Two-year dynamics of foliage labelling in 8-year-old <Emphasis Type="Italic">Pinus pinaster</Emphasis> trees with <Superscript>15</Superscript>N, <Superscript>26</Superscript>Mg and <Superscript>42</Superscript>Ca—simulation of Ca transport in xylem using an upscaling approach

• Introduction   

Atmospheric deposition is an important input of major nutrients into forest ecosystems. The long-term goal of this work was to apply stable isotope methodology to assess atmospheric nutrient deposition in forest systems.     

Lethal and sub-lethal effects from short-term exposure of <Emphasis Type="Italic">Rhyzopertha dominica</Emphasis> on wheat treated with Storicide II<Superscript>®</Superscript>

Hard red winter wheat was treated at 0 (untreated control), 25, 50, 75, and 100% of the label rate of the insecticide Storicide II ^® , which is chlorpyrifos-methyl and deltamethrin applied at label rates of 3 and 0.5 ppm, respectively. Paired male and female Rhyzopertha dominica F., the lesser grain borer, were exposed at 27°C and 60% RH on wheat treated at each of the five rates above for 2, 4, 8, 16, or 32 h, and then transferred to untreated wheat and held for 1 week at the same environmental conditions. After this 1-week holding period, the parental adults were removed, mortality was assessed, and the wheat was then held for 7 weeks at the same environmental conditions to determine progeny production. As the concentration and exposure interval increased, mortality of both sexes approached 100%, but at the intermediate concentration–time combinations male mortality was greater than female mortality. Progeny production also decreased with increasing concentration of Storicide II^® as the exposure time increased, with non-linear patterns of decrease at the lower concentrations and time combinations and linear decline at the higher levels of concentration and time. Results seem to indicate greater susceptibility of males to Storicide II^®, and also show delayed parental mortality from the insecticide exposure and sub-lethal effects of reduced progeny production.     

Food source provisioning and susceptibility of immature and adult<Emphasis Type="Italic"> Tribolium castaneum</Emphasis> on concrete partially treated with chlorfenapyr (Phantom<Superscript>®</Superscript>)

A series of experiments were conducted in which adults, pupae, and 4-week-old larvae of Tribolium castaneum (Herbst), the red flour beetle, were exposed separately on concrete arenas partially treated (14.4% of the total area) with the insecticide chlorfenapyr (Phantom^®) at 1.1 g of active ingredient/m². A flour food source (patch) was also provided in the untreated portions of the arenas. In the first trial, adult mortality averaged 60.0 ± 10.6%, but progeny production occurred in the provided food patches. Pupal mortality was only 8.3 ± 3.1%, indicating that when adult emergence occurred, those adults were able to escape exposure, and there was no difference in progeny production from that in untreated controls (P = 0.27). In the second trial, few larvae exposed in choice and no-choice arenas were able to emerge as normal adults. In a final trial, residual efficacy declined during a 3-week period, with larvae being more susceptible than adults. Results show mobility of life stage may be a determining factor when assessing susceptibility of T. castaneum to contact insecticides.     

Effect of botanical insecticide Nimbecidine<Superscript>®</Superscript> on food consumption and egg hatchability of the terrestrial snail <Emphasis Type="Italic">Monacha obstructa</Emphasis>

In the laboratory, a commercial neem-based insecticide—Nimbecidine^®—was evaluated as a potential pest management tool for the terrestrial snail, Monacha obstructa (Pfeiffer, 1842) (Hygromiidae). Effects of different concentrations of the botanical insecticide on food consumption and egg hatchability of the terrestrial snail were studied. Generally, food consumption of immature and adult snails decreased as the concentrations of Nimbecidine^® increased. At the highest concentration (10 ml/l), the snails avoided contacting with food completely. The food intake of immature individuals was significantly (p < 0.05) more affected by the Nimbecidine^® treatment (at 1.25 ml/l) than that of adults. LC₅₀ of Nimbecidine^® for the treated eggs was 2.18 ml/l, and eggs failed to hatch at concentration of 10 ml/l. Nimbecidine^® showed sufficient biological activity against the food consumption and eggs viability of M. obstructa, thus the preparation has a potential to protect field crops from this pest snails.     

