Flora Palinologica Italiana. Schede diCorylus avellana L. cv. Tonda Gentile delle Langhe (TGL) eCorylus maxima Miller e valutazioni statistiche

Riassunto Si sono allestite le schede morfopalinologiche compilate secondo le norme della ?Flora Palinologica Italiana?, perCorylus avellana L. cv. TGL eCorylus maxima Miller per polline acetolizzato e fresco. Le due specie rivestono interesse agronomico anche per l'ottenimento di ibridi interspecifici. La differenza del rapporto P/E fra le due entità risulta altamente significativa Tuttavia non è possibile un riconoscimento dei due tipi pollinici direttamente in analisi aerosporologiche.

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Summary Palynological cards ofCorylus avellana cv. TGL andCorylus maxima Miller are presented for fresh and acetolyzed pollens, according to the project ?Flora Palinologica Italiana?. Both species are interesting from the agricultural point of view, also for the possibility to obtain interspecific hybrids. The difference of the P/E ratio between the two entities is highly significant. In sprite of this fact, is not possible to discriminate the two pollen types in aerosporological analysis for their extreme similarity.

     

The role of air temperature in determining dormancy release and flowering ofCorylus avellana L.

Summary 7 years of airborne pollen monitoring in Perugia (central Italy) were used to determine the temperature requirements to break dormancy and to resume growth and bloom ofCorylus avellana L.,Corylus needs 1000 chill-units to complete its dormancy and this value, in the Perugian area, is met by the end of December or the first days of January. MoreoverCorylus trees require 220 growth degree hours before they are able to flower. If air temperature is high, this value can be achieved in only 10 days, but if the temperature remains too low, the heat accumulation can require up to 35 days. With these parameters it is possible to build a model to predict the date of the beginning ofCorylus avellana pollen season.     

不同品种(系)榛子坚果表型性状差异性分析及其综合评价

该研究以目前主栽的平榛、毛榛及25个平欧杂种榛品种(系)的坚果为研究对象,测定了不同品种(系)榛子坚果的17个表型性状指标,用方差分析、相关性分析、聚类分析和主成分分析方法对其进行差异性分析和综合评价,为国内榛树品种(系)的选优、开发及加工利用提供科学依据。结果表明：(1)不同品种(系)榛子坚果的17个表型性状指标存在显著差异,其中果壳质量、坚果体积和坚果质量差异最为明显,变异系数分别为31.49%、30.44%、27.50%,横纵径比、果形指数、伸长率、圆球度的变异系数均小于10%。(2)平欧杂种榛坚果的纵径、横径、侧径及坚果质量、果仁质量、出仁率等指标显著优于毛榛和平榛,其中杂种榛的平均果仁质量(0.70～1.46 g)和出仁率(31.48%～56.12%)显著高于平榛(0.51 g、35.13%)和毛榛(0.37 g、38.12%)。(3)榛子坚果表型性状指标间的相关性分析表明,榛子坚果体积越大,其质量和果仁质量也越大,果壳越薄则出仁率更高。(4)主成分分析结果发现,影响榛子坚果综合得分的主要指标为坚果的纵径、横径、侧径、质量和果仁质量,其次是果形指数、横纵径比、出仁率、果仁饱满...     

The response of <Emphasis Type="Italic">Corylus avellana</Emphasis> L. phenology to rising temperature in north-eastern Slovenia

Knowledge of plant–weather relationships can improve crop management, resulting in higher quality and more stable crop yields. The annual timing of spring phenophases in mid-latitudes is largely a response to temperature, and reflects the thermal conditions of previous months. The effect of air temperature on the variability of hazelnut (Corylus avellana L.) phenophases (leafing, flowering) was investigated. Meteorological and phenological data for five cultivars were analysed over the periods 1969–1979 (P1) and 1994–2007 (P2) in Maribor, Slovenia. Phenological data series were correlated strongly to the temperature of the preceding months (R ²: 0.64–0.98) and better correlated to daily maximum and mean temperatures than to daily minimum temperatures. About 75% of phenophases displayed a tendency towards earlier appearance and a shorter flowering duration during P2, which could be explained by the significant temperature changes (+0.3°C/decade) from December to April between 1969 and 2007. An increase in air temperature of 1°C caused an acceleration in leafing by 2.5–3.9 days, with flowering showing higher sensitivity since a 1°C increase promoted male flowering by 7.0–8.8 days and female flowering by 6.3–8.9 days. The average rate of phenological change per degree of warming (days earlier per +1°C) did not differ significantly between P1 and P2. An estimation of chilling accumulation under field conditions during 1993–2009, between 1 November and 28 February, showed that all four of these months contributed approximately similar amounts of accumulated chilling units. The growing degree days (GDD) to flowering were calculated by an estimated base temperature of 2°C and 1 January as a starting date, given the most accurate calculations. In general, thermal requirements were greater in P2 than in P1, although this difference was not significant. Longer-time series data extended to other agricultural and wild plants would be helpful in tracking possible future changes in phenological responses to local climate.     

