Anthocyanin and Oil Contents,Fatty Acids Profiles and Antioxidant Activity of Mexican Landrace Avocado Fruits

Mexican landrace avocados are naturally distributed mainly in high areas of central Mexico, where they have been produced and consumed since pre-Hispanic times. However, trees of these species are being replaced by improved varieties with greater global demand, and many species have been lost due to the destruction of their natural habitats. Many people in Mexico like to consume the pulp and peel of these fruits and have done so since pre-Hispanic times. This is because the peel of Mexican landrace avocados, unlike the peel of Hass avocados, is very thin and flavorful. The peel color may be bluish-purple or dark reddish due to the presence of anthocyanins, which are compounds with antioxidant activity. The objective of this study was to assess the oil and anthocyanin contents and to evaluate the antioxidant activity in fruits of 11 accessions collected from producing-regions of Mexico. The oil content was 16.2 to 32.3 g 100 g^?1 in pulp, and the main unsaturated fatty acids were oleic, linoleic and palmitoleic acids, depending on the accession. The anthocyanin contents in peels ranged from 0.64 to 47 mg g^?1 fresh weight. The highest antioxidant activity was found in the peel (53.3–307.3 mmol g^?1 fresh weight). The results confirm that the pulp and peel of dark-peel Mexican landrace avocados could be important nutraceuticals for humans.

     

Stratified sampling in fruit orchards using cluster-based ancillary information maps: a comparative analysis to improve yield and quality estimates

Precision Agriculture - Estimation of yield or other fruit quality parameter is of great interest to farmers to decide on management actions just before harvesting and, in any case, to anticipate...     

Domestication and saponins contents in a gradient of management intensity of agaves: <Emphasis Type="Italic">Agave cupreata</Emphasis>, <Emphasis Type="Italic">A. inaequidens</Emphasis> and <Emphasis Type="Italic">A. hookeri</Emphasis> in central Mexico

Saponins occur in numerous plants, including agaves, determining benefic and harmful properties to humans; their presence may favor using plants as soap and other products, but also they may cause caustic effects producing contact dermatitis. In domestication, favorable and unfavorable properties of saponins may cause an increase or decrease of their content, respectively. This study quantified and identified saponins among wild and managed populations of three agave species: A. cupreata Trel. et Berger, A. inaequidens Koch with wild and cultivated populations used for mescal production, and A. hookeri Jacobi, existing exclusively cultivated, used for production of the fermented beverage pulque. We studied 272 plants from 19 populations, quantifying contents of crude saponins through spectrometry. In 12 populations, the saponins types were identified by High Performance Liquid Chromatography–Mass-Spectrography-Time-of-Flight HPLC-MS-TOF. The highest crude saponins content was recorded in A. hookeri (26.09 mg/g), followed by A. cupreata (19.85 and 15.17 mg/g in wild and cultivated populations, respectively). For A. inaequidens, we recorded 14.21, 12.95, and 10.48 mg/g in wild, silvicultural managed and cultivated populations, respectively. We identified 18 saponins types, A. inaequidens showing all of them. A hecogenin glycoside (HG1) is found in high amounts in A. hookeri but in low quantities in A. inaequidens and A. cupreata. A. inaequidens had the greatest diversity of saponins. The contents of crude saponins in A. inaequidens and A. cupreata decrease with management intensity, but contrarily to what we expected, it was the highest in A. hookeri. We hypothesize that such high amount could be due to some saponins, probably HG1, may be precursors of sugars.     

