Bruno Romano

Temperature influence on differentiation and release of hazel pollen

PubMed, Apr 1, 1993

The aim of the present work was to identify the classic phenological stages, and to understand it... more The aim of the present work was to identify the classic phenological stages, and to understand its relation to catkin differentiation and growth, and its consequences for the start of pollination. Phenological observations and an aeropalynological survey on Corylus avellana, which is an example of an economically and allergologically interesting arboreal plant, were carried out during 1991-1992. The comparison between the different phenological phases and the aeropalynological data, showed that the pollen trap recorded hazel-pollen presence in the atmosphere immediately after the pollen release from the orchard. The start of catkin elongation in late winter, after the chilling requirement has been fulfilled, could be used to indicate the beginning of heat accumulation necessary for pollination.

Pollination seasons in Perugia area (Central Italy)

Studia botanica, Dec 17, 2009

It is very helpful for allergological and ecological purposes to formulate a "pollen calendar" fo... more It is very helpful for allergological and ecological purposes to formulate a "pollen calendar" for each zone,, to have mean data about the time and the cubic metre concentration in which the pollen grains occur in the atmosphere of investigated zone. The results of ten years of continuous monitoring of airborne pollen concentrations with a volumetric pollen trap in Perugia, have revealed some likeness and differences, concerning the time, the quantity and the quality of the monitored pollen grains during the studied period. In the atmosphere of Perugia, Cupressaceae/Taxaceae, Fagaceae (Quercus), Poaceae, Oleaceae and Urticaceae are the main taxa; the first peak at the end of the winter, Fagaceae (Quercus), Poaceae and Oleaceae in May and June, while Urticaceae has a very long period of pollination with many peaks during the spring-summer period.

Download

Fifteen-year phenological plant species and meteorological trends in central Italy

International Journal of Biometeorology, Feb 24, 2013

Download

Environmental Conditions and Microsporogenesis inOlea EuropaeaL. (Oleaceae)

Giornale botanico italiano, 1996

Download

Olive pollination: Flowers and pollen of two cultivars ofOlea europaea

New Zealand Journal of Crop and Horticultural Science, Jun 1, 2003

The economic and historical importance of this wind-pollinated species (Olea europaea) in the Med... more The economic and historical importance of this wind-pollinated species (Olea europaea) in the Mediterranean area has stimulated a lot of research. Some of these investigations have studied the reproductive phases up to fruit formation, with particular focus on the flowering period. To evaluate the pollinating process, micro-and macromorphological analyses were carried out for 3 years on an experimental olive grove with two cultivars ('Ascolana Tenera' and 'Giarraffa'). The macromorphological data show relevant differences (treecrown volume and number of inflorescences) and similarities (the mean number of flowers per inflorescence) between the cultivars. Micromorphological analyses determined the mean number of pollen grains per anther in 'Giarraffa', used as the "polliniser"; at the same time, for the stigmas, this analysis provided the potential pollen quantity captured by 'Ascolana Tenera' "used as the "pollinated" plant. This type of investigation improves knowledge on the formation cycle of olive fruit, taking into consideration that more than one olive cultivar is normally used in the groves, because of self-sterility.

Download

Cell division and expansion markers for understanding flower development in Petunia hybrida Hort

Pollen Morphology and Reproductive Performances in Opuntia Ficus-Indica (L.) Mill

Acta Horticulturae, 2015

The fruits of Opuntia ficus-indica (L.) Mill., the most worldwide cultivated species of Cactaceae... more The fruits of Opuntia ficus-indica (L.) Mill., the most worldwide cultivated species of Cactaceae family, contain viable seeds (100-250) of large size. This characteristic influences the commercial quality of the fruit. The study of floral biology in Opuntia allows to understand the behaviour of the plant during reproductive phase and perhaps to distinguish clones with different fruits behaviour (with seed and seedless). The study resulted in a palynological characterization by optical and scanning microscopy (SEM), followed by a qualitative analysis on the male line with pollen viability and in vitro germination tests, in addition to a pollenpistil interaction survey. The plant material collected, during June-July 2010, consisted of clonal samples of the same genetic origin collected from populations characterizing the Sicilian cultivation area and distinguished in seedly cultivar 'Gialla' (yellow) and 'Rossa' (red) and seedless cultivar 'Bianca' (white). The palynological characterization revealed that Opuntia pollen has a radio-symmetric shape with a reticulated surface, poly-panto-porate with a perimeter from circular to polygonal. Moreover, the membrane of the pore appears finely granulated. Scanning microscopy reveals that the pollen has an intectated, reticulated and hetero-brochated exine with about 20-24 pores with a thin membrane. The average viability of the pollen was 91.2% (± 4.6) in 'Bianca' cultivar, 82.40% (± 9.88) for both seedly cultivars. In vitro germination rate was 28.76% (± 6.59) in the white cultivar, 27.85% (± 5.15) as overall average in 'Gialla' and 'Rossa' cultivar. In vivo germination rate in the seedless cultivar (75.77% ± 5.32) was higher than what was that recorded in the other two (53.5% ± 6.5).

