Variation in Two Sorbus Species Endemic to the Isle of Arran, Scotland

A study of the morphology of plants from four species of Sorbus,S. arraensis, S. pseudofennica, S. aucuparia and S. rupicola,two of them endemic to North Arran, suggested that the originof the two endemic groups could have been by hybridization. Variation between individuals within the hybrid groups indicatesthat the two groups, probably of hybrid origin (S. arranensisand S. pseudofennica), could each consist of a set of geneticallyisolated clones reproducing by apomixis, with the possibilityin the case of S. pseudofennica of occasional genetic interchangeby sexual reproduction. The overlap of characters between the two hybrid groups suggeststhat the inflow of genetic material by hybridization and geneticmodification in these groups is continuing. Sorbus arranensis Hedl., Sorbus pseudofennica E. F. Warb., Sorbus aucuparia L., Sorbus rupicola (Syme) Hedl., interspecific hybridization, apomixis     

Water Distribution in Foliose Lichen Species: Interactions between Method of Hydration, Lichen Substances and Thallus Anatomy

Three lichens (Neofuscelia pokornyi, N. pulla and Xanthoriaparietina) from a semi-arid habitat were examined using low-temperaturescanning electron microscopy to evaluate the effects of hydrationmethod, lichen substances and thallus anatomy on the water distributionof hydrated thalli. In theNeofuscelia species, extracellularwater within the thallus was observed in association with cracksin its otherwise impervious upper cortex, while X. parietinashowed abundant extracellular water between medullary hyphae.Spraying the thalli followed by maintenance for 14–20h in a water-saturated atmosphere led to the disappearance ofthe external water film in X. parietina but not in the Neofusceliaspecies. Surface water was abundant in specimens of all speciesimmediately after spraying for 15 min. No extracellular waterwas observed inside the thallus 14–20 h after spraying,but after rinsing with acetone its presence was detected inall three species. Hydric strategy correlated with cortex hygroscopicity:X. parietina, an aero-hygrophytic species, had a more hygroscopicupper cortex than theNeofuscelia species, which are substrate-hygrophytic.The hygroscopicity of the upper cortex was linked with the amountof extracellular water in the thalline interior. Differencesbetween X. parietina and Neofuscelia in the polarity and distributionof their lichen substances agreed with species differences inthe presence and distribution of free water both as a film overthe surface and inside the thallus. Lichen substances appearto play a role in the maintenance of air-filled intrathallinespaces in species whose anatomy, habitat, or both, favour water-loggedconditions. Copyright 2000 Annals of Botany Company Lichen, water relations, semi-arid, lichen substances, LTSEM, thallus anatomy, extracellular water, Neofuscelia pokornyi(Körb.) Essl., Neofuscelia pulla(Ach.) Essl., Xanthoria parietina(L.) Th. Fr     

Acclimation of Respiratory Properties of Leaves of Spinacia oleracea L., a Sun Species, and of Alocasia macrorrhiza (L.) G. Don., a Shade Species, to Changes in Growth Irradiance

To clarify the way in which the light available for growth affectsrespiration in leaves of sun and shade plants, we examined therespiratory properties of mature leaves of Spinacia oleraceaL., a sun species, and of Alocasia macrorrhiza (L.) G. Don.,a shade species, that had been grown at various irradiances.In leaves of S. oleracea, the respiratory rates, on a dry massbasis, decreased with time during the night, and the higherwas the growth irradiance during the day, the higher was therespiratory rate. The marked decreases in the respiratory rateduring the night were accompanied by decreases in the concentrationof carbohydrates in the leaves. By contrast, the respiratoryrates of leaves of A. macrorrhiza were virtually constant throughoutthe night and the absolute rates were lower than those of S.oleracea even though the absolute value of the concentrationof carbohydrates and its decrease at night resembled to thosein S. oleracea. The maximum activities of respiratory enzymeswere also similar to those in S. oleracea. However, the leavesof A. macrorrhiza contained less soluble protein than thoseof S. oleracea. These results suggest that, in S. oleracea,the concentration of carbohydrates might determine the respiratoryrate while such is not the case in A. macrorrhiza. The lowerrespiratory rates in A. macrorrhiza might be due to a lowerdemand for ATP. (Received November 29, 1995; Accepted February 15, 1996)     

The Pattern of Respiration Rate in the Vegetative Barley Plant

In two experiments with young barley plants, respiration rate,carbohydrate content and growth rate of the whole plant weremeasured. When 18-day-old plants were darkened the rate of respirationand the levels of soluble carbohydrate fell in parallel overthe following 30 h. When the dark respiration rate of plantswas followed from 7 to 24 days respiration rate and solublecarbohydrate levels did not change together, nor did the respirationrate (R) follow the empirical relationship with photosynthesis(P) and d. wt (W) R = aW + bP, suggested by McCree. Hordeum distichum L. (Lam), barley, respiration, carbohydrate content     

