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1.
The hypothesis of Henriques and Fernandes that several Iberian species of Narcissus ( Amaryllidaceae) are tristylous is reconsidered. Contrary to the opinion of Bateman and most subsequent authors, we believe that the available evidence indicates that some populations of N. triandrus and N. fernandesii, at least, are tristylous; other populations of N. triandrus are distylous. Hugonia cf. penicillanthemum ( Linaceae) from new Caledonia is distylous, but it remains possible that other species of Hugonia are tristylous. The disputed occurrence of heterostyly in S. African species of Bauhinia ( Leguminosae), Cleome ( Capparaceae) and Aneilema ( Commelinaceae), and in Agelaea ( Connaraceae) is discussed. 相似文献
2.
The nucleotide sequences of ten SP11 and nine SRK alleles in Raphanus sativus were determined, and deduced amino acid sequences were compared with those of Brassica SP11 and SRK. The amino acid sequence identity of class-I SP11s in R. sativus was about 30% on average, the highest being 52.2%, while that of the S domain of class-I SRK was 77.0% on average and ranged from 70.8% to 83.9%. These values were comparable to those of SP11 and SRK in Brassica oleracea and B. rapa. SP11 of R. sativus S-21 was found to be highly similar to SP11 of B. rapa S-9 (89.5% amino acid identity), and SRK of R. sativus S-21 was similar to SRK of B. rapa S-9 (91.0%). SP11 and SRK of R. sativus S-19 were also similar to SP11 and SRK of B. oleracea S-20, respectively. These similarities of both SP11 and SRK alleles between R. sativus and Brassica suggest that these S haplotype pairs originated from the same ancestral S haplotypes. 相似文献
3.
Parasitism of Lygus lineolaris (Palisot de Beauvois) eggs by three species of Mymaridae, Anaphes iole Girault, Erythmelus miridiphagus Dozier and Polynema pratensiphagum Walley and one species of Scelionidae, Telenomus sp., was investigated at Ste-Anne-de-Bellevue, Québec. The maximum level of field parasitism of L. lineolaris eggs by individual species was 15.4, 53.8, 70.0 and 16,7%, respectively.
Parasitoids were retrieved from eggs of L. lineolaris inserted in stems and branches of Amaranthus retroflexus L., Chenopodium album L., Coronilla varia L., Rumex obtusifolius L. and Solanum tuberosum L.
Amaranthus retroflexus and S. tuberosum sustained a large population of L. lineolaris and egg parasitism was high enough to consider it as a potential control factor.
相似文献
4.
The taxonomic positions of Retzia, Desfontainia, and Nicodemia have been much discussed, and all three genera have been included in Loganiaceae ( Gentianales). We have made a cladistic analysis of rbcL gene sequences to determine the relationships of these taxa to Gentianales. Four new rbcL sequences are presented; i.e., of Retzia, Desfontainia, Diervilla ( Caprifoliaceae), and Euthystachys ( Stilbaceae). Our results show that Retzia, Desfontainia, and Nicodemia are not closely related to Loganiaceae or the Gentianales. Retzia is most closely related to Euthystachys and is better included in Stilbaceae. The positions of Desfontainia and Nicodemia are not settled, but Desfontainia shows affinity for the Dipsacales s.l. and Nicodemia for the Lamiales s.l. 相似文献
5.
The serological reaction of seed proteins provides evidence for a partly new systematic arrangement of Cytisus sect. Trianthocytisus and of Cytisus s.l. Proposed modifications agree with recent advances in morphological taxonomy. Sect. Trianthocytisus includes only two species, C. villosus and C. aeolicus. Its position is central within the genus, and this fact agrees with the proposed retypification of Cytisus (type species: C. villosus). C. emeriflorus, formerly included in the same section, constitutes the monospecific sect. Emeroides, which is intermediate towards the genus Lembotropis. This is serologically isolated and includes only L. nigricans. It is confirmed that C. sessilifolius should be removed from the genus Cytisus as a monospecific genus: Cytisophyllum
Lang which is closely allied to Hesperolaburnum and to Podocytisus, the most primitive genera of Genisteae. 相似文献
6.
