AirborneCorylus pollen monitoring: Preliminary data

Summary In 1984–5 and 1985–6 aerosporological data were collected in an experimental hazel-nut orchard in Cravanzana (High Langa) whereCorylus maxima andCorylus avellana cv. Tonda Gentile delle Langhe (TGL) were present with a prevalence of the latter. Inter variety crosses withC. avellana and interspecific hybridsC. avellana xC. maxima were also present. CultivatedCorylus flowering diagrams are known, while more evidence is needed on the spread and concentration of airborne pollens, especially during female anthesis which spans over a month on average. Pollen release periods were identified including onset of accessory periods. Aerosporological data helped identify TGL association in relation to spread of plants and quality of nut. Cultivars and hybrids, which have already been studied in terms of genetic compatibility, have been considered in terms of airborne pollen periods. Thanks to adequate pollinators we can rationalize orchards, increase productivity while maintaining nut quality. This work has been supported by “Ministero della Pubblica Istruzione” found 60%.      

Flora Palinologica Italiana. Una linea per aerobiologia

Riassunto Vengono presi sinteticamente in esame gli scopi, il programma e i metodi della Flora Palinologica Italiana e della Sezione Aeropalinologica che verrà sviluppata su ?Aerobiologia?. La sezione in oggetto illustra la morfobiometria di pollini importanti dal punto di vista aerobiologico e, inizialmente, tratterà specie dotate anche di interesse allergologico. In questo primo contributo è presentata, come esempio, la scheda palinologica diUrtica dioica L. (n. 168 della Flora Palinologica Italiana).      

Flora Palinologica Italiana,Sezione Aeropalinologica —S 238:Juglans regia L. (Juglandaceae)

Riassunto In accordo con il programma ?Flora Palinologica Italiana, Sezione Aeropalinologica? viene presentata la scheda morfopalinologica diJunglans regia L. (noce) relativa a polline fresco ed acetolizzato.      

Flora Palinologica Italiana,sezione aeropalinologica —S 235:Ostrya carpinifolia Scop

Riassunto Nell'ambito del programma della Flora Palinologica Italiana, è state redatta la scheda palinologica diOstrya carpinifolia Scop. Sono riportate alcune osservazioni morfologiche sul numero delle aperture e sulle principali differenze tra polline ?fresco? e acetolizzato.      

Flora Palinologica Italiana,Sezione Aeropalinologica — Specie esotiche - S 236:Cedrus libani A. Rich

Riassunto Nell'ambito del programma della Flora Palinologica Italiana, Sezione Aerobiologica, viene presentata la scheda palinologica diCedrus libani A. Rich. (specie esotica). Sono puntualizzate le differenze tra i parametri morfologici del polline «fresco» e acetolizzato.

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Summary According to the program «Palynological Italian Flora, Aeropalynological Section» the palynological card ofCedrus libani A. Rich. (exotic species) relevant to «fresh» and acetolyzed pollen grains is presented. The differences between the morphological parameters of fresh and acetolyzed pollen are pointed out.

     

Flora Palinologica Italiana,Sezione Aeropalinologica — Specie esotiche — S 231:Sequoia sempervirens (Lamb.) Endl. (Taxodiaceae)

Riassunto La scheda morfopalinologica diSequoia sempervirens (Lamb.) Endl. continua lo studio sulle Pinohyta ornamentali più frequenti in Torino. È esaminato polline fresco ed acetolizzato proveniente da due stazioni e la provenienza non determina variazioni significative dei parametri morfometrici.

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Summary The morphopalynological card ofSequoia sempervirens (Lamb.) Endl. is a new contribution to the comprehensive study on pollen of ornamental Pinophyta in Turin. Fresh and acetolysed grains from two stations are examined, and for all parameters no significative differences were observed in relation to the collection site.

Parole chiave: Sequoia sempervirens(Lamb.) Endl., Flora Palinologica Italina, Sezione Aeropalinologica.     

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     

Flora Palinologica Italiana,Sezione Aeropalinologica—S 303:Carpinus betulus L

Riassunto Nell'ambito del progetto «Flora Palinologica Italiana» e proseguendo lo studio delle Corylaceae, è qui presentata la scheda diCarpinus betulus L., con alcune osservazioni sul numero/posizione delle aperture e sulle principali differenze tra polline «fresco» e polline acetolizzato.

