Anthocyanin and flavonol variation in bog bilberries (Vaccinium uliginosum L.) in Finland.

The flavonoids, anthocyanins and flavonols, in bog bilberries (Vaccinium uliginosum L.) were studied from 15 populations in Finland on a south-north axis of approximately 1000 km. Four anthocyanidin xylosides and 14 flavonol glycosides were tentatively identified by means of HPLC-ESI-MS. Twenty-five major flavonoids were quantified by HPLC-DAD. The averages (+/-standard deviation) in the contents of anthocyanins and flavonols were 1425+/-398 and 1133+/-290 mg/100 g of dry weight, respectively. The most abundant anthocyanidin was malvidin, followed by delphinidin, petunidin, cyanidin, and peonidin. Quercetin was the major flavonol, followed by myricetin, laricitrin, syringetin, and isorhamnetin. Anthocyanins were mostly glucosides, whereas flavonols were mainly conjugated to galactose. The anthocyanin content in the berries from the south was the lowest. The delphinidin content was the highest but the proportion of malvidin the lowest in the north. The total flavonol content and the level of myricetin and quercetin were the highest in the north.

Characterization of anthocyanins in caucasian blueberries (Vaccinium arctostaphylos L.) native to Turkey.

High-performance liquid chromatography (HPLC) combined with diode array (DAD) and electrospray ionization mass spectrometric (ESI-MS) detections were used to characterize anthocyanins in the berries of Vaccinium arctostaphylos L. The dark purple-black berries were collected from five Caucasian blueberry populations in northeastern Turkey. The HPLC-DAD profile consisted of 19 anthocyanin peaks, but HPLC-ESI-MS revealed fragment ion patterns of 26 anthocyanins. Delphinidin, cyanidin, petunidin, peonidin, and malvidin were all glycosylated with four different monosaccharide moieties (galactose, glucose, arabinose, and xylose) with the first two also conjugated with rhamnose. Furthermore, anthocyanidin disaccharides, tentatively identified as anthocyanidin sambubiosides, were characteristic for these berries. The mean content of the total anthocyanins was 1420 mg/100 g dry weight. The most predominant anthocyanidins were delphinidin (41%), petunidin (19%), and malvidin (19%). Glucose was the most typical (61%) sugar moiety. This study revealed that wild Caucasian blueberries contain an abundance of bioactive anthocyanins and thus are ideal for various functional food purposes.

Analysis of anthocyanin variation in wild populations of bilberry (Vaccinium myrtillus L.) in Finland.

The berries of Vaccinium myrtillus L. are characterized by 15 anthocyanins. To study the variation in the anthocyanins on a south-north axis of about 1000 km in Finland, the berries from 179 individual bilberry plants in 20 populations were analyzed using an optimized RP-HPLC-DAD method. The mean content of the total anthocyanins was 2878 mg/100 g dry weight. There was extensive variation in the anthocyanin contents within and between the populations, suggesting differences in berry raw material. A significantly lower content of the total anthocyanins was observed in the berries of the southern region compared to those in the central and northern regions. Differences in the proportions of anthocyanins were also observed. The delphinidin glycosides dominated in the northern berries whereas the cyanidin glycosides were most common in the southern ones. Exceptional bilberry individuals were found mainly from eastern Finland with very low amounts of anthocyanidin glucosides. This is the first systematic study to reveal the extremely high variation in the content and distribution of anthocyanins in wild bilberries.

Effect of long-term forest fertilization on Scots pine xylem quality and wood borer performance.

We tested whether changes in long-term nutrient availability would affect the xylem quality and characteristics of Scots pine trees as a food source for the larvae of the xylophagous wood borer Hylotrupes bajulus L. (Cerambycidae). We looked for an effect of host plant growth and xylem structural traits on H. bajulus larval performance, and looked for delayed effects of long-term forest fertilization on xylem chemical quality. In general, larval performance was dependent on larval developmental stage. However, the growth of larvae also varied with host plant quality (increases in the concentration of nitrogen and carbon-based secondary compounds of xylem were correlated with a decrease in the larval growth rate). The greater annual growth of trees reduced tracheid length and correlated positively with second-instar H. bajulus growth rate. This is consistent with the hypothesis that intrinsic growth patterns of host plants influence the development of the xylophagous wood borer H. bajulus.

Long-term exposure to enhanced UV-B radiation has no significant effects on growth or secondary compounds of outdoor-grown Scots pine and Norway spruce seedlings.

The effects of long-term enhanced UV-B radiation on growth and secondary compounds of two conifer species were studied in an outdoor experiment. Scots pine (Pinus sylvestris) seedlings were exposed for two growing seasons and Norway spruce (Picea abies) seedlings for three growing seasons to supplemental UV-B radiation, corresponding to a 30% increase in ambient UV-B radiation. The experiment also included appropriate controls for ambient and increased UV-A radiation. Enhanced UV-B did not affect the growth of the conifer seedlings. In addition, neither the concentrations of terpenes and phenolics in the needles nor the concentrations of terpenes in the wood were affected. However, in the UV-A control treatment the concentrations of diterpenes in the wood of Scots pine decreased significantly compared to the ambient control. Apparently, a small increase in UV-B radiation has no significant effects on the secondary compounds and growth of Scots pine and Norway spruce seedlings.

Influence of carrot psyllid (Trioza apicalis) feeding or exogenous limonene or methyl jasmonate treatment on composition of carrot (Daucus carota) leaf essential oil and headspace volatiles.

