Prunus Fruticosa Research Articles

Intra-allelic variation in introns of the S 13 -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 for the first intron microsatellite and from 308 to 322 bp for the second. There were 34 combinations and, surprisingly, the lengths of the two microsatellites were correlated. Generally, the sweet, wild and sour cherries had different combinations, and the four examples of S13°- RNase were associated with three different combinations. Certain sequences associated with the microsatellites match footprints of transposons. The distribution of combinations indicated little overlap between the three populations analysed and provided useful insights into relationships of some of the accessions allowing some parentages to be checked. In the diploid sweet and wild cherries, S13 variants presumably resulted from slippage during replication, but in the tetraploid sour cherries, which can have more than one copy of S13 or S13°, intra-allelic crossing over may have generated new variants. The possible involvement of transposable elements in the origin of these microsatellites is considered.

Studies on genetic variation in cherry germplasm using RAPD analysis

Abstract Random amplified polymorphic DNA (RAPD) variation among eight cherry species and two interspecific progenies were analyzed. Out of 130, 48 arbitrary oligonucleotide primers were screened for PCR amplification to generate polymorphisms. The phylogenetic analysis was carried out using two distance-matrix methods and a dendrogram was generated to show the relationships among species and cultivars. The results showed that there were 840 amplified loci in total; 23 sweet cherry and four sour cherry cultivars were clustered together with 569 and 247 polymorphic loci respectively which accounted for 67.74% and 29.40% of the total variation. Prunus tomentosa T., Prunus fruticosa var. aucta P. and Prunus humilis B. formed a monophyletic group. A relationship between Prunus pseudocerasus L. and Colt, which formed another closely related group, was observed while Prunus avium L., Prunus cerasus L. and other cherry species were more divergent. The range of genetic distance was from 0.0623 to 0.2719 among the Prunus species, which were genetically distinct. The topology of the tree was generally in agreement with taxonomic classification. The results indicated that with the exception of the sweet cherry variety “Hongdeng”, there were one or more cultivar-specific RAPD markers in cherry species and cultivars. Using these specific markers, cherry species and varieties could be identified and there is therefore the potential to select for good characteristics of hybrids at an early stage.

Tissue culture propagation of Mongolian cherry (Prunus fruticosa) and Nanking cherry (Prunus tomentosa)

In vitro culture establishment, shoot proliferation and ex vitro rooting responses of Mongolian cherry (Prunus fruticosa L.), and Nanking cherry (Prunus tomentosa L.), were examined using various combinations of growth regulators. Dormant buds, taken during winter months, were used as explants. In both species, Murashige and Skoog Minimal Organic (MSMO) solid medium supplemented with 0.49 μM indole-3-butyric acid (IBA) and either 4.44 or 8.88 μM 6-benzylaminopurine (BA), was the best for culture initiation, and with 8.88–15.16 μM BA for shoot proliferation. Good rooting responses were also obtained with shoots produced on media containing 0.91 μM thidiazuron (TDZ). Auxin treatments were required for ex vitro rooting of approximately 20 mm long shoots in peat/perlite (1:1 v/v) mixture, at 25 °C, under mist. The best rooting (79%) was obtained with IBA/NAA (naphthaleneacetic acid) (9.80/2.69 μM) combination. A commercial rooting powder, Rootone F, containing IBA/NAA (0.057/0.067%), was also effective (73%). The ex vitro rooted plantlets did not require any additional acclimatization prior to transplanting to the regular greenhouse conditions.

Rootstocks for Cherries from the Department of Fruit Science Budapest

Cherry rootstock breeding started at the Department of Fruit Science, SSU Budapest by the late 50-s and the activity can be divided into three main groups. In the first stage the activity was focused on collection of native mahaleb cherry (Prunus mahaleb L.) varieties lead by L. Sebők. After evaluation in the nursery and orchard tests there are four promising rootstock cultivars selected from this material: 'Korponay' used as self fertile seed tree, its seedlings are recommended for sour cherries. The mahaleb varieties 'Bogdány' (vigorous), 'Egervár' and 'Magyar' (medium vigour) are propagated by cuttings. The next project has started in 1979 with the aim to select self fertile mahaleb seed trees producing homogeneous seedling populations with reduced vigour. Inbred populations from isolated flowering self fertile trees were produced and planted out in 1980. The inbreeding of 'Korponay' self fertile P. mahaleb variety resulted in specimens with different fruit colour (yellow, red, black), fruit shape and size. From among them self fertile trees were selected with various growth characteristics. Seedlings of that self fertile mother trees (S2 population) were tested in seedbed, they showed homogeneous phenotype characteristics as liners in the nursery. As rootstock of 'Érdi bőtermő' sour cherry in the orchard most of the S2 lines proved to be less vigorous in comparison to SI popuplations. 'Érdi bőtermő' trees budded on certain S2 lines in the orchard are more productive than those on S1 ('Korponay' seedling). Characteristics of the S2 generation as seed tree were studied as well. We expect to get morphologically homogeneous seedling populations with different growth vigour and good productivity in the later inbred generations. In the last couple of decades the research activity concerning ground-cherry and its hybrids resulted in dwarfing rootstocks. Prunus fruticosa Pall. hybrids from the natural flora of Hungary were collected and artificial hybrids were created between P. fruticosa and mahaleb cherry. Most of them are in the initial tests, only one of them is before registration, named 'Prob', which is a dwarf rootstock for sweet cherry. By the screening of new hybrids medium vigorous or semi dwarfing and precocious rootstocks seem to be promising for the cherry industry.

