bluuebunny/crossref_metadata_2025 huggingface dataset:
CORE AND PERIPHERAL POPULATIONS AND GLOBAL CLIMATE CHANGE
Authors: Safriel Uriel N. , Volis Sergei , Kark Salit
Published: April 2013

Environmental conditions outside the periphery of a species' distribution prevent population persistence, hence peripheral populations live under conditions different from those of core populations. Peripheral areas are characterized by variable and unstable conditions, relative to core areas. Peripheral populations are expected to be genetically more variable, since the variable conditions induce fluctuating selection, which maintains high genetic diversity. Alternatively, due to marginal ecological conditions at the periphery, populations there are small and isolated; the within-population diversity is low, but the between-population genetic diversity is high due to genetic drift. It is also likely that peripheral populations evolve resistance to extreme conditions. Thus, peripheral populations rather than core ones may be resistant to environmental extremes and changes, such as global climate change induced by the anthropogenically emitted “greenhouse gases”. They should be treated as a biogenetic resource used for rehabilitation and restoration of damaged ecosystems. Climatic transition zones are characterized by a high incidence of species represented by peripheral populations, and therefore should be conserved now as repositories of these resources, to be used in the future for mitigating undesirable effects of global climate change. Preliminary research revealed high phenotypic variability and high genetic diversity in peripheral populations relative to core populations of wild barley and the chukar partridge, respectively.
EFFECTS OF PINE PLANTATIONS ON ULTRAMAFIC VEGETATION OF CENTRAL ITALY
Authors: Chiarucci Alessandro , De Dominicis Vincenzo
Published: April 2013

The influence of pine plantations on typical ultramafic plant communities of Tuscany was investigated by means of thirty 5 × 5 m plots in three environmental situations with different pine canopy cover. The main changes in natural vegetation were an increase in species richness and ground cover, resulting from the spread of alien grassland and woody species, and the almost complete disappearance of therophytes and some of the serpentine plants. The typical Armerio-Alyssetum bertolonii, an endemic garigue-steppe association characterized by large areas of bare soil, was modified into a grassland community with almost complete ground cover. The main soil changes associated with the presence of a pine canopy were found to be increases in depth and organic matter. Exchangeable cation concentrations increased with pedological evolution and were positively correlated with organic matter content. The positive relationships between soil metal ion content, species richness, and ground cover suggest that hydrological and nutritional soil characteristics were more determinant for typical ultramafic vegetation than soil metal toxicity. Artificial pinewoods may be a serious threat to biodiversity conservation, because the α-diversity increase found at the spatial scale of the present study would correspond to a β- and γ-diversity decrease should pine plantations spread to all ultramafic areas.
SEASONAL CAMBIAL ACTIVITY AND PHYTOGEOGRAPHIC ORIGIN OF WOODY PLANTS: A HYPOTHESIS
Authors: Fahn Abraham
Published: April 2013

An attempt was made to examine the hypothesis that the annual course of cambial activity is a permanent feature of each woody plant, related to its phytogeographic origin. Existing data on cambial activity in woody plants growing in Israel have been presented in a comprehensive diagram which shows a correlation between the course of activity and the phytogeographic origin of the various plants. Some attempts to prevent the occurrence of a period of cambial dormancy in plants which normally have such a period were unsuccessful.
SIGNIFICANCE OF THE ROOT SYSTEM IN VERTICILLIUM WILT TOLERANCE IN POTATO AND RESISTANCE IN TOMATO
Authors: (Lahkim) Leah Tsror , Nachmias Abraham
Published: April 2013

Reciprocal (susceptible/resistant) grafting experiments were used to determine whether the root is the major site of resistance to Verticillium wilt disease in tomato and tolerance in potato. Increased resistance/tolerance was seen in both species when the resistant cultivar served as rootstock. In potato, however, stem-dipping experiments indicated that tolerance was independent of the root. In experiments designed to determine whether a major gene plays a role in Verticillium wilt tolerance in potato, tomato races 1 and 2 of V. dahliae did not show differential pathogenicity on tolerant potato cultivars inoculated by the root-dip method. The results indicate that the root system plays an important role in the defense mechanisms to Verticillium wilt both in tomato and potato.
THE BREEDING SYSTEMS OF THREE ANNUAL CLOVERS NATIVE TO NORTH SYRIA
Authors: Pagnotta M.A. , Cocks P.S. , Snaydon R.W.
Published: April 2013

The breeding systems of three clovers (Trifolium stellatum, T. tomentosum, and T. campestre) were studied by measuring (a) seed production under forced selfing and crossing, and (b) morphological variation between and within families derived from seeds collected in the field. The results indicate that all three species are both self- and cross-compatible. However, since morphological variation within families was small compared with variation between families, the three species seem to be predominantly inbreeding in the field. This is confirmed by the fact that field populations are genetically heterogeneous and composed of mainly homozygous individuals.
ROOT ELONGATION IN VARIOUS AGRONOMIC CROPS BY THE PLANT GROWTH PROMOTING RHIZOBACTERIUM PSEUDOMONAS PUTIDA GR12–2
Authors: Hall Jeremy A. , Peirson David , Ghosh Sibdas , Glick R. Bernard
Published: April 2013

