Japanese plums (P salicina) and cherry plums (P cerasifera) are diploid species, while European plum (P. domestica) cultivars are hexaploids. Most diploid species are self-incompatible while fertility relations of the hexaploid European plums are variable between self-incompatibility and self-compatibility. A...bout twenty S-alleles and six inter-incompatibility groups and one S-haplotype responsible for the self-fruitful phenotype were described in Japanese plum cultivars, but studies on cherry plums and even on the European plum cultivars are severely restricted. This review is focused on the available information obtained from myrobalans and European plums; and discusses recent hypotheses regarding the putative origin of the hexaploid plums, and thereby indicates the possibility of allele flow between different plum species.
European plum is an important fruit crop with complex, hexaploid genome of unknown origin. The characterization of the selfincompatibility (S) locus of 16 European plum cultivars was carried out using the PaConsI-F primer in combination with the EM-PC1consRD primer for the first intron and the EM-PC2consFD and EM-PC3consRD primers for the secon...d intron amplification. Altogether, 18 different alleles were scored indicating high genetic diversity. These alleles were labelled using alphabetical codes from SA to SS. We identified 5 different alleles in 9 cultivars, 4 alleles in 5 cultivars, while 3 alleles were shown in two of the assayed cultivars. A total of 16 different S-genotypes were assigned, and discrimination of all plum cultivars was successful based on their unique S-genotypes. However, further research is required to reliably identify the S-alleles based on their DNA sequence and clarify complete S-genotypes.
The rain induced fruit cracking is a big, serious problem especially for sweet cherry growers but in some year growers of other stone fruit species had also problem with fruit cracking caused by too much and heavy rainfalls in the ripening and harvesting season. Cracked stone fruits can be easily infected by different diseases like Monillinia s...p. Cracked and infected fruits can not be transported for long distance and using for preservation, they lost their market value by the destroyed fruit quality. It was decided to make a research work to determine the rain fruit cracking susceptibility of few stone fruit species (sour cherries, sweet cherries and European plums). Fruit cracking tests were occurred under laboratory conditions on the most common cultivars grown in Hungary. Furthermore we tried to find correlation between the fruit cracking and some fruit quality parameters (fruit size; total sugar content, fruit flesh firmness).
Our conclusions are the followings:
Sour cherries: There were found differences in the cracking ratio and the cracking dynamics of the tested sour cherry varieties when they were immersed in distillated water for 24 hours. Based on cracking test results under laboratory condition (immersing in distillated water) we made the grouping by cracking susceptibility of sour cherry varieties. Tested cultivars were divided three groups: very susceptible; susceptible; moderately susceptible (tolerant). Groups with varieties are: Very susceptible - ’Maliga emléke’, ’Piramis’, ’Érdi jubileum’,’Érdi nagygyümölcsû’ and ’Meteor korai; Susceptible (Sensitive) – ’Érdi bôtermô’, ’Pándy’ and Cigány 59. Moderately susceptible (tolerant) – ‘Éva’ and ‘Petri’as new rereleases. The most of tested sour cherry varieties are in agreement with the literature (Apostol, 2003) and four of them (’Maliga emléke’, ’Pándy 279’, ‘Éva’ and ‘Petri’) had higher average fruit weight than was mentioned in the literature (Apostol, 2003). Our fruit cracking results are in agreement with Zelinski’s (1964) and Christensen’s (1975) conclusions that there is no close relationship between fruit size and rain induced fruit cracking tendency. We found significant differences between the sugar content of tested cultivars. In contrast of Verner & Blodget (1931) our results confirm Tucker’s opinion that the sugar content is not correlation with the cracking tendency of cherry fruits (Tucker, 1934). Fruits firmness (elasticity) was measured by destructive method when juice was coming out from fruits. There were found big differences of fruit firmness and skin strength of observed cultivars. Our results are only partly agreement with Christensen’s (1996) opinion that cherry cultivars with firmer fruits are more prone to fruit cracking than softer ones. By this was seemingly we did not found close relationship between the fruit firmness and the cracking tendency of sour cherry fruits. We found that during fruits immersing in distillated water the fruit weight was increasing due to the absorbed water. Our opinion is that there is no close relationship between the scale of fruit cracking and the quantity of absorbed water. By results presented above we our opinion is that no very close relationship between the fruit cracking of sour cherries and the observed parameters (fruit size, fruit firmness, sugar content, amount of absorbed water) maybe other varietal effects and physiological characters (fruit skin structural parameters) play more important role in the fruit cracking mechanism of cherries.