A winter intercrop of faba bean and rapeseed for silage as a substitute for Italian ryegrass in rotation with maize

In order to combine the ability of legumes to fix atmospheric nitrogen and the cruciferous capacities to mobilize soil nutrients and herbicide action, the aim of this work was to evaluate an alternative winter intercrop (faba bean-rapeseed) as a replacement of Italian ryegrass culture in a rotational system with maize as summer crop. For this purpose, two adjacent plots were used during three agronomic years (2011–2012, 2012–2013 and 2013–2014) to evaluate the agronomic performance through the forage production, nutritional composition of forage and silage, and the effects on soil fertility. The Italian ryegrass was cultivated under conventional management: using chemical fertilization and recommended dosages of herbicides. The faba bean-rapeseed intercrop was cultivated under an alternative management: organic fertilization and less herbicide supply. The intercrop provides higher forage yield per hectare than Italian ryegrass, with greater protein (kg ha^?1) and similar energy (GJ ha^?1) yields. The intercrop allows reducing the inputs of chemical fertilization and herbicides, and it has a positive effect on the balance of soil nutrients, especially increasing the potassium, calcium and magnesium contents. The results show that faba bean-rapeseed intercrop could be an alternative to the Italian ryegrass as winter crop.     

Biomass,nitrogen and potassium dynamics in hydroponic rose production

Purpose: Roses are one of the ornamental species of major importance and economic value. Fertilisation programmes which maximise plant growth and quality, while minimising environmental impact are important. Here, we followed the N and K dynamics during rose development with the aim to define the nutrient demands as a basis for implementing fertigation programmes.

Materials and methods: Roses with one basal break were grown in a closed hydroponic system. Destructive samples were taken to determine dry weight, N and K content. In each sample, plants were sectioned into roots, rootstock, basal break, stems and leaves from the zone of active leaves and the zone of cutting flowers, as well as the flower bud in the latter.

Results: The shoots of the active leaves and cutting flowers zones exhibited a biphasic growth; dry weight, N and K increased after pruning of the zone of active leaves and the cutting flowers zone, however, in the second phase, total dry weight did not show a significant difference between the phenological phases, while the accumulation of N and K decreased throughout the entire plant.

Conclusions: Our results suggest that greenhouse roses develop a dynamic and complex balance between the aerial parts of the plants and the roots for storage and/or transport of photoassimilates, N and K. The total demand for N was 411 and 799?mg per plant for the initial shoot development of the active leaf zone and cutting flowers zone, respectively. The demand for K was 149 and 106?mg per plant for both shoots, respectively. The loss of N (555?mg per plant) and K (167?mg per plant) from roses plants to the root environment implies that lower fertiliser inputs can be used as these nutrients may be re-uptaken by new emerging roots.     

Performance of three-layer composites with densified surface layers of Nothofagus pumilio and N. antarctica from Southern Patagonian forests

Nothofagus pumilio and N. antarctica forests of Southern Patagonia, Argentina are currently being managed for production of saw logs with fast growing conditions. The result of these management strategies is faster growing forests, but also an increase in the percentage of low-density wood. The motivation for this study was to find a way to valorise this low-density wood. Surface and bulk densification treatments were applied these wood species and were then applied as face layers in three-layer composites. The mechanical properties of three-layer composites were studied. The modulus of elasticity, modulus of rupture, and modulus of hardness were improved compared to many types of structural composite lumber. This increase in mechanical properties of N. pumilio and N. antarctica wood opens the possibility for its use in structural composites and added value to these otherwise underutilised and undervalued species.     

Evaluation of the feeding value of <Emphasis Type="Italic">Dichrostachys cinerea</Emphasis> pods for fattening pigs in Cuba

Dichrostachys cinerea (L.) Wight & Arn. is a tropical leguminous shrub widely regarded as an invasive species in Cuba, after having invaded a significant proportion of its arable land during the past decades. Concurrently, smallholder pig producers are highly constrained by the scarcity of protein feeds. This study aimed to assess the feeding value of D. cinerea pod meal (DCPM) as an alternative protein supplement for pigs in Cuban smallholder production systems. An on-farm feeding trial was carried out with three groups (N = 10) of growing-fattening pigs over 60 days, where DCPM replaced 0, 15, and 30% in DM of a dietary commercial concentrate. Then, in an in vivo digestibility trial with eight growing pigs, apparent digestibilities of DCPM were determined for dry matter (DM), organic matter (OM) and crude protein (CP). Finally, in vitro digestibilities for OM (fecal and ileal) and CP (ileal) were determined. In the feeding trial, pig body weight gains were not affected by increased dietary substitution levels of concentrate for DCPM. Blood parameters, with a few exceptions, did not show significant differences among groups. Values for in vivo OM and CP digestibilities were 40.81 and 50.26%, and substantially higher than in vitro values. In conclusion, our results showed that at least 30% of DM in commercial concentrate could be substituted by DCPM without affecting pig growth performances under Cuban smallholder conditions. The low digestibility of DCPM is, however, not acceptable for intensive pig production systems. In vitro enzyme digestibility methods developed for commercial pig feeds are not suitable for DCPM without further calibration.     