Seeds of canola, lettuce, tomato, barley, wheat, and oats were inoculated with either the wild-type plant growth promoting rhizobacterium (PGPR),Pseudomonas putidaGR12–2, or the mutantP. putidaGR 12–2lacd68 (deficient in the activity of the enzyme 1-aminocyclopropane-1-carboxylate deaminase) alone and in conjunction with either an inhibitor of ethylene biosynthesis, L-α-(aminoethoxyvinyl)-glycine (AVG), or the chemical ethylene generator, (2-chloroethyl) phosphonic acid (ethophon). For the different treatments, variations in root length under gnotobiotic conditions were compared. Canola, lettuce, tomato, and wheat responded to all of the treatments in a similar manner: The root lengths increased when seeds were treated withP. putidaGR 12–2 and/or AVG but not with the mutant strain, in comparison with a MgSO4control treatment, while the ethophon treatment inhibited root elongation. With barley and oat, none of the treatments had any effect on root lengths; however, when the ethophon concentration was increased, root elongation of these two plants was also inhibited. These observations are consistent with a model in which promotion of root growth byP. putidaGR 12–2 is a consequence of inhibition of ethylene production within the developing seedling.
CHEMICAL AND BIOLOGICAL PROPERTIES OF CULTURE FILTRATES OF WESTIELLOPSIS PROLIFICA AND CHAETOPHORA ATTENUATA
Authors: Agrawal S.C. , Sharma U.K.
Published: April 2013

Westiellopsis prolificaJanet andChaetophora attenuataHazen cultures released sugars (glucose, fructose, and sucrose), organic acids (oxaloacetic acid and oxalic acid), amino acids, and protein.W. prolificacultures released the amino acids glycine, serine, cystine, glutamic acid, aspartic acid, and α-alanine, while C.attenuatacultures released glycine, serine, aspartic acid, and α-alanine.W. prolificaand C.attenuatacultures of all ages released more extracellular protein than total free amino acids. Cultures ofC. attenuatareleased more protein than cultures of the same age ofW. prolifica.The filtrates from old cultures ofW. prolificaand C.attenuatadecreased the total chlorophyll content of all algae tested, totally suppressed conjugation inSpirogyra deciminoand zoospore formation in C.attenuata, and drastically decreased spore germination inW. prolifica, thus producing stressful conditions affecting the growth and reproduction of these and other algae.
ALLOZYME GENETIC AND CLONAL DIVERSITY WITHIN POPULATIONS OF CHIMAPHILA JAPONICA AND PYROLA JAPONICA (PYROLACEAE)
Authors: Chung Myong Gi , Kang Soon Suk
Published: April 2013

Chimapliila japonica Miq., a rhizomatous evergreen subshrub, and Pyrola japonica Klenze, an evergreen herbaceous perennial, occur mainly in conifer forests in East Asia. The levels of genetic variability within populations of C. japonica are fairly low, whereas those of P. japonica are less so. Mean percentage of polymorphic loci within populations (P p), mean number of alleles per locus across populations (A p), and mean population genetic diversity (He p) were 14.8%, 1.15, and 0.030 for C. japonica and 18.4%, 1.35, and 0.087 for P. japonica. The degree of population differentiation observed in C. japonica (mean G ST = 0.028) and P. japonica (mean G ST = 0.147) was lower than that in other plants with similar life history traits. Considering the habit and pollen and seed dispersal mechanisms, it is suggested that the low G ST of C. japonica is caused by unifying selection. For C. japonica, the mean number of multilocus genotypes per population sample (G/N = 0.19) and mean genotypic diversity index (DG = 0.69) were relatively low. On the other hand, relatively high values of clonal diversity were observed in P. japonica (G/N = 0.39 and DG = 0.93). For C. japonica and P. japonica, 14% (3/21) and 6% (5/81) of multilocus genotypes were “widespread genotypes” (genotypes occurring in more than 75% of the populations), whereas the proportions of “local genotypes” (genotypes occurring in only one population) were 33% (7/21) and 40% (22/81). About 50% and 20% of the total samples examined were homozygous multilocus-genotypes for C. japonica and P. japonica, respectively. Relatively high numbers of these genotypes and low levels of clonal diversity in C. japonica are responsible for the low levels of expected heterozygosity within populations of the species. The results indicate that, for C. japonica, clonal reproduction may act as an enhancer of genetic drift by reducing the effective size of local populations.
ASSESSMENT OF LICHEN SENSITIVITY TO CLIMATE CHANGE
Authors: Insarov Gregory , Insarova Irina
Published: April 2013

Experimental data on net photosynthetie rate change of lichens in response to temperature and water stress were collected and standardized. The method of nonuniform hierarchical structured data interpolation was applied to assess lichen sensitivity to climatic stress for species and territories where sensitivity has not been measured in a laboratory. The alternative method of lichen sensitivity to climatic stress assessment is the analysis of species ranges, abundance, and occurrence. This approach is especially effective for areas with a manifest climatic gradient and where multiple floristic zone boundaries occur. Assessments of sensitivity of the Negev Desert lichens to long-term temperature increase were obtained using the second approach.
EFFECT OF SUCCESSIONAL STAGES ON THE ESTABLISHMENT OF QUERCUS CALLIPRINOS IN AN EAST MEDITERRANEAN MAQUIS
Authors: Alon Gila , Kadmon Ronen
Published: April 2013