Soil phosphorus and water effects on growth,nutrient and carbohydrate concentrations, δ<Superscript>13</Superscript>C,and nodulation of mimosa (<Emphasis Type="Italic">Albizia julibrissin</Emphasis> Durz.) on a highly weathered soil

Growth and physiological performance of multipurpose tree species can be severely constrained by low phosphorus (P) availability in highly weathered soils. Limitations to plant growth are accentuated by seasonal dry periods. The overall objective of this study was to examine P fertilization and irrigation effects on survival, growth, biomass partitioning, foliar nutrients, intrinsic water-use efficiency (WUE) indexed by δ¹³C, Rhizobium nodulation, and carbohydrate content as an indicator of resprouting potential, of mimosa (Albizia julibrissin Durz.), a N₂-fixing tree species being tested for browse in agroforestry practices in south-central USA. In a field experiment carried out during two growing seasons near Booneville, Arkansas, USA, mimosa had a strong growth response to irrigation. The trial was arranged in a split plot design with three replications with irrigation as main plot treatment and P as sub-plot treatment. Mean total plant aboveground biomass at the end of the second growing season was 9.8 and 44.1 g plant⁻¹ for the rainfed treatment without and with 300 mm of irrigation water, respectively. Placed P fertilization increased mean total aboveground biomass from 19 g plant⁻¹ for the 0-P treatment to 69 g plant⁻¹ for the treatment with 90 kg P ha⁻¹ year⁻¹. Similarly, irrigation consistently increased stem basal diameter, total height, survival, root, stem, foliar and total aboveground biomass, and number of nodules per plant. Phosphorus fertilization increased basal diameter, and root and stem biomass in both irrigation treatments, survival and nodulation in the rainfed treatment, and foliar and total aboveground biomass in the rainfed +300 mm irrigation treatment. There was a decrease of foliar δ¹³C suggesting that WUE decreased with P fertilization. In a pot experiment, seedlings were subjected to a factorial combination of two irrigation treatments and six P levels in a randomized complete block design. Irrigation increased basal diameter, root, stem, foliar and total biomass, leaf area and nodulation, whereas P fertilization (i.e., levels from 0 to 3.68 g P kg⁻¹ soil) had similar effect in all the above variables except foliar biomass. Foliar P concentration to obtain 90% of the maximum total plant biomass (critical level) was estimated at 0.157%. Total nonstructural and water soluble carbohydrate, and starch concentrations increased non-linearly with irrigation and P addition suggesting impaired re-growth potential after defoliation of seedlings with reduced water supply and at low soil P availability. Results of this study indicated strong limitations for growth and regrowth potential of mimosa on a highly weathered soil with very low P availability and seasonal water content shortages. Placed (i.e., near the plant base) application of P appeared to be a good strategy to fertilize perennial woody plants.     

Biological performance,water absorption,and swelling of wood treated with nano-particles combined with the application of Paraloid B72<Superscript>®</Superscript>

We evaluated fungal decay and mold resistance, leaching, and water absorption of nano-compounds and Paraloid B72^® (PB72) in treated wood specimens to develop new methods of consolidation by combining nano-particles and consolidants. Scots pine wood specimens were treated with dispersions of nano-CuO, nano-ZnO, nano-B₂O₃, nano-TiO₂, and nano-CeO₂. PB72 treatments of nano-particle-treated wood specimens were then carried out by either vacuum or immersion for 24 h. Previously, decayed wood specimens were also consolidated with the nano-compounds and PB72. PB72 treatments reduced element release from treated wood specimens. Nearly all nano-compounds + PB72 treatments increased the biological performance of treated wood specimens against decay fungi tested. PB72-only treated wood specimens had the highest weight losses in decay tests. No improvements were obtained in mold resistance tests when the nano-compounds and PB72 were combined. In nano-compound-only treatments, unleached specimens showed slightly lower water absorption values compared to untreated control specimens. Incorporation of PB72 into nano-compound-treated wood specimens resulted in considerably lower water absorption and volumetric swell. In previously decayed specimens treated with the nano-compounds and PB72 solution, water absorption after 2-h immersion declined compared to control specimens.     

<Emphasis Type="Italic">Euzophera bigella</Emphasis> (Zeller) (Lepidoptera: Pyralidae) and <Emphasis Type="Italic">Dasineura oleae</Emphasis> (F. Low) (Diptera: Cecidomyiidae): Emerging olive crop pests in the Mediterranean?