LTE1 encodes a homolog of GDP-GTP exchange factors for the Ras superfamily and is required at low temperatures for cell cycle progression at the stage of the termination of M phase in Saccharomyces cerevisiae. We isolated extragenic suppressors which suppress the cold sensitivity of lte1 cells and confer a temperature-sensitive phenotype on cells. Cells mutant for the suppressor alone were arrested at telophase at non-permissive temperatures and the terminal phenotype was almost identical to that of lte1 cells at non-permissive temperatures. Genetic analysis revealed that the suppressor is allelic to CDC15, which encodes a protein kinase. The cdc15 mutations thus isolated were recessive with regard to the temperature-sensitive phenotype and were dominant with respect to suppression of lte1. We isolated CDC14 as a low-copy-number suppressor of cdc15-rlt1. CDC14 encodes a phosphotyrosine phosphatase (PTPase) and is essential for termination of M phase. An extra copy of CDC14 suppressed the temperature sensitivity of cdc15-rlt1 cells, but not that of cdc15-1 cells. In addition, some residues that are essential for the Cdc14 PTPase activity were found to be non-essential for the suppression. These results strongly indicate that Cdc14 possesses dual functions; PTPase activity is needed for one function but not for the other. We postulate that the cooperative action of Cdc14 and Cdc15 plays an essential role in the termination of M phase. 相似文献
7.
Two lignicolous species of Mycena (Agaricales, Basidiomycetes) are described and illustrated from eastern, Japan: Mycena auricoma sp. nov., forming ephemeral coprinoid basidiomata and belonging to section Radiatae, was found on a dead fallen twig of Quercus serrata. It appears to close to a Malaysian species, “Trogia” crinipelliformis. Mycena spinosissima in section Sacchariferae, new to Japan, was collected from dead bark of Aphananthe aspera, a dead fallen inflorescence of Cryptomeria japonica, and a dead fallen twig of Quercus serrata. 相似文献
8.
Four collections of three species of Trimenia and one collection of Piptocalyx were studied; early-formed and later-formed wood was analyzed for one Trimenia. Liquid-preserved material permitted analysis of mucilage and starch storage in wood of T. neocaledonica and P. moorei. Because Piptocalyx is scandent whereas Trimenia is arborescent, wood differences relative to evolution of a climbing habit could be examined. Piptocalyx contrasts with Trimenia in having wider vessels, more numerous per mm 2, resulting in a conductive area five times greater per unit area than that of the Trimenia woods averaged. Piptocalyx has appreciably fewer bars per perforation plate and thus much greater conductive area per perforation plate than have the species of Trimenia. Rays in Piptocalyx are much taller and wider than those of Trimenia. Wood of Trimeniaceae is highly primitive in its scalariform perforation plates, scalariform lateral wall pitting on vessels, relatively long vessels elements, and heterocellular rays. Imperforate tracheary elements are septate nucleate fibertracheids (or even libriform fibers) rather than tracheids, but loss of borders on pits (and thus lowered conductive function of the imperforate tracheary elements) can be explained by the development of these elements into starchstoring cells. Some fiber-tracheids in T. neocaledonica are enlarged mucilagecontaining cells. Details of vessel structure in Trimeniaceae are similar to those of Monimiaceae (s. s.), but similarity to some other lauralean (annonalean) families may be found: in mucilage presence, Trimeniaceae resemble Lauraceae rather than Monimiaceae. Wood of Trimeniaceae may be regarded as highly mesomorphic, corresponding to the moist habitats in which all of the species occur. 相似文献
9.
TrnL (UAA)-trnF (GAA) chloroplast DNA spacer sequences of three species of Monanthes, Sedum surculosum (= Monanthes atlanticum) and S. jaccardianum were compared. S. surculosum, the systematic position of which has been disputed ever since its discovery, shares a phylogenetically highly significant 70 bp deletion with S. jaccardianum. In addition to this large deletion the two Moroccan species of S. ser. Monanthoidea differ in three more indels as well as in four nucleotide substitutions from the species of Monanthes. These data render strong support for the monophyly of S. ser. Monanthoidea and Monanthes. Spacer length in seven species and one subspecies of Monanthes is relatively uniform. 相似文献
10.
Recent systematic studies of Bartsia and Odontites showed the necessity to exclude the closely related perennial species Bartsia aspera (Portugal and northern Morocco) and Bartsia spicata (Central Pyrenees) from the genus Bartsia as a segregate genus named Nothobartsia. Morphologically this new genus combines characteristic features of Bartsia and of Odontites. Its autonomous systematic position is supported by the cladistic analysis, showing that Nothobartsia represents a relatively primitive genus standing close to the common ancestral root of Bartsia, Euphrasia, and Odontites. 相似文献
11.