A sowing experiment was conducted to investigate whether and how secondary succession affects the establishment success of Quercus calliprinos, a leading species of East Mediterranean maquis. Acorns of Q. calliprinos were sown at equivalent densities in experimental plots representing three different stages of the succession: open patches (gaps) dominated by annual plants, patches of low woody vegetation dominated by the early-successional dwarf shrub Sarcopoterium spinosum, and patches of mature Q. calliprinos trees. These patch types represent early, middle, and late stages of the succession. Seedlings that emerged in the experimental plots were monitored for survival and growth during two successive years. Seedling emergence was lowest beneath the canopy of Q. calliprinos trees (2%), intermediate in patches of S. spinosum (54%), and highest in gaps (85%). Seedling survivorship exhibited an opposite pattern: 67% beneath the canopy of Q. calliprinos trees. 43% in patches of S. spinosum, and only 4% in gaps. The combined probability of pre-emergence and post-emergence survival was 23% in patches of S. spinosum, 3% in closed-canopy patches, and 1% in gaps. These results indicate that (I) secondary succession may have considerable effects on the establishment success of Q. calliprinos in Mediterranean maquis, and (2) post-emergence death of Q. calliprinos seedlings may modify patterns of establishment generated by earlier germination and emergence responses. The significance of these results for the natural dynamics and management of maquis dominated by Q. calliprinos is discussed with respect to the concepts of “regeneration niche” and “succession models”.
EFFECT OF THINNING AND GRAZING ON TREE DEVELOPMENT AND THE VISUAL ASPECT OF AN OAK FOREST ON THE GOLAN HEIGHTS
Authors: Kaplan Didi , Gutman Mario
Published: April 2013

An attempt to create an open woodland was made in Israel by opening large tracks of maquis thickets by hand, cutting out lower shrubs, and thinning, coppicing, and pruning desirable trees. Three treatments were compared: moderate, heavy, and control with no thinning.

The effects of the treatments on the visual transparency of the forest were measured by a transparency index defined as the maximum distance from which a vertical post 1.8 meters high could be fully observed.

In general, thinning caused a 38.0% increase in the diameter of all the trunks over a seven-year period for heavy thinning, compared with 26.4% and 12.8% in the moderate and control treatments, respectively. The difference between heavy and moderate thinning was not always significant.

A combination of thinning and grazing successfully created an open woodland, without additional input of resources.

The “transparency index” used in this study can be used as a quantitative measurement index for accessibility and aesthetics.
ABSCISIC ACID PRODUCTION BY PLEUROTUS FLORIDA CULTURED IN VARIOUS CONDITIONS AND ITS RELATION TO GROWTH
Authors: ÜNyayar Serpil , Topcuoglu Ş. Fatih , Bozcuk Suna
Published: April 2013

The levels of endogenous free, bound, and total abscisic acid (ABA) and the changes in dry weight of the mycelium depending on the culture periods were examined inPleurotus florida (Basidiomycetes)cultured both in shaking and static media. The relationship between ABA production and the growth rate of the fungus was determined. Our findings show that this fungus synthesizes ABA as a secondary metabolite and the maximum total ABA is produced on the 24th day of the growth period in both shaking and static conditions. It was observed that, depending on the culture period, the dry weight of mycelium was enhanced in the primary metabolic phase, while it was constant in the secondary metabolic phase.

These results show that there is a negative relationship between growth rate of the fungus and ABA synthesis.
ANALYSIS OF THE DISTRIBUTION OF EPIPHYTIC LICHENS ON QUERCUS PUBESCENS ALONG AN ALTITUDINAL GRADIENT IN A MEDITERRANEAN AREA (TUSCANY, CENTRAL ITALY)
Authors: Loppi Stefano , Pirintsos Stergios Arg. , De Dominicis Vincenzo
Published: April 2013

The distribution of epiphytic lichens onQuercus pubescensin Tuscany, central Italy, was studied by means of multivariate techniques along an altitudinal gradient from 0 to 900 m. Great differences in community structure were found and the altitude of 500 m was identified as an ecotone. Epiphytic lichen vegetation on trees below the ecotone varied significantly in relation to bark pH. Climatic parameters (temperature and rainfall) were probably related to altitude. Dust was probably responsible for the rise in bark pH. The distribution of lichen species in the sampling belts fitted the core-satellite hypothesis. The use of core and satellite species as biomonitors of air pollution and bioindicators of environmental conditions is discussed.
PHENOLOGY OF SPECIES BELONGING TO THE GENUS CYTISUS AND ALLIES (GENISTEAE: LEGUMINOSAE)
Authors: González-Andrés Fernando , Ortiz Jesüs-María
Published: April 2013

The phenology of nineteeen accessions belonging to fourteen shrubby species of the genus Cytisus and allied taxa (Genisteae: Leguminosae) has been studied. The species are potentially interesting for introduction in agroforestry systems, or non-irrigated gardens, in extreme-climated dry mediterranean areas. The methodology used for the description of the phenology was based on nine key phenophases. This system can be generally applicable to most of the shrubby species interesting for the above-mentioned purposes. Cytisophyllum sessilifolium started the growth season significantly later than the rest of the species. Bloom extended from mid-March for some of the species to the beginning of June for others, and maturation of pods from the end of March to the beginning of August. The dendrogram obtained on the mean dates for every phenophase contributes to support Chamaecytisus hirsutus and Chamaecytisus supinas as consistently different species, as well as the close relation between Cytisus villosus and the genus Chamaecytisus.
POLLINATORS' STRATEGIES IN FINDING FLOWERS
Authors: Menzel Randolf , Gumbert Andreas , Kunze Jan , Shmida Avi , Vorobyev Misha
Published: April 2013

