Deterioration and spoilage of peanuts and desiccated coconuts from two sub-Saharan tropical East African countries due to the associated mycobiota and their degradative enzymes

A broad variety of fungi (84 species belonging to 36 genera) were identified with more taxa infesting peanut seed samples from two tropical countries (29 genera and 61 species) compared to those found in desiccated coconuts (20 genera and55 species) on both DRBC and DG18 media. This may be due to the higher moisture levels in peanuts (5.07–7.97%) compared with coconuts (1.5–4.17%). More taxa and propagules were recovered on DG18 in both cases. The dominant fungi from both substrates on both isolation media were Aspergillus andPenicillium, with other fungi from only one substrate/medium. The aflatoxigenic species (A. flavus) dominated Kenyan samples more so than Ugandan samples on both substrates. However only71.5% and 87% of the peanut kernels, on DRBC and DG18, respectively, were found to be infested with fungi. The aflatoxigenic species (A. flavus/parasiticus)were found in 75% of the samples, however only 15.75% and 13%of the kernels analyzed were infested. The most frequently isolated species from peanuts were A. niger followed by A. flavus and M. phaseolina. E. repens, E. amstelodami,E. rubrum and E. chevalieri dominated peanut seeds on DG18, and R. stolonifer, A. parasiticus,F. solani, L. theobromae and P. chrysogenumon DRBC. The mean count of fungal propagules in coconut samples were approximately 0.7× 10³ and 0.8× 10³on DRBC and DG18, respectively, with a high proportion of those propagules recorded for the aflatoxigenic species (about 0.17×10³ and 0.25× 10³ colonies/g). The mycobiota of desiccated coconut was dominated by A. niger, A. flavusand P. chrysogenum. Also A. ochraceu,P. waksmanii, Paecilomyces variotii,P. islandicum and R. mucilaginosa were more frequent on DRBC, while, species of Cladosporium,Chrysosporium and Eurotium were more frequent on DG18. Enzyme indices (or the activities) for each specific strain, when determined after 5 and 8 days of incubation, proved to be similar. A recommendation is given. The proteolytic and lipolytic potentialities of the most commonly encountered species from both peanuts and coconuts were studied. The most interesting observation is that most of the positive isolates, in both commodities had high enzymic activity compared to those reported earlier for isolates of the same species. Such capabilities suggest that these commodities are expected to deteriorate, since climatic conditions in tropical areas favour fungal proliferation. Emphasis on the proper harvesting, drying, handling, transportation and/or storage; and also education of the populace, especially those are dealing with these foods, should be taken into consideration by the relevant authorities. The contaminated foods constitute a health hazard for human consumption. This revised version was published online in June 2006 with corrections to the Cover Date.     

The Effect of Host Constitution on the Development of Plasmodium floridense*

More than 15,000 lizards from South Georgia were examined over a period of 16 years. Five percent of Sceloporus undulatus and 36% of Anolis carolinensis were found to harbor Plasmodium floridense. Development of 28 natural new infections was followed in detail as soon as they became patent and comparisons in the 2 host species made of intensity and duration of infections and of merozoite means during the periods of acute rise and decline. During the acute rise, the merozoite mean in Sceloporus was 10.6 ± 0.11 (8,495 segmenters counted), compared with 13.44 ± 0.15 in Anolis (3,805 counted); during the decline, the merozoite means were 8.55 ± 0.13 (3,305 counted) and 10.28 ± 0.09 (6,772 counted), respectively. It took an average of 150 (100–253) days for the infection to run its course in Sceloporus, compared with the average of 71 (60–90) days in Anolis; the peak of parasitemia in Sceloporus was 11,600 parasites/10,000 red cells, compared with 1,600 in Anolis. Both lizard genera produced 5–10% gametocytes.     

The characterization of pc-polylines representing protein backbones

The backbone of a protein is typically represented as either a C _α-polyline, a three-dimensional (3D) polyline that passes through the C _α atoms, or a tuple of ϕ,ψ pairs while its fold is usually assigned using the 3D topological arrangement of the secondary structure elements (SSEs). It is tricky to obtain the SSE composition for a protein from the C _α-polyline representation while its 3D SSE arrangement is not apparent in the two-dimensional (2D) ϕ,ψ representation. In this article, we first represent the backbone of a protein as a pc-polyline that passes through the centers of its peptide planes. We then analyze the pc-polylines for six different sets of proteins with high quality crystal structures. The results show that SSE composition becomes recognizable in pc-polyline presentation and consequently the geometrical property of the pc-polyline of a protein could be used to assign its secondary structure. Furthermore, our analysis finds that for each of the six sets the total length of a pc-polyline increases linearly with the number of the peptide planes. Interestingly a comparison of the six regression lines shows that they have almost identical slopes but different intercepts. Most interestingly there exist decent linear correlations between the intercepts of the six lines and either the average helix contents or the average sheet contents and between the intercepts and the average backbone hydrogen bonding energetics. Finally, we discuss the implications of the identified correlations for structure classification and protein folding, and the potential applications of pc-polyline representation to structure prediction and protein design.     