The olive is one of the most important crops in Greece as in many Mediterranean countries. Several insects are considered serious pests of the olive crop. In this study, we report two new pests for olive trees in Greece and possibly in the Mediterranean region: the quince moth Euzophera bigella (Zeller) (Lepidoptera: Pyralidae) and the olive leaf gall midge Dasineura oleae (F. Low) (Diptera: Cecidomyiidae). Although E. bigella is not considered a pest of olive trees, in the summer of 2011, the quince moth was recorded for the first time infesting olive trees in several orchards in the rural area of the Municipality of Amphipolis (Region of Central Macedonia). Infestation induced cracking and swelling symptoms on the bark of limbs and the periderm of trunks, accompanied by extensive internal bark necrosis, which caused the desiccation of limbs or even the death of whole trees. D. oleae has been reported infesting olive trees in Greece; however, it was not considered a pest of the crop. In February 2010, extensive infestations by D. oleae were detected in the coastal zone of Elounda, Lassithi (Region of Crete). Infestations were observed on the leaves causing elongate galls and deformations, while in highly infested trees defoliation was reported. Because of the scarceness of these infestations, the results reported in this study are discussed in relation to cases reported from other countries and/or on other crops. In addition, a review of the distribution, biology and control methods of these species is provided in an attempt to summarize the scattered information currently available.     

AFLP fingerprinting of <Emphasis Type="Italic">Populus deltoides</Emphasis> and <Emphasis Type="Italic">Populus </Emphasis>×<Emphasis Type="Italic"> canadensis</Emphasis> elite accessions

Amplified fragment length polymorphism (AFLP) was used in genetic fingerprinting of 22 elite Chinese Populus deltoides and Populus × canadensis accessions. The results indicated that each of the nine AFLP primer pairs selected generated fingerprint profiles that were unique to each of the accessions. Therefore, each accession was definitively identified by any of the nine primer pairs. Furthermore, the inter-accession genetic relationships inferred based on 461 polymorphic fragments from the nine AFLP primer pairs were largely consistent with phylogenetic relationships based on morphologic traits. Bootstrap analysis showed that three AFLP primer pairs were required to obtain genetic similarity values with a maximum CV of 10% while 10 AFLP primer pairs could give a maximum CV of 5%. Thus, AFLP can readily be applied for a rapid and accurate evaluation of the degree of similarity between poplar cultivars. In this study, the number of AFLP fragments used was sufficient to establish a reliable estimate of genetic similarity among accessions, with a maximum CV of 5.12%. Therefore, the information on the genetic relationships among the poplar accessions generated in this study in connection with knowledge on agronomic traits may have an impact on poplar breeding and planting in China.     

5<Emphasis Type="Italic">Α</Emphasis>-Reductase inhibitory tannin-related compounds isolated from <Emphasis Type="Italic">Shorea laeviforia</Emphasis>

Five tannin-related compounds – gallic acid, flavogallonic acid dilactone, valoneic acid dilactone, gallagyldilactone, ellagic acid – were isolated from the heartwood of Shorea laeviforia, and the inhibitory activity of each against rat liver 5-reductase was evaluated. Valoneic acid dilactone and gallagyldilactone exhibited positive inhibitory activity, but gallic acid and ellagic acid did not. Flavogallonic acid dilactone stimulated 5-reductase activity, even though this compound is structurally similar to valoneic acid dilactone. The kinetic study of valoneic acid dilactone and gallagyldilactone indicated that the inhibitory behavior of 5-reductase were not competitive against the substrate (testosterone) and were partially competitive against the cofactor (NADPH). Additionally, double inhibition analysis of valoneic acid dilactone and NADP⁺ showed synergetic inhibition. These results suggested that neither valoneic acid dilactone nor gallagyldilactone can affect the binding of testosterone but that either compound could interact with an enzyme–NADP⁺ complex to inhibit 5-reductase.     

Quantitative genetics of cold hardiness and growth in <Emphasis Type="Italic">Eucalyptus</Emphasis> as estimated from <Emphasis Type="Italic">E.</Emphasis><Emphasis Type="Italic">urophylla</Emphasis> × <Emphasis Type="Italic">E. tereticornis</Emphasis> hybrids