Influence of the 3'-UTR-length of mKIAA cDNAs and their Sequence Features to the mRNA Expression Level in the Brain

We have previously described the sequence features of 1500 mouseKIAA (mKIAA) genes in comparison with those of human KIAA genes(Okazaki, N., Kikuno, R., Inamoto, S., Hara, Y., Nagase, T.,Ohara, O., and Koga, H. 2002, DNA Res., 9, 179–188; Okazaki,N., Kikuno, R., Ohara, R., Inamoto, S., Aizawa, H., Yuasa, S.,Nakajima, D., Nagase, T., Ohara, O., and Koga, H. 2003, DNARes., 10, 35–48; Okazaki, N., Kikuno, R., Ohara, R., Inamoto,S., Koseki, H., Hiraoka, S., Saga, Y., Nagase, T., Ohara, O.,and Koga, H. 2003, DNA Res., 10, 167–180; and Okazaki,N., F-Kikuno, R., Ohara, R., Inamoto, S., Koseki, H., Hiraoka,S., Saga, Y., Seino, S., Nishimura, M., Kaisho, T., Hoshino,K., Kitamura, H., Nagase, T., Ohara, O., and Koga, H. 2004,DNA Res., 11, 205–218). To validate the orthologous relationshipbetween mKIAA and KIAA genes in detail, we examined their chromosomalpositions and evolutionary rate of synonymous substitutionsand confirmed that >93% of the mKIAA/KIAA gene pairs areorthologous. During the sequence analysis of mKIAA genes, wefound that 3'-untranslated region (3'-UTR) lengths of mKIAAand KIAA genes are extremely long. In the meanwhile, we havealso examined the tissue-specific expression of 1700 mKIAA genesusing cDNA microarray and verified predominantly their expressionin adult brain (Koga, H., Yuasa, S., Nagase, T., Shimada, K.,Nagano, M., Imai, K., Ohara, R., Nakajima, D., Murakami, M.,Kawai, M., Miki, F., Magae, J., Inamoto, S., Okazaki, N., Ohara,O. 2004, DNA Res., 11, 293–304). To connect these twoevidences, we statistically analysed the relationship betweenthem by using the mKIAA genes. Consequently, a positive correlationwas observed between the 3'-UTR lengths and the relative expressionintensities in adult brain. Furthermore, we searched sequenceelements in the 3'-UTR possibly related with their expressionand found some candidates regarding the brain-specific expression.     

The Effect of Wind Speed on Assimilation Rate--a Re-assessment

Deneke concluded from wind-tunnel experiments that CO₂ uptakeis increased by wind, but that this stimulation is proportionatelyless at higher wind speeds, and that above Ioo m./min. (I₆₇cm./sec.) no further increase results. His data in fact indicatea linear relationship between wind and assimilation rate overthe whole range investigated. The wind speeds he used were ofthe same order as those occurring in vegetation in the field. Published experiments on the effect of wind on dry-weight increase,on the other hand, show that wind reduces growth; but theseexperiments have used winds equivalent to 'gale' or 'hurricane',and at such speeds other, harmful effects of wind become important. Wind-tunnel investigations on stands of Brassica napus reconcilethese observations by showing growth-rates to increase withwind speed up to an optimum near 30 cm./sec., and to fall offat higher speeds. It is considered that the stimulating effectof wind on assimilation shown by Deneke's and these experimentsis likely to be significant in the field.     

农作物重大害虫发生规律研究与“九五”趋势分析

考查我国农作物重大害虫历史发生状况,研究粘虫Mythimna separata Walker、稻飞虱Nilaparvata lugens Sstal稻纵卷叶螟Cnaphalocrocis medinalis Guenee、二化螟Chilo sup pressalis Walker、三化螟Tryporyza incertulas Walker、麦蚜Schizaphis graminum Rondani、玉米螟Ostrinia furnacalis Guenee、棉铃虫Helicoverpar armigera (Hubner)等害虫的长期发生规律,初步发现粘虫、二化螟、稻飞虱、稻纵卷叶螟、玉米螟等长期变化有约16年周 期现象,稻飞虱、三化螟有12年左右周期性规律,二化螟、稻纵卷叶螟、麦蚜、棉铃虫等发生周期约11年。根据害虫规律性作出“九五”期间发展趋势预测。     

