S-GENOTYPING OF SOME SWEET CHERRY CULTIVARS RELEASED WITHIN BREEDING PROGRAMMES IN THE BALKAN REGION

Sweet cherry cultivars generally exhibit S-ribonuclease (S-RNase)-based gametophytic selfincompatibility and require pollination with pollen of compatible genotypes, which are indispensable to stable fruit production. Therefore, the determination of S-genotype provides relevant information for sweet cherry breeders and growers. The aim of this study was to identify the S-allelic constitution and incompatibility group in eight sweet cherry cultivars which were named and released at Fruit Research Institute, Čačak, Republic of Serbia (‘Asenova Rana’ and ‘Čarna’), Research Station for Fruit Growing, Iasi, Romania (ʻAlexusʼ, ʻBuciumʼ and ʻMargoniaʼ) and Fruit Growing Institute, Plovdiv, Republic of Bulgaria (ʻKossaraʼ, ʻRosalinaʼ and ʻRositaʼ). The use of the polymerase chain reaction (PCR) method with consensus primers for the second introns of S-RNase, as well as primers specific for S1S7 and S9 alleles enabled determination of the following S-genotypes in the assessed cultivars: S1S2 (ʻAlexusʼ), S1S4 (ʻČarnaʼ), S2S9 (ʻKossaraʼ and ʻRositaʼ), S3S6 (ʻBuciumʼ), S3S9 (ʻAsenova Ranaʼ and ʻRosalinaʼ) and S5S6 (ʻMargoniaʼ). In addition, the S-genotypes of two parental cultivars were reported in this manuscript for the first time ‘Boambe de Cotnari’ (S2S7) and ‘Ranna Tcherna’ (S1S2). Based on the obtained S-allelic constitutions, the assessed cultivars were assigned to the following incompatibility groups: I, II, VI, IX, XI, XIV, XV, XVI and XLIII. The results generated in this study provide a valuable resource for cross design in developing new cultivars and for orchard management in the efficient high-yielding fruit production

Study on the red-leaf hybrid no. 9-205 as a rootstock for peach and nectarine cultivars

The aim of the present study was to establish the growth characteristics of the red-leaf peach hybrid No. 9-205, grown in a nursery, targeting its submission in future for recognition as a new vegetative rootstock for peach and nectarine cultivars. The traditional seedling rootstock 'Elberta' and the vegetative one GF-677 were included in the study. Hybrid No. 9-205 was selected from a population obtained at the Fruit- Growing Institute in Plovdiv by open pollination of Rutgers Red Leaf seedling rootstock for peach, used in the past. It is characterized by high drought resistance and good resistance to diseases and pests. It is easily propagated under in vitro conditions and shows weaker growth compared to GF-677 rootstock. 18 cultivar/rootstock combinations were studied, including two cultivars of each peach type: for fresh consumption, for processing and of the nectarine type. 'Laskava' cultivar for fresh consumption, the processing cultivar 'Spasena' and the cultivar 'Gergana', which is of the nectarine type, are newly established in result of the implementation of the breeding programme at the Fruit-Growing Institute - Plovdiv. They were officially recognized in the period 2009- 2012. The percentage of survival and of grafted bud shooting is high enough and meets the requirements of the production practices in nurseries. The planting material of the vegetative rootstock No. 9-205 is uniform in plant height and stem width and it fully complies with the quality standards

BIOMETRIC PARAMETERS OF FRUITS AND STONES OF NEWLY INTRODUCED FLAT FRUIT PEACH CULTIVARS - PRUNUS PERSICA (L.) BATSCH. F. COMPRESSA

In this paper, a comparative analysis is made of the basic biometric characteristics of fruits and stones from 4 newly introduced cultivars of peaches and one nectarine belonging to Prunus persica (L.) Batsch. (f. compressa) (Flat fruit peach), selected in France (‘Platibelle’ and ‘Mesembrine’), Italy (‘UFO-4’) and Spain (‘ASF-2-80’ and ‘Flat Queen’). In Bulgaria they were imported from Spain in 2009. They are being studied in a collection plantation of the Fruit Growing Institute - Plovdiv. The highest value of fruit weight is measured for the ‘Flat Queen’ fruits – 136.01 g, and the smallest of the fruits are of the nectarine cultivar ‘Mesembrine’ - 65,24 g. It is established that in cultivars with flat-shaped fruits, the largest size is the thickness of the fruit, and the smallest is the height. The stones are small and range from 2.44 g in ‘UFO-4’ fruit to 3.35 g in ‘Flat Queen’. The relative share of the stone compared to the total fruit weight is also low and ranges from 2.26% for ‘ASF-2-80’ to 4.91% for ‘Mesembrine’. The relationship between the three fruit sizes (coefficient or index) indicates how much the shape of the fruit is closer or different than the sphere. In the sample group of cultivars close to or equal to 1 is only the width / thickness index, since the two sizes are of similar size

Overview of plum breeding in Europe

International audienceIn Europe, the plum is one of the main fruit species, occupying an area of about 500,000 ha and ensuring production of about 3,000 million tones. The important countries regarding to plums (Serbia, Romania, Italy, Germany, Bulgaria etc.) recorded declines of production due mainly to viral diseases which destroyed the orchards and impaired the fruit quality. Therefore, these countries developed extensive breeding programs with the common objectives (productivity, fruit quality and resistance / tolerance to PPV) and specific objectives (late blooming, self-fertility, short growing period, different ripening times, spur fructification, resistance to diseases and frost). In the last 20 years 170 plum cultivars from these programs were released (Romania 38 cvs., Germany 28 cvs., Belarus 15 cvs., Serbia 14 cvs., Italy 13 cvs., Sweden 12 cvs., Bulgaria 11 cvs., Republic of Moldova 10 cvs., Latvia 9 cvs., France 6 cvs., United Kingdom 3 cvs., Czech Republic 3 cvs. and Norway 1 cv.)