Paola Crinò

Rootstock resistance to fusarium wilt and effect on fruit yield and quality of two muskmelon cultivars

Pending the release of new genetic material with satisfactory resistance, grafting techniques may represent a quick, though expensive method for controlling race 1,2 of Fusarium oxysporum f. sp. melonis in Italian growing regions of melon (Cucumis melo L.). We evaluated the potential of grafting for resistance to this pathogen in 13 commercial melon rootstocks and various Cucurbitaceae spp. and determined productivity and fruit quality characteristics of grafting on resistant rootstocks. Following inoculation, P360 and PGM 96-05 commercial rootstocks, as well as Benincasa hispida, Cucumis metuliferus, Cucumis ficifolius, Cucurbita maxima, Cucurbita moschata, and Lagenaria siceraria were resistant to the race 1,2 of Fusarium. Yield and quality attributes of scion cultivars (Supermarket and Proteo) grafted on P360 and PGM 96-05 rootstocks were not improved relative to ungrafted controls. Grafts onto B. hispida negatively influenced both yield and fruit quality, while C. metuliferus, and C. zeyheri had negative impacts on productivity and fruit quality, respectively. These results indicate that rootstock influences on disease resistance as well as productivity and quality of scion fruit are important in determining the potential utility of grafting applications.

Characterization of Italian and exotic Lathyrus germplasm for quality traits

The aim of the following work is to characterize quality traits (protein, ashes, 100 seed weight and ODAP content) of 117 accessions of Lathyrus, from either Italian or foreign countries. Significant differences among entries were estimated for all traits and accessions were classified into similar genetic groups. Principal component and hierarchical cluster analyses produced five different groups. In particular, the absence of a strong association among the investigated traits and their dominant independent roles in each separate principal component allows the achievement of a useful recombinant in breeding work. An interpretation of each cluster, based on the data obtained from the accessions, provides practical information to establish a subset of grass pea collection for further activities.

Characterization of Italian spring globe artichoke germplasm: morphological and molecular profiles

Globe artichoke is native to the Mediterranean basin with Italy being the leading world producer. Italian autochthonous germplasm is at risk of genetic erosion due to the large cultivation of only a few varietal types, such as the micropropagated clone C3, and to the introduction of new seed-propagated genetic materials. The aim of our study is to assess the genetic variability existing in nine Italian globe artichoke landraces of spring type, using morphological descriptors and DNA markers (Amplified Fragment Lenght Polymorphism and Inter-Simple Sequence Repeats). A significant genetic differentiation among genotypes was found for many traits. Although some genetic variability found within each genotype was probably due to their multiclonal origin, most of them were genetically well-defined. Morphological and molecular profiles give important information to complete the genotype characterization and proceed with the selection of clones to be propagated and to develop lines and/or varieties. The present paper underlines the differences existing in the analyzed germplasm both within and among landraces and the genetic relations among different material, which is an important starting point for future plant breeding programs.

Identification of F1 hybrids of artichoke by ISSR markers and morphological analysis

Five different artichoke hybrid populations (crosses between a male sterile artichoke (MS6) and three American accessions (AMA3, AMA7, AMB1) and two Spanish accessions (SP2, SPA2)) plus a commercial hybrid population (Opal F1, Nunhems, Netherlands) were used for molecular and morphological characterisation in order to identify the purity of the F1 populations. Molecular analysis was carried out using the inter-simple sequence repeat (ISSR) technique with twenty primers. Out of these, nine were polymorphic, producing 82 DNA bands per primer on average, 56 of which were polymorphic among the populations. A dendrogram, drawn on the basis of a similarity matrix using the UPGMA algorithm, revealed that the 66 samples (10 plants per F1 populations and their respective progenitors) could be classified into two major clusters at a Nei’s genetic distance of 0.13. The male parents were genetically quite similar to all their respective progenies. In order to confirm hybrid purity, only the primers which amplified bands specific to the male parent of each hybrid were considered and the inheritance of the single locus for each cross-combination was analysed. Three ISSR markers (857c, 857g and 878) were able to confirm the hybrid purity. The morphological trait analysis showed that eight of the 17 morphological characters were significantly different among the six F1 populations. When the Mantel test was applied to the matrix of the Nei’s genetic distances and the matrix of morphological traits, a significant degree of correlation was observed between them. A selection method using ISSR markers based on cluster analysis is suggested to confirm the purity of artichoke hybrids and to predict the characters expected by any F1 hybrid offspring.