Sweet cherries: Similarly to sour cherries in the case of sweet cherries we also did not find close relationship between observed fruit parameters and cracking index. It was differences in the cracking ratio and the cracking dynamics of the tested sweet cherry cultivars when they were immersed in distillated water for 24 hours. It was found that the cracking ratio of very cracking susceptible sour cherry varieties had the same or higher cracking index than observed sweet cherries. It is in contrast with the general opinion (Chistensen, 1996) that sour cherries are less prone to rain induced fruit cracking than sweet cherries. We found differences between the cracking ration and cracking dynamic of the same cultivar in different years (2006 and 2013). It is in agreement Christensen’s (1996) opinion that the year effect cause big differences in the fruit cracking of cherries.
European plums: We found differences in the cracking ratio and the cracking dynamics of the tested plum varieties when they were immersed in distillated water for 24 hours. A shorter term (6 hours) immersing in water caused three groups by their cracking susceptibility: „Very susceptible”: ’Révfülöpi’ and ’Szarvasi’; „Susceptible”: ’Besztercei’; „Less sensitive”: ’Bluefre’ and ’Cacanska rodna’. A longer term (24 hours) immersing in water resulted only two groups with significant differences: „Susceptible group”: ’Révfülöpi’, ’Szarvasi’ and ’Besztercei’; „Less sensitive”: ’Bluefre’ and ’Cacanska rodna’ Similarly the cherries we did not find correlation between the fruit size and cracking susceptibility of European plum cultivars. It was based on: the big fruit sized ‘Bluefre’ and middle sized ‘Cacanska rodna’ cracked in the lowest scale, during the small sized ’Révfülöpi’, ’Szarvasi’ and ’Besztercei’ cultivars cracked in higher scale We found positive correlations between the cracking susceptibility and total sugar content of tested plum cultivars. Cultivars with significantly lower sugar content (‘Bluefre’ and ‘C. rodna’) showed lower fruit cracking susceptibility than cultivars (’Révfülöpi’, ’Szarvasi’ and ’Besztercei’) with higher sugar content). We found close relationship between the relative (%) absorbed water amount and the fruit cracking susceptibility. Cultivars with higher absorbed water amount (’Szarvasi’-’Révfülöpi’-’Besztercei’) had higher cracking susceptibility.
The aim of our drying trials was to determine the drying suitability of stone fruits. The tested species were sour and sweet cherries and European plums too. Data and results of sweet cherry drying were published earlier (Klincsek et. al. 2005, 2006).This article containing results of twenty sour cherry and six European plum varieties.... Laboratory tests, drying processes and sensory testing were done at Fruit Quality Testing Laboratory of Fruit Science Department of Corvinus University of Budapest. The sensory tests and their valuations were done by the instruction of National Institute for Agricultural Quality Control. In the case of sour cherries by one year data in 2004 we divided fruits to five categories by suitability for making dried fruit. Varieties in the first two groups are the followings: most suggested for making dried, fruits: 'Meteor korai' and `Érdi jubileum'; suggested: 'IV-3-48' and `Piramis'.In the case of European plums three varieties can be suggested for making dried fruits from the six tested cultivars: ‘Révfülöpi’, Althann gage' and `Besztercei'.
