ISSR molecular characterization and leaf volatiles analysis of Pittosporum undulatum Vent. naturalized in the Azores archipelago (Portugal)

Pittosporum undulatum from the Azores archipelago was characterized by both molecular and volatiles analyses. Inter simple sequence repeat (ISSR) evaluation was performed based on a random sampling of 77 individuals from a total of 123 samples collected on all the Azorean islands. Molecular studies grouped the samples mainly according to the geographical collection site, with some exceptions. Leaf volatiles were isolated by distillation-extraction and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) from all the 123 samples. Cluster analysis based on the leaf volatiles chemical composition defined three main clusters, not related to sample site collection, and was based mainly on the relative amounts of limonene (3-89%), sabinene (0.1-64%) and terpinen-4-ol (traces-43%). Clusters obtained from both molecular studies and volatiles composition were not superimposable and no correlation between ISSR markers and volatile oils could be drawn. The results suggest that there is a high genetic variability among individuals of P. undulatum that can explain the invasive ability of this species in the Azores archipelago. The detailed characterization of this alien weed species may assist finding potential commercial uses as well as management strategies to help its eradication and/or control.     

Nutritional evaluation of Tenebrio molitor meal as fishmeal substitute for tilapia (Oreochromis niloticus) diet

Fishmeal (FM) and soy meal (SM) are the most common protein sources used in fish feed, but they are associated with environmental, economic or production problems. Insects could be an interesting alternative source of protein. This work investigates the nutritive value of Tenebrio molitor meal (TM) and the effect of total replacement of SM by TM (TM/FM diet) or partial replacement of FM by TM (TM/FM/SM diet) versus a diet based in SM and FM (FM/SM diet) for tilapia. We studied the chitin content in TM, the in vitro protein digestibility, protease activity, oxidative stress and antioxidant defences, growth performance and nutrient utilization. The results indicate that an inclusion up to 500 g kg^?1 of TM in the diet did not affect feed intake, in vitro protein digestibility, muscle amino acid composition or biometric indexes. However, their inclusion reduced growth performance and affected the muscle fatty acid profile. The lowest values for protease activity, elevated FRAP in digestive tracts and ROS level in muscle and higher SOD activity were observed in fish fed with SM/FM diet. The use of TM requires better understanding of the role of chitin in digestion and the study of toxins that might affect fish growth.     

Impacts of cropping system and management practices on the assembly of weed communities

Understanding how weed communities assemble as a function of biotic and abiotic filters and transform through time has important implications for the sustainable management of agronomic systems. In a three‐year study, we evaluated weed community responses to lucerne (Medicago sativa, perennial) vs. continuous spring wheat (Triticum aestivum, annual, CSW) and weed management practices where weeds in the CSW system were managed with three contrasting approaches (herbicide, tillage or sheep grazing). Our results indicated no differences in weed diversity between the perennial and annual crops or across the different management practices in CSW. However, there were differences in weed community composition. Lucerne, with the exception of the establishing year, impeded the growth and reproduction of several annual weeds, including Amaranthus retroflexus, Thlaspi arvense, Lamium amplexicaule and Chenopodium album, but favoured perennial broad‐leaved weeds such as Taraxacum officinale and Cirsium arvense. The replacement of herbicide treatments in pre‐plant and post‐harvest in CSW with soil tillage or sheep grazing selected for different weed communities beyond the second year of establishment. The weed species driving the differences in CSW systems were Androsace occidentalis, more common in CSW managed chemically; Asperugo procumbens, more common in CSW managed with tillage; and T. officinale and Lactuca serriola, more common in CSW managed with sheep grazing. Understanding how cropping systems modify weed communities is a necessary step to shift from reactive weed control programmes to predictive management strategies.     

<Emphasis Type="Italic">In situ</Emphasis> conservation and genetic diversity of three populations of <Emphasis Type="Italic">Gossypium mustelinum</Emphasis> Miers ex Watt

Gossypium mustelinum Miers ex Watt is a native from Northeastern Brazil and belongs to the primary gene pool of the cultivated cotton. The unique places where the species was known to occur were visited to plan ex situ and in situ preservation. Two populations at Caicó became extinct, and only eleven individuals were found. At Jaguarari, although one population became extinct, a new one was localized with approximately 500 adult plants, where a fence avoided cattle feeding. The population from Macururé consisted of 28 plants protected from animals by thorns of Bromelia laciniosa Mart. ex Schult. f. Thirteen SSR primer pairs amplified 40 alleles, among which 30% were exclusive of one of the populations. The genetic differences between populations represented 58.3% of the total genetic variation observed. The high genetic distances are likely to be caused by geographical isolation as well as by the small number of individuals which contribute to new generations, and consequential genetic drift.     