The Occurrence of Schellackia and Plasmodium in two Georgia Lizards

SYNOPSIS. During a 15-year survey (1956–1970) involving more than 12,000 lizards, the incidence and annual fluctuations of both Plasmodium floridense and Schellackia occidentalis are reported. The occurrence of P. floridense in Anolis carolinensis from the Mainland (Fargo, Georgia area) varied from 52% (1958) to 10% (1964) with an average of 35%, while in Sceloporus undulatus from the same area during the same period it varied from 10% (1969) to 2% (1964) with an average of about 5%. The occurrence of Schellackia and Plasmodium in both Anolis and Sceloporus from Cumberland Island, and Schellackia from Anolis from 2 other Coastal Islands (Sapelo, 2% and Seahorse, 30%) are reported for the first time. On Cumberland, the only Georgia island thus far studied, where both Anolis and Sceloporus are found together, 16% of Anolis and 13% of Sceloporus had sporozoites of Schellackia sp. in the blood, while 11% of Sceloporus and 21% of Anolis harbored P. floridense.     

The effect of environmental factors on floating fresh marsh end-of-season biomass

We used both stepwise and quantile regression to determine the sources of environmental variation that explained the observed inter-annual variation in end-of-season freshwater floating marsh aboveground biomass over an 18-year period. The vegetation at our study site had high species diversity with an average of 20 species recorded from 10 0.25 m⁻² plots. However, Panicum hemitomon was clearly the dominant contributing 74% of the total biomass. Only three other species (Solidago sempervirens, Vigna luteola, and Thelypteris palustris) were so common that they were sampled in all years. We expected that the most important factors controlling interannual variation in aboveground biomass are temperature and nitrogen availability. We also expected that nitrogen availability to the plants is affected by water movement through and under the mat driven by precipitation (lower N), evaporation (transportation of higher N waters to roots), and local runoff (higher N). Stepwise regression analysis indicated that P. hemitomon average biomass was negatively related to average water level and positively related to maximum water level and had a curvilinear response with TKN. Using quantile regression the best fit for P. hemitomon maximum-biomass with two parameters was obtained using hot days (positive relationship) and maximum water level (negative relationship). Both analytical methods showed maximum water level (negative relationship) and cold front passage (positive relationship) to be the environmental parameters that best explained interannual variation in S. sempervirens biomass. V. luteola biomass was positively related to temperature. Stepwise regression added chloride concentration as an additional positive parameter explaining V. luteola biomass, while quantile regression identified nitrogen as an important positive parameter. Both analytical methods identified pH, TKN, and water level as environmental parameters that were negatively correlated with T. palustris biomass. The overall negative effect of water level on all species was unexpected in this floating mat system. We initially assumed that higher water levels were due to higher runoff which should have a positive effect on biomass. However, higher water levels may also be related to a higher retention time in this fresh-water tidal system, which decreases water exchange and nutrient replenishment.     

Univariate estimates of sexual dimorphism: The effects of intrasexual variability

The difference between male and female values of quantitative traits depends on the distribution of the variables within each sex, increasing with the rise in the difference between male and female average values and with the decrease of the dispersion of measurements in both sexes. This paper deals with the sensitivity of some widely used indices (relative difference between male and female mean values (MDI), Student's t, and the so-called Bennett-Chakraborty-Majumder D coefficient) with respect to intrasexual variability. The Kolmogorov-Smirnov distance (KS) is suggested here as a further index of dimorphism, although it is not usually utilized for this purpose. The theoretical approach is accompanied by the analysis of empirical data (metric variables obtained from a sample of present Sardinians) and by computer simulations under various assumptions. Indices based on the difference between male and female average values are not able to evaluate fully the various aspects of dimorphism. Student's t proved to be an adequate measure of whole sex differences, both in real and in simulated samples, as intrasexual variability is included in its formulation. The D index also proved to be a good measure of undivided sexual dimorphism, as it is the result of formal examination, and from application to empirical or to simulated cases. The Kolmogorov-Smirnov distance gave the best performance both in formal examination and in the whole simulation results, as it takes into account intrasexual variability, and is applicable to any kind of distribution. In simulated cases it was sensitive to variations of means and variances, and it was able to evaluate variance dimorphism. Since the last three indices measure the combined effect of size and variance dimorphism, the joint use of the MDI index is suggested in order to isolate the relative contribution of the difference between the means. Am J Phys Anthropol 109:501–508, 1999. © 1999 Wiley-Liss, Inc.     

