石耳科(子囊菌亚门)的间断分布和替代现象

本文报道了石耳科的两个亚洲的,也是美洲以外的新记录种,即角石耳与深色石耳。进一步证实了单果石耳在南大西洋的,即南美洲和南部非洲的间断分布。对于上述种类以及本科其它一些种类的间断分布和替代现象进行了分析讨论。     

CYTOGENETIC STUDIES IN THE DRYOPTERIS SPINULOSA COMPLEX. II.

Walker , S. (Liverpool U., England.) Cytogenetic studies in the Dryopteris spinulosa complex. II. Amer. Jour. Bot. 48(7): 607–614. Illus. 1961.—A comparison of the D. spinulosa complex, as represented in North America, is made with that in Europe. Although in North America, other Dryopteris species are known to hybridize with members of the complex, the report has been limited to species which compare directly with those in Europe. Three tetraploid species and 2 diploids, the latter representing at least 1 ancestral genome in the complex, are discussed together with the interspecific hybrids. Synthetic hybrids have been produced, involving taxa from both sides of the Atlantic. Evidence from these hybrids suggests that D. intermedia, of North America, and D. maderensis, of Madeira, are conspecific.     

New observations on Erioderma in North America

For the three species of Erioderma occurring in North America ( E . mollissimum (Samp.) Du Rietz, E. pedicellatum (Hue) P. M. Jørg. and E. sorediatun D. Gall. & P. M. Jørg), considerable range extensions are being reported together with ecological information that will help to understand the distribution of these lichens. Erioderma sorediatum has been recently discovered in North America by Sherwood and Pike (unpubl.), while E. mollissimum and E. pedicellatum are reported as new to Nova Scotia herein along with a number of new localities for the latter species in Newfoundland. Ongoing work on E. pedicellatum and its symbionts has been summarized and an attempt has been made to outline its possible postglacial history. It is postulated that the presently known ranges have been occupied by the lichen only within the past few thousand years (more recently in Europe than in North America), and that considerable migrations must have taken place prior to that. This is NRCC publication No. 20463.     

PHYLOGENETIC STUDY OF HEDYOTIS (RUBIACEAE) IN NORTH AMERICA

Lewis , Walter H. (Stephen F. Austin State Coll., Nacogdoches, Texas.) Phylogenetic study of Hedyotis (Rubiaceae) in North America. Amer. Jour. Bot. 49(8): 855–865. Illus. 1962.—Chromosome numbers for 39 taxa of Hedyotis separable into the subgenera Edrisia (Raf.) Lewis and Oldenlandia (L.) T. & G. are reported. The occurrence of basic numbers of x = 6, 7, 8, 9(10), 11, and 13, including infraspecific aneuploidy in H. nigricans (Lam.) Fosb., illustrates the importance of aneuploidy in the speciation of Hedyotis in contrast to most rubiaceous genera. In the North American subg. Edrisia, 25 species are ranked according to primitive and advanced expressions for 13 characters. It is postulated on the basis of these, ecologic, geographic, and chromosomal data that the x = 11 group gave rise to the x = 13 line by the gain of chromosomes and to the x = (10)9, 8, and 7 groups by reduction. Those species with a basic number of 6 are thought to have an Asian origin. Although aneuploidy has been dominant in the evolution of subg. Edrisia, only 12% of the species are polyploids. The development of polyploid races in 3 species, H. caerulea (L.) Hook., H. polypremoides (Gray) Shinners, and H. purpurea (L.) T. & G., however, suggests a greater role of polyploidy in the current evolution of Hedyotis.     

Resistance of Glycine species and various cultivated legumes to the soybean aphid (Homoptera: Aphididae)

The soybean aphid, Aphis glycines Matsumura, is a new pest of soybean, Glycine max (L.) Merr., in North America. It has become widespread on soybean in North America since it was first identified in the Midwest in 2000. Species of Rhamnus L. (buckthorn) are the primary hosts of A. glycines, and soybean is known as a secondary host. There is limited information about the secondary host range of A. glycines. Aphid colonization on various legume hosts was compared in choice experiments. Aphid colonization occurred on species in the genus Glycine Wild. No colonization occurred on Lablab purpureus (L.) Sweet, Lens culinaris Medik, Phaseolus vulgaris L., Pisum sativum L., or species of Vicia L. and Vigna Savi. Colonization was limited or aphids were transient on species of Medicago L., Phaseolus L., and Trifolium L. There were significant differences in aphid colonization among Medicago truncatula accessions with numbers ranging from 7 to 97 aphids per plant. Six Glycine soja Sieb. & Zucc. accessions were as resistant as G. max accessions to A. glycines; these may represent novel sources of A. glycines resistance not found in G. max. Antibiosis was found to play a large role in the expression of resistance in three of the G. soja accessions. Results of this study indicated that G. max and G. soja were the best secondary hosts of A. glycines; however, its secondary host range may include other leguminous species. Therefore, A. glycines did not seem to have a highly restricted monophagous secondary host range.     