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Summary According to the program «Palynological Italian Flora», and continuing the study of the Italian Corylaceae, the palynological card ofCarpinus betulus L. is shown. The study is carried out on pollen coming from three different localities and regards both «fresh» and acetolyzed pollen. For each sample, measurements are carried out on 30 «fresh» pollen grains in glicerol jelly and on 30 acetolyzed pollen grains in water/glicerol 1/1; general observations regard 500 «fresh» and 500 acetolyzed pollen grain/sample. Some morphological observations on the aperture number/position and differencies between «fresh» and acetolized pollen are pointed out.

     

Exogenous sugars overcome incompatibility in hazelnut (Corylus avellana L.)

Summary Petreatment of hazelnut (Corylus avellana L.) stigmas with L M or 2 M sugar solutions before pollination with incompatible pollen, or pollination with 11 mixtures of incompatible pollen and finely ground sugars, prevented rejection of incompatible pollen by the stigma surface. Lower sugar concentrations or lower ratios of sugar to pollen were less effective. No specificity for overcoming incompatibility was observed among 18 simple sugars and related sugar compounds.Oregon Agricultural Experiment Station Technical Paper No. 7613     

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.     

Exogenous polyamines improve rooting of hazel microshoots

A strong positive effect of polyamines on rooting of microshoots of adult hazel (Corylus avellana L., cv. Gironell) is described. The effect of polyamines, both in the root induction solution and in the actual rooting medium, was assessed in order to study the effect on the successive rooting phases. Polyamines improved rooting of indole-3-butyric acid-treated microshoots in a synergistic fashion, perhaps by favouring a better induction of roots, with an acceleration of the response (only half the time required for rooting compared to the control). When applied without indole-3-butyric acid, polyamines had only a limited positive effect on rooting, although longer exposure times and/or higher concentrations could increase their effect. Possible rapid uptake and translocation of polyamines in the xylem in our system is discussed. The results offer a new approach to enhance rooting ability of species that are normally difficult to root.Abbreviations BM basal medium - IAA indole-3-acetic acid - IBA indole-3-butyric acid - NAA 1-naphthaleneacetic acid - Put putrescine - Spd spermidine - Spm spermine     

Allozyme diversity and genetic structure of marginal and central populations of Corylus avellana L. (Betulaceae) in Europe

Corylus avellana L. (hazel, Betulaceae) is a long-lived, widespread shrub in Europe, having its northern range margin in Fennoscandia and a postglacial history involving range-expansion from refugial areas in southern Europe. In this study, we tested for a relationship between marginality and low within-population genetic diversity by assessing patterns of variation at 14 putatively neutral allozyme loci (comprising 43 putative alleles) within and between 40 natural populations of C. avellana along a north-south transect in Europe. Geographically marginal populations (central Sweden) showed lower levels of within-population diversity than populations in more central regions, as indicated by significant negative correlations between latitude and the percentage of polymorphic loci (r_S=–0.47, P < 0.001), the average number of alleles per locus (r_S=–0.65, P < 0.001), the expected heterozygosity (r_S=–0.19, P < 0.05), and the proportion of distinguishable genotypes (r_S=–0.56, P < 0.001). These patterns, combined with the unusually high between-population component of gene diversity (G_ST=19.7%) and allelic richness (A_ST=24%) in the marginal region, can be attributed to historical bottlenecks during the species postglacial range-expansion, but may also reflect a history of genetic drift in the small, isolated populations occupying the marginal region. Information on the spatial distribution of genotypes provide further support for a role of vegetative reproduction (layering) in the structuring of genetic variation within populations.     

Flora Palinologica Italiana,Sezione Aeropalinologica: S 205 -Pinus pinea L. (Pinaceae)

Summary According to the program Palynological Italian Flora, Aeropalynological section, the pollen morphological card ofPinus pinea L. is presented. The study is carried out on pollen coming from three Italian localities and regards fresh and acetolyzed pollen. For each sample, measurements are carried out on 30 fresh pollen grains in glicerol jelly with fuchsin and on 30 acetolyzed pollen grains in water/glicerol (1/1); general observations regard 1000 fresh and 1000 acetolyzed pollen grains/sample. Some observations on the main differences between fresh and acetolyzed pollen are mentioned.

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Riassunto Nell'ambito della Flora Palinologica Italiana, Sezione Aeropalinologica, è presentata la scheda morfopalinologica diPinus pinea L. nella versione su polline fresco e polline acetolizzato, su tre campioni di diversa provenienza. Vengono notate le principali differenze tra polline fresco e polline acetolizzato.

     

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.     

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).     

