0000000000150192

AUTHOR

Kenneth R. Tobutt

Intra-allelic variation in introns of the S13-RNase allele distinguishes sweet, wild and sour cherries

The cherry (Prunus avium), a self-incompatible diploid species, and the sour cherry (Prunus cerasus), a self-incompatible or self-compatible allotetraploid species derived from P. avium and Prunus fruticosa, share several S-RNase alleles, including S13. An inactive form, S13° ,i s found in some sour cherries. Two (AT) microsatellites are associated with allele S13-RNase, one in the first intron and one in the second. Their length polymorphisms were studied in 14 sweet and 17 wild cherries (both P. avium) and in 42 sour cherries. Fluorescent primers amplifying each microsatellite were designed and amplification prod- ucts sized on an automated sequencer. Variants ranged from 247 to 273 bp fo…

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The origin of the self-compatible almond ‘Supernova’

The almond cultivar 'Supernova' is reported in the literature as a late-flowering self-compatible mutant, obtained by the irradiation of the early-flowering self-incompatible cultivar 'Fascionello'. Our work to investigate the molecular basis of this form of self-compatibility has called into question the origin of 'Supernova'. Test selfing was performed both on 'Supernova' and on the accession of 'Fascionello' from which it was derived - 'Fascionello-Rome'. Both proved self-compatible. Amplification of S-RNase alleles, using consensus primers from the signal peptide region to the second conserved region of the S-RNase gene and primers specific for allele S f , confirmed 'Supernova' and 'Fa…

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The Sicilian peach (Prunus persica L. Batsch) germplasm: Evaluation of genetic diversity using SSRs

The decrease in worldwide consumption of peaches due to the poor flavour quality of the fruit has increased the demand for new tasty cultivars. The availability of plant genetic resources is an important prerequisite for improving fruit quality by breeding. In Sicily there is a large collection of local cultivated peaches, whose production fills a niche in the local markets, but which is at risk of disappearing. Their characteristics include highly aromatic fruit and late ripening. Because of their important agronomic characteristics, the Department of Colture Arboree of Palermo University has collected the most interesting accessions to safeguard them and to use the indigenous resources in…

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Preliminary identification of self-incompatibility genotypes of Sicilian almond landraces

Sicily is the main almond producer in Italy. The almond tree is one of the main protagonists of the Sicilian agrarian landscape, especially in the winter, when the bare branches are covered by white or pinkish flowers. Its presence is particularly significant in the province of Agrigento, in Syracuse and in Ragusa areas, where the almond nut is used for fresh consumption and for the preparation of typical sweets. The extremely rich Sicilian almond germplasm can be useful for genetic improvement, since many local landraces possess aromatic characteristics of the nuts of high value. Self-incompatibility in this species is gametophytic and controlled by a multi-allelic S locus, coding for the …

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Development of “universal” gene-specific markers from Malus spp. cDNA sequences, their mapping and use in synteny studies within Rosaceae

The Rosaceae contains many economically valuable crop genera, including Malus (apple), Fragaria (strawberry), and Prunus (stone fruit). There has been increasing interest in the development of linkage maps for these species, with a view to marker-assisted selection to assist breeding programs and, recently, in the development of transferable markers to permit syntenic comparisons of maps of different rosaceous genera. In this investigation, a set of Malus cDNA sequences were downloaded from the European Molecular Biology Laboratory database. The sequences were aligned with homologous full-length Arabidopsis genomic DNA sequences to identify putative intron–exon junctions and conserved flank…

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Molecular characterisation of Sicilian Prunus persica cultivars using microsatellites

In Sicily, a large indigenous population of cultivated peaches, nectarines, and platicarpa (flat peaches) shows a wide range of fruit quality and ripening periods. This diverse assortment of local cultivars is a resource, not yet exploited, for breeding programmes. The main purpose of this study was to fingerprint these indigenous accessions and to evaluate the molecular diversity between them. Forty indigenous and nine international accessions were analysed using 15 microsatellite, simple sequence repeat (SSR), markers. Some of the main morphological characteristics, such as flower type, petiole gland shape, flesh colour, and fruit ripening time, of these cultivars were also recorded. The …

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Morphological characteristics, microsatellite fingerprinting and determination of incompatibility genotypes of Sicilian sweet cherry cultivars

Sicily has extensive germplasm of diploid sweet cherry (Prunus avium L.) that has not been well studied. In this investigation, 39 cherry accessions, selected from collections and farms, were analysed using molecular markers and characterised for various morphological and other agronomic characters such as flesh colour, fruit size, quality and, in some cases, ripening periods. Thirteen Simple Sequence Repeat (SSR) primer pairs, as well as two primer pairs for the incompatibility (S) locus, which amplified across the first intron of the S-RNase gene and across the intron of the SFB gene, were used in three multiplexed reactions to analyse the accessions. The number of alleles per SSR locus r…

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A genetic linkage map ofPhysocarpus, a member of the Spiraeoideae (Rosaceae), based on RAPD, AFLP, RGA, SSR and gene specific markers

Physocarpus opulifolius is a deciduous shrub native to North America belonging to the Spiraeoideae subfamily of the Rosaceae. The cultivars 'Luteus' and 'Diabolo' are grown in gardens for their ornamental foliage, golden and purple respectively. We developed a linkage map of P. opulifolius with a view to detecting markers for the leaf colour genes, which are under major gene control. A total of 162 molecular markers (128 RAPDs, 27 AFLPs, three RGA, three STS markers and one SSR) and the leaf colour genes Pur and Aur were scored in the Physocarpus progeny and used to create a linkage map covering 586.1 cM over nine linkage groups. There was an average of 18.2 markers per linkage group and a …

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A new self-compatibility haplotype in the sweet cherry 'Kronio', S5' attributable to a pollen-part mutation in the SFB gene

‘Kronio’ is a Sicilian cultivar of sweet cherry (Prunus avium), nominally with the incompatibility genotype S 5 S 6 , that is reported to be naturally self-compatible. In this work the cause of its self-compatibility was investigated. Test selfing confirmed self-compatibility and provided embryos for analysis; PCR with consensus primers designed to amplify S-RNase and SFB alleles showed that the embryos were of two types, S 5 S 5 and S 5 S 6 , indicating that S 6 pollen failed, but S 5 succeeded, perhaps because of a mutation in the pollen or stylar component. Stylar RNase analysis indicated active S-RNases for both S 5 and S 6 . The S-RNase alleles were cloned and sequenced; and sequences …

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