Parasitism by Campoletis flavicincta on Spodoptera frugiperda in corn

Parasitism by Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) on Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) and consequent reduction of production losses were evaluated on caged corn plants in the field. Treatments consisted of plots infested with 0 (control), 15 and 30 pairs of C. flavicincta with egg masses per cage and plot infested without cage and liberation of the parasitoid. Parasitoid release was done when S. frugiperda larvae were three-day-old. Fifty corn plants (40%) per plot were collected seven days after infestation and S. frugiperda larvae present were reared in glass cups on an artificial diet. Number of S. frugiperda larvae was reduced by C. flavicincta but mortality of the pest and parasitoid sex ratio in laboratory were similar among treatments. Total progeny and female production from collected larvae were similar among densities of released parasitoid. Parasitism rate was higher on 30 than on 15 pairs of C. flavicincta. Damage on corn plants at seven and 14 days after S. frugiperda infestation had similar grades at 0, 15 or 30 C. flavicincta pairs and higher values than the plots without cage. Damage by S. frugiperda was lower at 30 C. flavicincta pairs after 21 days of infestation. Final stand, stand reduction by plant death and corn productivity were similar among treatments.

Sodium/hydrogen exchanger NHA2 is critical for insulin secretion in β-cells.

NHA2 is a sodium/hydrogen exchanger with unknown physiological function. Here we show that NHA2 is present in rodent and human β-cells, as well as β-cell lines. In vivo, two different strains of NHA2-deficient mice displayed a pathological glucose tolerance with impaired insulin secretion but normal peripheral insulin sensitivity. In vitro, islets of NHA2-deficient and heterozygous mice, NHA2-depleted Min6 cells, or islets treated with an NHA2 inhibitor exhibited reduced sulfonylurea- and secretagogue-induced insulin secretion. The secretory deficit could be rescued by overexpression of a wild-type, but not a functionally dead, NHA2 transporter. NHA2 deficiency did not affect insulin synthesis or maturation and had no impact on basal or glucose-induced intracellular Ca(2+) homeostasis in islets. Subcellular fractionation and imaging studies demonstrated that NHA2 resides in transferrin-positive endosomes and synaptic-like microvesicles but not in insulin-containing large dense core vesicles in β-cells. Loss of NHA2 inhibited clathrin-dependent, but not clathrin-independent, endocytosis in Min6 and primary β-cells, suggesting defective endo-exocytosis coupling as the underlying mechanism for the secretory deficit. Collectively, our in vitro and in vivo studies reveal the sodium/proton exchanger NHA2 as a critical player for insulin secretion in the β-cell. In addition, our study sheds light on the biological function of a member of this recently cloned family of transporters.

Ecophysiological response of Sorghum halepense populations to reduced rates of nicosulfuron

The control and regrowth after nicosulfuron reduced rate treatment of Johnsongrass (Sorghum halepense L. Pers.) populations, from seven Argentinean locations, were evaluated in pot experiments to assess if differential performance could limit the design and implementation of integrated weed management programs. Populations from humid regions registered a higher sensibility to reduced rates of nicosulfuron than populations from subhumid regions. This effect was visualised in the values of regression coefficient of the non-linear models (relating fresh weight to nicosulfuron rate), and in the time needed to obtain a 50% reduction of photosynthesis rate and stomatal conductance. The least leaf CO2 exchange of subhumid populations could result in a lower foliar absorption and translocation of nicosulfuron, thus producing less control and increasing their ability to sprout and produce new aerial biomass. The three populations from subhumid regions, with less sensibility to nicosulfuron rates, presented substantial difference in fresh weight, total rhizome length and number of rhizome nodes, when they were evaluated 20 week after treatment. In consequence, a substantial Johnsongrass re-infestation could occur, if rates below one-half of nicosulfuron labeled rate were used to control Johnsongrass in subhumid regions.