Two phases of foraging flights of hymenopteran pollinators are discussed: localization of food sources over far distances (hundreds of meters to several kilometers); and spotting of flowers within their visual catchment area. In the first part, evidence from navigational tasks with honeybees is presented which favors the interpretation that bees possess a rich and unique spatial memory of qualified and localized objects. Depending on the motivation, the bee is rather free to navigate with reference to this memory. In particular, bees are guided towards feeding places with specific expectations of their signal and reward properties. In the second part, the processes guiding the bee during its final approach to the flower are analyzed. When arriving in the close vicinity of a rewarding flower, bees first detect and recognize the achromatic green signal and then the chromatic color signal. The dependence on the optical signals of the flowers and the habitat features is studied in a comparison between plants growing in the Israeli Mediterranean and desert habitats. We find that the green contrasts of flowers in desert plants are less prominent than in Mediterranean plants because the green signal of the desert background is more similar to that of flowers, not because the green signals of desert and Mediterranean plants are different. These results are interpreted on the assumption that the green signal of flowers used in further distance detection is an adaptive property of plant species only in the context of all features supporting navigation of insects. The low density growth of desert plants may allow for the possibility that the plants are located by insect pollinators as specified places relative to landmarks. Therefore, further distance visual signals emanating from the flower may be less important in a desert habitat, and reduced green contrast does not become an unfavorable property in desert plants. We conclude that both habitat features and flower signals contribute to the navigational system of insect pollinators, and that the evolutionary development of flower signals needs to be evaluated in the context of the plant species' habitat.
HIERARCHICAL USE OF INFORMATION BY NECTAR-FORAGING CARPENTER BEES ON VERTICAL INFLORESCENCES: FLORAL COLOR AND SPATIAL POSITION
Authors: Orth Afonso I. , Waddington Keith D.
Published: April 2013

In many plant species, the appearance of flowers and the production of nectar change with flower age. In species where flowers are arranged in groups, on inflorescences, the position of nectar and the appearance of flowers may have nonrandom spatial patterns. Flower visitors may learn the location of nectar in association with spatial position of flowers or floral color. We observed carpenter bees, Xylocopa micans, foraging at vertical inflorescences of three artificial flowers one of which always contained nectar. In ten treatments, we manipulated the color and spatial position of the nectar-bearing flower to learn how they detected its location. Bees arrived at all three flowers equally frequently when neither spatial nor color information was predictably associated with the nectar-bearing flower or when all flowers were the same color (only spatial information available). Bees arrived almost exclusively at the nectar-bearing flower if the color of that flower differed from the color of the two empty flowers on the same inflorescence. Only in the absence of previously learned color-nectar associations did bees arrive at the nectar-bearing flower using spatial information. Across the treatments, the number of flower visits per inflorescence was negatively correlated with the proportion of arrivals at the nectar-bearing flower. We conclude that carpenter bees used a hierarchy of information to learn the location of the nectar-bearing flower. Color was primarily used to find it, but when no information was given by color the bees used spatial information.
FORAGING CHOICES OF BUMBLEBEES ON EQUALLY REWARDING ARTIFICIAL FLOWERS OF DIFFERENT COLORS
Authors: Keasar Tamar , Bilu Yonatan , Motro Uzi , Shmida Avi
Published: April 2013

Laboratory-reared bumblebees were allowed to forage on 30 artificial flowers which were identical in morphology and reward schedule, but were marked by either a human-blue, a human-green, or a human-white landing surface. The probability of nectar rewards in the artificial flowers, and their spatial distribution, were manipulated experimentally. The bees' color choices in the different experimental treatments were compared.

The proportions of visits to the three colors deviated significantly from the expected random choice (1/3,1/3,1/3) for more than 50% of the bees. Of these bees, 38%, 32%, and 30% formed a preference for human-blue, human-green, and human-white, respectively. The frequency of nonrandom color choice, and the strength of the deviation from random choice, were highest when the different colors were placed in separate clusters, lower when they were placed in adjacent clusters, and lowest when they were randomly intermingled. Nonrandom color choice was also more pronounced when the bees were rewarded according to a constant schedule, rather than probabilistically. A statistically significant preference for human-blue was found during the bees' first three visits. The bees' tendency for “runs” of consecutive visits to the same flower color can partially account for their non- random color choices. Effects of innate preferences, early learning, generalization, and search-image formation on color choice are discussed.
THE EFFICIENCY OF THE STRATEGY OF MUCILAGINOUS SEEDS OF SOME COMMON ANNUALS OF THE NEGEV ADHERING TO THE SOIL CRUST TO DELAY COLLECTION BY ANTS
Authors: Gutterman Yitzchak , Shem-Tov Shachar
Published: April 2013

Groups of dry seeds of four annual plant species which occur in the Negev highlands were placed on a natural, dry or wet loess soil crust surface near Sede Boker on the Zin plateau during the autumn before the first rains, and on the first day with rain (1.15 mm). Ant nests ofMessor rugosuswere 8 to 14m from the experimental plot. The length of time it took these ants to collect the free or adhered seeds was observed. When the mucilaginous ombrohydrochoric seeds ofAnastatatica hierochuntica, Plantago coronopus, andCarrichtera annuaadhere to wet soil that remains moist, most of the seeds may have time to germinate in proper conditions before they are collected by ants. However, all but 5% of theReboudia pinnataseeds were collected within 2 h. The adhered seeds that had been moistened by wet soil crust and then dried, were collected by ants, in most cases, faster than when seeds and soil remained moist. Within 2 h none of the dry and free seeds situated on the dry soil surface remained. The first free seeds were collected after 7 min. Findings are discussed together with the mechanisms and strategies involved in seed dispersal by rain and germination of these plant species.
ROLE OF THE SEED COAT IN GERMINATION OF CISTUS POPULIFOLIUS L.
Authors: Pérez-García Félix , Escudero Adrian
Published: April 2013