Interspecific hybrids of Eucalyptus urophylla S. T. Blake × E. tereticornis Smith were used for quantitative genetic analysis of cold hardiness (CH) and growth traits height (H), diameter at breast height (D) and volume (V) at 0.5, 1.5, 2.5 and 4 years of age. The effect of E. tereticornis male variance was significant (P < 0.05) for CH as well as 2.5- and 4-year-old growth except for H ₄, and E. urophylla female × E. tereticornis male interaction was significant for 0.5- and 1.5-year-old growth and CH except for CH _0.5, whereas E. urophylla female effect was not significant for the majority of traits analyzed. Both additive and dominance gene action were present in the genetics of all the traits measured at most ages, indicating that those traits may be improved by hybrid breeding. The σ _D ²/σ _A ² ratios tended to decline after 1.5 years of age in CH and growth traits, implying that breeding value predictions derived from older performance might be more reliable. Estimates of narrow-sense heritability (h ² ) for CH and growth ranged from 0.03 ± 0.05 to 0.28 ± 0.13, depending on trait and age. Additive genetic correlations between CH and V were 0.28 ± 0.48 and 0.69 ± 0.30 at ages 1.5 and 2.5, respectively, suggesting that selection for growth would cause a favorable increase in cold hardiness in E. urophylla × E. tereticornis hybrids.     

Fitness of heat and desiccation tolerant hybrid strains of <Emphasis Type="Italic">Heterorhabditis</Emphasis> <Emphasis Type="Italic">bacteriophora</Emphasis> (Rhabditidomorpha: Heterorhabditidae)

Entomopathogenic nematodes of the genus Heterorhabditis are a suitable alternative to chemical insecticides because of their high control effect against insects in cryptic environments and their environmental safety. The availability of H. bacteriophora hybrid strains with increased tolerance to environmental extremes could be a driving force for a more widespread use of nematode-based plant protection products. However, increase in heat and desiccation tolerance of hybrid strains could compromise their fitness regarding virulence, host penetration and reproductive capacity. The fitness of heat and desiccation tolerant hybrid strains was compared to the commercial strain EN 01. Only the heat tolerant strains were superior or similar in fitness to strain EN 01. The strains with increased desiccation tolerance were usually less fit, a possible result of a trade-off effect of selection for desiccation tolerance. Hybrid strains selected for enhanced tolerance after an adaptation to stress were generally better in fitness ranking compared to those for which adaptation prior to stress exposure was excluded. This might be a result of pleitropy. Host penetration and virulence was not correlated. The commercial strain had the highest reproduction per mean number of nematodes penetrating the host insect, which is a result of automatic selection of inbred lines with high reproduction potential during the commercial production process in liquid culture.     

Soil microorganisms alleviate the allelopathic effect of <Emphasis Type="Italic">Eucalyptus grandis</Emphasis> × <Emphasis Type="Italic">E</Emphasis>. <Emphasis Type="Italic">urophylla</Emphasis> leachates on <Emphasis Type="Italic">Brassica chinensis</Emphasis>

Soil microbes may be critical players in determining the allelopathic potential of some plants. Low levels of plant community biodiversity in Eucalyptus plantations have been attributed to the allelopathic potential of these tree species. The role of soil microbes in the allelopathic effect of leaf leachates of the hybrid tree Eucalyptus grandis × E. urophylla, was tested in Petri dish assays with Brassica chinensis as a receiver plant. Soils were collected from either a local garden (soil A) or a Eucalyptus plantation (soil B) and half of each soil was sterilized to remove microbes. These soils were then treated with E. grandis × E. urophylla leachates for 0–72 h. Seed germination of B. chinensis was significantly inhibited in soils treated with leaf leachates relative to untreated soils. The inhibitory effect of the leaf leachates was more pronounced in sterilized soils. Total phenolic content was obvious lower in nonsterile leachate-treated soils than in sterile soils. Biomass of B. chinensis was negatively correlated with the total phenolic content in soils. Our findings suggest that soil microbes can alleviate the allelopathic potential of Eucalyptus and thereby its negative impact on plant growth.     

Can drought tolerance of Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis> (L.) <Emphasis Type="Italic">Karst</Emphasis>.) be increased through thinning?

To investigate whether drought tolerance of individual trees can be increased through the provision of more growing space, trees from a thinning experiment were analysed for reductions in radial growth during drought years and their subsequent recovery. Tree-ring widths were quantified on increment cores as well as stem discs of 32 trees from stands of a thinning trial established in 1974 in 27-year-old spruce stands in the Alpine Foreland of Southwest Germany. Three different thinning regimes of the trial were selected for this study: unthinned control (8 trees), moderate (13 trees) and heavy thinning (11 trees) intensities. All trees sampled were of a co-dominant to dominant canopy status. The standardisation of growth data was carried out using the software program ARSTAN (University of Arizona). For the year 1976—a widespread and severe drought year in Germany—we found year ring widths were not reduced compared to those of the pre-drought years for all treatments. However, we observed the formation of false year rings and resin ducts for this year in all trees investigated. The drought events in 1992 and 2003 led to severe growth depressions in the year of the drought event in all trees, regardless of previous thinning regimes. However, the resilience—the recovery of basal area growth in subsequent years—was significantly more rapid in trees from heavily thinned stands, even if the drought event occurred more than 10 years after the last thinning intervention. This indicates a shorter stress period for trees with more growing space, which may reduce the susceptibility to secondary pathogens or pest species such as bark beetles.     