Evaluating Roadway Subsurface Drainage Practices - Phase II, TR-662, 2015

Well-performing subsurface drainage systems form an important aspect of pavement design by the Iowa Department of Transportation (DOT). The recently completed Iowa Highway Research Board (IHRB) project TR-643 provided extensive insights into Iowa subsurface drainage practices and pavement subdrain outlet performance. However, the project TR-643 (Phase I) forensic testing and evaluation were carried out in a drought year and during the fall season in 2012. Based on the findings of IHRB Project TR-643, the Iowa DOT requested an expanded Phase II study to address several additional research needs: evaluate the seasonal variation effects (dry fall 2012 versus wet spring/summer 2013, etc.) on subdrain outlet condition and performance; investigate the characteristics of tufa formation in Iowa subdrain outlets; investigate the condition of composite pavement subdrain outlets; examine the effect of resurfacing/widening/rehabilitation on subdrain outlets (e.g., the effects of patching on subdrain outlet performance); and identify a suitable drain outlet protection mechanism (like a headwall) and design for Iowa subdrain outlets based on a review of practices adopted by nearby states. A detailed forensic test plan was developed and executed for inspecting the Iowa pavement subdrains in pursuit of fulfilling the Phase II study objectives. The observed outlets with blockage and the associated surface distresses in newly constructed jointed plain concrete pavements (JPCPs) were slightly higher during summer 2013 compared to fall 2012. However, these differences are not significant. Less tufa formation due to the recycled portland cement concrete (RPCC) base was observed with (a) the use of plastic outlet pipe without the gate screen–type rodent guard and (b) the use of blended RPCC and virgin aggregate materials. In hot-mix asphalt (HMA) over JPCP, moisture-related distress types (e.g., reflection cracking) were observed more near blocked drainage outlet locations than near “no blockage” outlet locations. This finding indicates that compromised drainage outlet performance could accelerate the development of moisture-related distresses in Iowa composite pavement systems. ****** Note: This report follows on work report in "Evaluating Roadway Subsurface Drainage Practices, 2013" http://publications.iowa.gov/14902/ Note: This record contains links to the 210 page full report as well as the 3 page tech transfer summary. The summary is NOT deposited separately.

Parasitism of the mite Acarophenax lacunatus on Tribolium castaneum

The objective of this work was to assess the parasitism potential of Acarophenax lacunatus (Cross & Krantz) on Tribolium castaneum (Herbst). The experimental units encompassed Petri dishes containing 25 g of wheat infested with 20 adults of this beetle species. After seven days of infestation, different mite densities (0, 2, 4, 6, 8 and 10 females) were inoculated into the Petri dishes. The increase in mite density led to a linear increase in parasitism, and a consequent reduction in populations of this insect. It is possible to use this mite species in the biological control of T. castaneum.

Laboratory Study of the Leachate from Crushed Portland Cement Concrete Base Material, MLR-96-04, 1999

Since the 1980s, the Iowa Department of Transportation has increased its use of recycled Portland Cement Concrete (PCC) as drainable base material below some new pavements. Water flowing out of the longitudinal drains on projects having recycled PCC drainable bases was found to have a high pH value. The high pH water impedes vegetation growth and becomes a contributing factor to soil erosion at the drain outlet. In addition, the high pH water contributes to the growth of crystalline deposits on the drain outlet wire mesh rodent guard and in some cases caused it to become completely blocked. This research determined which of three choices of recycled PCC drainable base material, gradation, and design would give the lowest pH value in the drain discharge water. The drainable base material having its fines separated out and placed as a 2-in. (5.1-mm) bottom layer, below the remaining coarse material, generally gave pH values around 11.2 while other designs tested gave pH values around 11.5.

Effect of an ectoparasite on reproduction in great tits.

1. The effect of a haematophageous ectoparasite, the hen flea, on quality an number of offspring was experimentally investigated in the great tit. The experiment consisted of a controlled infestation of a random sample of nests with the parasitic flea and of a regular treatment of control nests with Microwaves in order to eliminate the naturally occurring fleas. 2. To assess the effects of fleas on variables related to offspring number, we considered the number of hatchlings and fledglings, the mortality between hatching and fledging, and the hatching and fledging success. For assessment of offspring quality, we measured body mass, tarsus and wing length, and calculated the nutritional condition of, nestlings as the ratio of body mass to tarsus length. A physiological variable, the haematocrit level, was also measured. 3. Hatching success and hatchling numbers did not differ between the two experimental groups. Offspring mortality between hatching and fledging was significantly higher in the infested broods (xBAR = 0.22 chicks dead per day) than in the parasite-free broods (xBAR = 0.07 dead per day). Fledging success was 83% in the parasite-free broods, but only 53% in the infested ones. The number of fledglings in infested broods (xBAR = 3.7 fledglings +/-2.1 SD) was significantly lower than in the parasite-free (xBAR = 4.9 +/- 1.1 SD) broods. 4. Body mass of chicks in the infested broods was significantly smaller than in the parasite-free broods both 14 days and 17 days after hatching. The chicks in the infested broods reached a significantly smaller tarsus length than the ones in the parasite-free broods. Close to fledging, the nutritional condition of chicks was significantly lower in infested broods. Haematocrit levels were significantly lower in the infested broods. 5. Brood size correlated differently with body mass and condition of chicks in infested and parasite-free nests. In parasite-free broods both body mass and condition of chicks at age 17 days, i.e. close to fledging, were significantly higher in small broods than in large ones. However, in the infested broods chicks were of the same body mass and condition in large as in small broods. Therefore, in parasite-free broods fitness can potentially be gained through offspring quality or number or both, whereas in infested broods it can be gained through offspring quantity only. In other words, a trade-off between quality and number of offspring is feasible only in the absence of the parasitic hen flea. 6. These results emphasize the need to study the effects of ectoparasites on ecological, behavioural and evolutionary traits of their bird hosts. A knowledge of these effects is essential for the understanding of population dynamics, behaviour and life-history traits of the hosts.

