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1.
Charles R. Gunn 《Brittonia》1972,24(2):169-176
The generic concept ofStictocardia is evaluated and accepted. Two species, whose nomenclature is interwoven withIpomoea alba andI. macrantha, are described, discussed, and illustrated.  相似文献   

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Medicinal uses ofOperculina turpethum by several groups of people are described, and linguistic evidence is used in connection with medicinal philosophies to reconstruct historic dispersal routes of the plants.  相似文献   

3.
The phylogeny ofFumariaceae, as inferred fromrps16 intron sequences, is compared with morphological data, and nrDNA-ITS. The different data sets are largely congruent and indicate that (1)Dicentra and the tribeCorydaleae as hitherto circumscribed are polyphyletic, (2)Lamprocapnos (=Dicentra spectabilis) is sister group to the rest of subfam.Fumarioideae, (3)Ehrendorferia, gen. nov. (=Dicentra chrysantha andD. ochroleuca) is basal in the latter group, (4) the morphologically aberrantIchtyoselmis, gen. nov. (=Dicentra macrantha) groups withDicentra s. str., (5) the genusCysticapnos should be included in the tribeFumarieae, (6)Dactylicapnos (=Dicentra subg.Dactylicapnos) is sister group toCorydalis, (7) the genusCorydalis is monophyletic, and consists of three subgenera:Chremnocapnos, stat. nov.,Sophorocapnos, stat. nov., andCorydalis. The following new combinations are validated:Ehrendorferia chrysantha, E. ochroleuca, Ichtyoselmis macrantha, andLamprocapnos spectabilis. Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday  相似文献   

4.
Two West Indian names inOperculina are briefly discussed and compared with the Old WorldO. turpethum (L.) S. Manso. The conclusions are made thatO. triquetra (Vahl) H. Hallier is a taxonomic synonym ofO. turpethum and thatO. ventricosa (Bertero) Peter may best be considered a variety ofO. turpethum. Typification ofOperculina is discussed, and it is found that, although S. Manso had a mixed concept ofO. turpethum, this species must be the type of the genus.  相似文献   

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The marine alga Valonia macrophysa contains in its cell sap K and Na in the proportion of 5.72 to 1. In a form regarded as closely related, Valonia ventricosa, growing in similar environment, the ratio of K to Na is as 0.0278 to 1. The former contains no Mg but in the latter it is present. There are other differences in the composition of the sap. These differences bring about a remarkable contrast in behavior in that Valonia ventricosa floats in sea water while Valonia macrophysa sinks.  相似文献   

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DNA base composition of species of the genusSaccharomyces   总被引:1,自引:0,他引:1  
DNA base compositions (GC content) ofSaccharomyces species are reported and discussed. Several amendments of the four groups given by van der Walt are suggested, viz. the transfer ofS. kluyveri to group 1, and ofS. eupagycus, S. cidri, S. montanus, S. microellipsodes andS. florentinus to group 2. The synonomy ofS. amurcae andS. cidri is suggested. The DNA base compositions revealed two possible pairs of sibling species:S. elegans andS. bailii, with a difference in GC content of 4.1%;S. dairensis andS. servazzii with a difference in GC content of ca. 3%.S. mrakii had a GC content of 47.3–48.5% the highest encountered in this genus and similar to that ofKluyveromyces thermotolerans.  相似文献   

10.
The chromosome ofAzotobacter vinelandii was digested with the restriction endonucleasesSpeI (5’-ACTAGT),DraI (5’-TTTAAA) andAsel (5’-ATTAAT) and the products were separated by pulsed-field gel electrophoresis. The sum of the sizes of the restriction fragments comes to around 4.5 megabasepairs. Our earlier studies had revealed the presence of about 80 copies ofnifH, nifD, nifK andleuB genes in a log-phase cell ofA. vinelandii. To determine whether there are multiple identical chromosomes inA. vinelandii or one large chromosome with identical segments joined in tandem, we have subjected gamma-irradiated DNA ofA. vinelandii andEscherichia coli to pulsed-field gel electrophoresis. The results suggest thatA. vinelandii chromosomes contain multiple identical chromosomes of about the same size as that ofE. coli.  相似文献   

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The chromosomes of different strains of the top or tree onion, ofAllium cepa andA. fistulosum, as well as of cloned progenies from reciprocal crosses between these two taxa have been studied by application of Feulgen- or aceto carmine-, Giemsa- and silver staining. It was possible to differentiate between the satellite chromosomes and 2–4 other chromosome pairs ofA. cepa andA. fistulosum. The phylogenetic origin of the top onions [A. ×proliferum (Moench)Schrad.] from hybridization ofA. cepa andA. fistulosum is substantiated, taking into consideration the variability in size and position of satellites and of active NORs.  相似文献   

14.
New species ofBletia from Mexico are described and illustrated:B. concolor, B. similis, andB. urbana. The identity ofB. campanulata Llave & Lex. is discussed, andB. reflexa Lindl. is considered to be a distinct species. Several South American epithets are treated as synonyms ofB. campanulata. A key to the recognized species ofBletia is given.  相似文献   

15.
The polyphyly ofSarcostemma sensu latu, suspected on morphological and karyological reasons is confirmed by analysis of thetrnL-F spacer region. With the exception ofCynanchum montevidense (subgen.Mellichampia, Sundell 1981), Old World and New World taxa belong to different clades.Sarcostemma sensu stricto andPlatykeleba show a strong affinity to Old WorldCynanchum; the affinities ofOxystelma cannot be determined at present.Philibertia andBlepharodon are sister groups, both are sister toFunastrum, andPentacyphus is basal to the New World clade.  相似文献   

