Genetic variation of the endangered Gentiana lutea L. var. aurantiaca (Gentianaceae) in populations from the Northwest Iberian Peninsula.

Gentiana lutea L. (G. lutea L.) is an endangered plant, patchily distributed along the mountains of Central and Southern Europe. In this study, inter-simple sequence repeat (ISSR) markers were used to investigate the genetic variation in this species within and among populations of G. lutea L. var. aurantiaca of the Cantabrian Mountains (Northwest Iberian Peninsula). Samples of G. lutea L. collected at different locations of the Pyrenees and samples of G. lutea L. subsp. vardjanii of the Dolomites Alps were also analyzed for comparison. Using nine ISSR primers, 106 bands were generated, and 89.6% of those were polymorphic. The populations from the Northwest Iberian Peninsula were clustered in three different groups, with a significant correlation between genetic and geographic distances. Gentiana lutea L. var. aurantiaca showed 19.8% private loci and demonstrated a remarkable level of genetic variation, both among populations and within populations; those populations with the highest level of isolation show the lowest genetic variation within populations. The low number of individuals, as well as the observed genetic structure of the analyzed populations makes it necessary to protect them to ensure their survival before they are too small to persist naturally.

Accumulation of antioxidants in apricot fruit through ripening: characterization of a genotype with enhanced functional properties.

Two apricot genotypes, 'Gonci magyarkajszi' and 'Preventa' were assayed at three ripening stages for flesh color indices (L*, a*, b*, C* and Hº), contents of total phenolics and vitamin C, and both water- and lipid-soluble antioxidant capacities (ferric reducing antioxidant power; 2,2'-diphenyl-1-picrylhydrazyl scavenging activity; total radical scavenging activity; and Photochem lipid-soluble antioxidant capacity) to compare their dynamics in the accumulation of antioxidant compounds and capacities through ripening. The increase in a*, b* and C* and decrease in Hº during ripening represented a color shift from green to yellow and orange due to carotenoid accumulation. Parallel to carotenoid accumulation, contents of total phenolics and vitamin C and antioxidant capacity increased significantly (p < 0.05) from unripe to fully ripe fruits. More phenolics and vitamin C accumulated in fully ripe fruits of 'Preventa' than 'Gönci magyarkajszi'. The accumulation patterns of these compounds were different: while the vitamin C contents in unripe fruit of 'Preventa' and 'Gönci magyarkajszi' were identical (approx. 6 mg/100 g fresh weight), unripe 'Preventa' contained even more phenolics (approx. 12 mmolGA/l) than fully ripe 'Gönci magyarkajszi' (8 mmolGA/l). Our results confirm that fully ripe 'Preventa' fruits are characterized by outstanding functional properties due to the increased accumulation of vitamin C and phenolics throughout the ripening process.

Accumulation of Antioxidants in Apricot Fruit through Ripening: Characterization of a Genotype with Enhanced Functional Properties

Two apricot genotypes, 'Gonci magyarkajszi' and 'Preventa' were assayed at three ripening stages for flesh color indices (L*, a*, b*, C* and Hº), contents of total phenolics and vitamin C, and both water- and lipid-soluble antioxidant capacities (ferric reducing antioxidant power; 2,2'-diphenyl-1-picrylhydrazyl scavenging activity; total radical scavenging activity; and Photochem lipid-soluble antioxidant capacity) to compare their dynamics in the accumulation of antioxidant compounds and capacities through ripening. The increase in a*, b* and C* and decrease in Hº during ripening represented a color shift from green to yellow and orange due to carotenoid accumulation. Parallel to carotenoid accumulation, contents of total phenolics and vitamin C and antioxidant capacity increased significantly (p < 0.05) from unripe to fully ripe fruits. More phenolics and vitamin C accumulated in fully ripe fruits of 'Preventa' than 'Gonci magyarkajszi'. The accumulation patterns of these compounds were different: while the vitamin C contents in unripe fruit of 'Preventa' and 'Gonci magyarkajszi' were identical (approx. 6 mg/100 g fresh weight), unripe 'Preventa' contained even more phenolics (approx. 12 mmolGA/l) than fully ripe 'Gonci magyarkajszi' (8 mmolGA/l). Our results confirm that fully ripe 'Preventa' fruits are characterized by outstanding functional properties due to the increased accumulation of vitamin C and phenolics throughout the ripening process.