Arbuscular mycorrhizal fungi mediate below-ground plant-herbivore interactions: a phylogenetic study

Ecological interactions are complex networks, but have typically been studied in a pairwise fashion. Examining how third-party species can modify the outcome of pairwise interactions may allow us to better predict their outcomes in realistic systems. For instance, arbuscular mycorrhizal fungi (AMF) can affect plant interactions with other organisms, including below-ground herbivores, but the mechanisms underlying these effects remain unclear. Here, we use a comparative, phylogenetically controlled approach to test the relative importance of mycorrhizal colonization and plant chemical defences (cardenolides) in predicting plant survival and the abundance of a generalist below-ground herbivore across 14 species of milkweeds (Asclepias spp.). Plants were inoculated with a mixture of four generalist AMF species or left uninoculated. After 1month, larvae of Bradysia sp. (Diptera: Sciaridae), a generalist below-ground herbivore, colonized plant roots. We performed phylogenetically controlled analyses to assess the influence of AMF colonization and toxic cardenolides on plant growth, mortality and infestation by fungus gnats. Overall, plants inoculated with AMF exhibited greater survival than did uninoculated plants. Additionally, surviving inoculated plants had lower numbers of larvae in their roots and fewer non-AM fungi than surviving uninoculated plants. In phylogenetic controlled regressions, gnat density in roots was better predicted by the extent of root colonized by AMF than by root cardenolide concentration. Taken as a whole, AMF modify the effect of below-ground herbivores on plants in a species-specific manner, independent of changes in chemical defence. This study adds to the growing body of literature demonstrating that mycorrhizal fungi may improve plant fitness by conferring protection against antagonists, rather than growth benefits. In addition, we advocate using comparative analyses to disentangle the roles of shared history and ecology in shaping trait expression and to better predict the outcomes of complex multitrophic interactions.