The Penaincisalia amatista species-group (Lepidoptera: Lycaenidae,Eumaeini) in Colombia,insights from mtDNA barcodes and the description of a new species

A synopsis of the P. amatista species-group in Colombia is provided. Five taxa are considered valid at species level, male and female phenotypes are associated, diagnosed and data on their distribution are given. The geographic variability of the species is discussed, and Penaincisalia celosia new species is described from specimens collected in an isolated branch of the central range in Colombian Andes. We present evidence to consider P. galeraensis (Salazar, Schmidt-Mumm, & Johnson) as a junior synonym of P. albalineata (Johnson). DNA barcodes provided additional information, which was in perfect agreement with the external characters in two of the five species. Interspecific distances were found to range from 0.6% to 6.6% (average 4.3), whilst their mean intraspecific variation ranges from 0.0% to 3.3% (average 0.7%).     

The absence of the somatic association of centromeres of homologous chromosomes in grass mitotic metaphases

Root-tip metaphases from Hordeum vulgare (19 cells), H. marinum (11 cells), Aegilops umbellulata (10 cells) and Zea mays (10 cells) were completely reconstructed from electron micrographs of serially sectioned nuclei. The identity of each chromosome was found by measuring the volumes of its two arms and the presence or absence of a secondary constriction at the nucleolar organising region. With the position of the centromere in three dimensions, these data were used to analyse the relative positions of homologous and heterologous centromeres. In 31 out of the 50 cells analysed, homologues were on average further apart than heterologues. Except for two nucleolar organising chromosomes, there was no evidence of any tendency for the distances between different homologue types to be differently distributed from distances between heterologues. Average distances between homologues of the single nucleolar organising chromosome (linkage group 6) of Zea (2n = 20) were lower than the average for heterologues and the interhomologue distances were distributed significantly differently from the separation distances of chromosome 6 to other chromosomes. Presumably this association occurred because of nucleolar fusion in the previous interphase. Homologues of one of the two nucleolar organising chromosomes of A. umbellulata were also distributed significantly differently from heterologues, with a tendency for homologues to lie farther apart than the average heterologous pair. These results do not support previous work using squashed and spread metaphase preparations (some including abnormal, marked chromosomes) for these species.     

The prevalence of obesity in ethnic admixture adults

Objective: To determine whether the prevalence of obesity in ethnic admixture adults varies systematically from the average of the prevalence estimates for the ethnic groups with whom they share a common ethnicity. Methods and Procedures: The sample included 215,000 adults who reported one or more ethnicities, height, weight, and other characteristics through a mailed survey. Results: The highest age‐adjusted prevalence of overweight (BMI ≥ 25) was in Hawaiian/Latino men (88%; n = 41) and black/Latina women (74.5%; n = 79), and highest obesity (BMI ≥ 30) rates were in Hawaiian/Latino men (53.7%; n = 41) and Hawaiian women (39.2%, n = 1,247). The prevalence estimates for most admixed groups were similar to or higher than the average of the prevalences for the ethnic groups with whom they shared common ethnicities. For instance, the prevalence of overweight/obesity in five ethnic admixtures—Asian/white, Hawaiian/white, Hawaiian/Asian, Latina/white, and Hawaiian/Asian/white ethnic admixtures—was significantly higher (P < 0.0001) than the average of the prevalence estimates for their component ethnic groups. Discussion: The identification of individuals who have a high‐risk ethnic admixture is important not only to the personal health and well‐being of such individuals, but could also be important to future efforts in order to control the epidemic of obesity in the United States.     

The impact of local spatial resistance on the movement behaviour of Tenebrio molitor L.