Lipid Mobilization During Dormancy Breakage in Oilseed of Corylus avellana

During the stratification necessary for the alleviation of dormancyin Corylus avellana L. there is a substantial reorganizationof metabolic processes. Changes in activities of some enzymesrelated to lipid mobilization were followed throughout a fruitstratification period at 5 °C and control treatment at 20°C. Significant increases in total lipase and isocitratelyase activities were found in both embryonic axes and cotyledonsof seeds from fruits stratified at 5 °C, whereas the activitiesremained consistently low in those held at 20 °C. Theseresults correlated with an earlier ultrastructural study whichshowed a reduction in storage lipid. The increased potentialfor lipolysis was concomitant with loss of dormancy as seenin germination tests. These findings suggest that lipid mobilizationduring stratification could be related to the overall patternof metabolic changes which are required for dormancy release. Corylus avellana L., hazel, lipid, catalase, isocitrate lyase, lipase, stratification     

Starch Synthesis During Dormancy Breakage in Oilseed of Corylus avellana

Dormancy in seed of Corylus avellana L. (hazel) is broken bya sustained period of cold stratification. During this timeboth cytological and metabolic changes occur. Starch was presentinitially at a low level but increased by 20% in the embryonicaxes of hazel seeds during stratification at 5 °C, whileit decreased rapidly and then remained constant in the embryonicaxes from seeds held at 20 °C. Histochemical study confirmedthis analytical result. A comparison of the developmental patternof starch level with bound and soluble ADP glucose-starch synthaseactivity at 5 and 20 °C showed that the accumulation ofstarch in the embryonic axes followed an enhanced activity ofthe granule-bound ADP glucose-starch synthase. Cold stratificationresulted in an increase in starch content, which was probablyas a result of gluconeogenesis from products of reserve lipidhydrolysis. Corylus avellana L., hazel, starch, ADP glucose-starch synthase, stratification     

Nondormant mutants in a temperate tree species,Corylus avellana L.

Summary Nondormant mutants in hazelnut (Corylus avellana L.) are described. In contrast to normal trees in which physiological rest, or dormancy, is induced by short days, mutants fail to respond to this stimulus. Shoot tips continue to grow, old leaves are retained until midwinter when they are frozen and/or pushed off by developing axillary buds, axillary buds begin to grow in December, 2–3 months before normal spring bud break, and cold hardiness does not develop. Nondormancy is controlled by a single recessive gene (dd). The mutation is not uncommon since eight cultivars, including the world's most important commercial cultivars, are heterozygous for this trait. The implications of nondormancy in a temperate tree species are discussed in relation to evolution, extension of the range of cultivation, breeding, and value for basic studies of fundamental mechanisms of dormancy.     

