Stomatal opening in isolated epidermis of Commelina benghalensis L. heterophasic response to KCl concentration

The pattern of stomatal opening in epidermal strips detached from leaves of Commelina benghalensis was examined. Two different phases could be distinguished in the stomatal response to KCl, one at low concentrations of KCl (up to 60 mM) and the other at high KCl concentrations (above 100 mM). The stomatal opening at low KCl concentrations was stimulated remarkably by light or fusicoccin and was suppressed by abscisic acid. At higher KCl concentrations, the stimulation by light or FC as well as the inhibition by ABA was limited. Both phases of stomatal response to KCl were sensitive to carbonyl cyanide-m-chlorophenyl hydrazone. The results suggest that illumination or FC favours selectively stomatal opening only at low KCl concentrations. The ionic participation in the stomatal opening is similar to the heterophasic uptake of ions by plant cells/roots.Abbreviations FC fusicoccin - ABA abscisic acid - CCCP carbonyl cyanide-m-chlorophenyl hydrazone     

Reproductive effort and sex allocation strategy in Commelina benghalensis L., a common monsoon weed

Commelina benghalensis L. exhibits variability in both foliar and floral features; every plant bears three types of branches and four types of flowers. The branches are negatively geotropic, positively geotropic and diageotropic. The flowers are uni- or bisexual, chasmogamous and cleistogamous. This variability influences the breeding system as well as resource allocation to male and female functions. The plants allocate c. 15% of their total resources to reproduction, the major part of which (68.9%) is devoted to production of aerial branches. The proportion of reproductive effort (RE) allocated to various branch systems is correlated with the availability of resources at the time of their differentiation. The pollen/ovule (P/O) ratio, female : male biomass ratio and reproductive output vary between different flower and branch types; variation is more pronounced in the latter. These variations notwithstanding, the results are in line with Charnov's sex allocation theory. The cleistogamous flowers of aerial branches are, however, an exception, being male- rather than female-biased. The reason behind the deviation is, in all probability, their recent evolution from chasmogamous flowers.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 403−413.     

Parmelia pustulifera,a new lichen from southeastern United States

A new species inParmelia subgenusParmelia sect.Hypotrachyna,P. pustulifera, is described from southeastern United States. It is similar in chemistry and fine structure of the cortex toP. livida Taylor and in gross morphology toP. formosana Zahlbr.     

Investigation ofJuniperus species of the United States for new Sources of Cedarwood Oil

Economic Botany - The 11 taxa of Juniperus with widespread distribution in the United States and with significant biomass production were investigated to determine their yields of cedarwood oil and...     

Two new species of Gomphidius from the Western United States and Eastern Siberia

Study of the genus Gomphidius from recent material from Asia and North America has been carried out using traditional taxonomy combined with molecular systematics. Two new species of Gomphidius (G. borealis and G. pseudoflavipes) are described, one from Eastern Siberia and a second from rarely collected habitats in the Western United States. One taxon has the longest spores reported for the genus and the second species appears to be associated with a Siberian larch.     

Tricharia vezdae (Ascomycetes: Asterothyriaceae), a new lichen species from the southeastern United States

Tricharia vezdae is described as new from specimens collected in Tennessee, Louisiana and Florida. It is characterized by a corticolous habit, the presence of only a few sterile hairs, the unusual structure of the conidia-like hyphae on the hyphophores and of the ascospores.

     

Phytophthora irrigata, a new species isolated from irrigation reservoirs and rivers in Eastern United States of America

A new species of Phytophthora, previously referred to as the 'Dre I' taxon, is named Phytophthora irrigata. Isolates of P. irrigata morphologically and physiologically resemble Phytophthora drechsleri. They are heterothallic, produce nonpapillate sporangia, and grow well at 35 degrees C. The above two species differ significantly in uniformity of mycelium, presence of chlamydospores, DNA fingerprint, and sequences of multiple nuclear and mtDNA regions. Phytophthora irrigata produces smaller sporangia and a distinct DNA fingerprint. Sequence alignments in the ribosomal DNA internal transcribed spacer regions place Phytophthora fallax and Phytophthora captisoa as its closest relatives. The optimal temperature for culture growth is above 30 degrees C and the maximum temperature is 40 degrees C. This new species is abundant in irrigation reservoirs and natural waterways in Virginia and was also isolated in Pennsylvania.     

Description of two new species of Clivina Latreille (Coleoptera, Carabidae, Clivinini) from southeastern United States

Two new species of the genus Clivina Latreille are described. One, Clivina choatei Bousquet & Skelley, belongs to the nominotypical subgenus and is known from six specimens collected in northern Florida. The species is structurally similar to Clivina myops Bousquet, known only from the holotype found in North Carolina, but differs among others by its smaller size and wider elytral striae. The second species, Clivina alabama Bousquet, belongs to the subgenus Antroforceps Barr and is known from two specimens collected in north-central Alabama. The species is structurally most similar to Clivina sasajii Ball, known only from Latimer County in Oklahoma, but differs among others in the absence of eyes and in having the pronotum and elytra proportionally wider.     