Download

Reproductive biology of Olive (Olea europaea L.) DOP Umbria cultivars

Sexual Plant Reproduction, 2006

Olive trees have a plentiful bloom but a low percentage of normal fruit set. To improve fruit set... more Olive trees have a plentiful bloom but a low percentage of normal fruit set. To improve fruit set, numerous investigations have sought to identify the obstacles that prevent full production. In this work, flower development in five DOP Umbria cultivars (Leccino, Frantoio, Moraiolo, Dolce Agogia and San Felice) was studied throughout different developmental phases, from before microsporogenesis and megasporogenesis to post-anthesis, by morphological and cytohistological observations. Dolce Agogia was the most precocious cultivar, while full flowering was simultaneous in Leccino, Frantoio, Moraiolo and San Felice. Frantoio and Leccino were also good pollen producers, having the highest percentage of pollen viability and germinability. Dolce Agogia can also be considered a good pollen producer in terms of the high quantity of released pollen, but it had the lowest levels of pollen viability and germinability and the highest percentage of aborted flowers and ovaries. Morphological and cytohistological observations on the number of flowers per inflorescence and the number of aborted flowers and ovaries suggest that fruit set was not influenced by the number of flowers per inflorescence, but rather by the number of inflorescences, which depends on the global fruiting potential of the tree.

Download

Temperature influence on differentiation and release of hazel pollen

Allergie et immunologie, 1993

The aim of the present work was to identify the classic phenological stages, and to understand it... more The aim of the present work was to identify the classic phenological stages, and to understand its relation to catkin differentiation and growth, and its consequences for the start of pollination. Phenological observations and an aeropalynological survey on Corylus avellana, which is an example of an economically and allergologically interesting arboreal plant, were carried out during 1991-1992. The comparison between the different phenological phases and the aeropalynological data, showed that the pollen trap recorded hazel-pollen presence in the atmosphere immediately after the pollen release from the orchard. The start of catkin elongation in late winter, after the chilling requirement has been fulfilled, could be used to indicate the beginning of heat accumulation necessary for pollination.

Dormancy and Chilling Requirement for Catkins in Hazel ( Corylus Avellana L., Corylaceae)

Giornale botanico italiano, 1994

Download

Study of the intercalary meristems in Triticum aestivum L. and Hordeum vulgare L

Pollination seasons in Perugia area (Central Italy)

It is very helpful for allergological and ecological purposes to formulate a "pollen calendar" fo... more It is very helpful for allergological and ecological purposes to formulate a "pollen calendar" for each zone,, to have mean data about the time and the cubic metre concentration in which the pollen grains occur in the atmosphere of investigated zone. The results of ten years of continuous monitoring of airborne pollen concentrations with a volumetric pollen trap in Perugia, have revealed some likeness and differences, concerning the time, the quantity and the quality of the monitored pollen grains during the studied period. In the atmosphere of Perugia, Cupressaceae/Taxaceae, Fagaceae (Quercus), Poaceae, Oleaceae and Urticaceae are the main taxa; the first peak at the end of the winter, Fagaceae (Quercus), Poaceae and Oleaceae in May and June, while Urticaceae has a very long period of pollination with many peaks during the spring-summer period.

Download

Environmental Conditions and Microsporogenesis in Olea Europaea L. (Oleaceae)

Giornale botanico italiano, 1996

Download

Relationship between olive flowering and latitude in two Mediterranean countries (Italy and Tunisia)

Theoretical and Applied Climatology, 2010

In phenological studies, the plant developments are analysed considering their relationships with... more In phenological studies, the plant developments are analysed considering their relationships with seasonal meteorological conditions; moreover, the influences of geographical features on biological responses have to be also considered. Different studies analysed the influence of latitude on phenological phases to investigate the possible different magnitude of biological response. In our experience, this type of geographic evaluation was conducted considering one of the more important plant species of Mediterranean shrub, the olive (Olea europaea L.) in fifteen olive monitoring stations, four located in Tunisia and eleven in Italy, from the southern Zarzis area at 33° to the northern Perugia area at 43° of latitude. The olive flowering phenomenon was studied, utilising an aerobiological monitoring method through appropriate pollen traps located inside olive groves from 1999 to 2008. The olive monitored pollen grains were recognised and evaluated to obtain daily pollen concentrations to define the flowering dates in the different study areas. The biometeorological statistical analysis showed the 7°C threshold temperature and the single triangle method for growing degree days (GDD) yearly computing as the better ones in comparison to others. Moreover, the regression analysis between the dates of full flowering and the GDD amounts at the different monitoring latitudes permitted us to evidence the biological response of olive species in geographic regions with different climate patterns. The specific biological response at different latitude was investigated, the slope results, as flowering days per heat amounts, evidenced that olive species behaviours are very constant in consequence to similar meteorological conditions independently to latitude variations. Averagely, the relationships between plant’s phenology, temperature trends and geographical features are very close, even if the yearly mesoscale meteorological variations force to consider, year by year, phenological advances or delays as local events.