Comparison of the evolution of low molecular weight phenolic compounds in typical Sherry wines: Fino,Amontillado, and Oloroso

Changes in the content of low molecular weight phenolic compounds (hydroxybenzoic and hydroxycinnamic acids, aldehydes, and their esterified derivatives, tyrosol and 5-(hydroxymethyl)-2-furaldehyde) during the aging of three different classes of Sherry wine, Fino, Oloroso, and Amontillado, have been studied. The samples studied were taken from each of the scales of the particular aging system applied to the three classes of wine. Clear differences were observed in the behavior of the low molecular weight phenolic in the three classes of wine. The wines subjected to oxidative aging presented a higher phenolic content overall, with the exception of the esterified derivatives of phenolic compounds that are mainly found in the samples that have not undergone any process of oxidation. MANOVA results confirmed that there are significant differences between all of the samples of the three types of wines. Using LDA, a classification of 100% of the samples has been made.     

Characterization and differentiation of sherry brandies using their aromatic profile

Aroma compounds of 48 Sherry brandies have been identified and quantified by the stir bar sorptive extraction method coupled to gas chromatography-mass spectrometry (SBSE-GC/MS). Analysis of variance and multivariate analysis techniques have been used to classify these brandy samples according to the commercial category (Solera brandy, Solera Reserva brandy, and Solera Gran Reserva brandy). From an univariate point of view (analysis of variance), several of the volatile compounds considered showed significant differences. Principal component analysis, using the global data matrix, showed that only the Solera brandy samples, with the shortest aging in wood, were well-differentiated from the others. Partial least-squares discriminant analysis (PLS-DA) results provided evidence of the ability of the content of volatile compounds to discriminate among the different commercial categories. Linear discriminate analysis allowed for a 93% differentiation according to the commercial category and, thus, the length of its aging process in wood. The results obtained show that it would be possible to ensure the commercial category of a Sherry brandy using its content of volatile compounds.     

Soil and rootstock influence on fruit quality of plums (Prunus domestica L.)

Soil and rootstock can particularly affect the ‘Rainha Claudia Verde’ (Prunus domestica) fruit quality, mainly its firmness characteristics. To investigate the variation in fruit quality, plums were harvested at commercial maturity from trees grafted on Marianna GF8-1 (Prunus cerasifera × munsoniana) and Marianna GF10-2 (P. cerasifera × munsoniana) rootstocks on two different soils: Haplic Luvisol and Vertic Luvisol. After harvest fruits were stored at 2 °C for 3 weeks. At the harvest day a small group of fruits were analysed without cold storage. During storage fruits were tested for firmness, soluble solids content, titratable acidity and fruit mineral content. Tree vigour was evaluated from trunk cross-sectional areas values.The GF8-1 rootstock promoted the highest vegetative development, comparing to GF10-2. This rootstock promoted the largest fruits size and the higher calcium fruit level. Positive correlations were found between higher concentrations of calcium in the pulp fruits and firmness. Fruits from two different rootstocks showed the same firmness at harvest but during cold storage, fruits from GF10-2 rootstock exhibited the highest firmness pulp values. There weren’t significant differences in fruit nitrogen and potassium levels for any studied factor.At harvest solids soluble content and solids soluble content/titratable acidity ratio weren’t affected by soil type or rootstock. As expected, solids soluble content during cold storage increased and solids soluble content/titratable acidity had a slight increase.GF10-2 revealed to be a good option as a ‘Rainha Claudia Verde’ rootstock for plums growers due to its intermediate-vigour. Also GF10-2 fruits presented better quality during storage comparing with GF8-1.     

Minimum number of measurements for efficient estimation of black spot resistance in papaya genotypes

European Journal of Plant Pathology - During a field survey in Tamil Nadu (2014–16), chilli plants showing chlorotic and necrotic ring spots and necrotic streaks on leaves and stems were...