Although the impact of vegetation and other environmental factors on the distribution of terrestrial invertebrates has been known since the 1950s, basic knowledge about their interaction with micro-landscape elements is lacking. In experimental model systems, the impact of varying local spatial resistance (LSR) on the distribution of Tenebrio molitor individuals was analysed in the laboratory. In the setups, LSR led to a reduction of the average distance covered (move step length) and a reduction of the velocity (the maximum speed ranging from 36.1 in the control groups to 20.4 [mm*step⁻¹] in areas with a maximum LSR). Also, the covered distances per individual varied among three groups, from 2.97 m in the control to 1.11 m in areas with medium LSR to 0.88 m in areas with maximum LSR. Thus, in areas with LSR, animals were forced by their habitats to perform shorter move steps on average and covered less distance. The distance covered (i.e., dispersal performances) were not correlated with such factors as sex, weight and length of the Tenebrio individuals from other studies. Analysis of the data for net squared displacement indicated that the dispersal of the beetles did not follow a diffusion process. The move step directions of the dispersal data showed pronounced autocorrelation, which means that in contrast to other findings, the individuals were not performing a random walk. This effect was strongly dependent on the temporal resolution (i.e. grain), and was also influenced by the experimental conditions. The entire array of data showed high variability among the sub-groups (as well as many outliers), revealing nonparametric characteristics. The results showed that the specific physical configuration of suitable habitat for Tenebrio is one of the key indicators of landscape connectivity on the micro-scale.     

The impact of Yangtze River discharge on the genetic structure of a population of the rock bream,Oplegnathus fasciatus

As a rocky reef species, Oplegnathus fasciatus displays significant geographic differences that may be congruent with patterns of molecular variation. We used 10 polymorphism microsatellite loci to characterize the genetic structure and test the impact of ocean currents and the Yangtze River on the population genetic connectivity of the rock bream, O. fasciatus, sampled from Jiaonan (JN), Zhoushan (ZS) and Taiwan (TW). The average number of alleles was 17.78, with a total of 160 alleles, and the average allele value in the East China Sea (ZS?=?13.70) was higher than that in the Yellow Sea (JN?=?6.70). The individuals at the ZS location showed the highest expected heterozygosity (He?=?0.86), Nei's genetic diversity (H?=?0.84) and Shannon genetic diversity (I?=?2.21). Genetic bottleneck tests showed that individuals had experienced a recent bottleneck effect in the JN location. AMOVA analysis showed that 12.19% of genetic variation existed among populations, indicating significant population genetic differentiation in the species. The values of the population pairwise differentiation index (F_st and Φ_pt) ranged from 0.01 to 0.29. The UPGMA tree showed two diverged genealogical branches corresponding to sampling localities (Clade A?=?JN, Clade B?=?ZS and TW) in the species. The AMOVA and STRUCTURE analyses suggested that O. fasciatus may be composed of two stocks in the examined range, and the freshwater discharge from the Yangtze River might act as a physical barrier to genetic exchange between north and south China stocks of the species.     

The Mating Call of Isoperla bipartita Aubert, 1962 (Plecoptera,Perlodidae)

The mating call of Isoperla bipartita is described. The male call is composed of 3–10 groups, each of 1–4 rubs. The times between rubs average 89.52 msec (between first and second), 43.52 msec (between second and third) and 35.28 msec (between third and fourth). The time between two groups averages 180.75 msec and varies from 142 to 290 msec. The female answer is composed of a beat and rub repeated at 479.09 msec intervals on average and interspersed between the male call groups between 94 and 184 msec (mean = 118.11 msec) after the last rub of the male group. The I. bipartita call can be considered as a ‘complex and modified pattern’ because the male produces calls of 1–4 rubs by group and the female answers overlapping the male call by percussion-rubbing-produced signals. Moreover, it is different from other studied Iberian Isoperla calls, being probably a species-specific behavioural pattern.     

The Structure of Neurospora crassa Glycogen

The mycelia of a wild type strain of Neurospora crassa (6068, IFO) contain a polysaccharide which is stained reddish brown by iodine. The polysaccharide purified by repeated precipitation with ethanol is made up of d-glucose and has a molecular weight of about (more than) 2 × 10⁷, 101 S on ultracentrifugation analysis, an average chain length of 10, β-amylolysis limit of 33.6%, and α-amylolysis limit of 58.3%. The highly branched structure, therefore, resembles to that of a typical glycogen. The properties of the glycogen from N. crassa are discussed in comparison with the commercial glycogens from shellfish and rabbit liver.     

