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In this study, RNAseq reads of apricots (Prunus armeniaca) were analyzed to see reliability of High-throughput sequencing (HTS) for virus detection. HTS reads produced from the tissues of 7 trees (7 leaves, 1 immature fruit and 1 petal) grown in Kayseri naturally infected by Plum pox virus (PPV) and from the tissues of 3 seed-borne seedlings (1 leaf, 1 root, and 1 cotyledon) grown in screen house were local blasted against to the complete RefSeq release of virus sequences of NCBI. The all 9 samples form the outdoor trees depicted fragments of PPV and also 7 of them showed Apricot latent virus (ALV) in their total RNA reads. The number of reads of PPV ranged from 215 437 in 'Esen3' to 4 in 'Roxana'. The highest number of ALV fragments (35,070) were observed in the total reads of 'SEO' accession. The three samples obtained from tissues from seed-borne seedlings protected in the screen house against to virus infection did not display fragments of PPV and ALV. The results pointed that HTS sequencing does not produce virus reads if the tissue is not infected, suggesting that HTS is reliable source for virus detection.

Morphology and ultrastructure of pollen grains were studied in nine apricot cultivars using scanning electron microscopy (SEM) technique. The following characteristics were examined in dried pollen grains: Length of polar axis (P), length of equatorial axis (E), P/E ratio, length of the colpus, width of the mesocolpium, and exine characteristics (number of ridges 100 μm-2 area, width of a ridge, and width of a furrow). All studied cultivars had isopolar, radially symmetric and tricolpate pollen grains, which had been classified as large in size. Length of polar axis ranged from 55.6 μm in 'Hungarian Best' to 59.5 μm in 'Goldrich', and length of equatorial axis from 27.0 μm in 'Sylred' to 30.5 μm in 'Goldrich'. Pollen shape was identified as prolate in six cultivars, and as perpolate in three cultivars. Colpus length and mesocolpium diameter varied in a range of 48.4-55.6 and 14.5-18.4 μm, respectively. All studied cultivars had striate exine ornamentation. Number of ridges 100 μm-2 of the exine surface was the lowest in cultivar 'NS-4' (21.3), and the largest in cultivar 'Laycot' (29.7). Ridge and furrow width varied in a range of 0.28-0.35 and 0.24-0.32 μm, respectively. SEM examination indicated that some pollen morphological characteristics such as size, shape, and exine ornamentation can potentially be used in the identification of apricot cultivars.

Agricultural biostimulants (ABs), products with specific action, natural or synthetic, mineral or organic, have been introduced recently as fertilizers that are applied in small quantities in order to increase nutrient uptake, growth and development of plants and improve quality, productivity, crop resistance and the environmental positive impacts. This trial aims to evaluate the effect of four different commercial ABs (Bion® 50 WG, Hendophit® PS, Ergostim® and Radicon®) on two cultivars of apricot ('Orange Rubis®' and 'Farbaly®'), grown in experimental field at Cerignola (Foggia district, Apulian region, southern Italy). The biostimulants used were related products of humic acids that induce effects on yield, fruit quality and grower income of some fruit trees. Several foliar treatments were applied at different times during the growth season of each crop. Total yield of fruits tree‑1 was also determined. Other than that related with vegeto-productive behaviour, many fruit quality parameters were evaluated, including also total polyphenols content and antioxidant activity. Experimental data showed some specific differences among the biostimulant treatments. Growth was not affected while productivity was only moderately affected in one of the two cultivars and not always positively. Main influences were found regarding qualitative attributes of fruits. The soluble solids content in 'Farbaly' was clearly positively affected by Bion® and Hendophyt® treatments while no effect of ABs was observed in 'Orange Rubis'. Results suggest that effects of ABs are 'genotype dependent' and that probably doses and scheduling of ABs application should be precisely defined in each agricultural context.

There is an ongoing need for sweet cherries and apricots that are improved over those existing. Improved and regular production, fruit size, firmness, time of maturity, packing, shipping and organoleptic characteristics are some traits that can be improved within the varietal maturity window. Over the last several years, we have released several sweet cherry cultivars (4 patented in Europe and others pending in the world) with early fruit ripening characteristics that are productive, with large fruit size, over a range of geographic locations with commercial potential. A number of apricots have been patented in Europe and the world and commercialized. We have identified pollination and production strategies toward maximizing the potential of these selections. The development of these cultivars and production strategies in Europe and worldwide will be discussed and reviewed as will future developments.

