Vera Rakonjac

Multivariate analysis of vineyard peach [Prunus persica (L.) Batsch.] germplasm collection

Thirty vineyard peach [Prunus persica (L.) Batsch.] genotypes were studied to determine the overall degree of polymorphism and to detect similarities among genotypes. The variation was observed for traits related to phenology, morphology, yield and fruit quality. Many fruit characteristics that are important to breeders are present in this collection. The majority of important correlations were determined between the characteristics representing fruit size (fruit width, fruit height, fruit weight and stone weight) and between those ones representing fruit quality (fruit attractiveness, taste, flavour and soluble solids content). Cluster and principal component analysis showed a considerable phenotypical diversity in the vineyard peach germplasm. Clustering of genotypes was in accordance with its purpose (fresh consumption or rootstocks production). Parameters with high discriminating values were those related to fruit size and fruit quality.

Classification and fingerprinting of different berries based on biochemical profiling and antioxidant capacity

O objetivo deste trabalho foi avaliar a composicao bioquimica de seis especies de pequenas frutas dos generos Fragaria, Rubus, Vaccinium e Ribes. As amostras das frutas foram coletadas em triplicata (com 50 frutas cada) de 18 diferentes especies ou cultivares dos generos mencionados, durante tres anos (2008 a 2010). Os teores individuais de acucares, acidos orgânicos, flavonois e acidos fenolicos foram determinados por cromatografia liquida de alta performance (HPLC), e os fenois totais (FT) e a capacidade antioxidante total (CAT), por meio de espectrofotometria. As analises de componente principal (ACP) e de agrupamento hierarquico (AH) foram utilizadas para avaliar as diferencas no perfil bioquimico das frutas. Os maiores teores de compostos bioativos foram encontrados em Ribes nigrum e em Fragaria vesca, Rubus plicatus e Vaccinium myrtillus. ACP e AH foram capazes de discriminar parcialmente as frutas com base em sua composicao bioquimica. Os acucares totais e individuais, a miricetina, o acido elagico, FT e CAT foram os parâmetros que mais impactaram na avaliacao da composicao bioquimica das pequenas frutas. AH fez a separacao de amora-preta, framboesa e mirtilo como grupos isolados, porem a classificacao do morango, da groselha-preta e da groselha-vermelha, em um grupo especifico, nao ocorreu. Ha grande variabilidade entre e dentro dos diferentes tipos de frutas vermelhas. A identificacao de metabolitos das pequenas frutas mostrou perfis bioquimicos unicos e combinacoes especificas de teores de compostos bioativos.

Chemical profile of major taste- and health-related compounds of Oblačinska sour cherry

BACKGROUND Oblačinska sour cherry, an autochthonous cultivar, is the most planted cultivar in Serbian commercial orchards. Owing to its long cultivation under different agro-ecological conditions, it is a mixture of different clones. To obtain comprehensive information on Oblačinska sour cherry fruit, the total carbohydrate composition, total phenolic content, total anthocyanin content, antioxidant activity and polyphenolic profiles of 39 clones were investigated. RESULTS Fructose was found to be the dominant sugar, followed by glucose, sorbitol and sucrose. Rutin and chlorogenic acid were the most abundant polyphenols. Some clones contained pinobanksin, hesperetin and galangin, which, to best knowledge, is the first time these compounds have been reported in sour cherry fruit. CONCLUSION The data obtained showed huge variation within the germplasm studied, confirming the fact that Oblačinska sour cherry is not a cultivar but a population.

Sugar Profile of Kernels as a Marker of Origin and Ripening Time of Peach (Prunus persicae L.)

Large amounts of fruit seeds, especially peach, are discarded annually in juice or conserve producing industries which is a potential waste of valuable resource and serious disposal problem. Regarding the fact that peach seeds can be obtained as a byproduct from processing companies their exploitation should be greater and, consequently more information of cultivars’ kernels and their composition is required. A total of 25 samples of kernels from various peach germplasm (including commercial cultivars, perspective hybrids and vineyard peach accessions) differing in origin and ripening time were characterized by evaluation of their sugar composition. Twenty characteristic carbohydrates and sugar alcohols were determined and quantified using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC/PAD). Sucrose, glucose and fructose are the most important sugars in peach kernels similar to other representatives of the Rosaceae family. Also, high amounts of sugars in seeds of promising hybrids implies that through conventional breeding programs peach kernels with high sugar content can be obtained. In addition, by the means of several pattern recognition methods the variables that discriminate peach kernels arising from diverse germplasm and different stage of maturity were identified and successful models for further prediction were developed. Sugars such as ribose, trehalose, arabinose, galactitol, fructose, maltose, sorbitol, sucrose, iso-maltotriose were marked as most important for such discrimination.

Cross-(in)compatibility in apricot (Prunus armeniaca L.).

Summary Eight apricot (Prunus armeniaca L.) cultivars and selections were self- and cross-pollinated in order to determine their pollen and stylar compatibility. Overall, 40 pollination combinations were examined. Pollen-tube growth in pistils pollinated in the laboratory was analysed using fluorescence microscopy. Three inter-incompatiblity groups of cultivars were found, of which two had not been described previously, while an existing group was expanded with one additional cultivar. The first group consisted of three Hungarian cultivars (‘Ligeti Orias’, ‘Cegledi Orias’, and ‘Szegedi Mammut’) and a Moldavian cultivar (‘Kostjuzhenskyi’). The second group consisted of two American cultivars (‘Stark Early Orange’ and ‘Nugget’). The third group consisted of two Serbian selections (‘Novi Sad Early’ and ‘Frushka Gora Early’). In the incompatible cultivar combinations, pollen-tube growth stopped in the style with the formation of the characteristic swelling. In the compatible combinations, the pollen tubes reached the ovary in the majority of the pistils examined.