Central Europe can be taken as a geographical and historical connection zone between the western growing countries and Asian gene centres of Prunus tree fruits. The determination of the S-genotype of stone fruit (mainly almond, plum, cherries and apricot) cultivars and landraces has both practical and theoretical significance. Our group has all...ocated complete S-genotypes for more than 200 cultivars and selections of almond, Japanese plum, sweet cherry and apricot. Among Eastern European almond cultivars, two novel cross-incompatibility groups (CIGs) were identified. S-alleles of a related species were also shown in P. dulcis accessions; a fact seems to be indicative of introgressive hybridization. Our results with Japanese plum clarified and harmonized two different allele nomenclatures and formed a basis for intensive international studies. In apricot, a total of 13 new S-alleles were identified from Eastern European and Asian accessions. Many Turkish and North African cultivars were classified into new CIGs, III–XVII. Results suggest that the mutation rendering apricot self-compatible might have occurred somewhere in south-east of Turkey and we were successful to confirm the presumed Irano-Caucasian origin of North African apricots based on the geographical distribution of S-alleles. In sweet cherry, new alleles have been identified and characterized from Turkish cultivars and selections. In addition, wild sweet cherry and sour cherry S-alleles were also shown indicating a a broader gene pool in Turkey as compared with international cultivars. We also used S-genotype information of Ukrainian sweet cherry cultivars to design crosses in a functional breeding program. Our results exhibit an increased number of S-alleles in tree fruit accessions native to the regions from Eastern Europe to Central Asia, which can be used to develop S-genotyping methods, to assist cultivation and draw inferences for crop evolution.
The author dealt with plum species representing different eco-geographic areas by their genetic adaptation and their hybrids, as European (P. domestica, P. italica, P. cerasifera), Asian (P. salicina, P. simonii, P. ussuriensis), American (P. ame...ricana, P. besseyi, P. munsoniana, P. tomentosa). The rootstocks of the trees examined were seedlings of C. 679 myrobalan with the exception of Laroda and Santa Rosa II, which were grown on three different stocks: seedlings of C. 174 myrobalan, C. 449 bitter almond and C. 471 sweet almond. The size of peduncle, length of pistil, stamen number per flower, relative stamen number (SN/PL) have been suitable for description and distinction of varieties. Similarly shape of leaves, length of petiole, length and width of blade helped the identification.
The ratio of the dimensions of leaves, length of petiole and of leaf blade, also contributed to the distinction of European, Asian and American plum species, notwithstanding their relations with ecological conditions as well as historical, technical properties, pomological features, etc. Computed indicators (relative stamen number and shape-index of leaves) also have been useful data.
Significant correlations have been found between colour of nectaries and mean values of variety-groups. The potential values of non-European varieties for purposes of commercial production could be forecasted from the point of view of quality, ecological, pomological as well as market value. It is important, however, to know the effect of the rootstock and growing site as well as their interaction, on the one hand, whereas the resistance or tolerance of the varieties as limiting factors, at least to the sharka (Plum pox) virus, Xanthomonas pruni, on the other hand (cf. Surányi & Erdős, 2004a and 2004b).
Observations and investigations performed in laboratory at several growing sites over a period of many years are summarised on established plum varieties as well as on new promising ones concerning their marketing value. The ripening period of plum varieties was enlarged substantially with the appearance of new varieties of extra late maturity ...(‘Elena’, ‘Tophit’, ‘Presenta’). The new varieties did not alter the traditional colour, more or less long, violet or blue character of the plum. The most known type, ‘Besztercei szilva’ with its accustomed taste was followed by the new varieties ‘Katinka’, ‘Tegera‘, ‘Hanita’ and ‘Presenta’. The fruit size are largely of the medium category, except the early ripening small ‘Katinka’, whereas the larger and attractive (~60 g) fruits are represented by the late ripening ‘Tophit’ and ‘Empress’. The stone/fruit ratio was lowest in 3% (‘Tophit’) and 6% (‘Besztercei Bt. 2’, ‘Hanita’, ‘Jojo’, ‘ ‘Čačanska rana’) at the other end of the scale. The width and thickness of the fruit fl esh between 28 mm (‘Besztercei szilva’) and 43-44 mm (‘Empress’, ‘Tophit’). The fi rmness of the fruit fl esh excelled in the late maturity varieties ‘Presenta’ and ‘Tophit’ (~4 kg/cm2). Water soluble solids were 12-13 Brix% (‘Čačanska rana’, ‘Katinka’, ‘Silvia’) and 20 Brix% (‘Presenta’, ‘Tophit’), whereas titrated acids are found between 0.2% (‘Besztercei Bt. 2’) and 1.2% (‘Tegera’).