African Hepatics: VIII. Diplasiolejeunea albifolia (Taylor) E. W. Jones comb.nov.

Abstract

The new combination Tetralophozia filiformis (Steph.) E. Urmi is proposed for Chandonanthus filiformis Steph. So far this species has been known only from Asia and N. America. Recent collections show it to occur also in Europe, in the Cantabrian Mts., Spain. Here it grows in sheltered places on siliceous rocks in oceanic conditions. From Tetralophozia setiformis (Ehrh.) Schljak. (=Chandonanthus setiformis) it is distinguished by its smaller size, the leaf lobes are always more than twice as long as wide and their margins are not inflexed towards the stem.     

Absence of genetic divergence between western corn rootworms (Coleoptera: Chrysomelidae) resistant and susceptible to control by crop rotation

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a major pest of corn, Zea mays L., in North America that has recently invaded Europe. A loss of ovipositional fidelity to cornfields has allowed the species to circumvent crop rotation as a means of control in part of its range in the United States. Analyses of variation at eight microsatellite loci provided no evidence for general genetic differentiation between samples of western corn rootworm collected in soybean, Glycine max (L.) Merr., fields and those collected in cornfields both inside and outside the rotation-resistance problem area. This result suggests that few or no barriers to gene flow exist between rotation-resistant and -susceptible rootworm populations. The implications of this result for the management of western corn rootworm in North America and Europe are discussed.     

Eragrostis scaligera ( Gramineae,Eragrostoideae) An overlooked species

Eragrostis scaligera Salzm. ex Steud., a native of northeastern Brazil, is redescribed and reported from Florida, the first record from North America. It has been mistaken forE. bahiensis Schrad. in Schult.,E. maypurensis (H.B.K.) Steud., andE. rufescens Schrad. in Schult., but is distinct in having axillary, intravaginal inflorescences in addition to terminal ones, and smooth, shining caryopses in which the longitudinal axis of the embryo is oriented at 45–90° to the axis between the style and attachment scars. The plants are tetraploid with the chromosome number 2n = 40 (n = 20).

     

Taxonomy and distribution of Clematis,sect. Atragene (Ranunculaceae), in North America

Two North American species ofClematis, sect.Atragene (L.) DC, are recognized.C. occidentalis (Hörnern.) DC. is divided into three varieties, native respectively to eastern North America, the Rocky Mountains, and the Cascade Mountains of Washington.C. columbiana (Nutt.) Torr. & Gray is divided into two extensively intergrading varieties, one prevailing in the southern Rocky Mountains, the other in the northern foothills and in outlying mountain ranges. After a study of the type specimen ofC. columbiana, it was concluded that this name should be applied to the species hitherto commonly known asC. pseudoalpina (O. Kuntze) A. Nels., rather than to the taxon with which it has usually been associated. The two species are evidently closely related and appear occasionally to have hybridized in nature.     

Evaluation of host range and larval feeding impact of Chrysolina aurichalcea asclepiadis (Villa): considerations for biological control of Vincetoxicum in North America

A biological control program has been initiated against European swallow-worts Vincetoxicum nigrum (L.) Moench. and V. rossicum (Kleopow) Barbar., which are invasive in North America. A population of the leaf beetle Chrysolina aurichalcea asclepiadis (Villa) originating from the western Alps has been under evaluation as a part of this program. The preliminary host range of C. a. asclepiadis was determined among 37 potential host plants. In addition, a prerelease impact study was conducted to determine the effect of larval feeding on the performance of V. nigrum. Under no-choice conditions beetle larvae completed development on nine plant species within the genera Artemisia and Tanacetum (Asteraceae) and Asclepias and Vincetoxicum (Apocynaceae). The host range of adults is broader than larvae (13 plant species within five genera received sustained feeding). Three of the six nontarget species supporting larval development are native to North America, however in separate oviposition tests, female beetles failed to produce eggs when confined to these hosts. In multiple-choice tests, neither larvae nor adults preferred Vincetoxicum spp. to nontarget species. Larval damage by C. a. asclepiadis at densities at and above five larvae per plant substantially reduced growth, biomass, and delayed reproduction of V. nigrum. However, this population of C. a. asclepiadis is polyphagous and unsuitable for biological control of Vincetoxicum because of potential risk of attack to Asclepias tuberosa L. and native North American Asteraceae, particularly Artemisia.     

