Additional index words. Malus 3domestica, Venturia inaequalis, Erwinia amylovora, Podosphaera leucotricha, fruit quality, S-genotype 'Artemisz', 'Cordelia', 'Hesztia', and 'Rosmerta' are the first four Malus 3domestica (Borkh.) cultivars developed in the apple breeding program of the Corvinus University of Budapest and their registration was accepted by the state in 2011 and 2012. They are mid-early to late-ripening cultivars with the following ripening dates: from the fourth week of August to the first week of September ('Hesztia'), the second week of September ('Artemisz'), the third week of September ('Rosmerta'), and the first 10 d of October ('Cordelia') in the growing region between the rivers Danube and Tisza, the central part of Hungary. All four cultivars are resistant to apple scab and also have good resistance to the apple powdery mildew. Their shoots have resistance or moderate resistance to fire blight. The flowers of 'Hesztia' exhibited moderate resistance to fire blight. The medium to large fruits (averaging 147 g in weight) of 'Artemisz' can be used for both fresh consumption and making into apple chips. 'Cordelia' has very large fruit, averaging 269 g, with great flesh firmness (8.3 kg • cm-2 on average) and high pectin concentration (0.87%). This cultivar has good storage ability. It is recommended to be used for fresh consumption; however, it can be used for processing purposes based on its physical and chemical properties, e.g., for processing into concentrates, applesauce, and apple chips.

Bacterial blight is one of the most serious diseases affecting Persian walnut (Juglans regia L.). Susceptibility to this disease was evaluated by artificial inoculation in an in vitro experiment for cultivars developed in Hungary and for selections from Transylvania. Thirty pieces of immature fruit of 11 walnut cultivars and 10 selections were inoculated by punction using a suspension containing a mixture of Xaj-isolates of controlled virulence. As control, a moderate resistant (mR) ‘Pedro’ and a highly susceptible (hS) ‘Milotai intenzív’ cultivars were used. After ten days the diameter of the necrotic area around the inoculation points was measured and the disease rate (DR) was noted. For the calculation of indexes it was taken the structure of the lesions (diffuse or defined margin) into consideration. None of the 21 cultivars/selections analysed were found to be hardly resistant, although all of them showed a higher degree of resistance than the susceptible control (‘Milotai intenzív’). The majority of the analysed cultivars fit into the moderate susceptible (mS) and moderate resistant (mR) group. ‘Milotai kései’ and SZEN-10, had a notable reaction as considered to be moderate resistant (mR), showed a similar degree of resistance compared to the control cultivar ‘Pedro’. It was concluded that these cultivars, based on their resistance to Xanthomonas arboricola pv. juglandis, could be proposed as resistance gene sources, as well as for production purposes in the environmental conditions of the Carpathian Basin.

The maturity date (MD) of Prunus stone fruit has been long known to be a quantitatively inherited trait. A NAC-type gene indicated as PpNAC1 (ppa008301m) has been found recently to be a strong candidate of a major gene influencing MD in peach. A 9-bp insertion in this gene resulted in earlier MD in two segregating peach populations. This study was carried out to test whether this mutation in the PpNAC1 gene can be used as a reliable functional marker for MD in a wide range of peach cultivars of various origins and phenotypic characters. A total of 125 peach cultivars were examined using a 3 × 3 custom chi-square contingency table according to their NAC genotype and MD (early, midseason, and late). Cramér's V equaled 0.478 and the Goodman-Kruskal index (l) was 0.37, indicating an extremely strong correlation between MD and NAC genotype. In addition, we determined 15 sequences from 10 cultivars of five Prunus species including peach, almond, apricot, sour cherry, and European plum with E-values ranging from 9e-88 to 2e-74, supporting their homology to PpNAC1. A total of 69 single nucleotide polymorphisms and two insertion/deletions were detected in the coding region of the partial NAC domain sequences with three mutations putatively inducing nonconservative amino acid replacements and a nonsense mutation in specific alleles of early ripening apricot and sour cherry cultivars. The results are discussed with focus on the putative molecular mechanisms of mutations in the NAC genes, crop evolutionary perspectives, and the opportunities for designing cost-efficient markers to predict MD in Prunus breeding programs.

Bacterial blight is one of the most serious diseases affecting Persian walnut (Juglans regia L.). Susceptibility to this disease was evaluated by artificial inoculation in an in vitro experiment for cultivars developed in Hungary and for selections from Transylvania. Thirty pieces of immature fruit of 11 walnut cultivars and 10 selections were inoculated by punction using a suspension containing a mixture of Xaj-isolates of controlled virulence. As control, a moderate resistant (mR) 'Pedro' and a highly susceptible (hS) 'Milotai intenzív' cultivars were used. After ten days the diameter of the necrotic area around the inoculation points was measured and the disease rate (DR) was noted. For the calculation of indexes it was taken the structure of the lesions (diffuse or defined margin) into consideration. None of the 21 cultivars/selections analysed were found to be hardly resistant, although all of them showed a higher degree of resistance than the susceptible control ('Milotai intenzív'). The majority of the analysed cultivars fit into the moderate susceptible (mS) and moderate resistant (mR) group. 'Milotai kései' and SZEN-10, had a notable reaction as considered to be moderate resistant (mR), showed a similar degree of resistance compared to the control cultivar 'Pedro'. It was concluded that these cultivars, based on their resistance to Xanthomonas arboricola pv. juglandis, could be proposed as resistance gene sources, as well as for production purposes in the environmental conditions of the Carpathian Basin.

The SSR (Simple Sequence Repeat) markers allow the discrimination of the cultivars and determination its specific DNA fingerprints. The aim of this research was to evaluate fifteen apricot (Prunus armeniaca L.) and fifty-one peach (Prunus persica L.) genotypes cultivated in Hungary to obtain their DNA fingerprints in 6 SSR (Simple Sequence Repeats) loci by allele numbers and sizes. DNAs were extracted from leaves. PCR was carried out with CY-5 fluorescent labeled Prunus microsatellite markers and the products were separated on polyacrylamide gel with ALF (Automated Laser Flourometer)-Express II. According to our results, in the case of peach genotypes, all 6 SSRs were able to amplify alleles. UDP 96 005 was the most informative marker and UCDCH 17 was the least due to its monomorphic pattern. Regarding the apricot samples BPPCT 041 did not amplify any allele. In the case of P. armeniaca UDP 96 005 had the highest heterozygosity index as well and the highest number of alleles. The least informative marker was the UCDCH 17. Since the 6 SSR were not enough to discriminate the apricot and peach genotypes, it is suggested to use more SSR primers.