Epistasis in the resistance of pepper to phytophthora stem blight (Phytophthora capsici L.) and its significance in the prediction of double cross performances

Summary Epistatic effects are present in the resistance to Phytophthora capsici in peppers (Capsicum annuum). Genetic statistical analysis shows that additive by additive epistasis as well as higher order epistatic effects contribute to the total variation of resistance, significantly. Higher order epistatic effects caused bias in the prediction of the performance of double crosses, the difference between observed and predicted performances being significant.The relative importance of higher order epistasis with respect to additive by additive epistasis seems to be correlated with the aggressiveness of the isolate of Phytophthora capsici.     

Comparison of Diclofenac Diethylamine Permeation Across Horse Skin from Five Commercial Medical Human Formulations

The aim of this study was to compare the penetration of diclofenac through horse skin in vitro and its efficacy in vivo when applied from five, commercially available, human medical formulations containing 1.16% diclofenac diethylamine. The rate of transdermal penetration of diclofenac varied between formulations. Also, estimated steady-state flux (Jss) was significantly different from that reported for human and rat skin. All the tested formulations produced a very weak and short-lasting antiedematous effect.     

Floristic and structural recovery of a laurel forest community after clear-cutting: A 60 years chronosequence on La Palma (Canary Islands)

We analyzed a post-clearcut chronosequence (0.5 to 60 years after harvesting) in the laurel forest of La Palma island (Canarian Archipelago) to determine the recovery of the stands with respect to species composition, richness, life strategies and structural parameters of the canopy. Multivariate analysis showed that exotic species, as well as annual ruderal species were confined to early-successional stages, while native perennials, typical of laurel forests, dominated the late-successional stages. Total species richness decreased significantly with time after clear-cutting. The relative fast recovery of understory native species may be due to low forest floor disturbance during harvesting. Shade-intolerant pioneer, pioneer-remnant and shade-tolerant late-successional species were the main life strategies of native tree species. Most structural parameters showed a continuous and monotonic increase (basal area, biomass) or decrease (density, percentage of photosynthetic biomass) during succession. Once clear-cutting, here performed with an interval of 8 years, is abandoned, the recovery of the laurel forest seems possible due to careful logging that protects the soil and a rapid asexual regeneration of native tree species, revealing this to be a sustainable management practice.     

Dynamics of ecosystem services in <Emphasis Type="Italic">Pinus sylvestris</Emphasis> stands under different managements and site quality classes

Timber and biodiversity are considered two antagonistic ecosystem services (ES), largely influenced by silviculture and site ecological conditions. In order to address the trade-offs between these two ES over time, we performed a retrospective study at compartment level in the Pinus sylvestris forests of the Spanish Central Mountain System. Archival data from Management Plans for eight forests with contrasting silvicultural systems (uniform shelterwood system, group shelterwood system, irregular shelterwood system,) and three different site quality classes were analysed. Timber production was assessed through stand volume, harvested timber volume and a stand volume index. Biodiversity was examined through structural diversity (Gini index, Shannon tree size diversity index, Simpson’s reciprocal index and evenness index, all applied to diameter classes) and the abundance of large living trees. For all silvicultural systems investigated, stand volume and harvested timber volume have grown since the beginning of the management plans (beginning of the twentieth century in some forests). The largest yields of timber corresponded to the best quality sites with more intensive silvicultural treatments (uniform and group shelterwood systems). The uniform shelterwood system showed lower figures for structural diversity, though not always significant. The best site qualities maintained notable structural diversity values, even under the most intensive management system. The application of the different management systems over decades has revealed a synergy between timber production and structural diversity, particularly in those systems maintaining more than one age class, although results are conditioned by forest harvesting history. The interaction between historical silvicultural treatment and site quality has been identified as an important source of information to understand forest dynamics and functioning of ES provision.     

Edible mushrooms: Role in the prevention of cardiovascular diseases

Edible mushrooms are a valuable source of nutrients and bioactive compounds in addition to a growing appeal for humans by their flavors and culinary features. Recently, they have become increasingly attractive as functional foods for their potential beneficial effects on human health. Hence, food industry is especially interested in cultivated and wild edible mushrooms.     