Invasions by Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) in the Western Hemisphere: implications for South America

The multicolored Asian lady beetle, Harmonia axyridis (Pallas), native to Asia, has recently been detected in South America after successfully invading North America and Europe. This coccinellid is a voracious predator; therefore, it is popular and effective in biological control. Unfortunately, H. axyridis also has associated adverse impacts (i.e., as a household pest, pest of fruit production, and threat to non-target organisms). To predict the potential geographic extent of impacts of H. axyridis in South America we review the history of its invasion in the Western Hemisphere and address various factors critical to the future invasion (i.e., arrival, establishment, and spread) of new areas of South America. The likelihood of continued introductions (i.e., arrival) of H. axyridis to South America seems high, due to its popularity as a biological control agent and through accidental introductions. Establishment also seems likely in broad regions of South America. Climate matching with the native range suggested that much of southern South America may be suitable for establishment. In contrast, habitat matching with the native range suggested that northern South America may be more suitable. In addition, prey availability should not limit establishment of this predator. Once established, H. axyridis seems likely to spread by flight and human-assisted means. Overall, the invasion of H. axyridis over broad areas in South America seems likely.     

Native arbuscular mycorrhizal fungi (AMF) from mountain grassland (Cordoba, Argentina) I. Seasonal variation of fungal spore diversity

Arbuscular mycorrhizal fungi (AMF) were studied in the rhizosphere of 3 Poaceae with metabolic pathway C(3) (Briza subaristata Lam., Deyeuxia hieronymi (Hack.) Türpe and Poa stuckertii (Hack.) Parodi), 2 Poaceae with C(4) metabolic type (Eragrostis lugens Nees and Sorghastrum pellitum (Hack.) Parodi.), and a Rosaceae (Alchemilla pinnata Ruíz & Pav.) from a natural mountain grassland in Central Argentina (South America). Host species, their metabolic type, seasonal changes, and grazing effects over AM fungal diversity were analyzed. Seventeen mycorrhizal fungi taxa were found, widespread in all families of Glomales. Density of endomycorrhizal fungi was found to be strongly influenced with seasons and host metabolic pathway, although biodiversity (H), richness (S) and evenness (E) did not change. In most cases grazing did not affect these variables.     

Alien flora of India: taxonomic composition, invasion status and biogeographic affiliations

The wide knowledge gaps in invasion biology research that exist in the developing world are crucial impediments to the scientific management and global policymaking on biological invasions. In an effort to fill such knowledge gaps, we present here an inventory of the alien flora of India, based on systematic reviews and rigorous analyses of research studies (ca. 190) published over the last 120 years (1890–2010 AD), and updated with field records of the last two decades. Currently, the inventory comprises of 1,599 species, belonging to 842 genera in 161 families, and constitutes 8.5% of the total Indian vascular flora. The three most species-rich families are Asteraceae (134 spp.), Papilionaceae (114 spp.) and Poaceae (106 spp.), and the three largest genera are Eucalyptus (25 spp.), Ipomoea (22 spp.), and Senna (21 spp.). The majority of these species (812) have no report of escaping from cultivation. Of the remaining subset of 787 species, which have either escaped from intentional cultivation, or spread after unintentional introduction, casuals are represented by 57 spp., casual/naturalised by 114 spp., naturalised by 257 spp., naturalised/invasive by 134 spp., and invasive by 225 spp. Biogeographically, more than one-third (35%) of the alien flora in India has its native ranges in South America, followed by Asia (21%), Africa (20%), Europe (11%), Australia (8%), North America (4%); and cryptogenic (1%). The inventory is expected to serve as the scientific baseline on plant invasions in India, with implications for conservation of global biodiversity.     