Morphological and cytological development and starch accumulation in hermaphrodite and staminate flowers of olive (Olea europaea L.)

Sexual Plant Reproduction, 2009

In olive (Olea europaea L.), the formation of functionally staminate flowers rather than fully fu... more In olive (Olea europaea L.), the formation of functionally staminate flowers rather than fully functional hermaphrodites is one of the major factors limiting fruit set, as flowers with aborted pistils are incapable of producing fruit. Studies conducted on various angiosperm species have shown a correlation between flower abortion and starch content. Thus, it is important to know if starch content plays a role in regulating pistil development in olive and if so, what mechanism regulates starch distribution. Cyto-histological observations of staminate and hermaphrodite olive flowers show that pistil development in staminate flowers is interrupted after the differentiation of the megaspore mother cell. At that stage, starch grains were only detected in the ovary, style and stigma of the hermaphrodite flowers. No starch was observed in the pistils of the staminate flowers. This finding suggests a tight correlation between starch content and pistil development. The secondary origin of starch within the flower is indicated by low chlorophyll content in the gynoecium, undetectable Rubisco activity in the pistils of these two kinds of flowers and by the ultrastructure of the plastids observed by transmission electron microscope analysis. The plastids have few thylakoid membranes and grana and in the staminate flowers appeared very similar to proplastids. Considering differences in starch content between staminate and hermaphrodite flowers and the secondary origin of the starch, differences in pistil development in the staminate and hermaphrodite flowers could be related to differences in the sink strength of these two types of flowers.

Download

Male sterility in birdsfoot trefoil (Lotus corniculatus L.)

Sexual Plant Reproduction, 1989

Summary This paper describes six male steriles in birdsfoot trefoil. Data on the following charac... more Summary This paper describes six male steriles in birdsfoot trefoil. Data on the following characters were recorded on these plants and on two male fertile plants: chromosome number, presence of pollen at tripping, percentage of irregularly shaped anthers, percentage of anthers with acetocarmine stainable pollen inside, maximum range of percentage of pollen fertility among anthers within a flower presenting pollen,

Patterns of cell division and expansion in developing petals of Petunia hybrida

Sexual Plant Reproduction, 2002

The definition of the patterns of cell division and expansion in plant development is of fundamen... more The definition of the patterns of cell division and expansion in plant development is of fundamental importance in understanding the mechanics of morphogenesis. By studying cell division and expansion patterns, we have assembled a developmental map of Petunia hybrida petals. Cycling cells were labelled with in situ markers of the cell cycle, whereas cell expansion was followed by assessing cell size in representative regions of developing petals. The outlined cell division and expansion patterns were related to organ asymmetry. Initially, cell divisions are uniformly distributed throughout the petal and decline gradually, starting from the basal part, to form a striking gradient of acropetal polarity. Cell areas, in contrast, increased first in the basal portion and then gradually towards the petal tip. This growth strategy highlighted a cell size control model based on cell-cycle departure time. The dorso-ventral asymmetry can be explained in terms of differential regulation of cell expansion. Cells of the abaxial epidermis enlarged earlier to a higher final extent than those of the adaxial epidermis. Epidermal appendage differentiation contributed to the remaining asymmetry. On the whole our study provides a sound basis for mutant analyses and to investigate the impact of specific (environmental) factors on petal growth.

Download

Isolation and expression analysis of organelle genes involved in the development of olive flowers (Olea europaeaL.)

Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2010

Abstract Recent research demonstrated that in olive, hermaphrodite and staminate flowers show a d... more

Census of Airborne Pollen Grains in the Atmosphere of Ascoli Piceno (Central Italy)

New Phytologist, 1983

SummaryHirst's Volumetric Sampler was employed in the aerial survey of atmospheric pollen of ... more SummaryHirst's Volumetric Sampler was employed in the aerial survey of atmospheric pollen of Ascoli Piceno. Altogether 67 pollen types are recognized. The highest concentrations of airborne pollen occur in April, May, June, with pollen of Gramineae, Corylaceae, Fagaceae, Urticaceae and Oleaceae predominant.

Download

Fifteen-year phenological plant species and meteorological trends in central Italy

International Journal of Biometeorology, 2013

Download

Uploads

Papers by Bruno Romano

Log In