Sensing pheromones : a role for the CNGA4 and TRPC2 proteins

Chez les mammifères, les phéromones sont des molécules clés dans la régulation des comportements sociaux au sein d'une espèce. Chez la souris, la détection de ces molécules se fait dans l'organe voméronasal (VNO] et implique le canal TRPC2 afin de dépolariser les neurones. Des différences de comportement entre des souris Trpc2-/- et des souris sans VNO suggèrent l'implication d'une autre protéine effectrice dans la voie de signalisation des phéromones. L'hypothèse étant que cette protéine formerait un canal hétéromérique avec TRPC2. CNGA4 est une protéine sans fonction connue dans le VNO des rongeurs. Elle appartient à la famille des protéines CNG qui joue un rôle important dans différentes voies de signalisation comme la vision ou l'olfaction. Etant donné sa présence dans le VNO, son rôle inconnu dans cet organe et son rôle important dans de nombreuses voies de signalisation, nous avons décidé d'étudier CNGA4 afin de connaître sa localisation, ses propriétés ou encore sa structure. Nous avons découvert que CNGA4 est exprimée dans les axons, les neurones immatures ainsi que sur les microvillosités des neurones de VNO. A l'aide de souris portant une version non fonctionnelle de CNGA4, nous avons pu montrer que cette protéine joue un rôle majeur dans la voie de signalisation des phéromones. Ainsi, les neurones du VNO portant une version non fonctionnelle de CNGA4 répondent moins fréquemment aux phéromones et par conséquent les phéromones activent également moins de neurones dans le bulbe olfactif accessoire, premier relais du VNO avec le cortex. Cette détection défaillante se traduit par une absence d'agressivité des souris mutantes ainsi que par une incapacité de ces souris à discriminer le sexe de leur conspécifique. Etant donné les propriétés similaires de CNGA4 et de TRPC2, nous avons supposé que les deux protéines pourraient interagir. Cette hypothèse a été confortée par l'observation que CNGA4 n'est plus exprimée dans les microvillosités du VNO des souris Trpc2-/-. A l'aide d'expériences d'expression hétérologue, nous avons pu observer que les deux protéines interagissent et forment un canal activé par un analogue du diacylglycérol suggérant que ce canal est fonctionnel. Ces résultats indiquent que CNGA4 formerait un canal hétéromérique avec TRPC2 et aurait dans ce canal une fonction modulatrice. Des expériences complémentaires sont nécessaires afin de connaître le rôle de chacune de ces protéines dans la voie de signalisation des phéromones. Sensing pheromones: a role for the CNGA4 and TRPC2 proteins Mammalian pheromones are key chemical signals in the regulation of intraspecies social behaviors. Detection of these pheromones, which takes place in sensory neurons of the vomeronasal organ (VNO), implies the activation of the transient receptor potential canonical channel 2 (TRPC2) as the final effector. Interestingly, discrepancies between Trpc2 /- mice and mice lacking a VNO suggest the implication of another protein in the pheromone signaling pathway. This protein could either form a heteromeric channel with TRPC2 or a separate homomeric ion channel. The cyclic nucleotide-gated channel subunit CNGA4 is also expressed in the rodent VNO but its role and properties in this organ remain unknown. CNGA4 belongs to the CNG channel family which is playing an important role in different sensory pathways such as in light and odorant detection. We thus decided to study the role of the CNGA4 protein in the mouse VNO. We found CNGA4 to be expressed in axons, dendrites and in the sensory microvilli. Using mice bearing a non-functional form of CNGA4 we further demonstrated the importance of the CNGA4 protein for the pheromone signaling pathway as neurons from mutant mice were responding less frequently to chemosensory cues. As a result, mutant mice displayed a non-aggressive behavior and an impaired sexual discrimination ability. Based on the CNGA4 localization and its role in the pheromone signaling pathway we hypothesized a possible interaction between CNGA4 and TRPC2 forming a heteromeric channel. First evidences for this interaction came from the absence of CNGA4 expression in the sensory microvilli of Trpc2-/- mice. Second, using transfected HEK cells as an expression system we could observe that CNGA4 and TRPC2 interact and translocate to the plasma membrane. Perfusion of a DAG analogue on co-transfected HEK cells resulted in a strong calcium entry suggesting that the two proteins form a functional channel. These results might suggest a modulatory role for CNGA4 in a heteromeric TRPC2+CNGA4 ion channel. Further experiments will give more insights on the combined role of these transduction ion channels in pheromone detection.

Risk analysis of climate change on coffee nematodes and leaf miner in Brazil

The objective of this work was to assess the potential impact of climate change on the spatial distribution of coffee nematodes (races of Meloidogyne incognita) and leaf miner (Leucoptera coffeella), using a Geographic Information System. Assessment of the impacts of climate change on pest infestations and disease epidemics in crops is needed as a basis for revising management practices to minimize crop losses as climatic conditions shift. Future scenarios focused on the decades of the 2020's, 2050's, and 2080's (scenarios A2 and B2) were obtained from five General Circulation Models available on Data Distribution Centre from Intergovernmental Panel on Climate Change. Geographic distribution maps were prepared using models to predict the number of generations of the nematodes and leaf miner. Maps obtained in scenario A2 allowed prediction of an increased infestation of the nematode and of the pest, due to greater number of generations per month, than occurred under the climatological normal from 1961-1990. The number of generations also increased in the B2 scenario, but was lower than in the A2 scenario for both organisms.

Cell death and autophagy after severe hypoxic-ischemic encephalopathy in term newborns

