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PubMed1996

Quantitative determination of the polyphenolic content of pomegranate peel.

The quantitative determination of total phenols, ellagic tannins and gallic and ellagic acids in the peel of the Tunisian pomegranate variety Chelfi, has been carried out. The ellagic tannin content is prominently less than the amount of total phenols, which led us to look for the presence of the condensed tannins. The determination of the content of catechic tannins in eight Tunisian varieties of the pomegranate was carried out using weekly samples over a period of 2 months.

Chromatography, High Pressure Liquid↗

PubMed1992

In vitro enzymatic hydrolysis of protein and protein pattern change of soya and faba beans during germination.

In addition to technological processes like heat treatment, germination can be an alternative process for the improvement of protein quality of legumes. This was demonstrated by enzymatic protein hydrolysis of flour of germinated faba and soya beans, using a pepsin-pancreatin enzyme system. SDS-PAGE was used to study the changes in protein pattern of these legumes during germination. In addition, the effect of germination on the content of condensed tannins in flour from germinated faba beans and trypsin inhibitors in flour from germinated soya beans were studied. Germination for five days resulted in a maximum increase in enzymatic protein hydrolysis by 21.3% in flour from faba beans and by 25.7% in flour from soya beans after 12 hours of germination. Protein patterns, obtained with SDS-PAGE demonstrated a considerable protein breakdown during germination between day 2 and 3 in faba beans and between day 1 and 2 in soya beans. The tannin content in flour from faba beans decreased by 29.7% after seven days of germination, but the tannin content of the hulls of the faba beans did not change during that period of germination. The trypsin inhibitors in flour from soya beans decreased by 25.5% after seven days of germination. We conclude that the increased enzymatic hydrolysis of protein in both legumes cannot be explained by a decrease of tannins or trypsin inhibitors. The possible explanation is that through degradation of proteins during germination of the legumes, the cleaved protein fragments are more susceptible for hydrolysis by pepsin-pancreatin.

Adsorption↗

PubMed2003

Phenological variation as protection against defoliating insects: the case of Quercus robur and Operophtera brumata.

Phenological synchrony between budburst and emergence of larvae is critical for the fitness of many spring-feeding insect herbivores. Therefore, large intraspecific variation in timing of budburst of the host may have a negative effect on the herbivore. We studied how asynchrony between emergence of larvae and budburst affects the fitness of Operophtera brumata (Lepidoptera: Geometridae), a major defoliator of Quercus robur, which can adapt to the phenology of a single tree. It is known that, in maturing leaves of Q. robur, accumulation of condensed tannins has a negative effect on growth of O. brumata. However, there is no information about the effect of hydrolysable tannins and other phenolics that are potential antifeedants. In this study, we also analysed changes in secondary chemistry of the foliage of Q. robur and how different compounds are correlated with growth and survival of O. brumata. The effect of asynchrony on O. brumata was studied in rearing experiments. The neonate larvae were incubated without food for different periods of time. The decline in nutritional quality of foliage was estimated by rearing cohorts of larvae with manipulated hatching times on the leaves of ten individual Q. robur trees. For the chemical analysis, the foliage of these trees was sampled at regular intervals. In the absence of foliage, mortality of neonate larvae started to increase exponentially soon after the larvae emerged. If the larvae missed budburst, the decline in nutritional quality of the foliage led to increased mortality and lower body mass (= fecundity). Hydrolysable tannins were not significantly correlated with performance of the larvae. Only condensed tannins were found to correlate negatively with the growth and survival of O. brumata. Certain individual trees were unsuitable hosts for O. brumata because the decline in quality of the foliage was very rapid. Based on regression equations for increasing rate of mortality and decreasing fecundity, we calculated that a relatively small mismatch of +/-30 degree days between budburst and hatching of larvae leads to a 50% decrease in the fitness of O. brumata. Thus, large phenological variation within a Q. robur stand can limit the colonisation of neighbouring trees by dispersing larvae. Furthermore, the hybridisation of moths adapted to phenologically different trees may lead to maladapted phenology of their offspring.

Adaptation, Physiological↗

PubMed2004

Allocation to defense or growth in dipterocarp forest seedlings in Borneo.