Effect of mechanical scarification, dry heat, hot water, and sulphuric acid on the germination behavior ofCistus populifoliusL. (rockrose) was studied. Untreated seeds after 60 days of incubation germinated less than 7%. After thermal treatments, 90% germination was achieved, and sulphuric acid pretreatment gave 61% germination. Soaking in distilled water did not increase germination, but scarification of the seed coat gave 57%. Hardness and impermeability of the seed coat appear to cause deep dormancy inC. populifoliusseeds.
POLLEN AND NUTLET MORPHOLOGY IN MOSLA (LABIATAE) AND THEIR SYSTEMATIC VALUE
Authors: Zhou Shi-Liang , Pan Kai-Yu , Hong De-Yuan
Published: April 2013

An SEM study of pollen morphology inMoslaand the representative species of the allied genera,Collinsonia, Elsholtzia, Keiskea, Perilla, andPerillula, reveals that the pollen surface sculpture ofMosla(exceptM. cavaleriei) andPerillahas discontinuous ridges, while that of the other genera has the suprareticulate ornamentation. The nutlet surface ornamentation ofMoslaandPerillais also unique. Both pollen and nutlet morphology suggest thatMoslaandPerillaare the most closely related and highly specialized among these genera. The SEM examination of pollen and nutlet ofMoslaprovides no support to the sectional subdivision in this genus.
AEGIALOPHILA PUMILA (L.) BOISS. (ASTERACEAE): A NEW SPECIES IN ITALY
Authors: Tornadore Noemi , Marcucci Rossella , Marchiori Silvano
Published: April 2013

Aegialophila pumila has recently been found in Apulia, Salento, SE Italy, and is new for Italy. Karyological study shows 2n = 22, and the karyotype differs from populations found in Crete and Libya. The species shows a 99% germination of seeds. The environmental and karyological data suggest the hypothesis that Aegialophila pumila (L.) Boiss. is native to Apulia.
A SHORT HISTORY OF STABILITY AND CHANGE IN PHYTOPLANKTON POPULATIONS IN LAKE KINNERET
Authors: Berman Tom , Pollingher Utsa , Zohary Tamar
Published: April 2013

From the beginning of detailed routine monitoring in 1968 (and probably before) until the end of 1993, annual and seasonal development of phytoplankton in Lake Kinneret showed a relatively constant pattern. In the late winter and early spring there were extensive blooms of the dinoflagellatePeridinium gatunense, followed in summer and autumn by much lower standing stocks of predominantly nannoplanktonic chlorophytes. AlthoughMicrocystisspp. were prominent (usually concomitant with the dinoflagellates) in the early 1970s, subsequently this genus and other cyanobacteria were generally unimportant contributors to phytoplankton biomass. Since early 1994, however, a marked change in seasonal phytoplankton development has been noted. There were record high blooms ofPeridiniumin 1994 and 1995; in the following years, 1996 and 1997, no dinoflagellate bloom appeared. In the late summer and fall of 1994 an exceptional bloom ofAphanizomenon ovalisporumoccurred; this was the first recorded instance of an outgrowth of a potentially toxic and N2,-fixing filamentous cyanobacterium in this lake. This organism has been observed in low numbers in each subsequent year. In 1995, 1996, and 1997Microcystisalso became prominent. Levels of primary production since 1994 have generally been higher than previous multi-annual averages.

The quality of water in Lake Kinneret is to a large extent determined by the nature and activity of its phytoplankton community. Because of the lake's central role as a national supply source of good-quality water, the apparent breakdown of previously regular patterns of the annual and seasonal algal development is a cause for concern. Integrated research and monitoring are needed to fully explain the causes of the observed and ongoing changes and to provide guidelines for future management policies aimed at maintaining water quality in Lake Kinneret.
INORGANIC CARBON UTILIZATION AND GROWTH ABILITIES IN THE MARINE RED MACROALGA GELIDIOPSIS SP.
Authors: Israel A. Alvaro , Friedlander Michael
Published: April 2013