Episodic Growth and Relative Shoot: Root Balance in Loblolly Pine Seedlings

Leaf, root and stem systems of loblolly pine seedlings are characterizedby a seasonal periodicity in growth, during which they alternatein spurts of activity. Despite this periodicity, the allometriccoefficient describing the ratio of the relative growth ratesof leaf to root remains constant for at least the first twoyears of development. In part, constancy results from the inabilityof variation in the allocation of growth increment during briefperiods to change a pre-existing structure accumulated overthe life of the seedling. In addition, alternating periods ofleaf, root and stem growth may represent the action of feedbackmechanisms which operate to maintain an adaptive balance betweenorgan systems. Pinus taeda L., loblolly pine, allometric coefficient, homeostatic control of growth     

Waterlogging Stress and Ethylene Production in the Dune Slack Plant, Scirpus americanus

The sedge, Scirpus americanus Pers., grows in dune slacks andother freshwater and brackish water wetland communities. Whenwaterlogged in a greenhouse, the concentration of ethylene increased4-fold in stems of S. americanus plants. This increase was associatedwith a decrease in plant height and an increase in aerenchymaas exhibited under waterlogged conditions. Endogenous ethyleneproduction in S. americanus was compared to that in anotherdune slack species, Panicum amarulum, and also to Spartina aherniflorafrom a salt marsh. These species did not respond by increasingendogenous ethylene upon waterlogging. In the field, a 16 cmrainfall significantly increased the endogenous ethylene productionin S. americanus. As the water table subsided the concentrationof accumulated ethylene in stem tissue decreased. Exposure ofS. americanus to exogenous ethylene inhibited stem extensionand increased aerenchyma formation, thus linking ethylene tothe morphological characteristics of waterlogged plants of thisspecies. These experiments support the hypothesis that ethylenemodulates S. americanus morphology in natural waterlogged environmentsand may be of importance in adapting this species to life inthe wetland environment. Key words: Dune slack, waterlogging, ethylene     

Current progress in bioinformatics 2007

Briefings in Bioinformatics is pleased to present our thirdannual ‘Current Progress in Bioinformatics’ specialissue. As in previous years, we have attempted to identify excitingor emerging fields of bioinformatics, and have asked leadersin these fields to present a brief summary of progress overthe last 18–24 months and an annotated biography drawingattention to papers of particular significance. Each year, we have a logistical task of setting the order ofthe articles to appear in this volume. Typically, we organizethem based on the linear logic of biology's central dogma: fromDNA to RNA to protein to function and phenotype. The centraldogma has undergone a transformation in the     

The Potential of Two Perennial C4 Grasses and a Perennial C4 Sedge as Ligno-cellulosic Fuel Crops in N.W. Europe. Crop Establishment and Yields in E. England

Three perennial C₄ rhizomatous species, Cyperus longus L., Spartinacynosuroides and Spartina pectinata Link, were examined as potentialrenewable energy crops. These species are unusual among C₄ plantsin showing natural distributions which extend into cool temperateregions. This study examined whether these species could beestablished in the cool temperate climate of eastern Englandand whether they could consistently attain the relatively highdry matter yields associated with C₄ plants of warmer regions.Clonally produced material was planted in 1986, on two siteswith contrasting soil types in Essex, eastern England. Plantingwas within a randomized-block design incorporating replicatedplots of each species, both with and without fertilizer. Survivorshipand stem demography were monitored at monthly intervals from1986 to Jun. 1989 for stem recruitment and to Dec. 1991 forstem density. Yields were determined from 1987 (the year followingestablishment) to 1993. Survivorship of the planted propagules over the first 12 monthswas 92% for S. pectinata , 96% for S. cynosuroides and 100%for C. longus. Recruitment of new stems peaked in Apr. of mostyears, although a significant number of new stems appeared asearly as Feb. Stem death peaked in Sep. or early Oct. and allabove-ground stems had died by mid-Nov. Stem density trendsindicated that 2-4 years were required to reach a steady-statedensity, depending upon species. The stem density of the twoSpartina species had reached more than 1000 m^-2 in 1989 althoughthat of S. pectinata fluctuated considerably in the subsequentyears. C. longus stem density rose to approx. 600 m^-2 by 1988and did not change significantly in the subsequent years. In the 6 years following establishment, annual yields averagedacross all fertilizer treatments and both sites were 1·0,1·1 and 1·3 kg m^-2 for C. longus, S. cynosuroidesand S. pectinata, respectively. The average annual yield ofall three species at the site with the heavier soil was 1·3kg m^-2. This was significantly greater than the 1·0 kgm^-2 on the lighter soil. Nitrogen addition did not significantlyincrease yield. Even in the absence of any nitrogen addition,the annual yield of S. pectinata averaged 1·2 kg m^-2over the 6 years, with no evidence of any decline with the increasingage of the stands.Copyright 1995, 1999 Academic Press Cyperus longus, Spartina cynosuroides, Spartina pectinata, energy crop, dry matter yield     