We quantified the allocation of net production to plant secondary metabolites (especially condensed tannins and lignins) to evaluate the investment into defense mechanisms of three tropical forest canopy species in Borneo vis-à-vis the resource availability hypothesis. In particular, we focused on Borneo ironwood (Eusideroxylon zwageri, Lauraceae), which seemed to employ an extreme defensive strategy. The wood of this species is extremely durable and has a high specific gravity with a very slow growth rate. The allocation to defense by Borneo ironwood was compared to two emergent species of Dipterocarpaceae, the dominant family in this forest community. We conducted shade-house experiments on seedlings under four controlled conditions (two light levels x two nutrient levels) and showed that the growth rate of E. zwageri was much lower than those of the other two species, and it allocated more of its net production to leaves and roots than to stems. The concentrations of condensed tannins and lignins were very high in the leaves and stems of this species, at about 20 and 30%, respectively. In total, E. zwageri allocated a maximum of about 35% of its net production to defensive substances (i.e., condensed tannins + lignins). In contrast, the two dipterocarp species allocated about 20-25% of their net production to defensive substances. The condensed tannins in E. zwageri help to prolong the lifespan of the leaves, and the lignins in the stems enhance the durability of the wood. Thus, although E. zwageri grows very slowly, the allocation to defensive substances seems to be an advantageous strategy for survival under dark conditions.

Analysis of Variance↗

PubMed2004

Variations in the concentration of phenolic compounds in the seagrass Posidonia oceanica under conditions of competition.

The concentration of phenolic compound was measured in the seagrass Posidonia oceanica when interacting with two Bryopsidophyceae, Caulerpa taxifolia and Caulerpa racemosa, between May 1999 and May 2000. These measurements were performed on adult and intermediate leaves and in sheaths of the seagrass. Sampling was carried out at three stations subject to increasing levels of interaction with Caulerpa. The number of tannin cells was also analysed. Five phenolic compounds were identified in P. oceanica, with a predominance of caffeic acid in the adult and intermediate leaves. For a given level of interaction (and for both caulerpa sp.), a significant seasonal variation in phenolic compounds was shown in the adult leaves (higher in November and lower in September and March for example for the interaction with C. taxifolia). Only for two compounds (corresponding to a mixture containing ferulic acid and the ester methyl 12-acetoxyricinoleate) were significant differences observed as a function of the level of interaction with C. taxifblia, and only in the adult leaves: higher concentrations of phenols were observed with increasing level of interaction. Thus,adult leaves gave values of 55.5 +/- 14.1 microg g(-1) dm without interaction (OCt) and 94.9 +/- 23.4 microg g(-l) dm with high interaction (2Ct),corresponding to an increase of 70%. No significant difference was observed with intermediate leaves and sheaths, or for interaction with C. racemosa. The number of tannin cells (supposed to produce the phenolic compounds) largely increased in the adult and intermediate leaves when the degree of interaction with C. taxifolia increased: 90 mm above the base of the sheath (in adult leaves), 16.7 +/- 10.6 tannin cells cm(-2) were found without interaction (OCt), and 57.8 + 21.2 tannin cells cm(-2) with high interaction (2Ct). No significant difference was found for C. racemosa interaction. It thus appears that when the seagrass P. oceanica is in interaction with C. taxifolia, it accelerates its production of secondary metabolites so as to limit invasion of the beds.

Alismatales↗

PubMed2005

Lack of effects of quebracho and sainfoin hay on incoming third-stage larvae of Haemonchus contortus in goats.

The effects of tannins on adult populations of Haemonchus contortus, Trichostrongylus colubriformis and Teladorsagia circumcincta in goats are characterised mainly by a decrease in egg excretion without any significant changes in worm number. In contrast, the impact of tannins on T. colubriformis or T. circumcincta third-stage larvae (L3) is associated with a significant reduction in worm establishment. The objective of the present study was to examine the effects of quebracho extract tannins on H. contortus L3. The consequences of consumption of sainfoin hay were also examined. Twenty-one naïve kids were divided into three experimental groups. Group Q received quebracho extract and group S received sainfoin hay from days D3 to D5. Group C remained as an infected control group. All kids received 1500 L3 H. contortus on D0, D1 and D2. On D18, post-infection, the kids were slaughtered and the worm populations compared in the different groups. Compared to the control values, the worm counts decreased, respectively, by 33% and 38% in groups Q and S but the differences were not significant. No differences were found in pathophysiological measurements between the three groups. The results confirm differences in tannin effect according to nematode species but not parasitic stage.

Anacardiaceae↗

PubMed2002

Identification of inhibitors of the HIV-1 gp41 six-helix bundle formation from extracts of Chinese medicinal herbs Prunella vulgaris and Rhizoma cibotte.

