Rosario Schicchi

Sorbus madoniensis (Rosaceae), a new species from Sicily

Abstract Sorbus madoniensis, a new species of Sorbus sect. Aria, is described, so far known only from two neighbouring localities on Mt. Carbonara (Madonie mountains, Sicily). It is related to S. graeca, which also occurs in the Madonie, and indeed shares with S. madoniensis one of its localities.

Essential oil components of orange peels and antimicrobial activity

Abstract In this study, the orange peel of 12 cultivars of Citrus sinensis from central-eastern Sicily was employed to obtain essential oils and extracts. The ones were extracted through steam distillation, the others through extraction in hexane. Chemical constituents were evaluated in terms of qualitative and quantitative analyses by gas chromatography/mass spectrometry. Fifty-four components were identified in the steam essential oils and 44 in the extracts. In all the cultivars, the main component is d-limonene (73.9–97%); discrete percentages of linalool, geraniol and nerol were also found. Cluster analysis based on essential oils composition showed a certain degree of affinity between cultivars of the same type. The antimicrobial activity was investigated against three micro-organisms (Staphylococcus aureus, Listeria monocytogens and Pseudomonas aeruginosa). ‘Sanguinello’ and ‘Solarino Moro’ essential oils are significantly active against L. monocytogenes, while ‘Valencia’ hexanic extract against all the tested micro-organisms.

Bioclimatology and Vegetation Series in Sicily: A Geostatistical Approach

Tackling the Sicilian woody vegetation as a case-study, this work aims to verify the correspondence between Rivas-Martínezs bioclimatic units and the main vegetation series in the Mediterranean region. Following this approach, one macrobioclimate and 25 bioclimatic type belts can be recognized in Sicily. By means of a geostatistical analysis based on WorldClim data sets, cartographic models of the distribution range of each single bioclimatic unit were obtained and combined with vegetation data, in order to develop a new regional spatial framework, integrating climatic and vegetation data. Fidelity of each vegetation unit to a given climatic range was then evaluated as percent distribution of the occupied surface within a given bioclimatic unit, while the predictive power of the WorldClim data sets was tested by using half of the spatial data of the processed vegetation units as independent variables. Our results suggest that: (1) any kind of numerical threshold used to define bioclimatic units is not effective a priori, but only after it has been adjusted to the territory and to the spatial scale used to set the model; (2) bioclimatic indices being an empirical tool, the model can be trained and eventually adjusted when applied to different territories; (3) fidelity of vegetation units to a given bioclimatic unit is highly variable; (4) the mechanistic pitfall that climatophilous vegetation has to be necessarily linked to a single bioclimatic unit should be avoided.

Detection of ephemeral genetic sub-structure in the narrow endemic Abies nebrodensis (Lojac.) Mattei (Pinaceae) using RAPD markers

A. nebrodensis (Nebrodi fir, Sicilian fir) is restricted to a small area of the Madonie Natural Park in Sicily. According to recent estimates, its only population consists of 30 adult individuals and a fluctuating number of juveniles derived from natural regeneration; besides, some hundreds of cultivated plants are preserved as ex situ collection. We used RAPD data from six 10-mer primers to examine the consequences of extensive historical clearance and human pressures on the extant population. Data from multiple life stages and different habitat conditions were considered, affording an opportunity to ascertain for the first time the structure of genetic variation in the extant uneven-aged population on both spatial and temporal scale. Consistent with previous works, we found that the history of disturbance and past land use did not affect drastically the biological diversity of the present-day population. Considerable levels of genetic variation were detected both in adult and juvenile sets. The non-significant correlation between genetic and physical distances (Mantel test; r = − 0.075) revealed a random distribution of genotypes in the natural stand. When the juvenile set was divided in 17 subsets, based on maternal provenance and growing conditions, Shannons index (54%) and AMOVA analysis (84%) indicated that most of genetic variation resides within subsets. Neighbour-joining cluster analysis supported the hypothesis of high cross-fertilization rates expected for a woody perennial species; nevertheless some grouping of related individuals suggested partial inbreeding and a weak pattern of genetic structure. Changes in structure can occur as the progeny ages and offspring thinning is responsible for moulding patterns of genetic diversity and population structure in time.

Micromorphological approach to the systematics of Mediterranean Isoëtes species (Isoëtaceae, Lycopodiophyta): analysis of the megaspore surface

Abstract Megaspore ornamentation is one of the few morphological characters used in the taxonomy of the genus Isoëtes. In the present work, we test the application of this character for distinguishing some Isoëtes species occurring in the Mediterranean: Isoëtes sicula, which according to some authors should be included as a variety in I. histrix, and the recently described I. todaroana, whose affinity with other taxa is currently unknown. Two additional species (I. duriei, I. velata) were also included in the analysis. The megaspores were studied using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy and chemical treatment. In all species, the megaspore surface is covered by a siliceous coating; removal of this coating reveals an underlying three-dimensional network of fused rodlets. A unique pattern of this network occurs in I. sicula, supporting its separation from I. histrix. Comparison between the patterns observed in the examined Mediterranean species shows that I. todaroana is most similar to I. histrix.

Notes on the karyology, genetics and ecology of Genista sect. Voglera in Sicily

Abstract To investigate the biosystematic and genetic relationships among Sicilian species of Genista sect. Voglera, four populations of three species, Genista aristata C. Presl, Genista cupanii Guss., and Genista madoniensis Raimondo, have been studied. Genista madoniensis is tetraploid, with a chromosome number of 2n = 48, as are the other two species. An isozyme study showed that G. madoniensis is taxonomically closer to G. aristata than to G. cupanii, the latter possessing four unique alleles. The results are discussed in the context of the ecological characteristics of each species.

