of which it is a component.Wang (1989) showed that the J genome inThinopyrum and the S genome have considerable homoeology, with a mean c-value of 0.35 in diploid SJ hybrids. A genetic coherence from S to SJe, Je, JeJb, and Jb can be expected, agreeing with the continuous morphologic variation pattern observed. Because of the absence of morphological discontinuities between the taxa,Pseudoroegneria (S),Elymus (SH, SY, sometimes with additional genomes),Elytrigia (SSH, SSHX), andThinopyrum (SJ, SJJ, J) are best treated as a single genus,Elymus, following the generic concept ofMelderis in Flora Europaea and Flora of Turkey. The basic genomic constituents ofElymus will then be the S and/or J genomes.Agropyron, with diploids, tetraploids, and hexaploids based on the P genome is morphologically distinct from other genera inTriticeae. In a few species ofElymus andPseudoroegneria, a P genome is an additional constituent. In these cases the P genome has a negligible morphological influence. Therefore, it seems reasonable to maintainAgropyron as a separate genus.  相似文献   

7.
Summary Cell extracts ofCandida guilliermondii grown ind-xylose,l-arabinose,d-galactose,d-glucose,d-mannose and glycerol as sole carbon sources possessed NADPH-dependent aldose reductase activity, but no NADH-dependent activity was detected.d-xylose andl-arabinose were the best inducers of aldose reductase activity. The highest enzyme activity ind-xylose orl-arabinose-grown cells was observed first withl-arabinose followed byd-xylose as substrates of the enzymatic reaction. However, only low activity was found ind-glucose,d-mannose andd-galactose-grown cells, indicating that these carbon sources cause catabolite repression. Enzyme activities induced ind-xylose-grown cells were twice as high as those obtained from the cells under resting conditions. Furthermore, the level of induction of aldose reductase activity depended on the initial concentration ofd-xylose. The present study shows that aldose reductase activity may be efficiently induced by pentose sugars of hemicellulosic hydrolysates and weakly by hemicellulosic hexoses.  相似文献   

8.
A recording technique for measuring the sugar uptake by cell suspensions using a polarimeter is described. The method makes it possible to calculate the uptake rates of the α-and β-anomers. The constitutive monosaccharide transport system ofSaccharomyces cerevisiae andSaccharomyces fragilis exhibits a higher affinity for the α-anomers ofd-glucose,d-manose andd-xylose than for the corresponding β-anomers, this resulting in a preferential uptake of the α-anomers from a mixture. The α-anomer ofd-xylose is preferred both during influx and efflux. The membrane transport ofd-xylose inSaccharomyces cerevisiae is not associated with a change of the anomer configuration. The facilitated diffusion system appears to possess a regulatory role for the utilization ofd-glucose andd-mannose in both yeast species investigated.  相似文献   

9.
The Gram-positive bacteriumCorynebacterium glutamicum is used for the industrial production of amino acids,e.g. ofl-glutamate andl-lysine. By cloning and expressing the various genes of thel-lysine pathway inC. glutamicum we could demonstrate that an increase of the flux ofl-4-aspartaldehydate tol-lysine could be obtained in strains with increased dihydro-dipicolinate synthase activity. Recently we detected that inC. glutamicum two pathways exist for the synthesis ofdl-2,6-diaminopimelate andl-lysine. Mutants defective in one pathway are still able to synthesize enoughl-lysine for growth but thel-lysine secretion is reduced to 50–70%. Using NMR-spectroscopy we could calculate how much of thel-lysine secreted into the medium is synthesizedvia the one and the other pathway. Amplification of the feedback-inhibition-insensitive-homoserine dehydrogenase and homoserine kinase in a highl-lysine-overproducing strain made it possible to channell of the carbon flow from the intermediate 4-aspartaldehydate toward homoserine, resulting in a high accumulation ofl-threonine. For a further flux froml-threonine tol-isoleucine the allosteric control of threonine dehydratase was eliminated. Dedicated to Dr. Z. Vaněk on the occasion of his 70th birthday Presented at theIUMS Congresses '94-7th International Congress of Bacteriology and Applied Microbiology Division, Prague, July 3–8, 1994 (Bacteriological Symposium BS-12Regulation of Microbial Product Overproduction).  相似文献   

10.
P. F. Galichet 《BioControl》1961,6(3):203-205
Summary Larvae ofDiparopsis watersi roths, are parasitized in the Tchad Republic by an unspecifiedMermitidae and byCarcelia evolans wied. (Tachinidae). TheMermis is only active during the rainy season, when 40% ofD. watersi larvae are commonly parasitized. More than one individual are able to develop inside the same host, a maximum of 44 being quoted; yet, solitaryMermis are of a greater length, the biggest recorded being 325 mm long. C. evolans is found all along the active life ofD. watersi. There is usually only one dipterous larva in each host: Out of more than a hundred cases, only twice two and thrice threeTachinidae were encountered in the same host. Evolution of theseC. evolans larvae is uncertain, only one of them developping into an adult. Association ofMermis andC. evolans, though exceptional, was also observed. This was described eight times through a three years survey; again, only one of the dipterous larvae developped into adult. The most extraordinary case reported concerns threeC. evolans encountered together with two Nematoda in the same host. An explanation to the unusual multiparasitism observed may be sought in an exceptional abundance ofC. evolans, combined with a relative scarcity of the host during the month of september 1956.   相似文献   