四川西部蝇科三新种(双翅目：蝇科)

整理1979～1996年采自中国四川省西部的蝇类标本中,发现蝇科三新种：树棘蝇属 Potamia Robineau-Desvoidy, 1830一新种：鬃跗树棘蝇Potamia setitarsis sp. nov.; 胡蝇属 Drymeia Meigen,1826一新种：四川胡蝇Drymeia sichuanensis sp. nov; 池蝇属 Limnophora Robineau-Desvoidy, 1830一新种：灰黄池蝇 Limnophora cinerifulva sp. nov。模式标本存北京军事医学科学院医学昆虫标本馆。     

Relative Embryo Growth Rates in the Annual Cicer L. Species

Early embryo growth rates were studied in the nine annual speciesof Cicer L., namely, C. arietinum L., C. bijugum Rech., C. chorassanicum(Bge.) M. Pop., C. cuneatum Rich., C. echinospermum Dav., C.judaicum Boiss, C. pinnatifidum J. and S., C. reticulatum Lad.and C. yamashitae Kit. The number of embryo cells increasedexponentially with time and was log linear in all the species.Species differed in their mean cell doubling time (MCDT). Cicerechinospermum and C. yamashitae had, respectively, the longestand the shortest MCDT which ranged from 9.67 to 16.15 h forthe nine species. Failure of successful interspecific hybridizationbetween C. arietinum and the wild annual species was only partlyexplained by differences in MCDT of the parental species. Relativegenetic closeness still plays the major role in determiningsuccess of interspecific hybridization in Cicer. Chickpea, Cicer, embryo, interspecific hybridization, suspensor     

Litter Decomposition in Four Woody Species in a Mediterranean Climate: Weight Loss, N and P Dynamics

Decomposition dynamics in leaves and needles of two Mediterraneanshrubs and two pine species growing in the Sierra de Filabres(Almería, Spain) was investigated during 2 years usingthe litter bag technique. The species studied are representativeof the vegetation of the study area and differ greatly in theirfoliar traits. Results are discussed in relation to the initiallitter quality (C, N and P) and through the application of theexponential decay model. The mass lost at the end of study variedin the order: Pinus pinaster < Pinus nigra < Cistus laurifolius< Adenocarpus decorticans. Differences in annual rates ofdecomposition among species are consistent with the particularchemical and structural attributes of their leaves. The massof decomposing litter remaining after 2 years was positivelyassociated with the initial C:N ratio. Weight loss and nutrientrelease were fastest in the leguminous A. decorticans. The resultssuggest the importance of both structure and elemental concentrationof initial litter for decomposition dynamics in Mediterraneanspecies. Copyright 2000 Annals of Botany Company Adenocarpus decorticans Boiss., C:N ratio, Cistus laurifolius L., litter decomposition, litter quality, Mediterranean environments, nutrient dynamics, Pinus pinaster Aiton, Pinus nigra Arnold, single exponential model, Southern Spain     

Transgenic Crops: The Next Generation, or an Example of 2020 Vision

Genetically modified, i.e. transgenic crops, are now being grownon several million acres throughout the world, mainly in NorthAmerica. Most of these ‘first generation’ productshave specific agronomic traits designed to improve the efficiencyof production. For example herbicide tolerant soybean and insectresistant corn are the two most widely grown transgenic crops.Increasingly, the new transgenic varieties under test containproduct quality or other higher value traits intended to providespecific benefits to the end user whether it be the producerof specialist chemicals or the consumer. This review describesexamples of these ‘second generation’ traits andattempts to predict the range of household, medical, industrialand environmental products that might become available overthe next 20 years. Copyright 1999 Annals of Botany Company Transgenes, transgenic plants, genetically modified plants, genetically modified food, plant breeding.     