An increasing portion of patients with HIV infection and/or AIDS cannot use currently FDA-approved anti-HIV drugs, including the reverse transcriptase and protease inhibitors, due to the adverse effects and the emergence of drug resistance. Thus, it is essential to develop new anti-HIV agents with a target different from the HIV reverse transcriptase and protease. Using a conformation-specific monoclonal antibody NC-1, we previously established a high throughput screening assay for identification of small molecular organic compounds that disrupt the HIV-1 gp41 six-helix bundle formation, a critical step of membrane fusion between the HIV and the target cell. In the present study, we used this assay to screen for inhibitors of the gp41 six-helix bundle formation from aqueous extracts of nine Chinese medicinal herbs with antiviral activity. We found that the extracts of two herbs, Prunella vulgaris and Rhizoma cibotte, showed potent inhibitory activity. The inhibitory activity of these two herb extracts significantly decreased after they were passed through polyamide resin mini-columns, which are able to bind polyphenols including tannin, an HIV-1 inhibitor with multiple mechanisms of action. The bound polyphenols were eluted from the polyamide columns and also showed potent inhibitory activity on the gp41 six-helix bundle formation. Tannin purchased from different commercial sources inhibited the gp41 six-helix bundle formation in a manner similar to the polyphenols isolated from the herb extracts. These results suggest that tannin may be one of major inhibitors of the HIV-1 gp41 six-helix bundle formation in the herb extracts and that tannin may inhibit HIV-1 entry by disrupting the gp41 six-helix bundle formation.

Antibody Specificity↗

PubMed2001

Biochemical and morphological changes in carp (Cyprinus carpio L.) liver following exposure to copper sulfate and tannic acid.

As a consequence of human activity various toxicants reach the aquatic ecosystems; humics may interact with them and may change their toxicity. Many fish are exposed to a considerable concentration of humics and pollutants. Because of paucity of data on the biochemical action of tannins in the presence of the fungicide CuSO4 a comparative study was undertaken. The alterations of redox-parameters in carp liver were monitored and tissue necrosis was followed by measuring the plasma transaminase activities and by electron microscopy. Tannic acid, a representative phenolic/humic compound, exerted prooxidant effects in carp, which may be partially due to formation of prooxidant intermediates/end-products via its biotransformation. Alternatively, tannic acid may partially inhibit the antioxidant enzymes of fish. The response to CuSO4 was more severe. Although tannic acid alone acted as a prooxidant in fish, electron micrographs demonstrated that it reduced the necrotizing effect of copper, which may be due to the complexing activity of tannic acid with the biomolecules of the hepatocytes and to the H2O2-degrading activity of tannin-CuSO4 combination. Our results indicate that the heavy metal-detoxifying capacity of tannin may be significant; however, tannin-exposure alone or combined with metals may be toxic for fish due to enzyme inhibition and oxidative stress induction.

Alanine Transaminase↗

PubMed2004

In vitro effects of three woody plant and sainfoin extracts on 3rd-stage larvae and adult worms of three gastrointestinal nematodes.

Most studies on the effects of tanniferous plants on nematodes have examined forages but have neglected the woody plants. Therefore, in vitro effects of extracts from 3 woody plants (Rubus fructicosus, Quercus robur, Corylus avellana) have been tested on trichostrongyles and compared to sainfoin, a legume forage. Because some in vivo results indicated that the effects of tannins differed depending on the parasitic species and/or stages, the effects were measured on 3rd-stage larvae (L3) and adult worms of Teladorsagia circumcincta, Haemonchlus contortus and Trichostrongylus colubriformis. The effects of plant extracts varied according to the plant sources, the parasite species and stages. For the woody plants, significant inhibitory effects were obtained on both stages of abomasal species. Results for T. colubriformis were more variable. Effects of sainfoin extracts were significant on T. colubriformis and H. contortus L3, and on abomasal adult worms. In order to assess the implications of tannins, polyethylene glycol (PEG), an inhibitor of tannins, was added to hazel tree, oak and sainfoin extracts. Without PEG, significant inhibitory effects on L3 and adult worms were confirmed. After addition of PEG, the larval migration and motility of adult worms were restored in most cases. These results confirm variations in effects depending on factors related to plants or parasites and suggest that tannins are partly responsible for the effects.

Animals↗

PubMed2003

Use of DSC to detect the heterogeneity of hydrothermal stability in the polyphenol-treated collagen matrix.