Starting dates and basic temperatures in phenological observations of plants

 Several methods have been used in plant phenology to find the best starting date in spring and the best threshold or basic temperature for growth and development of perennial plants. In the present paper the date giving the highest correlation coefficient for development to various phenophases, in relation to 24-hourly mean air temperatures was chosen as the best starting value in further analyses. For many woody plants this date was very often found to be 1 April based on phenological and climatological observations at about 60 sites in western Norway (at about 61°N). The early flowering species Corylus avellana and Salix caprea and the early leaf-bud breaking Prunus padus seemed to start development earlier in Spring, while the late sprouting Fraxinus excelsior showed the highest correlation coefficient using 15 April. If daytime temperatures were used in the calculations, the ”best” starting date was generally found to be later than for the 24-hour mean temperatures. This variation must be seen as resulting from the different basic temperatures for the development of various species. Estimates of basic temperatures in various species and periods may be given, for example by finding the value having the least variance in heat sums or by various regression analyses. A technique has been developed to minimise the influence of significance of correlation, using the intercept with the temperature axis by merging the two least squares rectilinear regression lines that can be found between plant development and mean air temperature (from the estimated best starting date) at r=+1 or –1. The basic temperature seemed to vary from –5.9°C for leaf-bud break of P. padus to 5.5°C for leaf-bud break of F. excelsior, with basic temperatures of several other woody plants having intermediate values. These values are compared with those found by other methods. Received: 26 May 1998 / Accepted: 7 September 1998     

Harvesting of the Kelp Ecklonia Maxima in South Africa Affects Its Three Obligate, Red Algal Epiphytes

In South Africa, more than 7000 t (f wt) of kelp (Ecklonia maxima) fronds are harvested annually to feed cultured abalone. Carpoblepharis flaccida, Gelidium vittatum and Polysiphonia virgata are conspicuous red algal epiphytes on older kelps and provide habitat and food for numerous animals. Over 4.5 y, we examined the effects of one destructive harvest of E. maxima on these 3 epiphytes. Two 20 × 20 m plots of kelp with similar epiphyte loads were demarcated. In one, all E. maxima sporophytes with stipes longer than 50 cm were harvested. The other plot served as a control. After 2.5 y the biomass of E. maxima in the harvested plot had recovered to control levels, but the epiphyte load (g epiphytes. Kg kelp⁻¹) was statistically lower in the harvested plot after 2.5 and 3.5 y, and only recovered after 4.5 y. While most commercial harvesters cut through the “heads” (primary blades) of the kelp, effectively killing them, a new, non-lethal method removes secondary blades 20–30 cm from their bases, leaving the meristems and primary blades intact. At 5 sites studied, G. vittatum and P. virgata were found almost entirely on stipes and primary blades, and harvesting only distal parts of secondary blades limited losses to about 50% of C. flaccida biomass. To protect epiphytes, non-lethal harvesting is recommended and permanent non-harvest zones have been established in addition to limiting kelp yields and disallowing harvesting in Marine Protected Areas.     

Auditory brainstem responses to airborne sounds in the aquatic frog Xenopus laevis: correlation with middle ear characteristics

In this study we recorded auditory brainstem responses to airborne sounds to determine the hearing sensitivity of Xenopus laevis frogs and correlated their hearing profiles with middle ear characteristics. In newly metamorphosed frogs (body mass 0.5–0.76 gm, snout-vent length 17–20 mm) best hearing sensitivities were measured in the 2.4–2.8 kHz range, whereas optimal hearing sensitivity of older adults (body mass 18–90 gm; snout-vent length 57–100 mm) ranged from 1.0 to 1.2 kHz. Middle ear volumes reconstructed from serial sections showed approximate volume of 0.002 cc and 0.04–0.07 cc in newly metamorphosed and older frogs, respectively. This inverse frequency–volume relationship is consistent with the properties of an acoustic resonator indicating that differences in best hearing sensitivity are at least in part correlated to variation in middle ear volumes for airborne sounds. These results are consistent with peak frequency vibrational velocity profiles of Xenopus tympanic disk that have been shown to be dependent on underlying middle ear volumes and corroborate the occurrence of peak amplitudes of otoacoustic emissions in the 1.0–1.2 kHz region in adult Xenopus frogs.     

Competition between Tuber melanosporum and other ectomycorrhizal fungi under two irrigation regimes

A glasshouse experiment was conducted to simulate the competition between artificially introduced Tuber melanosporum (Vitt.) and other symbionts, occurring on outplanted truffle-producing trees. Hazel (Corylus avellana L.) seedlings, previously inoculated with Tuber melanosporum, were rapidly infected with the competing truffle Tuber brumale (Vitt.), added to the soil as spores. Coexistence of both species on the root system was observed. Tuber melanosporum survived and continued to spread. Tuber brumale, which is naturally present in many truffle-orchard soils, protects the roots from other ectomycorrhizal symbionts. Although high water content is unfavourable for the development of T. melanosporum in the absence of other Tube species, Tuber brumale stimulates the development of T. melanosporum under these conditions.     