The effect of carrot psyllid (Trioza apicalis Förster) feeding and limonene and methyl jasmonate (MeJA) treatments on the essential oil composition and headspace volatiles of carrot (Daucus carota ssp. sativus), cvs. Parano and Splendid, leaves was studied. Carrot psyllid feeding significantly increased the concentrations of sabinene, beta-pinene, and limonene, whereas limonene treatment increased the concentration of (Z)-beta-ocimene in the leaves of both cultivars. The limonene treatment significantly increased the concentration of total phenolics in the leaves of both cultivars, and MeJA treatment increased phenolic concentration in the leaves of Parano. Exogenous limonene spray did not decrease the number of carrot psyllid eggs laid either 2 or 24 h after treatment. The results suggest that carrot psyllid feeding induces changes in the endogenous monoterpene pool in the carrot leaves. Limonene and MeJA treatments affect some induced defenses of the carrot, but the exogenous limonene spray is not an effective oviposition deterrent against carrot psyllid.

Drought stress alters the concentration of wood terpenoids in Scots pine and Norway spruce seedlings.

Drought is known to have an impact on the resistance of conifers to various pests, for example, by affecting resin flow in trees. Little is known, however, about the quantitative and qualitative changes in resin when trees are growing in low moisture conditions. We exposed Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings to medium and severe drought stress for two growing seasons and analyzed the monoterpenes and resin acids in the main stem wood after two years of treatment. In addition to secondary chemistry, we measured the level of nutrients in the needles and the growth response of seedlings. After the first year of treatment, drought stress did not affect the growth of seedlings, but in the second year, shoot growth was retarded, especially in Scots pine. In both conifer species, severe drought increased the concentrations of several individual monoterpenes and resin acids. Total monoterpenes and resin acids were 39 and 32% higher in severe drought-treated Scots pine seedlings than in the controls, and 35 and 45% higher in Norway spruce seedlings. In Scots pine needles, the concentrations of nitrogen and phosphorus increased, while magnesium and calcium decreased compared to controls. In Norway spruce needles, nutrient concentrations were not affected. The results suggest that drought stress substantially affects both the growth of conifers and the chemical quality of the wood. We discuss the potential trade-off in growth and defense of small conifer seedlings.

Contrasting effects of elevated carbon dioxide concentration and temperature on Rubisco activity, chlorophyll fluorescence, needle ultrastructure and secondary metabolites in conifer seedlings.

Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings were grown for 50 days in growth chambers in an ambient or twice ambient carbon dioxide concentration ([CO2]) at a day/night temperature of 19/12 degrees C or 23/16 degrees C. Although elevated [CO2] (EC) had only slight effects on the growth parameters measured, elevated temperature (ET) increased above ground dry mass of both species. Among treatments, biomass accumulation of both species was greatest in the combined EC + ET treatment. The EC treatment induced thylakoid swelling and increased numbers of plastoglobuli observed in Scots pine needles. Although EC had little effect on Rubisco protein or N concentration of needles, ET had a large effect on N-containing compounds and enhanced N allocation from 1-year-old needles. Terpenoids were more responsive to EC and ET than total phenolics. Generally, terpene concentrations were reduced by EC and increased by ET. Increased terpenoid concentrations in response to ET might be associated with thermotolerance of photosynthesis. In Norway spruce, EC decreased total phenolic concentrations in needles, probably as a result of increased growth. We conclude that, in seedlings of these boreal species, the effects of elevated [CO2] on the studied parameters were small compared with the effects of elevated temperature.

Resource partitioning to growth, storage and defence in nitrogen-fertilized Scots pine and susceptibility of the seedlings to the tarnished plant bug Lygus rugulipennis.

We tested how variable nitrogen availability affects the above-and below-ground growth of first-year Scots pine (Pinus sylvestris L.) seedlings and carbon allocation to defensive allelochemicals and storage. Concentrations of free ammo acids were considered as indicators of nutritive quality. Suitability of seedlings for polyphagous Lygus rugulipennis Popp. (Heteroptera: Miridae) was tested with oviposition preference and nymphal growth experiments. At the end of the growing season, needle length increased while root hiomass decreased with elevated N fertilization, but shoot length was not affected. Concentration of starch in needles and roots, representing carbon storage, was not significantly affected by N fertilization, although there was a decrease in the starch concentration of needles when nitrogen input increased. Nitrogen fertilization significantly increased the pool of total and non-essential ammo acids in the shoots. Arginine, proline and glutamine were the individual ammo acids most affected by elevated N. Of the carbon-based defence compounds, total resin acid concentrations in shoots were significantly reduced with elevated nitrogen in 9-wk-old seedlings. Palustric acid and neoabietic acid were the most affected individual) resin acids, where as foliar monoterpenes were not influenced by N availability. Total phenolics in shoot and root showed variable response. The increasing effect of nitrogen on the oviposition rate of Lygus females was almost linear. Mean relative growth rate of the nymphs was significantly affected by the level of N fertilization. but the mortality of nymphs was high in all treatments. The results suggest that in nitrogen-rich environments the needle growth of small Scots pine seedlings is improved, but their Susceptibility to insect attack is increased and they remain less defended as predicted by the carbon/nutrient balance hypothesis. Total phenolics and resin acids, representing phenylalanine and mevalonic acid pathways, respectively, were both reduced by increased nitrogen availability. Together with the simultaneous increase of foliar free nitrogen in the form amino acids, the nutritive value of seedlings is ameliorated and this might explain susceptibility of nursery-grown. N fertilized seedlings to polyphagous Lygus bugs.