The apple (Malus domestica Borkh) originally evolved to require temperatures below 7.2 °C for the induction of budding and flowering. In Brazil, breeders have overcome the climate barrier and developed the cultivars Anabela, Julieta, Carícia, and Eva, with low chilling requirements and good yield characteristics. These cultivars are grown in many warmer climate countries in South America, Africa, and the Middle East. The apple germplasm collection that originated these cultivars has several genotypes with pedigrees for a low chilling requirement. Knowledge of the variability and genetic relationships among these genotypes may be useful in the development of superior new cultivars. In this work, we first selected the best ISSR (inter-simple sequence repeat) primers for genetic studies in apple, and then we used the selected primers to evaluate the genetic variability of the apple germplasm collection at the Instituto Agronômico do Paraná. The evaluation of 42 ISSR primers in 10 apple genotypes allowed us to select the best nine primers based on the polymorphic information content (PIC) and resolving power (RP) indexes. The primer selection step was robust since the dendrogram obtained with the nine selected primers was the same as the one obtained using all 26 polymorphic primers. Primer selection using PIC and RP indexes allowed us to save about 60% of time and costs in the genetic variability study. The nine ISSR primers showed high levels of genetic variability in the 60 apple genotypes evaluated. The relevance of the primer selection step is discussed from the perspective of saving time and money in germplasm characterization. The high genetic variability and the genetic relationships among the genotypes are discussed from the perspective of the development of new apple cultivars, mainly aiming for a low chilling requirement that can better adapt to current climatic conditions or those that may arise with global warming.

Plum (Prunus salicina Lindl.) cultivation is seriously compromised in Brazil due to the occurrence of leaf scald, a disease caused by the bacterium Xylella fastidiosa subsp. multiplex. The objective of this study was to evaluate plum genotypes agronomically promising for resistance to leaf scald, under natural conditions of occurrence of the disease. Ten out of 50 plum genotypes belonging to the germplasm bank of “Instituto Agronômico do Paraná (IAPAR)” were selected. Five evaluations of leaf scald severity were carried out from January to February (2017 and 2018). Polymerase chain reaction (PCR) was also performed for samples of these genotypes to determine the presence of the bacterium X. fastidiosa subsp. multiplex. The genotypes differed in relation to their susceptibility to leaf scald. PR-1095 was the most resistant genotype and did not show any leaf symptom of the disease. In contrast, genotypes PR-1126 and PR-1137 had the greatest susceptibility to the disease, showing severe scald symptoms. However, PCR revealed the presence of the bacterium even in the most resistant genotypes, indicating, for example, that PR-1095, which had no symptoms of the disease, is probably tolerant to leaf scald.

O objetivo deste trabalho foi avaliar o enraizamento e brotação de estacas de pitaya (Hylocereus undatus) sob diferentes níveis de sombreamento. As tonalidades obtidas por tela foram: 37,8%, 49,6%, 86,3% e sob o sol. Foram analisadas as seguintes características: sobrevivência de estacas (%), brotação (%), número de brotações, comprimento médio dos brotos (cm), massa seca da parte aérea (g), estacas enraizadas (%), comprimento médio da raiz (cm) (mL), matéria seca da raiz (g) e concentração de clorofila aeb (mg g-1). As médias percentuais de sobrevivência foram entre 90 e 100%. As respostas para fotografar e secar a matéria seca foram quadráticas, com ponto máximo em 23,48% e 42,7% de sombreamento, respectivamente. Em relação ao enraizamento de estacas, as médias foram entre 80 e 95%. O volume radicular e a massa seca das raízes apresentaram redução linear de acordo com o nível de sombreamento. Os teores de clorofila aeb apresentaram aumento linear na função o nível de sombreamento. O sombreamento parcial (entre 23 e 42%) aumentou a porcentagem de estacas com brotações, o acúmulo de matéria seca sobre elas e o volume afetado e o acúmulo de matéria seca nas raízes de viveiros pitaya propagados por estacas.

The objective of this study was to evaluate of the genetic similarity among 129 sugarcane clones. For that, it was evaluated the number of stalks per plot, the average mass of the stalks, the mass of 10 stalks, the medium brix and the brix production in kilograms for each plot. The data were analyzed through several Canonic Variables and Tocher method using the Mahalanobis (D 2 ii') distance. The results obtained by Tocher method and graphic dispersion shown that the most dissimilar clone was TUC77519. On the other hand, the most similar clones were RB 975056 and RB 915006. The number of stalks per plot (NSP) and the brix production per kilograms per plot (BKP) were characteristics that most contributed most for the genetic variability.

The objective of this work was to evaluate the bromatological composition, bioactive compounds, antioxidant activities, and color of the leaves of olive cultivars Arbosana, Arbequina, Frantoio, Manzanilla, and Koroneiki in northwestern Paraná, Brazil. Leaves of each cultivar were collected for the experiment, which was carried out in a completely randomized design. The dry matter (DM) of olive leaves contains mostly carbohydrates (56.15 to 59.42 g 100 g-1 DM) and fibers (17.37 to 19.73 g 100 g-1 DM) in its bromatological composition. The total polyphenol content ranges from 13.27 to 22.81 mg GAE g-1, with cultivar Manzanilla standing out, and the flavonoid content from 6.50 to 7.65 mg QE g-1. Manzanilla shows the highest antioxidant activity of 93.56 and 78.15% in the DPPH and ABTS assays, respectively. When compared with the other cultivars, Manzanilla and Koroneiki have leaves with a higher green intensity and total chlorophyll content of 0.958 and 0.833 mg 100 mL 1, respectively. In the ABTS assay, there is a correlation both between total polyphenol content and antioxidant activity and between chlorophyll content and antioxidant activity. Olive leaves have characteristics that allow their application as an additive or ingredient for the development of food products with satisfactory antioxidant activity.