16.
Endophytic plant symbionts can have powerful effects on the way their hosts interact with pathogens, competitors, and consumers. The presence of endophytes in plants can alter food webs, community composition and ecosystem processes, suggesting that endophyte-plant symbioses may represent unique forms of extended phenotypes. We tested the impact of the fungal endophyte Alternaria alternata (phylotype CID 120) on the allelopathic effect of the invasive forb Centaurea stoebe when in competition with the North American native bunchgrass Koeleria macrantha in a greenhouse competition experiment. The allelopathic effect of C. stoebe on K. macrantha when infected with the fungal endophyte was more than twice that of endophyte-free C. stoebe. However, this allelopathic effect was a small part of the very large competitive effect of C. stoebe on K. macrantha in all treatments, likely because of the priority effects in our experimental design. To our knowledge, these results are the first experimental evidence for a symbiotic relationship between plants and fungal endophytes affecting allelopathic interactions between competing plants, and thus provide insight into the mechanisms by which fungal endophytes may increase the competitive ability of their hosts.  相似文献   

17.
Tod F. Stuessy 《Brittonia》1969,21(4):314-321
The type species ofUnxia, U. camphorata, long considered as a species ofMelampodium, andPolymnia suffruticosa are regarded as congeneric, andUnxia L. f., which is closely related toPolymnia in the Melampodiinae, is re-established. A discussion of generic relationships is followed by a taxonomic treatment ofUnxia.  相似文献   

18.
Although the genetic polymorphism of the alcohol-metabolizing enzymes was extensively studied at the molecular level by many investigators, the genetic polymorphism studies for ethanolmetabolizing enzymes in Mongolians are very rare. The present study was therefore performed to determine the genetic distribution of various forms of alcohol-metabolizing enzymes such as alcohol dehydrogenase 2 (ADH2, currently accepted nomenclature ADH1B), ADH3 (ADH1C), aldehyde dehydrogenase 2 (ALDH2) and cytochrome P4502E1 (CYP2E1) in 300 healthy Mongolian males. Genetic polymorphisms were determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) methods. The allele frequencies ofADH2 *1 andADH2 *2 were 0.24 and 0.76;ADH3 *1 andADH3 *2 were 0.92 and 0.08;ALDH2 *1 andALDH2 *2 were 0.96 and 0.04; andCYP2E1 *C andCYP2E1 *D were 0.15 and 0.85, respectively. Compared to the results reported by other investigators, the allele frequencies ofALDH2 *2 andCYP2E1 *C among Mongolian subjects were much lower than among East Asians (Korean, Japanese, and/or Han-Chinese), while those ofADH2 andADH3 were more similar. Interestingly, this study shows that the ineffectiveALDH2 gene (ALDH2*2 allele) among Mongolians is not as common as among East Asians.  相似文献   

19.
Saccharomyces cerevisiae mutants which exhibit phenotypes (calcium resistance and vanadate sensitivity) similar to those of calcineurin-deficient mutants were isolated. The mutants were classified into four complementation groups (crv1,2,3 and4).crv1 was allelic tocnb1, a mutation in the regulatory subunit of calcineurin. The nucleotide sequences ofCRV2 andCRV3 genes which complemented thecrv2 andcrv3 mutations, respectively, are identical to those ofBCK1/SLK1/SKC1/SSP31 andMPK1/SLT2, respectively, which are both involved in the MAP kinase cascade. A calcineurin-deletion mutation (Δcnb1), which by itself has no detectable effect on growth and morphology, enhanced some phenotypes (slow growth and morphological abnormality) ofcrv2 andcrv3 mutants. These phenotypes ofcrv2 andcrv3 mutants were partially suppressed by Ca2+ or by overproduction of the calcineurin subunits (Cmp2 and Cnb1). Like the calcineurin-deficient mutant,crv2 andcrv3 mutants were defective in recovery from α-factor-induced growth arrest. The defect in recovery of the Δcnb1 mutant was suppressed by overexpression ofMPK1. These results indicated that the calcineurin-mediated and the Mpk1- (Bck1-) mediated signaling pathways act in parallel to regulate functionally redundant cellular events important for growth.  相似文献   

20.
Five species ofDimorphotheca, seventeen species ofOsteospermum, and one species each ofCastalis andChrysanthemoides were evaluated at Chico, California for crop potential as a source of dimorphecolic acid. Several species includingD. sinuata were highly susceptible to a number of diseases. Date of planting strongly influenced flowering period ofD. sinuata andD. pluvialis. D. cuneata showed the most promise for crop development. It had limited disease, relatively good seed retention and cold-tolerance, and considerable variability. With improved disease resistance,D. cuneata could be handled as a perennial seed crop. Its lightweight seed, an important disadvantage, is associated with a high proportion of winged to unwinged seeds.Osteospermum caulescens, O. ecklonis, andO. muricatum also have characteristics that favor crop development.O. ecklonis probably could be handled effectively as a winter annual. Seed of these three species had bushel weights of 30 to 41 pounds, compared with four to five pounds forD. cuneata andD. sinuata. Some preliminary germination work showed seed dormancy, which is probably associated with an after-ripening requirement. Overall, the agronomic characteristics that need improvement were disease resistance, seed retention, and seed form. Prospects for agronomic improvement of the most promising species should be good, because variability was evident even in small test populations.  相似文献   

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