The suitability of five apricot cultivars: ‘Aurora’, ‘Laycot’, ‘Pinkcot’, ‘Sylred’ and ‘Veecot’ as pollenizers for ‘Goldrich’ were studied. The study included the phenology of flowering, pollen germination, fruit set and growth of pollen tubes in vivo in the pistil. Pollen germination was determined on the medium with agar and 15% sucrose. The growth of pollen tubes in the pistil was determined by fluorescence microscopy, and fixation of pistils was done in three terms (2, 4 and 6 days after pollination). Regarding the flowering time, all tested cultivars overlapped well with ‘Goldrich’. Besides, all tested cultivars had good pollen germination, ranging from 58 to 74%. The highest fruit set was obtained in combinations with ‘Veecot’ (34%) and ‘Sylred’ (30%). Significantly lower fruit set was obtained in combinations with ‘Laycot’ (17%) and ‘Pinkcot’ (15%), while the combination with ‘Aurora’ gave the lowest fruit set (4%). First pollen tubes at the base of the style were observed on the second day after pollination, but their number increased significantly on the fourth day after pollination. Later, on the sixth day after pollination, the number of pollen tubes was not significantly increased. Number of pollen tubes at the base of the style and in the ovary was significantly higher in variants with ‘Veecot’, ‘Sylred’, ‘Pinkcot’ and ‘Laycot’, comparing to the variant with ‘Aurora’. Based on these results, ‘Veecot’ and ‘Sylred’ can be recommended as the best pollenizers for ‘Goldrich’. Satisfactory results were given by ‘Pinkcot’ and ‘Laycot’, while ‘Aurora’ proved to be a bad pollenizer.

Twenty-nine apricot accessions from North China were analyzed with 55 simple sequence repeat (SSR) markers from a T×E map. All the SSR markers were analyzed throughout the genome and compared among eight linkage groups. Linkage group 4 performed well in number of alleles per locus (Na) and effective number of alleles (Ne), in which marker BPPCT040 was prominent, with an Ne of 8.46 and Na of 10. For assessment of genetic diversity, the observed (Ho) and expected (He) heterozygosity were measured, resulting in average values of 0.419 and 0.644, respectively. Furthermore, the highest values occurred in linkage group 4 compared with all chromosomes. The mean values of Shannon's information index ranged from 0.9859 in linkage group 2 to 1.4773 in linkage group 8, with an average of 1.2025. All the apricot accessions were calculated under K=4 and grouped into four clusters according to the Q value inferred by STRUCTURE software, using a model-based method. More than 85% of apricot accessions had a maximum Q, which was more than 0.80 for the four inferred Q values. Four subgroups of 29 apricot accessions were irregular in their geographical origins, based on the results from STRUCTURE. Principal coordinates analysis (PCoA) indicated that the three inferred subgroup gene pools were closely related. The north Chinese apricot gene flow in the Yellow River Basin area is very complex and frequent. The reason is likely the introduction of cultivation and selection by humans of North China during their long history, and the complexity between the various eco-geographical groups for germplasm penetration.

Cultivated apricot (Prunus armeniaca L.) is represented by a growing number of commercial cultivars featuring a wide variability of flesh texture and ripening evolution, affecting the entire chain from harvest to the final consumer. In order to establish fast and reliable tools easy applicable in the field to determine the harvest time, diverse commercial apricots were evaluated over 2 years for fruit ripening evolution by conventional and non-destructive methods. All fruit were harvested from a single tree at physiological ripening onset, then fruit were graded with a DA-meter® device, according to three ripening stages (physiological and commercial ripening, veraison), 30 fruit each. Fruit from each stage, after being scored by a near-infrared analyzer, were than randomly divided into three batches, each of which was subjected to standard ripening assessment: firmness (Fi) by using a digital penetrometer, soluble solids content (SSC) by using a digital refractometer, and total acidity (TA) by titration and pH measurement. Fi and SSC were assessed on both fruit sides, while TA and pH were determined on 10 homogenized fruits. The curves produced after optimization showed good predictability, particularly for TA, SSC and pH: R2 was 78.57, 79.17 and 80.56 (in cross-validation, respectively), despite the diversity of the assessed cultivars and the different stages of ripening. Some more work still has to be done to improve the predictability of Fi (R2=38.53), and further investigation has to be carried out to better fit the data from the penetrometer, or other devices measuring flesh texture. These results are to be considered as preliminary for the setting up of cultivar-specific harvest parameters.