Seed predation and dispersal of glabrous filbert (Corylus Heterophylla) and pilose filbert (Corylus Mandshurica) by small mammals in a temperate forest, northeast China

We investigated the seed dispersal of glabrous filbert (Corylus heterophylla) and pilose filbert (Corylus mandshurica), two large-seeded shrub species in a temperate forest, northeast China, September 2006. Small mammals such as Apodemus speciosus, Clethrlonomys rufocanus, and Eutamias sibiricus, were regarded as the main dispersal agents. More seeds were harvested by small mammals in pilose filbert (98%) than in glabrous filbert (87.5%) till our last survey. Seed removal rates differed between the two species. Fewer seeds of glabrous filbert (17.5%) were eaten in situ than pilose filbert (57.5%). More seeds of glabrous filbert were removed (70%), stay intact after removal (25.5%), eaten after removal (16%) than pilose filbert. However, more seeds were cached after removal in pilose filbert than in glabrous filbert (10.5 and 4%, respectively). Fewer tagged seeds of pilose filberts (14%) were missed than glabrous filberts (24.5%). About 8 and 12 primary caches were found in glabrous filbert and pilose filbert seeds respectively, indicating scatter hoarding. All of the removed seeds were distributed within 10 m of seed stations for both filberts. The average dispersal distances for glabrous filbert did not differ from pilose filbert. Only a small proportion of the caches remained till our last survey (2 and 1%, respectively). Based on the results, we found a difference in dispersal patterns of glabrous filbert and pilose filbert seeds. Evidences showed that glabrous filberts might be a less preferred seed species for small seed-eating mammals compared with pilose filbert, probably due to its harder and thicker husk and low seed profitability.     

Flora Palinologica Italiana,Sezione Aeropalinologica —S 103:Cupressus sempervirens L

Summary This contribution to the ?Palynological Italian Flora, Aeropalynological Section? deals withCupressus sempervirens L. (Mediterranean cypress). Palynological card regards fresh and acetolyzed pollen.      

Bioecologie deEubazus semirugosus,coeloïdes abdominalis etC. sordidator [Hym.: Braconidae] parasites dePissodes notatus [Col.: Curculionidae] dans le sud de la France

Résumé Cette étude porte sur différents aspects de la biologie deE. semirugosus, C. sordidator etC. abdominalis, se développant surP. notatus, ravageur du Pin maritime: comportement parasitaire à l'égard de ce charan?on, durée du développement, durée de la maturation sexuelle, espérance de vie des adultes, etc. Le cycle biologique de ces parasito?des est étudié ainsi que le problème de la co?ncidence temporelle entre ces braconides et leur h?te dans le cas d'une forêt du sud de la France.      

Effect of soil Pseudomonads on colonization of hazel roots by the ecto-mycorrhizal species Tuber melanosporum and its competitors

Hazel (Corylus avellana L.) seedlings, inoculated with the ecto-mycorrhizal fungus Tuber melanosporum (Vitt.) were grown in pots with soil previously inoculated with fluorescent Pseudomonads. These bacteria have been previously isolated from a typical truffle orchard soil. The effect of Pseudomonads on T. melanosporum synthesis proceeded by a two-stage process. Tuber melanosporum infection first declined and then resumed to almost the original level. Infection by competing mycorrhizal fungi declined after 6 months and was very low after 12 months, at the end of the experiment. The same dynamic process occurred with all bacterial strains tested, regardless of their taxonomical group or iron-chelating power. However, some isolates of Pseudomonads seemed to be more efficient than others. A protective effect of Pseudomonads against soil-borne competitors of mycorrhizae was postulated to occur in orchards, consequently favouring the continuation of the T. melanosporum symbiosis. Prospects for use of Pseudomonads in nurseries are discussed.     

Étude du phytoseiideCydnodromus chilenensis en vue de son utilisation contreTetranychus urticae en culture protégée de fraisier

Résumé La comparaison de deux espèces de PhytoseiidesP. persimilis etC. chilenensis sur le terrain et en laboratoire, montre qu'elles sont très semblables mais différent principalement pour leur résistance au je?ne et leur fécondité. Des lachers des deux espèces conjointement, ou deP. persimilis seul lorsqueC. chilenensis est présent, peuvent permettre d'utiliser le premier plut?t pour son effet de choc et le deuxième plut?t pour son effet de régulation.

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Summary The comparison between two species of predatory mites,Phytoseilus persimilis andC. chilenensis in the fields as well as in the laboratory shows that they differ from each other primarily in voracity. ReleasesP. persimilis, C. chilenensis being present, afford a good combination between the drastic effect of the former and the regulating one of the latter.