Genetic variation within the olive (Olea europaea L.) cultivar Oblica detected using amplified fragment length polymorphism (AFLP) markers

Oblica is the predominant olive cultivar in Croatia, spread widely in all the olive growing regions. Morphological variability within the cultivar is well documented but often it has been attributed to environmental factors rather than to genetic ones. In order to investigate intracultivar variability on the molecular level, olive samples from 4 growing regions in Croatia (South  Dalmatia, Middle Dalmatia, Kvarner islands and Iner Dalmatia) were screened for amplified fragment length polymorphisms (AFLP). DNA was extracted from leaf tissue and 9 AFLP primer combinations were used. Genetic distancesbetween individual trees were calculated using Dice similarity coefficient and the dendrogram based on UPGMA cluster analysis was constructed. Preliminary results of AFLP analysis indicate that the cultivar Oblica can be regarded as mixture of clonal variants

Morphological and pomological traits of almond phenotypes (Amygdalus communis L.) isolated from their natural population

Seven phenotypes were isolated from a natural population of almonds (Amygdalus communis L.) and more positive traits than the standard varieties that were cultivated, were identified. Over the period of three years, phenological and pomological research was conducted in situ, along with the observation of vegetative traits and productivity of isolated phenotypes. The research was conducted on the basis of the 2.11 (IBPGR) descriptor for the identification of Prunus varieties. Phenotypes K1, K4, K6 showed the best results. The research will be continued through a comparative experiment with the selected phenotypes in equal agro-ecological conditions

Addition of nitrogen had no effect on yield and quality of apples in an high density orchard carrying a dwarf rootstock A adição de nitrogênio não afetou o rendimento e a qualidade de maçãs em pomar com alta densidade e porta-enxerto anão

The effect of N addition on apple yield and quality may vary according to the tree vigor. Apple trees developed over vigorous rootstocks had shown no response to N application in Brazil. In this study it was evaluated the effect of N addition to the soil on yield and quality of &#180;Royal Gala&#180; apples grafted on a dwarf rootstock (M.9). The orchard was planted in 1995 (2,857 trees ha&#45;1) on an Oxisol containing 40 g kg&#45;1 of organic matter and pH 6.0. The experiment was carried out from 1998 up to 2005. Treatments consisted of rates of N (0, 50, 100 and 150 kg ha&#45;1 year&#45;1 from 1998 to 2001, and respectively 0, 100, 200 and 300 kg ha&#45;1 afterwards), all broadcasted within the tree row in two equal splits, at bud break and after harvest, as ammonium sulfate. Addition of N to the soil had no effect on fruit yield over the six years regardless of the applied rate. Averaged across treatments and years, fruit yield was 52.3 t ha&#45;1. Nitrogen in the leaves (average of 24 g kg&#45;1) or in the fruits (average of 346 mg kg&#45;1) as well as some attributes related to fruit quality (color, firmness, acidity, soluble solids, physiological disorders) were unaffected by N addition. Some plant parameters related to tree vigor, however, grew higher with the increase on N rate. Thus, it is not necessary to apply N to deep Brazilian soils containing high organic matter in order to assure good fruit quality and yield on high&#45;density orchards carrying dwarf rootstocks probably because the N required for tree growth and fruit production is supplied from soil organic matter decay.<br>O efeito da adição de N ao solo no rendimento e na qualidade de maçãs pode variar em função do vigor das plantas. Experimentos conduzidos no Brasil com macieiras cultivadas sobre porta&#45;enxertos vigorosos não têm apresentado aumento no rendimento de frutos pela aplicação de N. Este trabalho objetivou avaliar o efeito da aplicação de N no rendimento e na qualidade de frutos de macieira cultivada em alta densidade sobre porta&#45;enxerto anão (M.9). O pomar com a cultivar Royal Gala foi plantado em 1995, na densidade de 2.857 plantas ha&#45;1, em um Latossolo Bruno com 40 g kg&#45;1 de matéria orgânica e pH 6,0. O experimento foi implantado em 1998 e foi encerrado em 2005. Os tratamentos consistiram da aplicação anual de 0; 50; 100 e 150 kg ha&#45;1 de N de 1998 até 2001 e de, respectivamente, 0; 100; 200 e 300 kg ha&#45;1 de N a partir da safra 2002&#45;2003. Metade de cada dose foi aplicada no início da brotação, e o restante após a colheita, sempre na forma de sulfato de amônio. A aplicação de N ao solo não influenciou no rendimento de frutos em nenhuma das seis safras, independentemente da dose. Na média das doses e dos anos, o rendimento foi de 52,3 t ha&#45;1. A adição de N também não afetou a concentração de N nas folhas (média de 24 g kg&#45;1) e nos frutos (media de 346 mg kg&#45;1), nem tampouco os atributos relacionados com a qualidade dos frutos (cor da epiderme, firmeza da polpa, acidez, sólidos solúveis, desordens fisiológicas). Alguns atributos relacionados com o vigor das plantas, entretanto, aumentaram com o aumento da dose de N. Portanto, em solos profundos do Sul do Brasil, com alto teor de matéria orgânica, não é necessário aplicar N para obter altas produtividades e frutos de boa qualidade em pomares de 'Royal Gala' contendo porta&#45;enxerto anão (M.9) e alta densidade de plantas, provavelmente porque a necessidade das árvores é suprida pelo N oriundo da decomposição orgânica