In apricot (Prunus armeniaca L.), fruit quality at consumption and shelf-life potential are strictly related to the ripening stage reached at harvest. As a result, definition of the optimal harvest time is a crucial issue and, nowadays, this is performed on the basis of fruit size, skin color and some internal quality traits, such as flesh firmness (FF), soluble solids content (SSC) and titratable acidity (TA), that are determined by standard techniques that require destruction of the fruit sample. Recently, extensive research has focused on the development of non-destructive visible/near-infrared spectroscopy (vis/NIRs) techniques that allow the ripening stage to be expressed as a new maturity index, called the index of “absorbance difference” (I(AD)). The I(AD) is used to establish, under field conditions, the optimal harvest time related to the ripening stage at harvest with a portable DA meter. More recently, a stationary DA machine prototype has been realized, allowing the grouping of fruits in classes of homogeneous ripening at the packing-house level. Preliminary results obtained with this prototype on some apricot cultivars grown in Valais (Sion, Switzerland) are reported. The results obtained showed that the I(AD) values obtained with the stationary DA allow fruit to be grouped according to their ripening stage. The data were comparable with those obtained with a portable DA meter, and correlate with standard internal quality traits.

Golden apricot (Prunus armeniaca) achieved a fruit setting rate of 62.30% after artificial cross-pollination, as against 56.77% for natural pollination by bees. Self-pollination produces no fruit, indicating that this particular species is self-incompatible and infertile. We used fluorescence microscopy to examine the pollen tubes of golden apricot plants at regular intervals after artificial cross-pollination with a mixture of pollen from 'Katy' and 'Golden Sun' apricots, natural pollination, or self-pollination. All experiments took place in a greenhouse. Our observations showed that pollen from the same plant was capable of germinating on the stigma and growing through the style, but when it reached a point 3/5 of the way down the style, at around 96 h post-pollination, the pollen tube appeared to bend backwards. This behavior appears to be characteristic of species with gametophyte self-incompatibility. Dissections of golden apricot embryos suggested that, after cross-pollination, pollen grains germinate normally, grow through the stigma, and enter the ovary to complete the fertilization process. A diploid zygote is formed at 19 days after pollination. It subsequently forms an embryo that in turns globular, heart-shaped, and torpedo-shaped at 31, 35, and 42 days post-pollination, respectively. Eventually, the cotyledon is formed at 46 days post-pollination. Our results provide a reference that will facilitate future cultivation of this species under greenhouse conditions.

According to historical records, Chinese plum (Prunus salicina) and apricot (Prunus armeniaca) trees have been cultivated in Sichuan for at least 2000 years. With a long history of cultivation and a rich variety of resources, Sichuan is one of the regions of origin of P. salicina and is also one of the main plum-producing areas in China. In recent years, the Chinese plum and apricot industry has developed rapidly and has become a major industry in Sichuan. This paper provides a profile of the Sichuan plum and apricot industry, including acreage and yield, growing areas, main cultivars, culture technologies, and economic benefits, along with the advantages and main problems of the industry, in different ecological zones. Future prospects and proposals for the sustainable development of the plum and apricot industry of Sichuan are also analyzed.

Chilling requirements for breaking dormancy and heat requirements for flowering were studied in 10 apricot cultivars in the region of Belgrade during a 2-year period. Chilling requirements were determined using the Utah chill unit (CU) model. To determine the date of dormancy breaking, 1-year-old shoots were collected weekly from December to February and kept under controlled conditions. Heat requirements were calculated as growing degree hours (GDH) accumulated from the breaking of dormancy to the beginning of flowering using a base temperature of 4 degrees C. The cultivars studied showed a range of chilling requirements, from 834 CU in 'Ninfa' and 'Goldrich' to 1442 CU in 'Re Umberto'. The heat requirements for flowering ranged between 2624 GDH in 'Magyar kajszi' and 3469 GDH in 'Tomcot'. The latest flowering cultivar ('Re Umberto') finished dormancy 42 days after the earliest flowering cultivar ('Ninfa'). The results indicate that flowering time of apricot in the studied region is influenced more by chilling requirements than by heat requirements. Identification and selection of cultivars with higher chilling requirements and later flowering is important for apricot production, especially in regions with the frequent occurrence of late spring frosts.