The hydrothermal stability of the collagen matrixes treated with plant polyphenols (tannins) depends on not only the strength of the polyphenol-collagen interactions but also the distribution uniformity of polyphenolic molecules within the collagen fibrils. Traditional methods of uniformity tests rely heavily on the expertise of workers and are thus subjective. This paper describes a differential scanning calorimetry (DSC) study of the sheepskin collagen samples treated with hydrolyzable tannins, including two commercial tannins' extracts (chestnut and valonea), two pure ellagitannins (vescalagin and castalagin), and six synthetic gallotannins (di-galloyl-ethylene glycol (DGE), tri-galloyl-glycerol, tetra-galloyl-meso-erythritol, penta-galloyl-adonitol, penta-galloyl-glucose, and hexa-galloyl-ducitol). The collagen sample without polyphenol treatment and the sample treated with DGE showed a single sharp peak in their DSC thermogram with a full peak width at half height (fwhh) of 3-4 degrees C. The samples treated with other tannins all showed multiple peak DSC profiles with the fwhh of each peak at about 3-4 degrees C. These multiple peak profiles imply that in these polyphenol-treated samples, there is a distribution of collagen molecules having different hydrothermal stability. The results have demonstrated that DSC offers an objective method to detect the stability heterogeneity of collagen matrixes in the solid state, providing a useful tool for the leather industry to evaluate the uniformity of leather tanning.

Animals↗

PubMed2004

Electrophoretic method for the identification of a haze-active protein in grape seeds.

A simple, fast, and more selective approach is presented in this study for the identification of haze-active proteins. Grape seed proteins were unfolded by 1% SDS and then interacted with different amounts of tannin at 4 degrees C, followed by gel electrophoresis. It was found that the intensity of the band at 45 kDa was decreased as tannins increased. The amino acid composition of this isolated 45-kDa protein was higher in proline (9.49%) than the average proline content of total grape seed proteins (4.85%). To verify the selectivity of the proposed method, a globular protein (bovine serum albumin, BSA) and a proline-rich protein (gelatin) were selected and used in the model system. As expected, gelatin was removed as it reacted with the increasing added tannins, whereas BSA did not. These results showed that it is possible to identify haze-active proteins by modulating the accessibility of protein to tannins, suggesting this new method can be used by the beverage industry to trouble-shoot haze problems and for quality control.

Amino Acids↗

PubMed2005

Antioxidants in raspberry: on-line analysis links antioxidant activity to a diversity of individual metabolites.

The presence of antioxidant compounds can be considered as a quality parameter for edible fruit. In this paper, we studied the antioxidant compounds in raspberry (Rubus idaeus) fruits by high-performance liquid chromatography (HPLC) coupled to an on-line postcolumn antioxidant detection system. Both developmental and genetic factors were assessed by comparing fruits from a single cultivar of different ripening stages and by comparing ripe fruits of 14 raspberry cultivars, respectively. The HPLC-separated antioxidant compounds were identified using HPLC-photodiode array coupled to mass spectrometry (quadrupole time-of-flight tandem mass spectrometry), using a reference lock mass for determining accurate masses. The dominant antioxidants could be classified as anthocyanins, ellagitannins, and proanthocyanidin-like tannins. During fruit ripening, some anthocyanins were newly produced, while others, like cyanidin-3-glucoside, were already present early in fruit development. The level of tannins, both ellagitannins and proanthocyanidin-like tannins, was reduced strongly during fruit ripening. Among the 14 cultivars, major differences (>20-fold) were observed in the levels of pelagonidin type anthocyanins and some proanthocyanidin type tannins. The content of ellagitannins varied approximately 3-fold. The findings presented here suggest that the content of individual health-promoting compounds varies significantly in raspberry, due to both developmental and genetic factors. This information will assist in the future development and identification of raspberry lines with enhanced health-promoting properties.

Anthocyanins↗

PubMed2005

Different polyphenolic components of soft fruits inhibit alpha-amylase and alpha-glucosidase.

