Francesco Paolo Marra

Genetic relationships, structure and parentage simulation among the olive tree (Olea europaea L. subsp. europaea) cultivated in Southern Italy revealed by SSR markers

In this work, we assess both the morphological and genetic diversity of 68 important olive cultivars from three Southern Italian regions: Calabria, Campania and Sicily. Twenty-five phenotypic traits were evaluated and 12 simple sequence repeat (SSR) markers were analysed. All SSR primers were polymorphic and reliable. The total number of alleles per locus varied from 5 to 19 with an average number of 13.1 and a mean polymorphic information content (PIC) of 0.81. These results suggested high genetic diversity within these three olive germplasm collections. Morphological traits also showed significant variability amongst cultivars. Two cases of identity were found and ten statistically significant cases of putative parent/sibling were discovered by performing a SSR-based parentage simulation analysis with CERVUS. The Mantel test indicated low but significant correlations between the morphological data and SSR allelic frequency, origin and SSR allelic frequency, and origin and morphology. Structure software allowed inference of relationships between the three olive germplasm collections and allowed us to obtain the most consistent grouping and to identify putative admixed or exchanged cultivars. Cluster and multivariate analysis, based on morphological traits, revealed geographic grouping in agreement with UPGMA dendrogram and structure analysis using SSRs. Sicilian cultivars showed a more homogenous genetic makeup, probably due to geographical isolation, whilst Calabrian and Campanian cultivars seemed to have a less distinct genetic structure, with a greater degree of intermixing. A correlation between the presence of certain SSR alleles and fruit size was also found.

Molecular and morphological diversity of on-farm hazelnut (Corylus avellana L.) landraces from southern Europe and their role in the origin and diffusion of cultivated germplasm

Hazelnut (Corylus avellana L.) is a traditional nut crop in southern Europe. Germplasm exploration conducted on-farm in five countries (Portugal, Spain, Italy, Slovenia, and Greece) identified 77 landraces. The present work describes phenotypic variation in nut and husk traits and investigates genetic relationships using ten simple sequence repeat (SSR) markers among these landraces, 57 well-known references cultivars, and 19 wild accessions. Among the 77 landraces, 42 had unique fingerprints while 35 showed a SSR profile identical to a known cultivar. Among the 42 unique landraces, morphological observations revealed high phenotypic diversity, and some had characteristics appreciated by the market such as nut round and caliber. Analysis of genetic relationships and population structure allowed investigation of the origin and spread of the cultivated germplasm in southern Europe. Our results indicate the existence of three primary centers of diversity in the Mediterranean basin: northwestern Spain (Tarragona) and southern Italy (Campania) in the West and Black Sea (Turkey) in the East. Moreover, the data suggest the existence of secondary gene pools in the Iberian (Asturias) and Italian (Liguria and Latium) Peninsulas, where local varieties were recently domesticated from wild forms and/or from introduced ancient domesticated varieties.

Toward the definition of a carbon budget model: seasonal variation and temperature effect on respiration rate of vegetative and reproductive organs of pistachio trees (Pistacia vera)

This study, as a preliminary step toward the definition of a carbon budget model for pistachio trees (Pistacia vera L.), aimed at estimating and evaluating the dynamics of respiration of vegetative and reproductive organs of pistachio tree. Trials were performed in 2005 in a commercial orchard located in Sicily (370 m a.s.l.) on five bearing 20-year-old pistachio trees of cv. Bianca grafted onto Pistachio terebinthus L. Growth analyses and respiration measurements were done on vegetative (leaf) and reproductive (infructescence) organs during the entire growing season (April-September) at biweekly intervals. Results suggested that the respiration rates of pistachio reproductive and vegetative organs were related to their developmental stage. Both for leaf and for infructescence, the highest values were observed during the earlier stages of growth corresponding to the phases of most intense organ growth. The sensitivity of respiration activity to temperature changes, measured by Q(10), showed an increase throughout the transition from immature to mature leaves, as well as during fruit development. The data collected were also used to estimate the seasonal carbon loss by respiration activity for a single leaf and a single infructescence. The amount of carbon lost by respiration was affected by short-term temperature patterns, organ developmental stage and tissue function.

Seasonal variations of antimicrobial activity and chemical composition of essential oils extracted from three Citrus limon L. Burm. cultivars.

In order to investigate the seasonal variations of antimicrobial properties and chemical composition of essential oils (EOs), three different cultivars of Citrus limon L. Burm. spp. (Femminello Santa Teresa, Monachello and Femminello Continella) were collected at 6-week intervals, from December 2012 to April 2013, for a total of four harvests. The EOs were extracted from lemon peel by hydro-distillation. The antimicrobial activity, tested by paper disc diffusion method, was evaluated against common food-related pathogenic bacteria (Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica and Enterobacter spp.). EOs were more effective against Gram-positive than Gram-negative bacteria at each collection time, but a strong strain dependence was evidenced. Monachello EOs showed the highest inhibition power. The chemical characterisation of the EOs performed by gas chromatography/mass spectrometry identified from 36 to 42 molecules. The chemical difference registered among samples and seasons may explain the different antimicrobial efficacies recorded.

Genetic similarity among Tunisian cultivated olive estimated through SSR markers

Olive (Olea europaea L. subsp. europaea var. europaea) is one of the oldest fruit tree in the Mediterranean basin, and is cultivated for oil and canned fruit. Part of this interest is driven by the economic importance of olive oil which is increasing throughout the world due to its beneficial effect to human health. In Tunisia, olive has great socio-economic importance, with more than 60 millions olive trees cultivated for olive oil production including a wide range of cultivars which are widely extended from the north to the south regions of the country for its high economic value. Here, we applied microsatellites (SSRs) molecular markers to assess the genetic variability of the most important Tunisian olive cultivars. In total, the 10 simple sequence repeats (SSR) loci revealed 73 alleles with a mean number of 07 alleles per locus were detected. The polymorphism index content (PIC) values were high (0.72) ranging from 0.86 at GAPU 103 to 0.56 at EMO 90. The analysis of the dendrogram showed six main separate groups.