Prunus domestica (European plum) and Prunus armeniaca (apricot) are related species which can be hybridized. However, there are only very few reports on true interspecific hybrids between P. domestica and P. armeniaca. These hybrids must not be confused with the so called pluots or plumcots which are hybrids between P. salicina (Japanese plum) and P. armeniaca. In 2005, a program for breeding interspecific hybrids between P. domestica and P. armeniaca was initiated at Technische Universitat Munchen. As female parent, a P. domestica clone with hypersensitivity resistance to Plum pox virus (PPV) was used. As male parent, apricot cultivars with different degrees of susceptibility to PPV were chosen. Several interspecific hybrids were obtained. Leaves, shoots and fruits of the seedlings are intermediate between European plum and apricot. The seedlings were tested for their resistance to PPV. Interspecific hybrids with strong resistance to PPV could be obtained. To the best of our knowledge, this is the first report on the generation of PPV resistant hybrids between European plum and apricot. The hybrids could help to better understand the genes which are involved in hypersensitivity resistance to PPV. Moreover, the interspecific hybrid can be used for transferring the PPV resistance to the apricot genome by repeatedly backcrossing them with apricot. The interspecific hybrids represent a new kind of fruit species as the outer and inner fruit traits are intermediate between the parent species.

UMR AGAP - équipe AFEF - Architecture et fonctionnement des espèces fruitières UMR AGAP - équipe AFEF - Architecture et fonctionnement des espèces fruitières; International audience; The nature of axillary production along shoots is one of the main factors influencing both vegetative and reproductive growth in apricot. This study aimed at analyzing the morphology and branching pattern of one-year-old shoots of 'Velkopavlovicka' cultivar in comparison with 'Bergeron'. 'Velkopavlovicka' is a classical, medium vigor, Czech cultivar which has naturally a spherical crown. In twelve-year-old trees grafted on apricot seedlings and pruned to an open vase, lateral branches were described from the second to the fourth orders. Each shoot was described as a sequence of metamers, and for each metamer the fate (latent, vegetative or floral) of the central bud as well as the number of associated flowers were noted. The presence or absence of development of axillary shoots from vegetative buds was also considered. A hidden semi-Markov chain was built for each cultivar on the basis of the sample of bivariate sequences corresponding to the two observed categorical variables, pooling all one-year-old annual shoots whatever the year. Both cultivars could be characterized by a similar organization in zones, but with different probabilities of occurrence of the median flower bud zone as well as by different mean number of central and associated flowers within this zone. Cultivar 'Bergeron' proved to be more floribund than 'Velkopavlovicka'. Moreover, they revealed biennial bearing in Central European conditions, but different reasons could be responsible for this behavior depending on the cultivar.

The evaluation of nine introduced apricot cultivars originating from the United States was carried out in the region of Belgrade over a period of six years (2009-2014). Control cultivar for comparison was 'Hungarian Best'. Introduced cultivars flowered 2-5 days before the control, while their harvest occurred 3-17 days earlier than in the control cultivar. Compared to the control, significantly higher yield was achieved in 'Orangered', 'Tomcot' and 'Goldrich', while significantly higher fruit weight was found in 'Goldrich', 'Robada' and 'NJA-55'. Introduced cultivars had lower content of soluble solids than the control. Cultivars 'Goldrich' and 'Orangered' stood out for both fruit appearance and quality. Of the cultivars studied, the following can be recommended for growing in Belgrade region: 'Goldrich', 'Orangered' and 'Tomcot'.

Sichuan province is located in the southwest hinterland of China, and contains as landforms plateau, hill, basin, and more. The diverse climates of these areas have contributed to rich germplasm resources, and therefore apricots (Prunus armeniaca) are widely distributed in Sichuan. According to a recent survey, there are more than 18 apricot cultivars in Sichuan. Here, I describe two special cultivars: a wild type, named 'Daofu' apricot, is distributed in high-altitude areas in western Sichuan. The other, a breed native to Luding County named 'Wangjia' apricot, has been selected by nature for a long time. Both have many advantages over other cultivars. In this paper, the ecological conditions, botanical features, biological characteristics, and important economic traits of these two cultivars are briefly described.