Genetic analysis of Citrus aurantium L. (Rutaceae) cultivars by ISSR molecular markers

Abstract Eight cultivars of Citrus aurantium L., showing peculiar morphological traits of the fruits and leaves, were analyzed genetically. Inter simple sequence repeat (ISSR) was chosen as molecular markers because they represent a highly efficient system for investigating variability at intraspecific level. The particular morphological traits were discussed, the genetic identity and distance matrix based on Nei index was calculated, and the unweighted pair group method with arithmetic mean (UPGMA) dendrogram was generated. A total of 53 clearly distinguished DNA bands were considered for the ISSR analysis of which 24 were polymorphic. A basic C. aurantium fingerprinting pattern was obtained. The ISSR profiles allowed to discriminate only two cultivars, while the other six ones did not show polymorphisms, although their phenotypes were notably different, indicating that mutations must have occurred without significantly modifying the DNA length between the simple sequence repeats. The results showed a very low level of genetic variability among the cultivars; “Canaliculata” formed a separated cluster with C. sinensis Osbeck, suggesting a probable hybrid origin derived from crossing between sour and sweet orange. This study confirmed the reliability and reproducibly of ISSR markers for Citrus fingerprinting purposes, although some morphological differences could not be detected; therefore, both morphological and genetic characters must be considered for cultivar or variety identification.

Evaluation of the DNA barcoding approach to develop a reference data-set for the threatened flora of Sicily

The Mediterranean Basin is one of the most significantly altered World Biodiversity Hotspots with extensive habitat loss and fast genetic population erosion, for which urgent biodiversity reconnaissance and preservation actions are required. In particular, Sicily has about 600 taxa classified as threatened or near-threatened. The correct recognition and identification of such biodiversity is required for supporting further activities. The objective of this work is to assess the ability of the DNA barcoding approach to identify different taxonomic groups from a collection of the most threatened plant taxa, throughout natural Sicilian populations. The evaluation of the DNA barcoding core markers, rbcL and matK, was carried out on 30 taxa belonging to 13 families. DNA barcode fragments were recovered from all taxa (100%). The rbcL gene was recovered from 97% of the taxa and matK gene from 73%. In this test, 19 taxa overall (63%) were totally resolved at the specific or subspecific level, by at least one of the core markers. Fourteen of the 17 most threatened taxa (EN, CR) included in this work were totally discriminated. The matK and rbcL locus, respectively, resolved 64% and 48% of the taxa successfully sequenced. The matK gene expressed the highest genetic distance (K2P value), from 0.4% to 8.6%, against a range of 0.1–2% of rbcL gene. However, the rbcL gene appeared a good compromise between PCR, sequencing success and species-level resolution. Cryptic groups suggest the implementation of additional barcoding markers or different primer combinations, particularly for matK, in order to increase the performances. However, this preliminary result confirms the potential of the barcoding approach for quick identification of unknown and heterogeneous plant groups to generate a dedicated reference data-set of the threatened Sicilian flora for a wide range of applications.

Potential impact of genetically modified Lepidoptera-resistant Brassica napus in biodiversity hotspots: Sicily as a theoretical model: Impact of Bt oilseed rape on butterflies

The general increase of the cultivation and trade of Bt transgenic plants resistant to Lepidoptera pests raises concerns regarding the conservation of animal and plant biodiversity. Demand for biofuels has increased the cultivation and importation of oilseed rape (Brassica napus L.), including transgenic lines. In environmental risk assessments (ERAs) for its potential future cultivation as well as for food and feed uses, the impact on wild Brassicaeae relatives and on non‐target Lepidoptera should be assessed. Here we consider the potential exposure of butterflies as results of possible cultivation or naturalization of spilled seed in Sicily (Italy). Diurnal Lepidoptera, which are pollinators, can be exposed directly to the insecticidal proteins as larvae (mainly of Pieridae) through the host and through the pollen that can deposit on other host plants. Adults can be exposed via pollen and nectar. The flight periods of butterflies were recorded, and they were found to overlap for about 90% of the flowering period of B. napus for the majority of the species. In addition, B. napus has a high potential to hybridise with endemic taxa belonging to the B. oleracea group. This could lead to an exposure of non‐target Lepidoptera if introgression of the Bt gene into a wild population happens. A rank of the risk for butterflies and wild relatives of oilseed rape is given. We conclude that, in environmental risk assessments, attention should be paid to plant–insect interaction especially in a biodiversity hotspot such as Sicily.

Seed cryopreservation of Fraxinus angustifolia Vahl

Fraxinus angustifolia is used for afforestation and for production of both valuable timber and manna , a substance with pharmacological applications. The aim of this research was to establish the optimized condition for cryopreservation of F. angustifolia seeds, in order to protect the germplasm of this species. Germination percentage and mean time of germination of non-treated seeds (control) and liquid nitrogen-treated seeds were established in water or in 10 -6 M gibberellic acid (GA 3 ). The seeds could be cryopreserved with 3% of moisture content (MC) and germinated easily in water (70.0 ± 5.0%), while seeds cryopreserved with 6% MC showed a physiological dormancy. This state could be efficiently removed by addition of GA 3 , which increased germination to 76.0 ± 2.4%. Liquid nitrogen did not impair embryo viability, allowing a successful cryopreservation of seeds. The results are particularly useful for both germplasm conservation programs and in narrow leaved ash nurseries. Keywords : Fraxinus angustifolia , germination, germplasm conservation, seed cryopreservation African Journal of Biotechnology Vol. 12(16), pp. 1930-1936