We studied the effects of NH4+, photosynthetic photon flux (PPF), and temperature on growth rates, together with inorganic carbon (Ci) utilization properties of Gelidiopsis sp. cultivated in tanks. At 25% sunlight, weekly growth rates and dry weight yields increased up to 6-fold with increasing NH4+(0–2 mM); however, at 5% or 100% sunlight the effects were much lower. Contents of photosynthetic pigments (chlorophyll a and phycoerythrin) increased in correlation with increases of NH4+. Maximal chlorophyll a concentrations occurred under high PPF, while phycoerythrin concentrations were higher at low PPF. Ash amounts in Gelidiopsis sp. did not vary significantly with different NH4+ or PPF levels. Optimal temperatures and PPFs for growth were 20–25 °C and 170–320 μmol m−2 s−1, respectively, correlating with short-term photosynthetic O2 evolution measurements. The pH of both thallus surface and bulk medium increased during photosynthesis, reaching average values of 8.75, and resulting in low rates of O2 evolution. Activities of carbonic anhydrase (CA) were detected inside and outside the cells and were apparently involved in the Ci uptake system of Gelidiopsis sp. since both acetazolamide (membrane-impermeable) and ethoxyzolamide (membrane-permeable) inhibited photosynthetic O2 evolution by 89% on average. Half-maximal rates of photosynthetic O2 evolution (K0.5) were reached at 17 μM CO2 at pH 5.0 and 2–3 mM Ci at pH 8.0, indicating high affinity for CO2 and close to saturated photosynthesis at Ci levels of seawater. Thus the Ci uptake system of Gelidiopsis sp. probably uses an extracellular CA catalyzed conversion of HCO3− to yield CO2, which could diffuse into the cells, and an intracellular CA catalyzed HCO3− ↔ CO2 interconversion which may assure CO2 for Rubisco. Direct uptake of HCO3− may also be required based on the K0.5 (CO2) estimated for Gelidiopsis sp. and the pH generated at the thallus surface at which CO2 concentrations would only be approximately 10 μM. Therefore, in addition to limitations of low NH4+ concentrations and high temperatures during the summer, growth of Gelidiopsis sp. from the Israeli Mediterranean may also be restricted by its limited Ci utilization system and the low CO2 concentrations prevailing in seawater.
WILD ROBUSTA COFFEE (COFFEA CANEPHORA FROEHNER) SEEDLING RECRUITMENT AND SURVIVAL IN KIBALE NATIONAL PARK, UGANDA
Authors: Oryem-Origa Hannington , Magambo MichaelJ.S. , Kasenene M. John
Published: April 2013

Survival of wild robusta coffee (Coffea canephora) seedlings on the forest understorey in Kibale National Park was monitored and analyzed in response to a number of mortality factors, such as fungal diseases, herbivory, desiccation, trampling, and litter of other plant species. A comparison was made with wild coffee seedlings germinated in the laboratory and transplanted in the Botanic Garden under two light conditions.

There was a general decrease in the number of coffee seedlings with time under all treatments and in all sites. Seedling mortality rate was initially rapid but later slowed down to a steady rate. Seedling mortality was highest on plots with intact ground vegetation cover and lowest on plots without ground vegetation and leaf litter. In the Botanic Garden, seedlings grown on plots partially illuminated had a much lower mortality rate and longer half-life than those grown on fully illuminated plots.

Fungal infection affected the largest percentage of coffee seedlings, followed by herbivory. Trampling had the least effect on coffee seedlings. The effects of all mortality factors on coffee seedlings decreased with age under all treatments.
PALYNOLOGICAL INTERPRETATION OF GAMMA RAY AND COLCHICINE INDUCED MUTATION IN CHRYSANTHEMUM CULTIVARS
Authors: Datta Kalyani , Datta K. Subodh
Published: April 2013

Palynological investigation on five cultivars ofChrysanthemun morifoliumRamat. and their induced somatic flower color mutants obtained through gamma irradiation and colchicine treatment has been carried out using LM and SEM. The objective of the work was to analyze the changes in the pollen morphology which occurred in mutagen-induced somatic flower color mutants and to verify if there is any correlation between the changes in flower color/type and pollen morphology. Chromosomal status of all the cultivars and their somatic mutants is hexaploid (6n= 54), but different types of chromosomal aberrations have been observed. Significant increase in pollen grain sterility was found in all the mutants. The pollen grains of all the cultivars and their mutants are basically 3(-4) zonocolporate with tectate spinose exine having perforations. No appreciable variation in pollen apertural character was noticed in any of the mutants. Significant changes in pollen exine surface pattern were found in 4 mutant varieties. The changes are inconsistent and do not correspond to the intensity of radiation.
15N NMR SPECTROSCOPIC STUDY OF AMMONIUM ION ASSIMILATION BY SPIRODELA OLIGORRHIZA—LEMNACEAE—AS AFFECTED BY LIGHT AND CARBON SUPPLY IN GREEN AND EXTOLIATED PLANTS
Authors: Monselise Edna Ben-Izhak , Kost Daniel
Published: April 2013

Nitrogen assimilation and amino acid production inSpirodela oligorrhizaplants exposed to 30 mM15NH4Cl was studied usingl5N NMR spectroscopy. Green and etiolated plants were studied under different light regimes and in the presence of added carbon, either as sucrose or as α-ketoglutarate. Etiolated plants are capable of ammonium assimilation and, as in green plants, this occurs via the glutamine synthetase/glutamine oxoglutarate amine transferase (GS/GOGAT) and the aspartate aminotransferase/asparagine synthetase pathways. The major assimilation products in both etiolated and green plants were glutamine and asparagine. Thus our results confirm that N-amides are key detoxification products when plants are exposed to external ammonium ion, and act as storage reservoirs or sinks for assimilated ammonium. In plants grown under continuous light, ammonium ion was taken up and assimilated to completion. L-methionine DL-sulfoximine, a GS inhibitor, inhibited ammonium ion assimilation but not its uptake. Addition of azaserine, a GOGAT inhibitor, resulted in the disappearance of α-amino signals, andl5N incorporation into the glutamine amide-N position only. This is evidence for the operation of the GS/GOGAT pathway, as opposed to the glutamate dehydrogenase (GDH) pathway, in both green and etiolated plants. Even in the dark and under various stress conditions, no sign of ammonium ion assimilation via the GDH pathway could be detected.