Intergeneric crosses were made between representatives of the genomically-defined genera Elymus, Agropyron, Elytrigia, Pseudoroegneria, and Thinopyrum. The genomic constitution of Elytrigia repens, the type species of Elytrigia, is shown to be SSH, a genomic combination otherwise found only in Elymus. The S genome of Pseudoroegneria 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 in Thinopyrum 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 SJ e, J e, J eJ b, and J b 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), and Thinopyrum (SJ, SJJ, J) are best treated as a single genus, Elymus, following the generic concept of Melderis in Flora Europaea and Flora of Turkey. The basic genomic constituents of Elymus 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 in Triticeae. In a few species of Elymus and Pseudoroegneria, a P genome is an additional constituent. In these cases the P genome has a negligible morphological influence. Therefore, it seems reasonable to maintain Agropyron as a separate genus. 相似文献
12.
An investigation of pseudocopulation behaviour in species of Ophrys from southern Spain confirms the close relationship between Campsoscolia ciliata ( Scoliidae) and Ophrys speculum, and between Eucera nigrilabris ( Apoidea) and Ophrys tenthredinifera. It could be demonstrated that Eucera barbiventris is the pollinator of Ophrys scolopax subsp. scolopax, whereas other species of Eucera and Tetralonia which are active at the same time show no interest at all for the flowers of this species. Special attention was paid to the forms of the taxonomically confused Ophrys fusca group: O. fusca s. str., O. iricolor, O. omegaifera and O. atlantica. While O. fusca s. str. is widespread, small-flowered and has late anthesis, O. iricolor has very large flowers and early anthesis. Each of the four members of O. fusca agg. in S. Spain is pollinated by a different bee, and selective experiments show that each of these four species of bees is specifically attracted only to one of the Ophrys species: Andrena flavipes is the pollinator of O. fusca s. str., Colletes cunicularius infuscatus of O. iricolor, Anthophora atroalba of O. omegaifera, and Chalicodoma parietina of O. atlantica. These four pollinators belong to 4 different bee families ( Andrenidae, Colletidae, Anthophoridae, Megachilidae). As this type of pollination represents a very effective pregamic isolation mechanism, these four taxa of Ophrys fusca agg., at least in southern Spain, behave and should be regarded as genuine species. 相似文献
13.
Ambient light and the circadian clock have been shown to be capable of acting either independently or in an interrelated fashion to regulate the expression of conidiation in the ascomycete fungus Neurospora crassa. Recently several molecular correlates of the circadian clock have been identified in the form of the morning-specific clock-controlled genes ccg-1 and ccg-2. In this paper we report studies on the regulation of ccg-1, an abundantly expressed gene displaying complex regulation. Consistent with an emerging consensus for clock-controlled genes and conidiation genes in Neurospora, we report that ccg-1 expression is induced by light, and show that this induction is independent of the direct effects of light on the circadian clock. Although circadian regulation of the gene is lost in strains lacking a functional clock, expression of ccg-1 is still not constitutive, but rather fluctuates in concert with changes in developmental potential seen in such strains. Light induction of ccg-1 requires the products of the Neurospora wc-1 and wc-2 genes, but surprisingly the requirement for wc-2 is suppressed in conditional mutants of cot-1, a gene that encodes a cAMP-dependent protein kinase. These data provide insight into a complex regulatory web, involving at least circadian clock control, light control, metabolic control, and very probably developmental regulation, that governs the expression of ccg-1. 相似文献
14.
The floral biology of Tetrastylis ovalis and its pollination by bats was studied in southeastern Brazil. The flowers of T. ovalis seem more fitted to bat-pollination than those of Passiflora mucronata, the other known chiropterophilous passionflower. Two species of bats were observed visiting flowers of T. ovalis: the phyllostomids Glossophaga soricina and Rhinophylla pumilio. Due to the attributes of Tetrastylis, its presumed primitiveness and a better defined bat-pollination syndrome we suggest that chiropterophily evolved independently in the former genus and in Passiflora. 相似文献
15.
A taxonomic revision of Verbesina sect. Ochractinia is presented. 40 species plus 7 additional infraspecific taxa are recognized. A table of the distribution of the species, key to the species and synonymy are included. Relationships to other sections of Verbesina and species relationships within sect. Ochractinia are discussed. 相似文献
16.