The study was carried out in the conditions of South-East of Romania, at the Research Station for Fruit Growing Constanta, during 2003-2009. The behavior of nine clonal Prunus rootstocks was studied: 'Scoldus', 'Galbior', 'Saint Julien A' (from Prunus domestica), 'Cs 5', 'Cs 4', 'Apricor’, 'Cs 1' (interspecific hybrids between Prunus cerasifera x Prunus armeniaca), 'Otesani 8' (clonal selection from P. Domestica)) and 'Miroper' (interspecific hybrid between P. cerasifera x P. persica) grafted with 3 apricot cultivars: 'Sirena', 'Selena' and 'Sulmona'. The aim of this study was to estimate the influence of these rootstocks on survival and agronomic performances of 3 apricot cultivars from the 19th to the 25th years after planting. An experimental orchard was planted in spring of 1984, at 4.5 by 3 m, with trees trained as vase. The following traits were recorded: % of trees loss, the growth of shoots, yield on tree, trunk cross sectional area, productivity. As results of the investigations we found that: 'Saint Julien A', 'Otesani 8', 'Scoldus' and 'Miroper' rootstocks had induced longevity to apricot grafted cultivars, having the smallest % of trees loss. 'Saint Julien A' and 'Otesani 8' rootstocks had induced a good capacity of shooting to apricot grafted cultivars. The vigor of the cultivar - rootstock combinations was differed according to cultivar and rootstock. 'Miroper' rootstocks induced a lower vigor while 'Cs 1' and 'Apricor' have induced a higher vigor to the grafted cultivars. Among rootstocks, 'Galbior' and 'Apricor’ have improved productivity to cultivars grafted them.

In order to improve the apricot cultivar assortment in Serbia the work has been conducted in two directions. The first one is the creation of new domestic cultivars, and the second one is the introduction of foreign cultivars. Nine new apricot cultivars have been released in Serbia so far: 'Cacansko zlato', 'Cacanska pljosnata', 'Vera', 'Biljana', 'Aleksandar', 'NS-4', 'NS-6', 'Novosadska rodna', and 'Novosadska kasnocvetna'. This paper presents the most important properties of these cultivars, as well as the best introduced apricot cultivars. Of all Serbian apricot cultivars, 'Novosadska rodna' and 'NS-4' have shown the best characteristics. These cultivars start to spread in the commercial plantings, especially in the northern part of Serbia (Vojvodina). At the Faculty of Agriculture in Belgrade, the properties of 75 introduced apricot cultivars were studied in the period of 1996-2005. The best results in the group of early maturing cultivars were manifested by 'Harcot', in the group of medium-late maturing cultivars by 'Ligeti Orias' and 'Kostjuzhenskyi', and in the group of late maturing cultivars by 'Roxana' and 'Silistrenska Kompotna'. In the period after 2005, more than 100 new apricot cultivars were introduced. Among them, the following cultivars were singled out as promising: 'Aurora', 'Tomcot', 'Legolda', 'Pincot', 'Laycot', 'Sylred', 'Goldrich', 'Silvercot', 'Harrow Star', and 'Bergarouge'. In addition to pomological properties, self-(in) compatibility of apricot cultivars was also studied by means of fluorescence microscopy. All Serbian cultivars were self-compatible, while most of the introduced cultivars were self-incompatible.

Sharka (Plum pox virus - PPV) is considered one of the most devastating diseases of stone fruits in terms of agronomic impact and economic importance. The disease is very detrimental to apricot, peach and plum trees because it reduces quality and causes premature drop of fruits. The dynamics of virus infection in F1 and F2 Romanian apricot cultivars (Prunus armeniaca) were analyzed in natural infection conditions. The F1 and F2 Romanian apricot progenies were serologically tested by DAS-ELISA using PPV-D and PPV-M specific monoclonal antibodies. Molecular tests were done by RT-PCR using P1/P2 primers. PPV detection by conventional serological and molecular methods was performed during the dormant period (wintertime). This period has important drawbacks due to both false negative results (sensitivity) and also false positive results (specificity). The Romanian apricot F1 and F2 progenies evaluated were initially classified into three groups: susceptible to PPV, partially resistant to PPV, and resistant to PPV. After that, the most important genotypes were grafted onto infected peach 'GF 305' in greenhouse conditions. The goals of the work presented in this communication are the introduction and development of marker-assisted selection (MAS) for PPV resistance in F1 and F2 progenies of Romanian apricot cultivars.