Incompatibility alleles in Corylus avellana L. cultivars

Summary Pollen-stigma compatibility relationships are reported for 55 filbert cultivars (cvs) (Corylus avellana L.). A total of 11 S-alleles have been identified amongst 36 cvs for which one or both S-alleles have been established. For the 20 cvs with only one known allele and the 17 for which neither allele have been identified further information is provided as to which alleles can be excluded as possibilities.Oregon Agricultural Experiment Station Technical Paper No. 4985. Corvallis, Oregon 97331     

Characterization and evaluation of microsatellite loci in European hazelnut (Corylus avellana L.) and their transferability to other Corylus species

In this work, 18 microsatellite loci were developed in the European hazelnut (Corylus avellana L.) using three enriched genomic libraries. They were evaluated on a set of 20 accessions of this species on the basis of number of alleles (mean: 7.1), expected heterozygosity (mean: 0.67), power of discrimination (mean: 0.77) and polymorphism information content (mean: 0.64). Cross‐species transferability was evaluated using seven other Corylus species. All primer pairs amplified in all species, except for CaT‐C505 in Corylus ferox and CaT‐A114 in Corylus californica.     

Dominance relationships among S-alleles in Corylus avellana L.

Summary Pollen-stigma compatibility relationship were studied in 50 cultivars and more than 800 seedlings of the European hazelnut (Corylus avellana L.). A total of 22 unique S-alleles have been identified. Dominance relationships in 75 of the possible 231 pairs of alleles have been determined in both pistil and pollen. In the pistil, all alleles exhibited independent action, whereas in the pollen, alleles exhibited either dominance or codominance. The dominance relationship was linear with 7 levels of dominance.Oregon Agricultural Experiment Station Technical Paper No. 8542     

Characterization of Chlorophyll–protein Complexes Isolated from Two Marine Green Algae, Bryopsis maxima and Ulva pertusa, Growing in the Intertidal Zone

Three Chl–protein complexes were isolated from thylakoid membranes of Bryopsis maxima and Ulva pertusa, marine green algae that inhabit the intertidal zone of the Pacific Ocean off the eastern coast of Japan by dodecyl-β-d-maltoside polyacrylamide gel electrophoresis. The slowest-moving fractions showed low Chl a/b and Chl/P-700 ratios, indicating that this fraction corresponds to complexes in PS I, which is large in both algae. The intermediate and fastest-moving fractions showed the traits of PS II complexes, with some associated Chl a/b–protein complexes and LHC II, respectively. The spectral properties of the separated Chl–proteins were also determined. The absorption spectra showed a shallow shoulder at 540 nm derived from siphonaxanthin in Bryopsis maxima, but not in Ulva pertusa. The 77 K emission spectra showed a single peak in Bryopsis maxima and two peaks in Ulva pertusa. Besides the excitation spectra indicated that the excitation energy transfer to the PS I complexes differed quite a lot higher plants. This suggested that the mechanisms of energy transfer in both of these algae differ from those of higher plants. Considering the light environment of this coastal area, the large size of the antennae of PS I complexes implies that the antennae are arranged so as to balance light absorption between the two photosystems. In addition, we discuss the relationships among the photosystem stoichiometry, the energy transfer, and the distribution between the two photosystems.     

Holocene forest development in the central Scandes Mountains, Sweden

Pollen analyses of sediment cores from two small lakes within the boreal forest in the central Scandes Mountains help to elucidate the Holocene forest dynamics of the region. Analyses of pore/pollen grain diameter ratios of Alnus grains indicate the early Holocene presence of Alnus glutinosa in the study area. The results are discussed in conjunction with available pollen records to evaluate the importance of thermophilous trees during the early Holocene and to deduce the regional spread of Picea abies. Corylus avellana, Alnus glutinosa and Ulmus glabra were probably common constituents of the early Holocene forest. Tilia cordata may have occurred there as a rare tree. Pollen stratigraphies from the region do not indicate the occurrence of Quercus robur. The regional spread of Picea abies can be separated into two phases: a mid-Holocene establishment or first expansion of small outpost populations and a late-Holocene population expansion. The mid-Holocene shift in vegetation composition may have been caused by changes in the westerly airflow.     