Live-weight gains of Holstein × Zebu heifers grazing a <Emphasis Type="Italic">Cratylia argentea</Emphasis>/Toledo-grass (<Emphasis Type="Italic">Brachiaria brizantha</Emphasis>) association in the Mexican humid tropics

The legume Cratylia argentea associated to Brachiaria brizantha—Toledo-grass (Bb + Ca) and Toledo-grass alone (Bb) were evaluated under grazing conditions by Holstein × Zebu heifers. Three evaluation periods during three consecutive years, were performed. We measured, daily live-weight gains of heifers (DWG, g/day); biomass dry matter (BDM, kg/ha) at beginning and end of each grazing period. On plant samples, were measured percentages of crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, in situ DM degradability (ISDMD), and voluntary biomass DM intake (VBI, g/LW^0.75) using the Cr₂O₃/in situ indigestibility technique. A completely randomized design was applied, using heifers as experimental units for DWG gains and VBI. At the beginning of the grazing, the BDM for Bb + Ca and Bb–considering the three periods-averaged, 3065 and 936 kg/ha, respectively. Crude protein content of C. argentea was around 20 %; and for Bb + Ca or Bb, ranged from 8.7 to 4.6 %. In either treatment, in situ DM degradability averaged 72.6 % (P ≥ 0.05), regardless of the botanical component type. Biomass DM intake was 83.02 (Bb + Ca) and 89.22 (Bb) g/LW^0.75. The DWG gains (g/heifer) for Bb + Ca and Bb were (per period): 829 and 574 (first); 469 and 118 (second); and 534 and 508 (third). This study showed that the Bb + Ca association was better to improve the daily gain of F1 Holstein × Zebu heifers, as compared to Bb alone. Also, C. argentea associated to a low to medium-quality grass improved the nutritional value of the diet without affecting the biomass DM intake.     

Plantlet regeneration through somatic embryogenesis in Nordmann’s fir (<Emphasis Type="Italic">Abies nordmanniana</Emphasis>)

I studied the influence of various combinations of auxin and cytokinin concentrations, and the increased content of zinc and enzymatic casein hydrolizate in SH medium on initiation and proliferation of embryogenic callus of Abies nordmanniana (Steven) Spach. Additionally, the effect of ABA, PEG-4000 and different wavelengths on the maturation of somatic embryos was tested. The use of optimum composition of modified SH medium with BA, KIN and 2.4-D while simultaneously ensuring appropriate external conditions resulted in 15.5 % embryogenesis. Finally, satisfactory results of micropropagation of A. nordmanniana by somatic embryogenesis were obtained providing seven lines of embryogenic callus with high proliferation capacity. Those lines gave properly developed seedlings in white LED light with a wavelength of 400-700 nm, preceded by eight-week vernalization treatment of the callus. This paper may provide a protocol by which all stages of somatic embryogenesis of A. nordmanniana can be carried out, including the preceding 24-h seed disinfection with NaOCl and PVP, which resulted in 100 % frequency of uninfected zygotic embryos that were capable of starting embryogenesis.     

Effect of major inorganic nutrients on <Emphasis Type="Italic">β</Emphasis>-thujaplicin production in a suspension culture of <Emphasis Type="Italic">Cupressus lusitanica</Emphasis> cells

 The optimum conditions for β-thujaplicin production in a Cupressus lusitanica cell suspension culture were investigated. The conditions required for β-thujaplicin production were clearly different from the conditions for cell growth. The initial phosphate concentration and pH did not affect β-thujaplicin production. A total nitrogen source concentration higher than 3.2 mM suppressed production due to the presence of the ammonium ion. β-Thujaplicin production was observed at 95 mg/l without adding the ammonium ion to the medium. Strict control of major inorganic nutrients was not necessary to produce β-thujaplicin. This finding seems to be favorable for future automated production of β-thujaplicin in commercial cell culture plants.