This research had the aim to study, under the Mediterranean climatic conditions, the genetic variation of the Chilling Requirement (CR) character in progenies originated from parents with low-medium and very high CR. Adult apricot seedlings of seven year old, growing under the climatic conditions of the Tuscan coastal area, Italy (lat. 43,02N, long. 10,36E), were randomly selected from two families obtained by crossing cultivars with different CR: 1) 30 genotypes from 'Portici' x 'Stark Early Orange' (medium and very high CR, respectively); 2) 24 genotypes from 'Sungold' × 'Moniqui' (medium and high CR, respectively). The following determinations were periodically performed on flower buds during the winter season: a) endo- and ecodormancy overcoming through biological observations (forcing method); b) changes on glutathione (GSH, GSSG) contents through biochemical analysis; c) blooming entity. The results confirm that the female parents ('Portici' and 'Sungold') need a medium CR, while the male parents ('Stark Early Orange' and 'Moniqui') are characterized by a high or a very high CR with a scantly flowering. Analysing the flower bud dormancy evolution of genotypes of the two progenies, a different distribution of character CR in relation to the cross combination was observed. From deep to the end of dormancy, the glutathione oxidised form GSSG was depleted and the active reduced form (GSH) increased, altering the GSH/GSSG ratio. Although, this behaviour was different in relation to the genotypes, glutathione is one of the putative key compounds inducing the resumption of flower bud growth.

Numerous famous specialists, such as Couranjou, (1975, 1989), Keubemen et al., (1979), Bailey and Hough, (1977), Cociu and Hough), (1985), Audergon et al., (1995, 2006); Balan et al., (1999, 2006); Bassi, (1990, 1999); Badenes et al., (2006); Muleo et al., (2006), emphasized the genetics of apricot maturity, the exploitation of the initial and induced genetic variability, and the employment of corresponding improvement methods. On these bases, since 2000 a large set of cultivars have been created, such as: 'Rares', 'Valeria', 'Carmela', 'Viorica', 'Auras', 'Cristal', 'Fortuna'. They are characterized by their early fruit maturation in the Romanian climatic conditions (15-20 June), and their qualitative, agronomic, and adaptability features, which inscribe them into the new generation of cultivars created in European countries with long tradition in apricot culture.

New apricot cultivars are yearly introduced in Italy by nurseries and growers. These cultivars come from both Italian and foreign breeding programmes and most of them have been selected in climatic and environmental conditions noticeably different from those of the main Italian apricot growing areas. So far, acquired experience on apricot has shown that environmental adaptability is hard to be foreseen and, for this reason, the introduction of cultivars in new areas often causes commercial failures. In order to reduce this problem and to help growers in choosing new cultivars, in 1992 a National Programme was launched to draw up an annual list of "Recommended fruit varieties" for fruit-tree growers. This means that each new apricot cultivar, bred in Italy or in other countries, enters the collection created by the 10 Operating Units and is assessed for its vegetative, pomological, horticultural and technological characteristics, according to a common evaluation protocol. Basing on the resulting features, lists with recommended/not recommended cultivars are filled in. In order to highlight the strong variability among Italian growing areas and the need for a proper collegial evaluation, a summary of some pomological and phenological features has been drawn up and discussed. Selected data have been collected on 10 sites all over Italy for two consecutive years (2006-2007) characterized by noticeably different climatic conditions. This last aspect could also lead to some considerations about the future adaptation of apricot cultivar to climatic changes.

Over the past twenty years, the winter climate has shown a tendency to become progressively milder. We asked ourselves how a collection of apricot varieties, growing in a Mediterranean Tuscan coastal area, reacts to a strong reduction in the Chilling Unit accumulation as recorded during the last autumn-winter season. In the following spring, between March 1 st and April 10 th , on more than 200 apricot adult accessions, observations were conducted on the bud phenological stage evolution, amount of flowering and fruit set. The climatic trend for the year 2006-2007 allowed classifying the genotypes based on their yield response. Some genotypes coming from the southern Mediterranean area show the ability to heavy crop also under unusually mild winter conditions.