The segment polarity genes wingless ( wg) and engrailed ( en) have been shown to play important roles in pattern formation at different stages of Drosophila development in the thoracic imaginai discs. We have studied the patterns of expression of these genes in genital discs from
wild type larvae, pupae and pharate adults and also from hetero-allelic mutant combinations of these genes. Our results suggest
that these genes play vital roles in the normal development and differentiation of genital discs and gonads. In the absence
of normal wg or en functions, the flies showed a complete lack of internal accessory reproductive organs and specific defects in the external
genitalia. In addition, the testes in such males were small, rounded and with an abnormal cellular organization, although
the ovaries in females appeared normal. Temperature shift experiments using the conditional mutant allele of wg, ( wg
IL-114
) indicated a requirement of wg signaling from second instar onwards for normal development and differentiation of the accessory reproductive organs. Using
a heat-shock allele ( Hs-wg) we also show that the spatially regulated expression of wg as a pre-requisite for normal development and differentiation. Based on the expression patterns of en and hedgehog ( hh) we suggest that even in the genital disc development and differentiation the action of en is mediated through hh. 相似文献
17.
Catinaria grossa is lichenized with Dictyochloropsis splendida var. gelatinosa, var. nova. When cultured isolated from the fungus the cells of this variety are covered individually by thick gelatinous envelopes. The phycobionts of Megalospora gompholoma subsp. gompholoma and M. atrorubicans subsp. australis belong to a new variety of D. symbiontica, i.e. var. pauciautosporica, which preferentially reproduces by zoo- and aplanospores. The phycobiont of Pseudocyphellaria aurata does not belong to Myrmecia reticulata as formerly thought, but to Dictyochloropsis symbiontica. Specimens from one locality in Tenerife and from New Zealand are lichenized with a strain of D. symbiontica var. symbiontica, those from another locality in Tenerife with a strain of D. symbiontica var. pauciautosporica. These strains differ in certain characters from other lichenized strains of these varieties. 相似文献
18.
RFLPs of cpDNA were examined for 18 species of Aster, six species of Kalimeris, two species of Miyamayomena and one species and one variety of Heteropappus from Japan, using 16 restriction endonucleases. Approximately 275 restriction sites were surveyed, and a total of 74 restriction
site mutations was detected, and 31 of these were phylogenetically informative. Sixteen most parsimonious trees constructed
from Wagner parsimony analysis indicated the polyphyly of Kalimeris and Miyamayomena sensu Kitamura; K. miqueliana belongs to a different clade from the remaining species of Kalimeris, and two species of Miyamayomena did not make a single clade. This result suggests that the shortening or loss of pappus have happened parallelly in different
evolutionary lineages. We must be careful to assess the pappus character in taxonomy and phylogeny, and it is desirable to
examine their phylogenetic relationships using a molecular data. 相似文献
19.
Summary Members of the Polycomb ( Pc) group of genes are required for the correct determination of segment identity, and are thought to be negative regulators of the bithorax and Antennapedia complexes. This hypothesis has been tested molecularly for only some members of the Pc group. Here, we examine the distribution of Ultrabithorax ( Ubx), Antennapedia ( Antp), and Sex combs reduced ( Scr) proteins in the epidermis, central nervous system, and midgut of embryos homozygous for mutations in ten Pc group genes. We show that zygotic loss of most Pc group genes causes ectopic expression of Ubx and Antp, but that there are differences in time and tissue-specificity. Five Pc group mutations lack midgut constrictions and also exhibit ectopic or suppressed Ubx expression and suppression of Antp expression. Distribution of Antp is upset earlier than distribution of Ubx in the central nervous system of every Pc group mutant affecting both genes. Loss of the zygotic products of Polycomb, extra sex combs, and Additional sex combs cause ectopic expression of Scr in epidermis, and all Pc group genes except Psc have suppressed Scr expression in the nervous system. These results are discussed with respect to the function of the Pc group. 相似文献
20.
The genusSabazia is expanded to include the genusTricarpha, Calea palmeri, and several newly described taxa,S. tridacoides var.tridacoides and var.latifolia, S. palmeri var.lancifolia, andS. longiradiata. Comparative studies of several morphological features suggest thatSabazia is most clearly related toSelloa andGalinsoga. Karyological data reinforce this observation: inSelloa andGalinsoga x = 8 whereas inSabazia x = 4 andn = 4, 8, 16, or 24. Several species ofCalea are very similar toSabazia in floral features and may be of close phyletic affinity, but most species ofCalea differ conspicuously, suggesting more remote relationships. Other taxa in the Galinsoginae apparently fairly closely allied toSabazia includeOteiza andTridax. 相似文献
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