The effects of spontaneous mutation on competitive fitness in Drosophila melanogaster

Abstract We have analysed the effect of 288 generations of mutation accumulation (MA) on chromosome II competitive fitness in 21 full‐sib lines of Drosophila melanogaster and in a large control population, all derived from the same isogenic base. The rate of mean log‐fitness decline and that of increase of the between‐line variance were consistent with a low rate (λ ≈ 0.03 per gamete and generation), and moderate average fitness effect [E(s) ≈ 0.1] of deleterious mutation. Subsequently, crosses were made between pairs of MA lines, and these were maintained with effective size on the order of a few tens. In these crosses, MA recombinant chromosomes quickly recovered to about the average fitness level of control chromosomes. Thus, deleterious mutations responsible for the fitness decline were efficiently selected against in relatively small populations, confirming that their effects were larger than a few percent.     

The botanical diversity in the Ayawasi area, Irian Jaya, Indonesia

In the karst-dominated Ayawasi area (Bird's Head peninsula), the botanical diversity and its relation to soil and geological substratum were studied. An inventory in 22 plots of 0.1 ha was made of all plants (1945) with a dbh 10 cm (mainly trees). Myrtaceae, Burseraceae, and Euphorbiaceae were the most frequent families (considering relative number of individuals), whereas Myrtaceae, Lauraceae, and Meliaceae were most species-rich. The most frequent genera were Syzygium, Haplolobus, and Lithocarpus, and most species-rich were Syzygium, Garcinia, Elaeocarpus, and Pouteria. The most frequent species were Anisoptera thurifera, Tristaniopsis ferruginea, and Gymnacranthera farquhariana var. zippeliana. Species richness was greater in plots in mixed forest (38–57 species, average 48) than in limestone forest (26–42 species, average 33) and secondary forest (21–46 species, average 34). Some very common species, such as Xanthophyllum novoguineense (Polygalaceae) and Macaranga suwo (Euphorbiaceae), were hitherto herbarium rarities, known from very few collections only. Species dominating earlier investigated forests elsewhere in the Bird's Head Peninsula range from being less important to absent in the presently investigated forest. Explanatory factors for this phenomenon are variation due to the geographical distance, the high beta-diversity of tropical forests in general, habitat differences, and differences in research methods, in particular in their scale.     

The Food Amount Rating Scale: Development,Reliability, and Validity

Objective: Implied in measures of binge eating is the assumption that individuals agree on what comprises a large amount of food. However, whether individuals estimate food amounts similarly or whether estimation of food amounts varies as a function of personal characteristics is unknown. The Food Amount Rating Scale (FARS) is a standardized set of stimuli for assessing individuals’ judgment of food amounts. Research Methods and Procedures: Two versions of the FARS were developed, and their psychometric properties were assessed. These versions are the same in all respects except that the rater is instructed to rate various food amounts for the average woman on Form W and for the average man on Form M. Results: Content validity was confirmed by 14 researchers and research assistants in the field of eating disorders. The FARS is a 24-item inventory with adequate test–retest reliability (Form W = 0.85; Form M = 0.87) and split–half reliability (Form W = 0.90; Form M = 0.89). Convergent validity is suggested by the finding that ratings for the average woman (Form W) were significantly higher than ratings for the average man (Form M). Discussion: The FARS is a psychometrically sound tool for use in basic research focused on identifying whether the subjective judgment of food amounts varies as a function of personal characteristics and in clinical research where it may be important to know how individuals judge food amounts.     

Heterorhabditis sonorensis n. sp. (Nematoda: Heterorhabditidae), a natural pathogen of the seasonal cicada Diceroprocta ornea (Walker) (Homoptera: Cicadidae) in the Sonoran desert

A new Heterorhabditis species was isolated from nymphal stages of the seasonal cicada Diceroprocta ornea (Walker) in an asparagus field in the state of Sonora, Mexico. Concomitantly, another isolate of the same nematode species was also collected from an oak woodland habitat in the Chiricahua mountain range in southeastern Arizona. Morphological and molecular studies together with cross-hybridization tests indicate these two isolates are conspecific and represent a new undescribed Heterorhabditis sp. This new species is distinguished from other species in this genus by a combination of several qualitative and quantitative morphological traits. Key diagnostic features include: presence of a pronounced post-anal swelling in the hermaphrodite; male with nine pairs of bursal rays, with pairs 4 and 7 bent outwards and one pair of papillae placed on the cloacal opening, value of D% (average: 79); infective juveniles with a well developed cuticular tooth, long tail (average: 105 μm) and values of D% (average: 90) and E% (average: 99). In addition to these diagnostic characters, cross-hybridization tests between the new species with H. bacteriophora and H. mexicana yielded no fertile progeny. Comparison of ITS rDNA sequences with other available sequences of described species depicted the two isolates as a new species. Phylogenetic analysis of these sequence data placed H. sonorensis n. sp. as a member of the indica-group.     