Introduction: Various studies from hypoxic-ischemic animals haveinvestigated neuroprotection by targeting necrosis and apoptosis with inconclusive results. Three types of cell death have been described: apoptosis, necrosis and more recently, autophagic cell death. While autophagy is a physiological process of degradation of cellular components, excessive autophagy may be involved in cell death. Recent studies showed that inhibition of autophagy is neuroprotective in rodent neonatal models of cerebral ischemia. Furthermore, neonatal hypoxia-ischemia strongly increased neuronal autophagic flux which is linked to cell death in a rat model of perinatal asphyxia. Following our observations in animals, the aim of the present study was to characterize the different neuronal death phenotypes and to clarify whether autophagic cell death could be also involved in neuronal death in the human newborns after perinatal asphyxia. Methods: we selected retrospectively and anonymously all newborns who died in our unit of neonatology between 2004 and 2009, with the following criteria: gestational age >36 weeks, diagnosis of perinatal asphyxia (Apgar <5 at 5 minutes, arterial pH <7.0 at 1 hour of life and encephalopathy Sarnat III) and performed autopsy. The brain of 6 cases in asphyxia group and 6 control cases matching gestational age who died of pulmonary or other malformations were selected. On histological sections of thalamus, frontal cortex and hippocampus, different markers of apoptosis (caspase 3, TUNEL), autophagosomes (LC3-II) and lysosomes (LAMP1, Cathepsin D) were tested by immunohistochemistry. Results: Preliminary studies on markers of apoptosis (TUNEL, caspase 3) and of autophagy (Cathepsin D, LC3II, LAMP1) showed an expected increase of apoptosis, but also an increase of neuronal autophagic flux in the selected areas. The distribution seems to be region specific. Conclusion: This is the first time that autophagic flux linked with cell death is shown in brain of human babies, in association with hypoxicischemic encephalopathy. This work leads to a better understanding of the mechanisms associated with neuronal death following perinatal asphyxia and determines whether autophagy could be a promising therapeutic target.

Grafted eggplant yield, quality and growth in infested soil with Verticillium dahliae and Meloidogyne incognita

The objective of this work was to evaluate the effect of grafting (onto Solanum torvum Sw.) on plant growth, yield and fruit quality of the Pala and Faselis eggplant (Solanum melongena L.) cultivars, grown in a soil infested with Verticillium dahliae Kleb. and Meloidogyne incognita, or in noninfested soil. Soil infestation decreased yield, plant height, final above-ground biomass, and also reduced fruit mean weight and shoot dry weight depending on cultivar or grafting. Grafting decreased fruit oxalic acid and the soluble solid contents, and increased mean fruit weight, depending on cultivar and soil infestation. Grafting also reduced the negative effects of the pathogens on disease index, plant height and shoot dry weight. Cultivar Pala was more vigorous than Faselis, and S. torvum was a vigorous rootstock. The combination of a vigorous rootstock with a weak cultivar (Faselis) is more profitable than that of a vigorous rootstock and a vigorous cultivar (Pala). Using S. torvum as a rootstock for cultivar Faselis, grown in soil infested with the pathogens, is most likely to be useful in conventional and low-input sustainable horticulture, since grafting increases protection against the pathogens, and reduces the losses in quality and yield.

Habitat fragmentation, ecology and sexual selection in forest bird species in Monteverde, Costa Rica