Apricot is one of the least sensitive stone fruit to aphids, but infestations of the mealy plum aphid may commercially damage fruits ready to harvest. Management of aphid infestations in organic orchard should also consider enhancing beneficial insects and limiting aphid species hard to control (wax-protected aphids). Green lacewings management through lures should represent a potential way to enhance the efficiency of this generalist predator against aphids. To evaluate this strategy, tests were performed in the frame of the P.O.N. BRIMET project (cod. MIUR 12929), between 2005 and 2007, in organic orchards in Southern Italy, near Nova Siri Marina (MT). Experimental design was used to assess attractiveness of a mixture of phenylacetaldehyde, methylsalicylate and acetic acid, and to evaluate the influence on oviposition of green lacewings. The experimental field was parcelled out into two similar lots, one of which with the lure in the central area. Trials on apricot were compared to the results obtained in peach orchards of the Centro di Ricerca per la Frutticoltura, near Rome. Results prove the attractiveness of this chemical lure towards Chrysoperla carnea (Stephens), but with a slight increase of oviposition in the apricot parcel with tested substances through the years. Only in 2007 we could measure an evident increase of oviposition on apricot trees. Better results were achieved on peach orchard where we could notice a more complex entomofauna. On apricot, the aphid presence can be assumed as a key factor for lacewings oviposition, and the presence of this lure as a secondary factor for a higher oviposition rate. Further basic researches on lacewings oviposition strategies are evidenced; moreover, an on-time application of lures upon the early symptoms of aphid infestations could represent the best application strategies to enhance natural population of lacewings on field.

The research was carried out at the Research Station for Fruit Growing Constanta, Romania, during 6 years, to study the behaviour of 5 generative rootstocks for apricot tree in the research nursery fields: Constanta 14, Constanta 16, C74-8-P2, C74-8-P5 and RR 15-20. All rootstocks were grafted with four Romanian apricot cultivars: Tudor, Fortuna, Orizont and Traian. The results of these investigations showed that the rootstocks were suitable for the tested apricot cultivars. The rootstocks, in the seedlings field, proved to be suitable because they had adequate seed germination, seedlings growth and good seedlings yields. The rootstocks-cultivars combinations gave good yield of standard grafted trees. Scion - rootstock compatibility was satisfactory with no external deformation.

The choice of apricot rootstock is first determined by the soil conditions; the adaptation to particular soil conditions being crucial for tree survival. Additionally, growers could be interested in low-vigour rootstocks for better vigour control and fruit quality. In Switzerland, apricots are traditionally cultivated on Myrobolan, which is too vigorous for high soil fertility and, thus, not adapted for high-density planting. Therefore, an enlarged vigour range is needed in order to produce high quality fruits. The aim of this study was to assess the influence of different rootstocks on survival and agronomic performances of the cultivar Luizet. A trial with ten different rootstocks was carried out in 1992 in the conditions of central Valais (Switzerland). Trees were traditionally trained as free-standing multiple leader (5.0 m x 3.5 m; 571 trees/ha). The rootstocks were selected according to their compatibility with light-sandy soil, slightly limestone (pH 7.6) and to cover the largest vigour range. From the 3 rd to the 12 th year, vigour evolution (trunk cross-area), productivity, yield as well as fruit size were determined. Citation, Rubira and Jaspi showed a vigour reduction of 35 to 45% compared to Myrobolan, while GF655-2, W61, Pixy and Torinel showed a decrease of 15 to 25%. GF43 and Myrabolan were of similar vigour and Julior showed a 20% higher vigour. The productivity was increased by 30% for Citation and reduced by 3%, 4% and 33% for Jaspi, Torinel and Julior, respectively. These four rootstocks induced a better fruit weight compared to Myrobolan. High decline rate has been observed with GF655-2, W 61, Pixy and Rubira; therefore, these selections cannot be recommended in our conditions. On the contrary, Citation is promising where densification requires dwarfing rootstocks. Torinel is a good alternative to traditional Myrobolan, inducing a slight vigour reduction and better fruit size, and Julior could be useful where hillside situation or poor soil fertility require stronger vigour.