Graft union formation in artichoke grafting onto wild and cultivated cardoon: An anatomical study

In order to develop a non-chemical method such as grafting effective against well-known artichoke soil borne diseases, an anatomical study of union formation in artichoke grafted onto selected wild and cultivated cardoon rootstocks, both resistant to Verticillium wilt, was performed. The cardoon accessions Belgio (cultivated cardoon) and Sardo (wild cardoon) were selected as rootstocks for grafting combinations with the artichoke cv. Romolo. Grafting experiments were carried out in the autumn and spring. The anatomical investigation of grafting union formation was conducted by scanning electron microscopy (SEM) on the grafting portions at the 3rd, 6th, 10th, 12th day after grafting. For the autumn experiment only, SEM analysis was also performed at 30 d after grafting. A high affinity between artichoke scion and cardoon rootstocks was observed, with some genotype differences in healing time between the two bionts. SEM images of scion/rootstock longitudinal sections revealed the appearance of many interconnecting structures between the two grafting components just 3d after grafting, followed by a vascular rearrangement and a callus development during graft union formation. De novo formation of many plasmodesmata between scion and rootstock confirmed their high compatibility, particularly in the globe artichoke/wild cardoon combination. Moreover, the duration of the early-stage grafting process could be influenced not only by the scion/rootstock compatibility, but also by the seasonal conditions, being favored by lower temperatures and a reduced light/dark photoperiod.

Antioxidant Properties of Seeds from Lines of Artichoke, Cultivated Cardoon and Wild Cardoon

The artichoke (Cynara cardunculus L. subsp. scolymus L.), the cultivated cardoon (Cynara cardunculus var. altilis DC.) and the wild cardoon (Cynara cardunculus var. sylvestris L.) are species widely distributed in the Mediterranean area. The aim of this research was to evaluate the antioxidant properties of seeds from lines of artichoke and cultivated and wild cardoon in both aqueous-organic extracts and their residues by FRAP (Ferric Reducing Antioxidant Power) and TEAC (Trolox Equivalent Antioxidant Capacity) evaluations. Both artichoke and cardoon seeds are a good source of antioxidants. Among artichoke seeds, hydrolysable polyphenols contribution to antioxidant properties ranged from 41% to 78% for FRAP values and from 17% to 37% for TEAC values. No difference between cultivated and wild cardoon in antioxidant properties are reported. Our results could provide information about the potential industrial use and application of artichoke and/or cardoon seeds.

First detailed karyo-morphological analysis and molecular cytological study of leafy cardoon and globe artichoke, two multi-use Asteraceae crops

Abstract Traditionally globe artichoke and leafy cardoon have been cultivated for use as vegetables but these crops are now finding multiple new roles in applications ranging from paper production to cheese preparation and biofuel use, with interest in their functional food potential. So far, their chromosome complements have been poorly investigated and a well-defined karyotype was not available. In this paper, a detailed karyo-morphological analysis and molecular cytogenetic studies were conducted on globe artichoke (Cynara cardunculus Linnaeus, 1753 var. scolymus Fiori, 1904) and leafy cardoon (Cynara cardunculus Linneaus, 1753 var. altilis De Candolle, 1838). Fluorescent In Situ Hybridization In Suspension (FISHIS) was applied to nuclei suspensions as a fast method for screening of labelling probes, before metaphase spread hybridization. Classic Fluorescent In Situ Hybridization (FISH) on slide, using repetitive telomeric and ribosomal sequences and Simple Sequence Repeats (SSRs) oligonucleotide as probes, identified homologous chromosome relationships and allowed development of molecular karyotypes for both varieties. The close phylogenetic relationship between globe artichoke and cardoon was supported by the very similar karyotypes but clear chromosomal structural variation was detected. In the light of the recent release of the globe artichoke genome sequencing, these results are relevant for future anchoring of the pseudomolecule sequence assemblies to specific chromosomes. In addition, the DNA content of the two crops has been determined by flow cytometry and a fast method for standard FISH on slide and methodological improvements for nuclei isolation are described.