RESUMO
Composition and antioxidant properties of sixteen pecan [Carya illinoinensis (Wangenh) K. Koch] cultivars grown simultaneously in a single experimental orchard in Uruguay were evaluated to characterize their nutritional properties and nutraceutical potential. The percentage of oil, moisture, ash, minerals, and proteins were determined and also the fatty acid profile. Total phenolic compounds [18-41 mg gallic acid equivalents (GAEs)/g], condensed tannin [2-12 mg catechin equivalents (CEs)/g], and tocopherols (110-163 µg/g) contents were estimated in nut kernels. Total phenolic compounds (32-117 mg GAE/g), condensed tannins (130-357 mg CE/g), and total anthocyanins (1-3 mg 3-glucoside cyanidin/g) were also determined for pecan shells. The antioxidant activity in shells [57.15-578.88 µmol Trolox equivalents (TEs)/g] was 5 times higher compared with the kernels (23.15-156.60 µmol TEs/g) measured with hydrophilic ORAC. Bioactive compounds concentrations present statistically significant genetic variability between cultivars studied (p < 0.05). The presence of phenolic compounds was related with high-antioxidant capacity in kernels and shells, and a strong correlation between content of total phenolic compounds and condensed tannins in pecan shells was found. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) show association between cultivars and the observed variables. The nutritional profile in the different cultivars showed the trends described in other countries, but this work shows some significant differences that could be attributed to the specific edaphoclimatic conditions of cultivation in Uruguay.
RESUMO
Scab, caused by the plant-pathogenic fungus Venturia effusa, is a major disease of pecan in South America, resulting in loss of quantity and quality of nut yield. Characteristics of the populations of V. effusa in South America are unknown. We used microsatellites to describe the genetic diversity and population structure of V. effusa in South America, and determined the mating type status of the pathogen. The four hierarchically sampled orchard populations from Argentina (AR), Brazil (BRC and BRS), and Uruguay (UR) had moderate to high genotypic and gene diversity. There was evidence of population differentiation (Fst = 0.196) but the correlation between geographic distance and genetic distance was not statistically significant. Genetic differentiation was minimal between the UR, BRC, and BRS populations, and these populations were more clearly differentiated from the AR population. The MAT1-1 and MAT1-2 mating types occurred in all four orchards and their frequencies did not deviate from the 1:1 ratio expected under random mating; however, multilocus linkage equilibrium was rejected in three of the four populations. The population genetics of South American populations of V. effusa has many similarities to the population genetics of V. effusa previously described in the United States. Characterizing the populations genetics and reproductive systems of V. effusa are important to establish the evolutionary potential of the pathogen and, thus, its adaptability-and can provide a basis for informed approaches to utilizing available host resistance and determining phytosanitary needs.
Assuntos
Ascomicetos , Carya , Ascomicetos/genética , Brasil , Carya/genética , Carya/microbiologia , Fungos do Gênero Venturia , Genes Fúngicos Tipo Acasalamento/genética , Variação Genética , Genética Populacional , Doenças das Plantas/microbiologiaRESUMO
Worldwide olive industry has expanded into new climatic regions outside the Mediterranean basin due to an increase in extra virgin olive oil demand posing new challenges. This is the case of Uruguay, South America, where the olive crop area reached 10,000 hectares in the last 15 years and is intended to the production of EVOO. Uruguay has a temperate humid climate with mean precipitations above 1,100 mm per year but unequally distributed, mild winters, and warm summers, with mean annual temperatures of 17.7°C. Different agroecological conditions require local knowledge to achieve good productivity whereby the objective of this work was to show the feasibility and potential of olive oil production under our climatic conditions. For this the agronomic performance of Arbequina, Barnea, Frantoio, Leccino, Manzanilla de Sevilla, and Picual cultivars was evaluated along 10 years of full production. Phenology behavior, vegetative growth rate, productive efficiency, alternate bearing, and oil yield were determined. Sprouting and flowering processes occur in a wide window within the annual cycle between the months of August to November with great interannual variation. More than 8 t/ha fruit yield and 40% oil yields in dry weight basis were obtained in promising cultivars. However, alternate bearing arose as the main production limiting factor, with ABI values greater than 0.60 for most cultivars. We conclude that olive oil production in humid climate regions is feasible and the most promising cultivars based on productive efficiency are Arbequina and Picual.