Winter food caches of beavers<Emphasis Type="Italic">Castor fiber</Emphasis> in NE Poland

Winter food caches of beaversCastor fiber Linnaeus, 1758 were examined in 16 locations within the Suwałki region (north-eastern Poland). Four caches were selected to represent each of four habitat types: river, lake, farmland, and oligotrophic small reservoir called ‘suchar’. Altogether, 92 509 twigs and branches of 15 woody species were identified and measured. Individual caches, with one exception, included branches of only 4 or 5 species. WillowsSalix sp., birchesBetula sp., alderAlnus glutinosa, trembling aspenPopulus tremula, and mountain ashSorbus aucuparia occurred in caches from all four habitats studied. Willows alone constituted 62.5% of the total number of branches cached. Willows, together with birch, hazelCorylus avellana, alder, and trembling aspen, amounted to 97% of all branches in caches. The remaining 10 species provided only 3% of the branches cached. Most branches were 0.5–1 m long and <3 cm thick at their base. Contents of food caches provided a good indication of winter diet and possibly food preference of beavers.     

Changes in cytokinin and auxin concentrations in seaweed concentrates when stored at an elevated temperature

Two seaweed concentrates were made from the kelps Ecklonia maxima and Macrocystis pyrifera using a cell burst method. Cytokinin- and auxin-like activities were measured using the soybean callus and mungbean bioassays, respectively. Cytokinin-like activity was detected in both seaweed concentrates, being equivalent to approximately 50 μg L⁻¹ kinetin. Auxin-like activity was also detected in both concentrates with the E. maxima derived concentrate having higher biological activity, equivalent to 10⁻⁵–10⁻⁴ M indole-butyric acid. Two replicates of each concentrate were stored at 54 °C for 14 days to accelerate the effects of storage. Both fresh and stored samples of the two seaweed concentrates were analysed for their endogenous cytokinin and auxin content. The samples were purified using a combined DEAE-Sephadex octadecylsilica column and immunoaffinity chromatography based on wide-range cytokinin and IAA specific monoclonal antibodies. These extracts were analysed by HPLC linked to a Micromass single quadrupole mass spectrophotometer. Eighteen and nineteen different cytokinins were detected, respectively, in the two concentrates, with trans-zeatin-O-glucoside being the main cytokinin present. Accelerated storage of the concentrates caused an increase in the total cytokinin concentration with a large increase in the aromatic meta-topolin. Indole-3-acetic acid was the main auxin in both seaweed concentrates. Indole conjugates, including amino acid conjugates, were also quantified. The total auxin concentration decreased with accelerated storage for both concentrates. This revised version was published online in August 2006 with corrections to the Cover Date.     

Ambrosia pollen in the air of Lublin, Poland

Studies on Ambrosia pollen concentrations were carried out in Lublin in the period 1995–2004. The effects of a number of meteorological factors were analysed. In the first period of the study, the gravimetric method was used (1995–1999), while in the second period, the volumetric method was applied. The results show an increasing trend in the amount of airborne pollen. The Ambrosia pollen season in Lublin lasts from August to October. Over a period of 5 years, the highest number of pollen grains was recorded in September (53%), followed by August (44%) and October (3%). There were wide variations in annual totals. The annual total pollen counts was 167–1180 grains, with the peak value in 2002. Maximum daily pollen concentrations (56–312 pollen grains m⁻³) were recorded in the first half of August and in the first half of September. On the days when high Ambrosia pollen concentrations occurred, the temperature was above 21°C and the winds were mainly from the southeast, south and east. Maximum intradiurnal concentrations of pollen grains occurred in the afternoon hours. These results indicate, to some degree, that Ambrosia pollen is transported for long distances before descent.     

Corylomyces: a new genus of Sordariales from plant debris in France

The new genus Corylomyces, isolated from the surface of a hazelnut (Corylus avellana) in the French Pyrenees, is described, illustrated and compared with morphologically similar taxa. It is characterised by tomentose, ostiolate ascomata possessing long necks composed of erect to sinuose hairs, and one- or two-celled, opaque, lunate to reniform ascospores. Analyses of the SSU and LSU fragments rDNA gene sequences support its placement in the Lasiosphaeriaceae (Sordariales).