Abstract Forest fragmentation is often associated with local extinction and changes in species abundance patterns. The main topic of this thesis is the effect of forest fragmentation on birds in Monteverde, Costa Rica. This thesis also studies aspects of sexual selection and ecology of Long-tailed Manakins, Chiroxiphia Linearis. Chapter 1 investigates bird species assemblages in two degrees of forest fragmentation. It is shown that the distribution, abundance and diversity of forest bird species are strongly influenced by the amount of forest in the landscape matrix. Presence of cattle within the forest influences the presence of some bird species. The prevalence and intensity of ticks and blood parasites on birds in relation to fragmentation is described in Chapter 2. Overall tick prevalence is 3%. Understory birds are significantly more infested with ticks than species at intermediate heights. Tick prevalence on birds does not differ significantly between two degrees of forest fragmentation and individual tick loads tend to be higher in High- than in Low-fragmentation sites. Infestations by the blood parasites Haemoproteus sp. was low except in white-eared ground sparrow, Melozone leucotis, that is 28% and is significantly higher in High- than in Low-fragmentation sites. In chapter 3 results on the ecology and habitat movements of the Bare-necked Umbrellabird, Cephalopterus glabricollis, are presented. The abundance of umbrellabirds at high elevations during the breeding season coincides with the highest peak of fruit abundance. Birds leave the protected area during the non-breeding season moving to unprotected forest fragments. In chapter 4 ontogenetic changes in feather morphology through sexual maturity in Long-tailed Manakins are described. In adult males, rectrices length is positively correlated to testis volume. Changes in male morphology during ontogeny in the long-tailed manakin appear to be associated with their specific-display behaviours. Significant interpopulation differences in the morphology of Long-tailed Manakins are shown in chapter 5. These differences are more accentuated in morphological traits related to flight displays. A field experiment demonstrates that long rectrices impose flying costs for males and females. A reduction in flying ability was found to be strongest in males from a population presenting the highest degree of sexual dimorphism. Résumé La fragmentation des forêts est souvent associée avec des modifications dans l'abondance des espèces et des extinctions locales. Le thème principale de cette thèse est l'étude de l'effet de la fragmentation des forêts sur les oiseaux de Monteverde, Costa Rica. Elle décrit par ailleurs certains aspects de la sélection sexuelle et l'écologie du manakin à longue queue, Chiroxiphia linearis. Dans le Chapitre 1 je montre que la distribution, l'abondance et la diversité des assemblages d'oiseaux vivant dans la forêt sont fortement influencées pas le degré de fragmentation de celle ci. Par ailleurs, la présence ou l'absence de bétail dans les forêts influence la présence de certaines espèces d'oiseaux. Dans le chapitre 2 j'ai étudié la prévalence et l'intensité d'infestation par des tiques ainsi que la présence de parasites sanguins chez les oiseaux en relation avec la fragmentation des forêts. La prévalence globale de tiques est de 3 %, les oiseaux vivant au niveau du sol étaient plus souvent infectés par des tiques que les espèces se déplaçant à un niveau plus élevé. La prévalence de tiques sur les oiseaux n'était pas significativement différente entre les paysages avec différentes fragmentations. Les parasites sanguins du genre Haemoproteus sp. étaient présents à très basse fréquence à l'exception chez Melozone leucotis ou la prevalence était de 28% et significativement plus élevée chez les oiseaux vivant dans les forêts à forte fragmentation. Dans le Chapitre 3 je présente des résultats sur l'écologie et les mouvements entre habitats chez le "Bare-necked umbrellabird", Cephalopterus glabricollis. Cette espèce endémique du Costa Rica niche à haute altitude durant la période d'abondance des fruits et réalise une migration altitudinale vers des zones basses durant la saison de non reproduction. Dans le chapitre 4 je présente les changements ontogénétiques dans la morphologie du plumage des manakins à longue queue. Chez les mâles, les changements de morphologie semblent être associés avec leurs comportements de parade spécifiques. Dans le chapitre 5 je présente des différences morphologiques significative entre deux populations chez le manakin à longue queue et je montre que la capacité de vols chez les mâles est plus fortement influencée dans la population avec le degré de dimorphisme sexuel le plus prononcé.

Leaf mineral composition of grafted eggplant grown in soil infested with Verticillium and root-knot nematodes

The objective of this work was to determine differences in leaf mineral composition between ungrafted and grafted onto (Solanum torvum) eggplant (Solanum melongena), cultivars 'Faselis' and 'Pala', grown in a soil infested with Verticillium dahliae and Meloidogyne incognita, or in a noninfested soil. Grafting increased leaf P and Mn concentrations, and decreased N concentrations, in both soils. Grafting also enhanced leaf Ca concentration of 'Pala', but it did not affect that of 'Faselis' depending on the cropping year. Leaf Mg concentration of grafted plants in infested soil was lower than that of ungrafted ones in noninfested soil. Results showed that, under the same fertilization program, the grafted 'Faselis' plants used the nutrients more efficiently than the 'Pala' ones. Use of S. torvum as a rootstock for 'Faselis' resulted in an effective protection against multiple pathogen infestation. Fertilization may be necessary when grafted 'Faselis' plants are grown in a soil infested with the pathogens, since grafting and infestation generally decrease leaf N, Mg, Ca and Fe concentrations, either by reducing the nutrient concentrations directly or by increasing leaf Mn concentration.

The contribution of a pollinating seed predator to selection on Silene latifolia females.

Interactions, antagonistic or mutualistic, can exert selection on plant traits. We explored the role of Hadena bicruris, a pollinating seed predator, as a selective agent on its host, the dioecious plant Silene latifolia. We exposed females from artificial-selection lines (many, small flowers (SF) vs. few, large flowers (LF)) to this moth. Infestation did not differ significantly between lines, but the odds of attacked fruits aborting were higher in SF females. We partitioned selection between that caused by moth attack and that resulting from all other factors. In both lines, selection via moth attack for fewer, smaller flowers contrasted with selection via other factors for more flowers. In LF females, selection via the two components was strongest and selection via moth attack also favoured increased fruit abortion. This suggests that the moths act as more of a selective force on flower size and number via their predating than their pollinating role.