The amount of amino acid metabolites strongly depended on the light regime and the extent of external carbon supply. Supply of α-ketoglutarate to the etiolated plants increased ammonium ion uptake and assimilation. Ornithine and arginine were also formed, consistent with the operation of the ornithine cycle.
PCR-RFLP ANALYSIS OF THE CHLOROPLAST GENE trn K IN THE PINACEAE, WITH SPECIAL REFERENCE TO THE SYSTEMATIC POSITION OF CATHAYA
Authors: Wang Xiao-Quan , Han Ying , Hong De-yuan
Published: April 2013

The molecular phylogeny of the Pinaceae represented by 13 species of 10 genera was constructed from PCR-RFLP analysis of the chloroplast genetrnK, which was approximately 2557 bp long. Ninety-two restriction sites, of which 68 were variable, were identified by 16 restriction enzymes. Thirty-five of the 68 polymorphic sites were phylogenetically informative. The restriction site data were analyzed by PAUP (version 3.1.1) with both the Wagner parsimony method and the Dollo parsimony method. As a result, Dollo and Wagner parsimonious trees have similar topologies except for the position ofCedrus.TheAbies-Keteleeria-Tsuga-Pseudolarixclade was well resolved in all trees.Pseudotsugais closely related toLarix, whileAbiesis relatively closely related toKeteleeria.As an isolated genus,Cathayais distantly related to theAbies-Keteleeria-Tsuga-Pseudolarixclade, and is not very closely related to any other genus of the Pinaceae.
THE RELATIONSHIPS BETWEEN FRUIT RIPENESS, WASP SEED PREDATION, AND AVIAN FRUIT REMOVAL IN PISTACIA PALAESTINA
Authors: Izhaki Ido
Published: April 2013

Substantial variation in fruit removal between individual Pistacia palaestina plants was observed in northern Israel. To elucidate the causes of this variation, I examined several proximal sources of between-individual variation in fruit removal and dispersal efficiency. Crop size, tree height, and diameter explained some between- individual variation in fruit removal. Dispersal efficiency was mainly influenced by the proportion of the unripe fruits (including aborted and parthenocarpic fruits). Comparison of several reproductive parameters of P. palaestina with another Pistacia species (P. terebinthus) in Spain, revealed that P. palaestina produces larger fruit crop, faces higher seed prédation by infesting wasps, and has lower proportions of parthenocarpy and fruit abortion than Pistacia terebinthus. Fruit removal and dispersal efficiency of the former is much higher than the latter.
DO LIGHT AND LITTER INFLUENCE THE RECRUITMENT OF CISTUS SPP. STANDS?
Authors: Trabaud Louis , Renard Philippe
Published: April 2013

After a major disturbance (such as fire or soil upsetting), large numbers ofCistusspp. seedlings may appear and ensure population recruitment, but in the absence of such disturbances seedlings are rare or nonexistent in matureCistusstands. What are the causes? Two factors, little studied until now, have been examined: the influence of litter and of light reaching the soil surface. In two types of stands, one dominated by C.monspeliensisand the other byC. albidus, an experiment was undertaken by removing the vegetation cover and by the presence or absence of litter to examine the establishment of seedlings. The seed bank in the soil was also studied to determine its size. Seeds were also subjected to a temperature of 52 °C to simulate exposure to full sunlight in summer and determine whether this had any affect on their germination rate.

Light and litter had no effect on the germination, irrespective of the quality or intensity of light reaching the soil or the presence or absence of litter; there were always few seedlings and there was no significant difference in numbers between treatments. There was a large seed bank in the soil and these seeds were capable of germinating following experimental conditions: the heat stress applied proved to be too slight to break seed dormancy, although they were viable because they germinated after scarification. In existingCistusspp. stands,Cistusspp. seeds germinate with difficulty, and lack of recruitment could lead to disappearance of local communities unless they are subjected to disturbances.
FIRE IMPACT ON A MAQUIS SOIL SEED BANK IN CABAÑEROS NATIONAL PARK (CENTRAL SPAIN)
Authors: Ferrandis Pablo , Herranz José M. , Martínez-Sśnchez Juan J.
Published: April 2013

The direct impact of fire on the soil seed bank and the changes observed one year later were studied by analysis of seed content in sample layers at depths of 0–2 cm and 2–5 cm. Fire had a severe but selective impact on the soil seed bank: species with transient seed reserves accumulating on the soil surface were eliminated, whereas species with persistent buried seed reserves tended to remain in the soil after the passage of fire. Thick seed coats were shown to be an efficient mechanical protection barrier to fire. One year after fire, trade-off between input and output into seed bank produced a conspicuous recovery of seed density and species richness on the soil surface, and a pronounced impoverishment in the 2–5-cm-depth soil layer. In general, seed banks of woody species were severely depleted due to the lack of replacement following fire, with the exception ofErica, which maintained a high seed bank density in the upper soil layer. The post-fire recovery of soil seed populations was mainly due to two clearly differentiated groups of annuals. The first group was of species whose seeds survived fire, germinated, and completed their phenological cycle. They were mainly fire-ephemerals. The second group consisted of wind-dispersed species whose soil seed banks had suffered a very severe (even total) depletion by fire. They were mainly Gramineae and Compositae species which behaved as opportunistic fire-sensitive invaders.
WATER ABSORPTION BY MUCILAGINOUS ACHENES OF ARTEMISIA MONOSPERMA: FLOATING AND GERMINATION AS AFFECTED BY SALT CONCENTRATIONS
Authors: Huang Zhenying , Gutterman Yitzchak
Published: April 2013

Artemisia monospermais a dominant perennial desert shrub occurring in active sand dunes and stabilized sand fields. A cyanobacterial crust develops on stabilized sand and, as a result, runoff water may occur after rains. The mucilaginous achenes may float on the runoff water and disperse into depressions or cracks.