A Brugia species infecting rabbits in the northeastern United States

Brugia sp. microfilariae were observed in more than 60% of wild rabbits collected on Nantucket Island, Massachusetts. The microfilariae measured 294-344 microns in length and had the characteristic subterminal and terminal nuclei observed in other Brugia microfilariae. The microfilaria is similar to those described for Brugia leporis in rabbits in Louisiana. This may be the Brugia species responsible for 21 documented cases of human infection in the northeastern United States.     

饭包草种子萌发过程中养分运输和 消耗的细胞学过程初探

对饭包草大粒种子萌发过程中胚结构变化、养分运输和肖耗的细胞学过程进行了观察.结果显示:种子萌发时萌发孔盖张开,胚根、胚芽、胚轴、子叶鞘和子叶柄突破种皮生长,子叶片呈球状留在胚乳内吸收营养;透射电镜观察显示胚乳养分运输主要通过传递细胞运输、穿壁运输、胞间通道运输三种方式;细胞内养分消耗过程是细胞程序性死亡的过程,多膜小体...     

The taxonomic status of Astragalus mokiacensis (Fabaceae), a species endemic to the southwestern United States

Astragalus mokiacensis has been a problematic species since it was first described in 1877. Every major revision delimited this taxon differently. A principal components analysis of morphological data from herbarium specimens was used to determine the affinities between type specimens and extant populations ofA. mokiacensis. The taxon recently recognized asA. lentiginosus var.trumbullensis is morphologically similar to the lectotype ofAstragalus mokiacensis. Astragalus lentiginosus var.trumbullensis is herein recognized as a lowelevation minor variant and considered a synonym ofA. mokiacensis. A taxonomic key and complete synonymy are included.     

Pseudaptinus (Thalpius) nobilis Liebke, new to the United States, and a key to the species of subgenus Thalpius LeConte in North America, including Mexico (Coleoptera, Carabidae, Zuphiini)

The Mexican carabid species Pseudaptinus (Thalpius) nobilis Liebke is documented from the United States for the first time based on two specimens captured in southeastern Texas. A new taxonomic key distinguishes the 10 members of subgenus Thalpius known in North America, including Mexico. Pseudaptinus (Thalpius) dorsalis, which is found to be highly variable in its dorsal coloration, is compared to similar Pseudaptinus (Thalpius) hoegei. Geographic ranges are extended for several species.     

Species displacements are common to two invasive species of leafminer fly in China, Japan, and the United States

Under field conditions, species displacements have occurred in different directions between the same invasive species of leafminers (Diptera: Agromyzidae). Liriomyza sativae (Blanchard) was displaced by L. trifolii (Burgess) in the western United States, with evidence suggesting that lower insecticide susceptibility of L. trifolii is a factor. However, in Japan, the opposite has occurred, as L. trifolii was recently displaced by L. sativae. This displacement is probably because of the higher fecundity of L. sativae and differential effects of parasitoids on the two leafminer species. Here, we carried out long-term surveys of these same two invasive leafminer species during January through March in 1999, 2007, and 2011, as well as June through July in 2011, in eight locations (Sanya, Dongfang, Haikou, Leidong, Lingshui, Wuzhisan, Qionghai, and Danzhou) across Hainan Island of southern China. Our results indicate that, between 2007 and 2011, L. trifolii rapidly replaced L. sativae as the predominant leafminer of vegetables on Hainan Island, similar to the situation in the western United States. Further surveys of growers revealed that avermectins and cyromazine are the two most frequently used insecticides against leafminers on Hainan Island. Dose-mortality tests showed that L. trifolii populations from Hainan Island are less susceptible to avermectins and cyromazine compared with L. sativae populations. This lower insecticide susceptibility of L. trifolii may be associated with the displacement of L. sativae by L. trifolii, although additional ecological or environmental factors cannot be ruled out.     

The United States and the new law of the sea

Abstract

The official U.S. statement on the 32nd meeting of the International Whaling Commission (IWC termed the outcome a “modest success.”; However, from the point of view of conservationists—i.e., governments and private groups seeking greater protection for the world's endangered whales—the results of the 1980 IWC session can be described at best as satisfactory. The disappointing U.S. performance at this and other recent Commission proceedings strongly suggests the need for a reassessment of American cetacean policy and the way in which we pursue this policy in the IWC.

The discussion will begin with a review of U.S. objectives in the IWC in relation to national and international law governing cetaceans. The focus will then turn to the role played by the United States in the Commission's deliberations on selected issues in 1980. The conclusion will set forth recommendations for improvements in American policy and strategy in the IWC.