11.
Z. Mendel 《BioControl》1986,31(2):127-137
Information on parasitoids of bark beetles infesting conifers and broadleaves is presented to show the relations between host and parasitoid size, and parasitoid sex ratios. Sticky traps were employed to determine the sex ratios of parasitoid species operating on beetle-infested material. A wide range in body length was found for most species. Females ofCerocephala eccoptogasteri Masi,Cheiropachus quadrum Febr.,Eurytoma morio Boheman,Heydenia pretiosa Forster,Metacolus unifasciatus Forster,Rhaphitelus maculatus Walker andRoptrocerus xylophagorum (Ratz.) were usually significantly longer than their males, whereas the males of all fourDendrosoter spp. were significantly longer than the females. Body lengths of the males and females were almost identical inEntedon ergias Walker andEcphylus caudatus Rusch. The sex ratio varied markedly within most species; the mean ratio for 5 of them differed significantly from 1∶1. The sex ratio ofM. unifasciatus andE. morio was significantly related to host size. The sex-ratio of parasitoids trapped on sticky traps varied with time in relation to the phenology of the host beetle. Females were more numerous during the larvae development while males were more abundant between the pupal stage and emergence of the host. Male courtship behaviour ofDendrosoter caenopachoids Rusch.,D. protuberans (Nees),M. unifasciatus andR. xylophagorum is described. The effect of host size, the diversity in sex ratios, and possible interaction between parasitoid size and sex-ratio are discussed. Contribution from the Agricultural Research Organization, Bet Dagan, Israel. N° 1328-E, 1984 series.  相似文献   

12.
l-Methionine anddl-ethionine decreased production of thiolutin and aureothricin inStreptomyces kasugaensis. In the presence ofl-methionine the culture also produced 3-methylthioacrylic acid, 3-methylthiopropionic acid and 3,6-bis-(2-methylthioethyl)-2,5-dioxopiperazine. Production of the metabolites depended on the concentration ofl-methionine in the medium.  相似文献   

13.
Summary In brush border membrane vesicles from the midgut ofPhilosamia cynthia larvae (Lepidoptera) thel- andd-alanine uptake is dependent on a potassium gradient and on transmembrane electrical potential difference. Each isomer inhibits the uptake of the other form: inhibition ofl-alanine uptake byd-alanine is competitive, whereas inhibition ofd-alanine uptake byl-alanine is noncompetitive. Transstimulation experiments as well as the different pattern of specificity to cations suggest the existence of two transport systems. Kinetic parameters for the two transporters have been calculated both when Kout>Kin and Kout=Kin.d-alanine is actively transported also by the whole midgut, but it is not metabolized by the intestinal tissue.  相似文献   

14.
Matings and acts of cannibalism were observed in the crab spiderPhilodromus vulgaris, some of which were carrying a first-instar larva of the mantispidMantispa uhleri. Larval mantispids did not transfer during the copulation of their spider hosts but did switch from spider to spider during cannibalism. Twenty-three of 27 total cannibalisms in which the cannibalized spider carried a larva resulted in larval transfers, for a transfer rate of 85%. Copulation times inP. vulgaris were found to be extremely short in comparison to lycosids such asSchizocosa ocreata, whose long copulation time supports the larval transfer ofClimaciella brunnea. The time required for larval transfer during cannibalism inP. vulgaris was measured. Cannibalisms were much longer than copulations but larvae transferred to the cannibalizing spider in a comparatively short period of time.  相似文献   

15.
Molecular access to amino acid excretion by Corynebacterium glutamicum and Escherichia coli led to the identification of structurally novel carriers and novel carrier functions. The exporters LysE, RhtB, ThrE and BrnFE each represent the protoype of new transporter families, which are in part distributed throughout all of the kingdoms of life. LysE of C. glutamicum catalytes the export of basic amino acids. The expression of the carrier gene is regulated by the cell-internal concentration of basic amino acids. This serves, for example, to maintain homoeostasis if an excess of l-lysine or l-arginine inside the cell should arise during growth on complex media. RhtB is one of five paralogous systems in E. coli, of which at least two are relevant for l-threonine production. A third system is relevant for l-cysteine production. It is speculated that the physiological function of these paralogues is related to quorum sensing. ThrE of C. glutamicum exports l-threonine and l-serine. However, a ThrE domain with a putative hydrolytic function points to an as yet unknown role of this exporter. BrnFE in C. glutamicum is a two-component permease exporting branched-chained amino acids from the cell, and an orthologue in B. subtilis exports 4-azaleucine.  相似文献   