In these experiments, almost half of the achenes remained afloat on distilled water for 3 days and on different concentrations of salt solutions, more achenes remained afloat for longer. High concentrations of salt inhibit germination. NO,” may influence achene germination on cyanobacterial sand crust. Mucilaginous achenes absorb water within about 60 min, and after 120 min reach their water capacity. The achenes from which the mucilage has been removed can float for a longer period and germinate earlier than intact ones. Seedlings that developed from achenes with mucilage had greater vigor than those without.

The ecological significances of mucilaginous achenes is discussed.
FIRE, BEES, AND SEED PRODUCTION IN A MEDITERRANEAN KEY SPECIES SALVIA FRUTICOSA MILLER (LAMIACEAE)
Authors: Ne'eman Gidi , Dafni Amots
Published: April 2013

The typical Mediterranean phrygana has a very rich biodiversity of plants and of solitary bees. Fire may kill the brood of soil-nesting and other solitary bees and may affect pollen and nectar sources. Such changes would be expected to influence seed production in populations of post-fire obligate seeder species and thus also their population dynamics. We compared nectar standing crop, flower visitation rate of bumble bees and solitary bees, and consequent seed production in a typical Mediterranean shrub (Salvia fruticosa Miller) growing in unburned east Mediterranean phrygana vegetation and in an adjacent burned area. The volume of nectar standing crop in the burned area was higher than in the unburned area, while the nectar concentration showed the opposite trend. The mean frequency of Bombus' visits was higher in the burned area, while solitary bees visited flowers only in the unburned habitats. The seed production of S. fruticosa was significantly lower in the burned area. This reduction might have a long-term effect on post-fire species composition and abundance due to the fact that this species is an obligate post-fire seeder. The present evidence indicates that the bee-dependent pollination environment was not re-balanced even six years after fire. This situation has important implications concerning plant species and their bee pollinator diversity.
ENHANCEMENT OF POLLEN GERMINATION BY PROMOTIVE FACTORS IN INCOMPATIBLE POLLEN
Authors: Eisikowitch Dan , Wetzstein Hazel Y.
Published: April 2013

Cultivated and wild almonds are self-incompatible and thus require outcrossing by insect pollinators to produce viable seed. In commercial production, considerable efforts are directed towards placement and selection of cultivars for cross-pollination. However, since honeybees do not distinguish between the different cultivars, stigmas are usually covered by a mixture of both compatible and incompatible pollen. Using in vitro assays, we demonstrated that pollen extracts promoted germination in self pollen with no inhibitory effects observed. Elemental analyses of pollen extracts showed that enhanced levels of Ca, Mg, K, Na, and P were eluted from the grains. From this, we raise the question of possible interaction between compatible and incompatible pollen, and speculate that incompatible pollen grains may support and enhance germination of adjacent compatible pollen.
RESISTANCE RESPONSES OF PLANTS REGENERATED FROM TOMATO ANTHER AND SOMATIC TISSUE CULTURES TO CLAVIBACTER MICHIGANENSE SUBSP. MICHIGANENSE
Authors: Sotirova Violeta , Shtereva Lydia , Zagorska Nedjalka , Dimitrov Boyan , Bogatsevska Nevena
Published: April 2013

The production of gametoclonal and somaclonal variants in tomato is of great importance for the genetic improvement of tomato hybrids and cultivars. The possibility to obtain tomato plants resistant to Clavibacter michiganense subsp. michiganense (Cmm) through anther and tissue culture was investigated in the present study. Regenerants from anther and tissue cultures and their progenies (R1-R3) in the cultivars Roma ms and Bella, lines L. 24–13, and L. 6944, as well as the hybrids Roma ms × UC 82A, Roma ms × L. 31, Roma ms × Bella, and Cristy, were tested for resistance to Cmm. The regenerants differed in their resistance to Cmm. All regenerants from the anther culture of the genotype Roma ms and Roma ms × UC 82A are susceptible to the disease, while those from Bella and Roma ms × L. 31 vary from susceptible to resistant. The highest number of regenerants obtained from somatic tissue culture lacking disease symptoms until the end of the vegetation was observed in the genotypes Cristy and L. 24–13. Variation in regenerant resistance is found in R1, Rb, and R3. The results suggest that the gametoclonal and somaclonal variation may be efficiently applied to obtain tomato plants resistant to Cmm.
THE GENUS HOFFMANNSEGGIA CAV. (FABACEAE, CAESALPINIOIDEAE), NEW FOR THE MEDITERRANEAN FLORA
Authors: Camuñas Elena , Crespo Manuel B.
Published: April 2013

Hoffmannseggia glauca (Ortega) Eifert is a perennial herb native mostly to Central and South America, which is reported for the Iberian and European floras from material collected in the coastal, warm, and dry territories of Alicante province (southeastern Spain). This seems to be the first record of the genus and the species in Europe and the Mediterranean basin, and it is also the first extra-American record for the genus. This plant is briefly described, and chorological, ecological, biological, and phytosociological data are also presented.
A NEW ALYSSUM RECORD FOR THE FLORA OF TURKEY
Authors: Orcan Nermin
Published: April 2013

Alyssum obovatum(C.A. Meyer) Turc. (Cruciferae/Brassiceae) is reported, for the first time, as new to the flora of Turkey. A description and illustrations based on the new Turkish material are provided.