In the period 2001-2006 studies on the effect of some soil herbicides on the vegetative habits of yellow plum and apricot seedling rootstocks used in the production of certified planting material of apricot were carried out at the Fruit-Growing Institute - Plovdiv. The investigations were conducted under field conditions and by model pot experiments with sand (sand culture) and alluvial-meadow soil. The results about the effect of the soil herbicides napropamid, pendimethalin and metolachlor on the vegetative habits of yellow plum and apricot - two widely used seedling rootstocks for the apricot cultivars - were reported. Visual symptoms of phytotoxicity in the yellow plum and apricot seedlings after treatment with napropamid and pendimethalin were not observed. Treatment of the yellow plum seedling rootstocks with metolachlor (Dual Gold 960 EC) suppressed the plant growth. Application of the active substance metolachlor is not recommended. A depressing effect on growth and development of apricot seedlings was established after treatment with napropamid (Devrinol 4 F - 4 L/ha) only under the conditions of sand culture. The results obtained showed that in the production of yellow plum and apricot seedling rootstocks the use of some of the following herbicides could be recommended for an efficient weed control - napropamid (Devrinol 4 F - 4 L/ha) and pendimethalin (Stomp 33 EC -4 L/ha), which should be applied after sowing the seeds immediately before sprouting of the seedlings.

The following parameters were studied in apricot fresh fruits: colour (lightness, hue angle and chroma); ferric reducing ability (FRAP); DPPH-radical scavenging activity; total radical scavenging capacity measured with chemiluminescence methods; as well as total phenol (TPC) and vitamin C contents measured with spectrophotometer and HPLC-DAD, respectively. Altogether, 29 apricot cultivars and 18 hybrids obtained from the apricot breeding programme of Corvinus University of Budapest were evaluated. High levels of variation could be detected among genotypes in all tested redox parameters, while colour indices suggested lower levels of variation in fruits' carotenoid content. The variations in antioxidant capacity of different genotypes could be attributed mainly to the phenolics, but vitamin C also had a considerable contribution. A perspective hybrid with an outstanding antioxidant capacity and content could be identified, which might be used as a donor genotype in future functional breeding programmes.

This study was aimed at assessing the quality characteristics of 21 apricot genotypes such as Turfanda Eski Malatya, Karacabey, Paviot, Zerdali No.1, Aprikoz, Soganci, Hasanbey, Levent, Royal, Şekerpare, Çataloglu, Kabaaşi, Stark Early Orange, Sakit-3, Sam, Hacihaliloglu, Iri Bitirgen, Casna Drenova, Çöloglu, Ordubat, Imrahor that are grown in Malatya provinces of Turkey. Main soluble sugars of experimental varieties were separated, identified and quantified using high-performance liquid chromatography with refractive index detection. According to the results, sugar composition of apricot genotypes was different from one genotype to another. Sucrose, glucose, and fructose were determined as the major sugars in all apricot varieties and our local genotypes were detected to have higher concentration in terms of identified sugars.

An apricot breeding programme was started at the University of Bologna (northern Italy) at the beginning of the 1980's and it's now co-led by the University of Milan. The basic goal of the project is to provide the southern Po Valley region with adapted cultivars to be grown in an environment featuring fluctuating temperatures at the end of the winter and the beginning of springtime, often ending in poor yield. Other goals are to obtain apricots of superior eating flavour and overall fruit quality, including appearance and firmness and/or slow ripening. Parents are chosen among germplasm collected from local cultivars (when featuring outstanding fruit flavour or tree hardiness) or from foreign sources, taking advantage of good cooperation with breeding programmes worldwide, aimed at exchanging either pollen or grafting material. One special goal is the resistance to Plum Pox Virus (PPV), as well as to the most common diseases (e.g. brown rot), or to fruit cracking. The project for PPV resistance is run in cooperation with the Italian Universities of Bari and Udine and has brought so far very promising results in terms of several advanced selections and one recently introduced cultivar ('Bora'), all field resistant to the two main PPV strains, D and M. The early ripening 'Ninfa' was the first introduction (1993) and an estimated half a million trees were sold in Italy since then, without mentioning other countries like Greece, Spain and Turkey. Among the more noteworthy recent introductions, in addition to the PPV resistant 'Bora' (large and firm fruit, with nice appearance), 'Petra', 'Pieve' and 'Pieve tardiva' are also to be mentioned because of their outstanding eating quality.