Two new planting systems for early ripening peaches (Prunus persica L. Batsch): Yield and fruit quality in four low-chill cultivars

SummaryTrees of peach cvs Flordastar, Flordaprince, Flordacrest and Maravilha, low in chill requirement (Flordaprince 150; Flordacrest 350 C.U.), with a short fruit development period (Flordaprince 90; Flordacrest 110 d) and a very early ripening time (Flordastar mid May; Flordacrest first week of June), were planted in Sicily (37° 30′ Lat. N) both in a medium (667 trees per ha) and a high density (2000 trees per ha) plantation system. In the medium density planting system, the trees were trained to a Fusetto, and in the high density to a Y-shape. Both in the Fusetto and Y, the size of the trees was controlled by severe pruning soon after harvest, consisting in the shortening of most of the one year old wood. From mid June to October, the trees of all four cultivars were able to recover a “fruiting canopy”; flower bud density, flower fertility, fruit set, fruit quality and crop efficiency were not affected by the severe summer pruning. Due to the planting density and the pruning, the tree growth was restr...

Planting density, above-ground dry-matter partitioning and fruit quality in greenhouse-grown `Flordaprince' peach (Prunus persica L..Batsch) trees trained to ``free-standing Tatura''

SummaryThe effect of planting density on yield, fruit quality and above-ground dry-matter partitioning into vegetative and reproductive organs of six year old peach trees was investigated in Sicily on the very early-ripening cv Flordaprince in greenhouse. Increasing the number of trees per hectare from 1500 to 5000 significantly reduced total above-ground dry matter, trunk cross-sectional area and total leaf area. Differences in growth did not result in substantial modifications in the source-sink relationships between the vegetative and the reproductive organs of the above-ground part of the tree, as shown by the lack of statistical differences in dry-matter partitioning into fruit, leaves, shoots, one year old wood and trunk 1 branches among the treatments. Yield and number of fruits per tree diminished as planting density increased though, due to the number of trees per ha, differences in terms of yield per unit of soil surface area were not significant. Yield was on average 21.0.t per ha, a noteworthy...

Seasonal dynamics of photosynthesis and total carbon gain in bearing and nonbearing pistachio (Pistacia vera L.) shoots

Seasonal changes in leaf gas exchange, assimilation response to light and leaf area were monitored in bearing and nonbearing pistachio shoots. Shoot bearing status did not directly affect leaf photosynthetic rate. However, photosynthetic light-response curves strongly varied during the season demonstrating the dominant effect of the tree’s seasonal phenology on assimilation. Early in the season low photosynthetic rates were associated with high rates of dark respiration indicating limited photosynthesis in the young leaves. As leaves matured, dark respiration decreased and assimilation reached maximum values. Photosynthetic efficiency was strongly reduced late in the season due to leaf age and senescence. Fruit load precipitated an early leaf senescence and drop that resulted in a 53% decrease in leaf area in bearing vs. nonbearing shoots, strongly decreasing the seasonal photosynthetic performance of bearing shoots. Bearing shoots produced a 26% lower seasonal carbon gain compared to nonbearing shoots.

S-genotype identification, genetic diversity and structure analysis of Italian sweet cherry germplasm

In this study, 186 local sweet cherry accessions from 12 Italian regions, plus eight reference accessions, were analysed for the first time, using 13 microsatellite markers. Moreover, their S-incompatibility genotypes were identified with consensus primers for the S-RNase and SFB genes. A total of 161 unique genotypes were found; 18 groups of synonyms, along with the discovery of cases of misidentification. The average number of alleles per locus was 9.7, the mean expected heterozygosity (He) was 0.63, the mean observed heterozygosity (Ho) was 0.65 and the mean polymorphic information content (PIC) was 0.58. The structure analysis revealed the presence of six populations, which reflected in some cases geographical areas, the exchange of material among regions and introduction of material from abroad. A total of 17 different S-alleles were found, combined in 24 incompatibility groups of the 47 reported so far. Furthermore, 10 new incompatibility groups, from XLVII to LVI, were identified. Seven genotypes with unique S-allele combinations were included in the pollen donor group 0. The mutant allele of the pollen SFB5′ was found in early ripening genotypes from Sicily and Sardinia. The variability of SSRs present in both introns of the allele S13 was also explored; new combinations of variants were found and some accessions presented SSR variants typical of wild cherry. It is evident that the Italian sweet cherry germplasm collection represents a relevant source of genetic diversity that needs to be preserved for future breeding programmes.

A fuzzy multi-criteria decision-making methodology to optimise olive agro-engineering processes based on geo-spatial technologies

In southern Italy, the olive oil sector is an important part of the primary sector and its development requires support from research to ensure its sustainability. This work proposes the first step for set up a decision support system (DSS) for establishing mechanisation in agricultural operations for different olive groves. To contribute to this goal researches have been carried out to test the ability of remote sensing (RS) and geographic information system (GIS) to map olive groves and their agronomic characteristics. In detail, this study aimed to classify olives grove areas in terms of agronomic suitability and detect horticultural characteristics of olive groves in order to develop a fuzzy multi-criteria decision-making method for managing mechanical harvesting and pruning. The detection and interpretation of horticultural traits was conducted on two different olive groves areas of Sicily. Results demonstrate that fuzzy technique for order performance by similarity to ideal solution can be a useful decision-making tool combined with the automatable methodology for data acquisition.