Microsatellite markers for identification of Prunus spp. rootstocks

Cultivar characterization for fruit trees certification requires fast, efficient and reliable techniques. Microsatellite markers (SSR) were used in the molecular characterization of 29 Prunus spp. rootstocks. The DNA from the rootstocks was analyzed using five pre-selected SSR primers (UDP96-005, UDP96-008, UDP96-013, UDP96-18 and UDP98-414) and revealed 81 alleles, which allowed each genotype to be identified. The UDP96-005 marker generated the most information, i.e., 23 well-distributed, polymorphic alleles among all genotypes. The 21 polymorphisms produced by UDP96-013 occurred mainly as a result of high degree of variability among genotypes of the Prunophora subgenus. In the dendrogram, the five markers allowed the 29 rootstocks to be grouped into subgroups corresponding to the subgenus they belong to, either Prunophora or Amygdalus. Suitable cophenetic correlation coefficient (r=0.82) and good bootstrapping fitting value among the Prunophora subgroup cultivars were obtained. SSR markers proved to be efficient and reliable for the molecular characterization of Prunus spp. rootostocks

Cloning and mapping multiple S-locus F-box genes in European pear (Pyrus communis L.).

European pear, as well as its close relatives Japanese pear and apple, exhibits S-RNase-based gametophytic self-incompatibility. The male determinant of this self-incompatibility mechanism is a pollen-expressed protein containing an F-box domain; in the genera Petunia (Solanaceae), Antirrhinum (Plantaginaceae), and Prunus (Rosaceae), a single F-box gene determines the pollen S. In apple and Japanese pear, however, multiple S-locus F-box genes were recently identified as candidates for the pollen S, and they were named S-locus F-Box Brothers. These genes were considered good candidates for the pollen S determinant since they exhibit S-haplotype-specific polymorphisms, pollen-specific expression, and linkage to the S-RNase. In the present study, S-locus F-Box Brothers homologs have been cloned from two of the most agronomically important European pear varieties, "Abbé Fétel" (S104-2/S105) and“Max Red Bartlett" (S101/S102), and they have been mapped on a genetic linkage map developed on their progeny. Our results suggest that the number of Fbox genes linked to the S-locus of the European pear is higher than expected according with previous reports for apple and Japanese pear, since up to five genes were found to be linked to a single S-haplotype. Moreover, two of these genes exhibited an incomplete linkage to the S-RNase, allowing the identification of low-frequency recombinant haplotypes, generated by a crossing-over event between the two genes. These F-box genes are most likely placed in close proximity of the S-locus but do not belong to it, and they can thus be excluded from being responsible for the determination of pollen S function

The role of research and technology in shaping a sustainable fruit industry: European advances and prospects

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L'ortofrutticoltura oggi

Il lavoro illustra la situazione attuale del comparto ortofrutticolo in Italia, anche in rapporto al contesto internazionale in quanto è un comparto la cui produzione è destinata per buona parte all'esportazione. In particolare, sono analizzati compiutamente il trend produttivo, le tendenze commerciali ed i fattori di cambiamento dell'ortofrutta

Innovazioni del miglioramento genetico convenzionale e biotecnologico delle piante da frutto.

A heated debate is currently taking place in the scientific community about the use of two distinct breeding approaches: the conventional breeding (based on crossing and selection assisted by molecular-selective technologies such as MAS and MAB) and the breeding that uses the new techniques made available by the modern biotechnologies (an alternative or complementary way to reach goals that are not achievable by conventional breeding). This second approach allows the transfer of resistance genes to pathogens or to abiotic stresses (such as drought, salinity and weather anomalies) as well as the improvement of the fruit nutritional value without affecting the quality standards of cultivars. Today, in addition to the classic transgenic approach (GMOs), the new plant breeding technologies (NPBT), such as “genome editing” and cisgenesis, are available. The genome sequence of the main fruit tree species and the support of specific molecular markers for the identification of gene responsible for target traits made the breeding goals achievable in a much shorter time. Protocols for the analysis of molecular markers (SSR, SCAR, SNP) linked to monogenic and polygenic traits (eg. QTLs), such as fruit quality traits, their sensory features and the tree adaptability to environmental conditions are available. The new genotyping technologies allow the early selection at genome level in each single plant as well as the screening germplasm (ancient genetic heritage) looking for genes (or gene allelic variants) with the aim to recover traits that have been lost during crop evolution or because of an environmental selective pressure. Furthermore, the markers are useful to "build" customized fruits to prevent diseases or to improve fruit quality and storage. The potential offered by new plant breeding technologies to the current breeding of fruit tree species are certainly achievable by cisgenesis (but with the risk that the obtained plants will neither be admitted to field trials nor authorized for commercial release). As for genome editing (not to be confused with GMOs), the development of new technical CRISPR variants, adapted to fruit trees, is particularly crucial. In addition to the insertion of modification in the target regions and the guarantee of the absence of heterologous DNA, this will provide assurance on the variety genome preservation and the maintenance of the related fruit high quality standards

European Pear

Among the fruit tree species, the European pear (Pyrus communis L.) has the most stable cultivar structure. Although the selection activity in the last several centuries has produced several hundred cultivars, only a few pear cultivars are currently grown. Within the Pomoideae (Pyrinae) there are 22 Pyrus species, along with another ten or so that have been variously described and assignable to synonyms of the more important species. Perhaps the most widely known species, if not the most widely cultivated, is P. communis L. The European pear is essentially the only Pyrus species currently grown in Europe while in North America both the European and the Oriental pear are grown. The European pear and its ancestral species, P. pyraster Burgsd., grow wild throughout Europe, and it was here where it was domesticated as early as 300 bc. The pear and apple appear to be amphidiploid or allotetraploid species, i.e., those formed by the gametic union of two Rosaceae species of 8 and 9 chromosomes. The high level of genetic recombination combined with selection for fruit size, appearance, flavor, postharvest storability, and resistance to pathogens and diseases has resulted in a diverse array of cultivars. There has been major advances in fruit appearance (shape, color, attractiveness), size, ripening season (summer and fall are predominant) and postharvest traits. Much effort is being invested by researchers to find resistance genes to the main biotic adversities of pear: the fire blight bacterium (Erwinia amylovora), the European pear psylla (Cacopsilla pyri), which is the vector of the phytoplasma causing pear decline, the scab causing fungi Venturia pyrina, and the black spot fungus Stemphylium vesicarium

Stato dell'ortofrutticoltura oggi

Il lavoro fa il punto sullo stato dell'ortofrutticoltura nel contesto nazionale, evidenziando i fattori critici e di cambiamento, nonch\ue9 le prospettive

Determinazione delle componenti fenoliche associate alla resistenza alla ticchiolatura nel melo

Il lavoro riporta la messa a punto della tecnica HPLC/DAD per la determinazione simultanea delle diverse componenti fenoliche in diverse cultivar di melo caratterizzate da un diverso livello di resistenza a ticchiolatura. Le analisi sono state effettuate per stabilire se la resistenza al patogeno può dipendere dal livello di fenoli costitutivi o indotti in seguito all'inoculazione con il patogeno