The flowering phenology, blooming time and inter-fertility relations of 63 European plum varieties has been studied at growing sites with different ecological conditions during a 10 year long period. The purpose was to develop a system of variety combinations which approaches an optimum in fertility as long as inter-fertility relations will cea...se to be a limiting factor of yield. According to their blooming time, varieties are assigned to 5 groups: very early, early, medium, late and very late. As for their fertility relations, four groups are formed: self-sterile (0%), partially self-fertile (0.1 to 10 %), self-fertile (10.1 to 20 %) and highly self-fertile (more than 20 % fruit set with self pollination). The four categories of fruit set at free pollination are also relevant to the grower: low (less than 10 %), medium (10 to 20 %), high (20 to 40 %) and very high (more than 40 % fruit set).
By artificial cross pollination, one combination Cacanska najbolja x Stanley proved to be mutually inter-incompatible. Blocks planted to a single self-sterile variety flanking a pollinizer variety proved the spacial distribution of the pollen. The reduction in fruit set was already apparent in the second row away from the pollinizer trees. In a large plantation, without bee hives, relatively low yield was stated on self-sterile trees even close to the pollinizer.
In the case of self-sterile and partially self-fertile varieties, a combination of three varieties is recommended. The blooming period of the pollinizer variety should overlap the period of the self-sterile variety at least by 70 %, and the distance should not exceed 15 to 20 meters. Association of self-fertile varieties may also enhance the productivity of the trees. In that case an overlap of 50 % in blooming time and a maximum distance between the varieties of 30 to 40 meters will be sufficient.
The worldwide tendency to increase the intensity of fruit growing technologies prefers generally for every fruit species rootstocks with week or mediocre vigour. From this viewpoint, the use of rootstocks for plums are rather unilateral in Hungary, where 95–99% of plum plantations are grafted on mirobalan seedlings (P. cerasifera v. mirobalan...a). The score of plum rootstocks abroad is much more diversified. The present study summarises the respective knowledge referring to the literature available.
Information concerning the blooming time of stone fruit varieties is, first of all, an important condition of finding suitable pollinisers securing adequate fruit set. For that purpose, varieties are assigned to blooming-time-groups. Depending on the number (3 or 5) of the groups, i.e. the length of intervals separating the groups established, ...pollenisers are to be chosen for self-incompatible and partially self-fertile varieties belonging to the same blooming-time-group. The mutually most overlapping blooming periods of the respective varieties should be found by raising data of their blooming phenology, i.e. dynamics, which is compared by drawing their phenograms and calculating blooming (V) indices. Variety combinations have to be checked, however, concerning mutual fertility relations of the respective pairs of varieties. That is most important in the case of Japanese plums because of the abundant incompatible combinations. Synchronous blooming has been determined by assigning the varieties to blooming-time-groups, or comparing overlaps of blooming phenograms, or by blooming (V) indices. Synchronous blooming phenology has been studied in European plum varieties (111 varietiy combinations) Japanese plums (156 variety combinations) and apricots (153 variety combinations) under Hungarian conditions, over several seasons. In determining overlaps, the less favourable season has been considered as decisive. Polliniser combinations have been chosen with at least 70% synchronous blooming. Blooming time of varieties is an important part of the variety descriptions. Blooming dates may serve also for the estimations of frost risk or security of yield.