Polyphenol-rich extracts from soft fruits were tested for their ability to inhibit alpha-amylase and alpha-glucosidase. All extracts tested caused some inhibition of alpha-amylase, but there was a 10-fold difference between the least and most effective extracts. Strawberry and raspberry extracts were more effective alpha-amylase inhibitors than blueberry, blackcurrant, or red cabbage. Conversely, alpha-glucosidase was more readily inhibited by blueberry and blackcurrant extracts. The extent of inhibition of alpha-glucosidase was related to their anthocyanin content. For example, blueberry and blackcurrant extracts, which have the highest anthocyanin content, were the most effective inhibitors of alpha-glucosidase. The extracts most effective in inhibiting alpha-amylase (strawberry and raspberry) contain appreciable amounts of soluble tannins. Other tannin-rich extracts (red grape, red wine, and green tea) were also effective inhibitors of alpha-amylase. Indeed, removing tannins from strawberry extracts with gelatin also removed inhibition. Fractionation of raspberry extracts on Sephadex LH-20 produced an unbound fraction enriched in anthocyanins and a bound fraction enriched in tannin-like polyphenols. The unbound anthocyanin-enriched fraction was more effective against alpha-glucosidase than the original extract, whereas the alpha-amylase inhibitors were concentrated in the bound fraction. The LH-20 bound sample was separated by preparative HPLC, and fractions were assayed for inhibition of alpha-amylase. The inhibitory components were identified as ellagitannins using LC-MS-MS. This study suggests that different polyphenolic components of fruits may influence different steps in starch digestion in a synergistic manner.

Anthocyanins↗

PubMed2006

Effect of flash release treatment on phenolic extraction and wine composition.

The flash release (FR) process, consisting of rapidly heating the grapes and then applying strong vacuum, has been proposed to increase the polyphenol content of red wines. Its impact on polyphenol extraction kinetics and on the polyphenol composition of red juice and wines was studied over two seasons on different grape varieties (Grenache, Mourvedre, Carignan). The FR process allows fast extraction of all phenolic compounds (hydroxycinnamic acids, flavonols, anthocyanins, catechins, proanthocyanidins) and can be used to produce polyphenol-enriched grape juices. However, the concentration of all polyphenols dramatically decreased throughout fermentation when pressing was achieved immediately after FR. The FR wines made with pomace maceration were also enriched in polyphenols compared to the corresponding control wines. Increasing the duration of high-temperature exposure in the FR treatment further increased extraction of phenolic compounds but also accelerated their conversion to derived species. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase, higher after FR than in the control, and even higher after longer heating. FR resulted in an increased tannin-to-anthocyanin ratio and an increased conversion of anthocyanins to tannin-anthocyanin adducts showing the same color properties as anthocyanins. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase that also contained larger amounts of orange sulfite bleaching-resistant pigments.

Anthocyanins↗

PubMed2003

Inheritance patterns of phenolics in F1, F2, and back-cross hybrids of willows: implications for herbivore responses to hybrid plants.

The aim of this study was to determine the inheritance pattern of phenolic secondary compounds in pure and hybrid willows and its consequences for plant resistance to leaf-feeding insects. F1, F2, and back-cross hybrids along with pure species were produced by hand pollination of pure, naturally-growing Salix caprea (L., Salicaceae) and S. repens (L.) plants. Leaf concentrations of condensed tannins and seven different phenolic glucosides were determined by using butanol-HCI and HPLC analyses. Insect herbivore leaf damage was measured on the same leaves as used for chemical analyses. We found hybrids to be approximately intermediate between the parental species: S. caprea with high levels of condensed tannins and no phenolic glucosides. and S. repens with low levels of condensed tannins and high levels of phenolic glucosides. We also found a negative correlation between concentrations of condensed tannins and phenolic glucosides, suggesting a trade-off in production of these two substances. F2 hybrids and the hybrid back-crossed to S. caprea were significantly more damaged by insect herbivores than the parental species and the F1 hybrid, indicating reduced resistance and possibly a selective disadvantage for these hybrid categories.

Adaptation, Physiological↗

PubMed2003

Phytochemical determination for leaf food choice by wild chimpanzees in Guinea, Bossou.

The feeding selection of leaves by chimpanzees was investigated from the perspective of phytochemistry and leaf availability. Field data were collected for 6 months from 1995 to 1996 and 8 months from 1997 to 1998 in Bossou, Guinea. Time budgets of leaf consumption by chimpanzees were analysed and the abundance of young leaves of each tree species for each month was estimated. Analyses of dried materials, stratified by leaf maturity and edibility, for the relative amounts of crude protein, crude fat, neutral detergent fiber, ash, and condensed tannin were determined. It was found that 1) leaves consumed by chimpanzees had higher levels of ash and lower levels of condensed tannin than leaves that were not eaten; 2) feeding selectivity was correlated with crude protein content; and 3) the availability of young leaves was not correlated with the percentage of feeding time, neither by seasonal changes nor by tree species. Chimpanzees preferred leaves containing higher protein content, but did not consume leaves containing high condensed tannin regardless of protein content. It seems reasonable to consider that a different rule exists for "whether chimpanzees eat it or not" and "whether they prefer it or not" in phytochemical determinants of leaves. Some Moraceae species, which had low levels of condensed tannins, even in mature leaves, were an important food source for the Bossou chimpanzees.