16.
In a survey at 5 sites in southern Romania for parasites of pupalLymantric dispar (L.), 8 species were recovered: 3Tachinidae (Dip.); Blepharipa pratensis (Meigen),Parasetigena silvestris (Robineau-Desvoidy), andExorista larvarum (L.); 1Chalcididae (Hym.); Brachymeria intermedia (Nees); 4Ichneumonidae (Hym.); Theronia atalantae atalantae (Poda),Coccygomimus instigator (F.),C. turionellae turionellae (L.), andEphialtes compunctor compunctor (L.). This was the 1 st reported recovery ofE. c. compunctor from L.dispar. Overall parasitism was low, and it is unlikely that additional surveys in this area will yield new parasites for introduction into the U.S.
Résumé Cinq localités dans le sud de la Roumanie ont été prospectées pour recenser les parasites des nymphes deLymantria dispar (L.). Huit espèces de parasites ont été obtenues:Blepharipa pratensis (Meigen),Parasetigena silvestris (Robineau-Desvoidy),Exorista larvarum (L.),Brachymeria intermedia (Nees),Theronia atalantae atalantae (Poda),Coccygomimus instigator (F.),C. turionellae turionellae (L.), etEphialtes compunctor compunctor. Cette dernière espèce étant nouvelle surL. dispar. Le parasitisme total étant très bas, les auteurs en déduisent que des prospections supplémentaires dans cette région ont peu de chance d'être valables en vue de l'introduction aux états-Unis de nouvelles espèces contreL. dispar.
  相似文献   

17.
The five annual species ofAdonis L., sect.Adonis, growing in Israel, form a series of diploid, tetraploid and hexaploid species. Their somatic chromosome numbers are 2n = 16 inA. annua L.,A. dentata Del. andA. palaestina Boiss., 2n = 32 inA. microcarpa DC., 2n = 48 inA. aestivalis L.; counts forA. dentata, A. palaestina andA. microcarpa are new records. There are indications that alloploidization may have been involved in the process of speciation in sect.Adonis. A taxonomic survey of the 8 species of the section reveals that a higher ploidy level is usually combined with a larger distribution area.  相似文献   

18.
The mycelium of the wood-rotting fungus,P. ostreatus, contains NAD-dependent glutamate synthase inhibited by azaserine.l-Glutamine andl-glutamate are the most important free amino acids in the mycelium. Feeding of the mycelium with nitrogenous substrates showed thatl-glutamate,l-aspartate andl-alanine are interconnected by way of transaminases. After the inhibition of glutamine synthetase by methionine-S-sulfoximine the synthesis ofl-glutamate was inhibited and the level of all free amino acids decreased. The15N-NMR spectra of mycelia after the addition of15NH4Cl confirmed that the GS/GOGAT is the only pathway of ammonia assimilation inP. ostreatus and NAD-glutamate dehydrogenase should be the deaminating enzyme.  相似文献   

19.
Penial morphology was studied in six preserved specimens of the Japanese macaque,Macaca fuscata. Structure of the glans penis and baculum inM. fuscata is essentially similar to that in the rhesus macaque,M. mulatta. With age the skin of the penis inM. fuscata apparently becomes progressively more darkly and extensively pigmented, and the baculum becomes progressively longer. One immature specimen examined, with penial skin unpigmented and baculum cartilaginous, appears to be abnormally retarded in penial development. Penial morphology suggests that the allopatric speciesM. fuscata, M. mulatta, M. cyclopis, andM. fascicularis constitute a closely interrelated group. Contrary to a previous report, there is no evidence that penial morphology inM. fuscata is transitional to that inM. radiata andM. sinica. InM. fuscata, M. mulatta, andM. fascicularis, latitudinal variation of body size and relative tail length conforms toBergmann's rule andAllen's rule; external proportions in three specimens ofM. cyclopis only partly conform to this pattern.  相似文献   

20.
Summary Pogonomyrmex colei is a workerless inquiline ant known only from nests ofP. rugosus, its closest relative. Ten of 776 (1.3%) host nests were parasitized at a site in central Arizona, while none of 1499 potential host colonies were parasitized at two other locales. Colonies ofP. colei are perennial, and host alate females in 9 of 10 colonies demonstrates that host queens survive parasitism. Three of 10 colonies died over 19 colony years of observation, while only 1 of 601 colonies became newly parasitized. Mating occurs in morning for up to 2–3 days following summer and fall rains and in afternoon during cool fall days. Mating is intranidal just outside the nest entrance, with males returning to the natal nest. MaleP. colei may be flightless because their wing area is reduced compared to host males. Females fly from the nest and locate potential host colonies by following trunk trails. Workers are the largest barrier to nest establishment, as they removed over 90% ofP. colei females placed in trunk trails or that entered host nests. Males and females ofP. colei andP. anergismus, the only other congeneric inquiline species, are diminutive compared to their hosts, with females 30% lighter than host workers. Fat content is lower and water content is higher inP. colei andP. anergismus females than in their hosts.  相似文献   

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