Adaptations to captive breeding of the longhorn beetle Morimus funereus (Coleoptera: Cerambycidae); application on amylase study

Captive breeding has been suggested as a method of conservation for many vertebrates, and is increasingly being proposed as a strategy for invertebrates. In this study, the growth, development and fertility of adults of the vulnerable cerambycid Morimus funereus reared in captivity are examined. Two oviposition cycles; from May to September and from January to March were studied and larvae from wild adults and from the progeny of captive adults (second generation larvae) were examined. Five to 12 instars were observed during larval development. Larval development was completed in 218 days (average) for the progeny of wild adults with an average mortality rate of 10.3% and in 226 days (average) for larvae from captive adults with mortality rate of 34.9%. First generation larval body weights were disparate during development, while second generation larvae had similar weights with no significant differences. In this study we have tested the potential of captive breaded M. funereus larvae as a model for investigation of digestive enzymes. Amylase from the midgut of larvae reared under laboratory conditions showed twofold higher specific activities with a decreased number of isoforms expressed, as compared to the enzyme from field-collected larvae. Captive breeding of M. funereus can be used in the future as a part of an effective conservation strategy for this rare insect species.     

The geographical distribution of rarity

Summary This paper asks the question: are most species that are censused as rare in particular localities rare throughout most of their geographic ranges, or are they common in substantial portions of their ranges elsewhere? The first alternative is labeled suffusive rarity and the second diffusive rarity. To answer this and similar questions, rarity can be measured as the fraction of censuses from some locality (e.g., a quadrat) in which a species occurs (occurrence rarity), or the relative or absolute abundance of the species averaged over all censuses from some locality (abundance rarity). The question was analyzed for occurrence-rarity data from Australian terrestrial birds distributed over 1° (10⁴-km²) quadrats. The great majority of species that are rare in a particular quadrat are not rare and are often common in a substantial number of other quadrats, i.e., these avian species are much closer to the diffusive than suffusive portion of the rarity continuum. The data also show that 1) the distribution of sizes of geographic ranges, whether breeding or total, is highly skewed, appearing exponential to more concave; 2) species are much rarer in their nonbreeding than breeding ranges; 3) more widespread species, whether breeding or total ranges are considered, tend to occur more rarely in a slightly but significantly greater fraction of their ranges; and 4) hawks and owls, typified by high abundance rarity, show occurrence rarity in a greater fraction of their ranges than the average nonraptorial species. Although continental birds may be especially predilected toward diffusive rarity, the present analysis points to identification of centers of abundance as major ways of preserving those species contributing most to recorded instances of rarity. Similar analyses with other kinds of organisms would be most welcome.     

The influence of air temperature on the starting date of Quercus pollination in the South of Europe

In temperate zones the air temperature influences many aspects of the plant growth and also the time of flowering is often correlated with this environmental parameter. It is a generally accepted idea that higher temperatures in the period preceding ripening of the flowers determine earlier pollination. To verify if a correlation between the air temperature and the date of onset of the pollination period of Quercus spp. exists, a comparative study was carried out over 7 years (1995–2001) in two South-European towns: Vigo (Spain) and Perugia (Italy). Quercus pollen is released in the atmosphere of Perugia on average in the last two weeks of April while in the Spanish region the pollination occurs on average one month before.

In order to overcome the dormancy period Perugia requires 1110 Chilling Hours (CH)-884 Growth Degree-Days (GDD°C) and Vigo 709 CH-861 GDD°C. With the Ashcroft method Perugia needs 1075 CH-1000 GDD°C and Vigo 625 CH-1512 GDD°C. Heat accumulation from the end of winter dormancy to the onset of pollination, showed the highest significance when mean temperature in Perugia and maximum temperature in Vigo were used. Every year we have found that the colder station needed a lower heat accumulation: Perugia required a higher quantity of chilling and heat than Vigo. However, the correlation detected between temperature and flowering was, on average, less significant that those found in the same regions for other arboreal taxa that present winter pollination (e.g. Corylus, Alnus). This preliminary study suggests that there is an effect of air temperature on Quercus pollination, but other environmental factors, such as photoperiod, hours of light, rainfall, relative humidity, may be of great influence in determining the onset of pollination in plants with a spring flowering.