中国梣属植物的研究(一)

梣属(Fraxinus L.),隶属于木犀科(Oleaceae)木犀亚科(Oleo-ideae)的梣族(Fraxineae),又称为白蜡树属,包括许多经济价值很高的乔灌木,有许多质地优良的用材树种以及绿化、观赏树种。白蜡树Frxinus chirensis Roxb。     

Fruit structure and generic delimitation of Athanasia (Asteraceae-Anthemideae) and related South African genera

Within South African Asteraceae-Anthemideae there is a group of genera containing furanosesquiterpenes rather than the common polyacetylenes. Of these genera, Asaemia (Harv.) Ham. ex Benth. & Hook., Athanasia L., Eumorphia DC., Gymno-pcnfzia Benth., Phymaspermum Less. and Sfilpnophyfon Less. have been investigated morphologically especially with respect to fruit structure. As a result of the investigations Stilpnophyton has been reduced to synonomy under Athanasia L. emend. Källersjö (with 36 spp.) and five species of Athanasia , together with Phaeocephalus S. Moore., are placed in the revived genus Hymenolepis Cass. (with 7 spp.). Brachymerk DC. and four misplaced species of Aihanasia are included in Phymaspermum Less. emend. Källersjö (with 17 spp.). Nine other misplaced species of Athanasia and one Pentzia Thunb. species have been described as a new genus Inulanihera Källersjö (with 10 spp.), a group without furanosesquiterpenes. The two monotypic genera Asaemia and Gymnopentzia , and Eumorphia (with 6 spp.) remain unchanged. The interrelationships of the genera possessing furanosesquiterpenes are shown in a cladogram. There are 25 new combinations in Afhanasia, Znulanthera, Hymenolepis and Phymaspermum .     

Brain and physics of many-body problems

Summary On the basis of a recent physical theory of many-body problems developped in our Institute, a model of the brain is formulated, and it is shown how some of its typical features, such as learning and memory processes, find therein a natural and simple explanation. In the Appendix a short surview of the necessary mathematical formalism is finally given.A brief outline of the model presented in this paper was unformally given by one of the authors (L.M.R.) at the I.S.P. Neurosciences Research Program; Boulder Colorado, in July 1966.This work has been sponsored in part by: Air Force Avionics Lab., Research and Technology Div., Wright Patterson Air Force, Air Force System Commend-U.S.A.F.-Government of United States of America. Contract No. AF 33(615)-2786.     

Festuca brachyphylla, F. saximontana and related species in North America

American material of Festuca brachyphylla Schult. & Schult., F. saximontana Rydb. and related species was studied. Based on morphology and anatomy F. brachyphylla was separated into three subspecies, two of which are only found in very restricted areas of the southern part of North America, one in California (ssp. breviculmis Frederiksen ssp. nov.) and one in Colorado and neighbouring states (ssp. coloraden–sis Frederiksen ssp. nov.). F. jenseni Gjaerevoll & Ryvarden was found to be the same as F. brachyphylla i.flavida Polun. and the forma level is chosen. F. brachyphylla var. groenlandica Schol. is raised to F. groenlandica (Schol.) Frederiksen. Within F. saximontana a new combination (f. saximontana Rydb. var. purpusiana Frederiksen & Pavlick) is made. American distribution of the taxa studied is mapped. A key including all the taxa has been prepared.     

Bryophytes as experimental models for the study of environmental stress tolerance: Tortula ruralis and desiccation-tolerance in mosses

The development of a complete understanding of how plants interact with the environment at the cellular level is a crucial step in advancing our ability to unravel the complexities of plant ecology particularly with regard to the role that many of the less complex plants (i.e., algae, lichens, and bryophytes) play in plant communities and in establishing areas for colonization by their more complex brothers. One of the main barriers to the advancement of this area of plant biology has been the paucity of simple and appropriate experimental models that would enable the researcher to biochemically and genetically dissect the response of less complex plants to environmental stress. A number of bryophytes model systems have been developed and they have been powerful experimental tools for the elucidation of complex biological processes in plants. Recently there has been a resurgent interest in bryophytes as models systems due to the discovery and development of homologous recombination technologies in the moss Physcomitrella patens (Hedw.) Brach & Schimp. In this report we introduce the desiccation-tolerant moss Tortula ruralis (Hedw.) Gaert., Meyer, and Scherb, as a model for stress tolerance mechanisms that offers a great deal of promise for advancing our efforts to understand how plants respond to and survive the severest of stressful environments. T. ruralis, a species native to Northern and Western North America, has been the most intensely studied of all bryophytes with respect to its physiological, biochemical, and cellular responses, to the severest of water stresses, desiccation. It is our hope that the research conducted using this bryophyte will lay the foundationfor not only the ecology of bryophytes and other less complex plants but also for the role of desiccation-tolerance in the evolution of land plants and the determination of mechanisms by which plant cells can withstand environmental insults. We will focus the discussion on the research we and others have conducted in an effort to understand the ability of T. ruralis to withstand the complete loss of free water from the protoplasm of its cells.