Size and surface morphology of pollen has been studied in 87 twit varieties of 10 fruit species during the period of 1990-1995. No preceding work of that type came to our knowledge, yet.
The samples comprised a wide variety of cultivars included male sterile, self-incompatible, partially self-fertile stone fruits, diploid and hexaploid ...plums, diploid and triploid apples.
The large number of species and varieties facilitated the comparison of items within and between the respective species.
It was stated that the size, shape and surface morphology of pollen is genetically determined and those data, combined with other variety characters, are suitable for the classification and distinction of varieties.
In assessment of pollen size and shape, their moisture content is crucial. The major diameter of the swollen pollen as well as the length and width of the dry grains are characteristic to species and/or to variety.
The width and shape changes largely with moisture content. Large grains are proper to quince, apricot, peach and almond, medium sizes are found in apple, sweet cherry, sour cherry, European plum, whereas small size is typical to Japanese plums.
The low number of varieties studied does not allow conclusions concerning differences within pears, quinces and almonds as species. In the rest of species, valid differences have been registered as between varieties.
Within species, as apple and plum, the effect of ploidy (i.e. number of chromosomes) was expressed in the size of their pollen. In stone fruit species, the correlation between size. of anthers and size of pollen grains was positive.
Genetic relations between the self-fertile sour cherry varieties of the Pándy type (Debreceni bőtermő, Kántorjánosi, Újfehértói fürtös) as well as the self-incompatible apricots of "giant" fruit size are supposed to be analysed by pollen studies but there did not turn out any decisive conclusion, yet. Other characters also should be considered.
The assembly of pollen characters is decisive in the determination of the variety. The ratio of empty pollen grains, the grain size and the density as well as the size of the pits on the surface are best suited to distinguish pollen lots.
This review endeavours to collect all recent and substantial contributions to the quickly deepening fields of tree fruit self-incompatibility studies and hence updating previously published reviews. Studies carried out to discover the molecular basis of gametophytic self-incompatibility are summarized and a newly described model for the solanac...eous plants is also outlined. We describe recent findings in all economically important fruit tree crops involving apple, European pear, sweet and sour cherries, almond, Japanese plum, sloe, Japanese apricot, European apricot and peach. Additional DNA sequences are now available for both the pistil and pollen component genes in several species and their molecular, evolutionary or economic implications are discussed in the light of the fruit setting behaviour.
Hungary is traditionally a food producer country. 63% of its total land area can be cultivated. Horticulture is one of the fundamental agricultural branches. The country has a moderate continental climate, with a mean temperature of 10 °C. The average hours of sunshine ranges 1,700 to 2,100 hours. Under the geographical condition in the Carpat...hian Basin the chemical composition of the fruits has a good harmony. The total fruit acreage is 97,000 ha with a crop of 800,000 to 900,000 tons yearly. In 1982 1,934,000 tons of fruit crop were produced since then it has decreased. The most important fruits are apple, European plum, sour cherry and raspberry. The percentage of apple reaches almost up to 60%. In the new plantings sour cherry, apple and black elderberry is popular. The most important fruit-producing region is situated at the North-eastern part of the country. More than 40% of Hungary's fruit production is concentrated there. In ranking the 2nd place is taken by fruit growing area in the middle of Hungary, where the production of stone fruits and small fruits has a considerable proportion.
In the 70s and 80s of last century there was a developed research structure and wide range of research activity in Hungary. From that time the research capacity has considerably decreased first of all in the field of technological development. The main research area is fruit breeding and variety evaluation.
Fruit scientists and fruit grower specialists are held together by the Hungarian. Society for Horticultural Sciences which has a membership in ISHS. Fruit researches and scientists having academic degree are belonged to the Horticultural Board of Hungarian Academy of Sciences.