Antioxidant and antiradical capacities in apricot (Prunus armeniaca L.) fruits: variations from genotypes, years, and analytical methods.

The fruit quality parameters and antioxidant capacity (ferric reducing antioxidant power, FRAP) and total phenolic content (TPC) were determined in 27 apricot cultivars and hybrids of diverse origins. Twenty one- to 35-fold variations were measured among FRAP and TPC values. Besides genotype, harvest year also contributed significantly (P≤0.05) to the variations of TPC presumably due to the climatic differences between years. A subset of genotypes (15) was also analyzed for their antiradical activities (2,2'-diphenyl-1-picrylhydrazyl, DPPH; total radical-scavenging activity, TRSA; water-soluble antioxidant capacity, ACW; and lipid-soluble antioxidant capacity, ACL), and vitamin C contents as well as color indices (CIE H°, L*, and chroma). The hybrid "Preventa" had outstanding FRAP (>10.4 mmol ascorbic acid/L), DPPH (74.45%), TRSA (0.002%), ACW (33587.5 nmol AA/L) and ACL (78.65 nmol Trolox/L), TPC (>2890.0 mg gallic acid/L), and vitamin C (16.17 mg/100 g FW) levels and an average carotenoid content estimated from the hue angle (66.99°). Most antioxidant and antiradical activities correlated significantly except for TRSA; the closest correlation was observed between FRAP and ACW (r=0.952). Only TRSA showed significant correlations with color indices, H° and chroma, suggesting TRSA measures at least a fraction of the antioxidant capacity attributable to apricot carotenoids.

Origin and dissemination of the pollen-part mutated SC haplotype which confers self-compatibility in apricot (Prunus armeniaca).

In China, its centre of origin, apricot (Prunus armeniaca) is self-incompatible. However, most European cultivars are self-compatible. In most cases, self-compatibility is a result of a loss-of-function mutation within the pollen gene (SFB) in the SC haplotype. Controlled pollinations performed in this work revealed that the cross 'Ceglédi óriás' (S8S9)x'Ceglédi arany' (SCS9) set well, as expected, but the reciprocal cross did not. Apricot S8, S9 and SC haplotypes were analysed using a multilevel approach including fruit set evaluation, pollen tube growth analysis, RNase activity assays, polymerase chain reaction (PCR) analysis and DNA sequencing of the S-RNase and SFB alleles. SFB8 was revealed to be the first known progenitor allele of a naturally occurring self-compatibility allele in Prunus, and consequently SC=The first intron of SC-RNase is a phase one intron, indicating its more recent evolutionary origin compared with the second intron. Sequence analysis of different cultivars revealed that more single nucleotide polymorphisms accumulated in SC-RNase than in SFBC. New methods were designed to allow high-throughput analysis of S genotypes of apricot cultivars and selections. S-RNase sequence data from various sources helped to elucidate the putative origin and dissemination of self-compatibility in apricot conferred by the SC haplotype.

Genetic diversity of different apricot geographical groups determined by SSR markers.

Forty apricot cultivars with different geographic origins belonging to the germplasm collections of St. Istvan University (Budapest, Hungary) and the Instituto Valenciano de Investigaciones Agrarias (IVIA) (Valencia, Spain) were studied by means of SSR markers. The aim of the study was to determine the genetic relationships among genotypes from different eco-geographical groups. Sixteen primer pairs flanking microsatellite sequences in the peach genome were assayed. Eleven of them were polymorphic in the set of cultivars studied and allowed every genotype to be unambiguously distinguished. Genetic diversity in the population studied was analyzed using several variability parameters. A total of 34 alleles were detected with a mean value of 3.1 alleles/locus. The expected heterozygosity mean was 0.46 and the observed heterozygosity was 32% on an average leading to a high value of the Wright's fixation index (0.32). Additionally, UPGMA cluster analysis based on Nei's genetic distance grouped genotypes according to their geographic origins and pedigrees. SSR markers have proved to be an efficient tool for fingerprinting cultivars and conducting genetic-diversity studies in apricot.