Predicting the Growth Interactions between Plants in Mixed Species Stands using a Simple Mechanistic Model

The Conductance model is a simple mechanistic model used topredict the growth of species in monoculture or mixtures fromparameter values derived from plants grown in isolation. Incontrast to many mechanistic models that require extensive parameterization,the Conductance model is able to capture the growth of a broadrange of species using a few simplified assumptions regardingplant growth and easily derived species-specific parameter values.We examine the assumptions within the Conductance model thattotal leaf area per plant is proportional to total plant weight,and that an isolated plant has a projected crown zone area thatis proportional to the 2/3 power of its weight. Power ratherthan linear relations were found between weight and leaf areafor Brassica oleracea, Daucus carota, Matricaria inodora, Solanumnigrum,Stellaria media , Trifolium repens and Veronica persica.For all seven species, the value of the power was less thanunity. All species also exhibited a power relation between crownzone area and weight, with the slope of this relation beingless than 2/3 for B. oleracea, D. carota and S. media. Althoughmorphology type accounted for some of the variation in the parametervalues relating to light interception, there were considerabledifferences between species within upright or prostrate foliagespecies groups. The Conductance model was used to predict yieldsof B. oleracea, S. nigrum and V. persica grown in both monocultureand binary weed-crop mixtures over a range of temporal and spatialscales. After calibrating the model to non-competing plants,the model was used to predict growth of the weed and crop speciesin contrasting densities and stand types. In some crop-weedcombinations, predicted crop and weed weights were within 17%of observed values, with no systematic deviations. In others,systematic and large deviations occurred.Copyright 2001 Annalsof Botany Company Brassica oleracea L., Daucus carota L., Matricaria inodora L., Solanum nigrum L.,Stellaria media L., Trifolium repens L., Veronica persica L., competition, growth, leaf area, crown zone area, light, shoot morphology, canopy architecture     

Transformation of Solarium and Nicotiana Species using an Ri Plasmid Vector

Davey, M. R., Mulligan, B. J., Gartland, K. M. A., Peel, E.,Sargent, A. W. and Morgan, A. J. 1987. Transformation of Solanumand Nicotiana species using an Ri plasmid vector.—J. exp.Bot. 38: 1507–1516. Five Nicotiana species (N. benthemiana, N. debneyi, N. occidentals,N. plumbaginifolia, N. tabacum) and three Solanum species (S.dulcamara, S. nigrum, S. tuberosum) were transformed by wild-typeand engineered Ri plasmids. Depending on the host plant, rootstransformed by Agrobacterium strain A4TIII with an Ri plasmidcarrying a chimaeric nopaline synthase-kanamycin resistancegene, were 3 to 40 times more resistant to kanamycin than rootstransformed by the wild-type plasmid of strain A4T. Similarly,plants regenerated from A4TIII-derived roots of N. debneyi,N. plumbaginifolia and N. tabacum were 8 to 16 times more resistantthan A4T plants, and survived at 400 µg cm³ of kanamycin.A4TIII plants of S. nigrum flowered in vitro at 600–1000µg cm³ of kanamycin. Transformed roots and most regeneratedplants synthesized Ri-speciflc opines, while DNA hybridizationconfirmed the presence of DNA homologous to that from wild-typeand engineered Ri plasmids in transformed plants of S. nigrum. Key words: Agrobacterium, Ri plasmid, transformed roots, plant regeneration, kanamycin resistance.     

Boron deficiency effects on peroxidase, hydroxyproline, and boron in cell walls and cytoplasm of Helianthus annuus L. hypocotyls

Boron-deficient sunflower hypocotyls have, on a fresh weightbasis, more cytoplasmic and cell wall peroxidase, more cytoplasmichydroxyproline but equal cell wall hydroxyproline, and slightlyless cell wall boron, than controls. Incubation of either Bdeficientor control cell wall suspensions with Sclerotium rolfsii culturenitrate released 80% of the peroxidase activity, but only 14to 30% of the hydroxyproline. This differential extraction suggeststhat the hydroxyproline-containing protein of cell walls isnot identical with peroxidase. Boron deficiency increased thesusceptibility of cell walls to degradation by fungal enzymes,as measured by release of peroxidase and hydroxyproline, butnot by reduction in dry weight. ¹Scientific article No. A1847, Contribution No. 4756 of theUniversity of Maryland Agricultural Experiment Station. Thisresearch represents part of a thesis for the M.S. degree, Universityof Maryland, by J.B.S., Jr. This paper is dedicated to ProfessorHugh G. Gauch on the occasion of his sixtieth birthday. (Received December 5, 1972; )     

Complementary Association of an Endophytic Red Alga and a Shell-encrusting Green Alga

Endophytic filaments of a red alga in the shell-encrusting greenalga Pseudulvella consociata S. & G. collected from subtidaland intertidal habitats in the San Juan Islands, WashingtonState, U.S.A., have been identified as Audouinella sparsa (Harvey)Dixon. The association appears to be complementary. Pseudulvella consociata, Audouinella sparsa, alage, Rhodophyta, Chlorophyta, endophyte