Animals↗

PubMed2004

Seasonal variation of organogenetic activity and reserves allocation in the shoot apex of Pinus pinaster Ait.

BACKGROUND AND AIMS: To understand better the basic growth characteristics of pines and the fundamental properties of the shoot apical meristem (SAM), variations within the shoot apex of buds were studied. METHODS: A detailed structural comparison of meristem dimensions, organogenetic activity, and the presence of lipids, starch grains and tannins was performed on shoot apices of juvenile, and male and female adult Pinus pinaster at five different times in the annual growth cycle. KEY RESULTS: There were significant correlations among traits and differences in the pattern for juvenile and adult shoots. In juvenile shoots, peaks of organogenesis were present in spring and autumn, but not in summer. In adult shoots, one peak, characterized by an increase in meristem dimensions, was present in summer. The accumulation of starch grains beneath the SAM and of tannin in sub-apical pith parenchyma were at their maximum when organogenetic activity was high in spring and autumn in juvenile plants, and in summer in adult plants. In juvenile and adult plants, lipids were stored within the SAM in autumn, filling a large part of the bud in winter, and were depleted in the cortical parenchyma and then in the pith during shoot elongation. CONCLUSIONS: Depending on the sites of accumulation within the SAM and on the stage of the annual growth cycle, lipids, starch and tannins may be involved in different processes. In spring, energy and structural materials released by lipid hydrolysis may contribute to stem elongation and/or cell-to-cell communication. During organogenesis, energy and structural materials released by starch hydrolysis may influence developmental programmes in the SAM and adjacent cells. Tannins may be involved in cellular detoxification. At the end of the growing season, accumulation of lipid and starch is positively correlated with the onset of dormancy.

Lipid Metabolism↗

PubMed2004

Effects of genetic variability and habitat of Qualea parviflora (Vochysiaceae) on herbivory by free-feeding and gall-forming insects.

BACKGROUND AND AIMS: Differences in the chemical and physical traits of plants caused by both genetic and habitat characteristics may influence attack by herbivores. Leaves of Qualea parviflora (Vochysiaceae), a common tree of different habitats in the Brazilian Neotropical savannas (cerrado), are susceptible to severe attack by herbivorous free-living and gall-forming insects. Attack by free-living and gall-forming insects within and between populations of Q. parviflora were examined and it was determined to what extent genetic variability (detected by RAPD markers), phenotypic characteristics of the plants and habit traits influence the number of free-living and gall-forming insect species and individuals attacking the plants, and the intensity of attack. METHODS: On four occasions in 2000, leaves were sampled from ten individual trees in each of three types of vegetation in the cerrado: campo sujo, cerrado sensu stricto and cerradão at the Ecological Station of Pirapitinga (ESP), in Três Marias, north-western Minas Gerais, Brazil. Genetic variability was detected by RAPD markers, and concentrations of nutrients, phenols and tannins, sclerophylly and pre-dawn water potential of leaves were measured. Water and nutrient contents in the soil below each tree characterized the habitat. The free-living and gall-forming herbivorous insects were determined. KEY RESULTS: Of 69 RAPD markers analysed, 41 were polymorphic and were used for analyses of genetic variability of Q. parviflora. Most of the variability occurred within habitats, accounting for 97.65 % of the genetic variability. Plants in the cerrado sensu stricto and campo sujo were the most similar. There were no significant associations between genetic similarity and the chemical and physical traits of Q. parviflora, or with habitat, nor was there significant correlation between phenotypic and habitat traits. Increasing concentrations of tannins and sulphur, C : N ratio and sclerophylly correlated with increasing percentage of leaf area damaged by herbivores. Decreased sclerophylly, concentration of tannins and C : N ratio, and increased concentration of nutrients in leaves correlated with increased severity of attack by gall-forming insects. CONCLUSIONS: Nutrient concentration in the soil had more influence, indirectly, on free-feeding insects than did composition of Q. parviflora leaves. However, gall-forming insects are affected more by leaf quality, attacking fewer sclerophyllous leaves, with larger nutrient but smaller tannin concentrations.

Animals↗