Rootstocks for Cherries from the Department of Fruit Science Budapest

Cherry rootstock breeding started at the Department of Fruit Science, SSU Budapest by the late 50-s and the activity can be divided into three main groups. In the first stage the activity was focused on collection of native mahaleb cherry (Prunus mahaleb L.) varieties lead by L. Sebők. After evaluation in the nursery and orchard tests there are four promising rootstock cultivars selected from this material: 'Korponay' used as self fertile seed tree, its seedlings are recommended for sour cherries. The mahaleb varieties 'Bogdány' (vigorous), 'Egervár' and 'Magyar' (medium vigour) are propagated by cuttings. The next project has started in 1979 with the aim to select self fertile mahaleb seed trees producing homogeneous seedling populations with reduced vigour. Inbred populations from isolated flowering self fertile trees were produced and planted out in 1980. The inbreeding of 'Korponay' self fertile P. mahaleb variety resulted in specimens with different fruit colour (yellow, red, black), fruit shape and size. From among them self fertile trees were selected with various growth characteristics. Seedlings of that self fertile mother trees (S2 population) were tested in seedbed, they showed homogeneous phenotype characteristics as liners in the nursery. As rootstock of 'Érdi bőtermő' sour cherry in the orchard most of the S2 lines proved to be less vigorous in comparison to SI popuplations. 'Érdi bőtermő' trees budded on certain S2 lines in the orchard are more productive than those on S1 ('Korponay' seedling). Characteristics of the S2 generation as seed tree were studied as well. We expect to get morphologically homogeneous seedling populations with different growth vigour and good productivity in the later inbred generations. In the last couple of decades the research activity concerning ground-cherry and its hybrids resulted in dwarfing rootstocks. Prunus fruticosa Pall. hybrids from the natural flora of Hungary were collected and artificial hybrids were created between P. fruticosa and mahaleb cherry. Most of them are in the initial tests, only one of them is before registration, named 'Prob', which is a dwarf rootstock for sweet cherry. By the screening of new hybrids medium vigorous or semi dwarfing and precocious rootstocks seem to be promising for the cherry industry.

Evaluation of Prunus cerasus Germplasm for Cold Resistance

Knowledge of the level of cold stress resistance and how this resistance is inherited in sour cherry is essential to cultivar development and future germplasm collection. Twig and flower bud samples of two sweet cherries (Prunus avium L.), 12 sour cherries (Prunus cerasus L.), and one ground (Prunus fruticosa Pall.) were collected once a month from Aug. 1990 to Mar. 1991, preconditioned, and subjected to freeze tests and differential thermal analysis. LTEs were detected in all stems of P. cerasus investigated and were strongly correlated to xylem ITs in December to March. LTEs were strongly correlated to phloem-cambium ITs in November. Xylem ITs were the selected method for evaluating sour cherry cold resistance in December to March. Phloem-cambium ITs were the selected method for November. The degree of hardiness of the phloem-cambium in late fall and early spring is a factor determining P. cerasus germplasm geographic distribution and commercial production. The principal component (PC) analyses, of the phloem-cambium and cortical tissues, depict gradations between minimum survival temperatures of the two presumed progenitor species of sour cherry, sweet cherry and ground cherry suggesting that cold is a major selective force, contributing to sour cherry population variation.

Wildgehölze aus der familie Rosaceae als natürliche reservoire von viren des kern- und steinobstes

Summary Wild-growing woody plants of species taxonomically related to cultivated pome and stone fruits were surveyed for the presence of fruit tree viruses in order to determine their importance as natural virus sources. Among wild-growing roses ( Rosa canina L., R. corymbifera Borckh. , R. elliptica Tausch , R. rubiginosa L.) no plants investigated were infected by ilarviruses (Prunus necrotic ringspot virus, prune dwarf virus) or nepoviruses (especially Arabis mosaic virus). Wild-growing apple trees ( Malus sylvestris Mill .) proved to be not infected by closteroviruses (apple chlorotic leaf spot virus) or by the apple Spy decline agent. In wild-growing mountain ash ( Sorbus aucuparia L. em. Hedl .) neither closteroviruses (apple chlorotic leaf spot virus, apple stem grooving virus) nor ilarviruses (apple mosaic virus) were detectable, although 7 % of the trees investigated were infested by the mountain ash ringspot disease. Mazzard cherries ( Prunus avium (L.) L. var. avium ) were free from nepoviruses (Arabis mosaic virus, cherry leaf roll virus, raspberry ringspot virus, strawberry latent ringspot virus, tomato black ring virus), but tomato bushy stunt virus was present in this species with 1.2%. Wild-growing European dwarf cherry ( Prunus fruticosa Pall .) proved to be free from ilarviruses (Prunus necrotic ringspot virus, prune dwarf virus), while escaped sour cherry shrubs ( Prunus cerasus L.) were shown to contain Prunus necrotic ringspot virus at a rate of 40%. Wild-growing or escaped rose, apple, mountain ash, mazzard cherry or European dwarf cherry plants therefore seem not to be dangerous virus sources for cultivated apples and cherries, because of lack of virus infestation. The main danger of virus spread seems to originate from cultivated pome and stone fruit trees itself.

Rooting Capacities of Some Prunus fruticosa × P. avium Hybrids1

Abstract Rooting capacities of semihard wood cuttings from 33 Prunus fruticosa Pall, × P. avium L. and reciprocal crosses were compared under intermittent mist. Seven selections rooted with greater than 80% success, and 16 clones with less than 30% success. Roots developed from petioles of one clone.