The role of silicon fertilization in the synthesis of phenolic compounds on chestnut plants infected with P. cinnamomi and C. parasitica

Journal of Plant Diseases and Protection - Silicon is considered a beneficial nutrient for agricultural crops by conferred protection against diseases. The antifungal effect of the phenolic...     

Dynamic stock model for analysing semi‐intensive production of whiteleg shrimp Litopenaeus (Penaeus) vannamei affected by the acute hepatopancreatic necrosis disease: Assessment of disease severity indicators and relationships with pond water quality parameters

The production of Litopenaeus vannamei was analysed when affected by the acute hepatopancreatic necrosis disease using a dynamic stock model and primary data of seven production cycles from a shrimp farm in Mexico from 2013 to 2016. Significant results (p < .05) of the correlation analysis indicated that during those years mortalities by the disease were more severe when water salinity was high and productivity was low. Significant results from ANOVA showed that throughout the period, disease severity and salinity diminished while pond productivity initially declined but subsequently improved. Significant results from regression analyses conducted for each production cycle also indicated the importance of salinity and productivity on disease severity and showed that early mortality by the disease occurred in ponds with warmer water. Within the observed range of water quality parameters, increases of 1 cm in water transparency and 1 g/L in salinity resulted in increments within 0.17%–0.25% and 1.7%–3.1% in shrimp mortality by the disease. When increases of 1°C in water temperature were recorded, outbreaks occurred 0.2–1.57 weeks earlier. In conclusion, the disease strongly determines the dynamics of shrimp production, and the role of salinity, productivity and temperature is worthy of further delving.     

Effect of dietary protein‐to‐energy ratio on reproduction in female redclaw crayfish Cherax quadricarinatus

The effect of eight diets with different protein‐to‐energy ratios (P–E ratio=10, 11, 14, 16, 18, 20, 22, 24 mg kJ^?1) on reproduction of female redclaw crayfish Cherax quadricarinatus was tested under laboratory conditions. After 75 days, there was a significant effect of the P–E ratio on final weight, spawning females and the number of juveniles per female. Using the broken‐line and quadratic equations, optimal values for the P–E ratio were: 16.0, 17.1 and 16.0 mg kJ^?1. The P–E ratio significantly affected protein and carbohydrate content and energy in the hepatopancreas. The broken‐line model indicated that the respective recommended values of the P–E ratio for these parameters were: 21.8, 16.7 and 18.6 mg kJ^?1. The concentration of carbohydrates and energy in muscle tended to significantly diminish as the P–E ratio increased. From broken‐line regression analysis, the recommended P–E ratio was 16.6 and 20.2 mg kJ^?1 respectively. No significant differences were found in survival, fecundity, vitellin content in eggs, protein and lipid content in muscle and lipids in the hepatopancreas. We concluded that, overall, a P–E ratio of 18±2 mg kJ^?1 is optimal for reproductive activity of female redclaw crayfish.     

Promotion and contribution of biota in low water exchange ponds farming blue shrimp Litopenaeus stylirostris (Stimpson)

An experimental study was conducted during 20 weeks in Bahia Kino, Sonora, Mexico, in order to evaluate the feasibility of promoting biota in low‐water exchange ponds farming blue shrimp, Litopenaeus stylirostris. The effect of that promotion on the production parameters of cultured shrimp as well as on the water quality parameters was evaluated. Treatments consisted of: (i) ponds fed formulated food (FF), and (ii) ponds fed formulated plus promoted natural food (NFF). Phytoplankton, zooplankton and benthos were effectively promoted during some weeks of the culture period. Growth and feed conversion ratio (15.16 g and 1.79 respectively) were significantly better in treatment NFF than in treatment FF (13.89 g and 2.02 respectively). Differences in some of the water quality parameters were observed among treatments. Phosphates (0.15 mg/L versus 0.53 mg/L), and total ammonia‐N (0.09 mg/L versus 0.12 mg/L) presented greater concentrations in treatment FF than in the NFF.