Intensive grazing and maize silage to enhance the sustainability of small-scale dairy systems in the highlands of Mexico

Tropical Animal Health and Production - The effects of two innovative feeding strategies—intensive grazing (GR) and maize silage (MS)—on the sustainability of small-scale dairy systems...     

Gaussian covariance graph models accounting for correlated marker effects in genome‐wide prediction

Several statistical models used in genome‐wide prediction assume uncorrelated marker allele substitution effects, but it is known that these effects may be correlated. In statistics, graphical models have been identified as a useful tool for covariance estimation in high‐dimensional problems and it is an area that has recently experienced a great expansion. In Gaussian covariance graph models (GCovGM), the joint distribution of a set of random variables is assumed to be Gaussian and the pattern of zeros of the covariance matrix is encoded in terms of an undirected graph G. In this study, methods adapting the theory of GCovGM to genome‐wide prediction were developed (Bayes GCov, Bayes GCov‐KR and Bayes GCov‐H). In simulated data sets, improvements in correlation between phenotypes and predicted breeding values and accuracies of predicted breeding values were found. Our models account for correlation of marker effects and permit to accommodate general structures as opposed to models proposed in previous studies, which consider spatial correlation only. In addition, they allow incorporation of biological information in the prediction process through its use when constructing graph G, and their extension to the multi‐allelic loci case is straightforward.     

Response to the letter on “Climatic distribution of citrus black spot caused by <Emphasis Type="Italic">Phyllosticta citricarpa.</Emphasis> A historical analysis of disease spread in South Africa” by Fourie et al. (2017)

In a previous study, Martínez-Minaya et al. (European Journal of Plant Pathology 143, 69–83, 2015) performed an analysis of climate-based distribution of citrus black spot (CBS) in South Africa. It was found that CBS was initially confined to humid areas with summer rainfall, but later spread to arid steppe and even desert climates. A strong spatial autocorrelation of CBS distribution was found. Fourie et al. (European Journal of Plant Pathology, 2017) take a critical view of our study, but without presenting any analysis of results to refute our findings. Furthermore, Fourie et al. (European Journal of Plant Pathology, 2017) appear to have misunderstood our work, since many of their criticisms relate to the potential distribution of CBS in Europe, which is beyond the scope of our original study. Fourie et al. (European Journal of Plant Pathology, 2017) highlight the limitations of climate classifications in species distribution modelling. However, this was made explicit in our study, indicating that it was a preparatory work and further advanced modelling studies, including spatial effects, will be needed. Fourie et al. (European Journal of Plant Pathology, 2017) incorrectly assume that we used all of South Africa as the background in the spatial autocorrelation analysis. However, only citrus areas were used and a strong spatial autocorrelation was detected at all distances evaluated. Contrary to what Fourie et al. (European Journal of Plant Pathology, 2017) suggest, similar climate distributions of CBS were obtained at 5′ and 30′ resolution, and also with the national land-cover map of South Africa. The figure comparison presented by Fourie et al. (European Journal of Plant Pathology, 2017) appears to ignore the fact that the maps we used were grid cells of 10 × 10 km and not the line polygons they suggest. Therefore, we consider the conclusions from the Martínez-Minaya et al. (European Journal of Plant Pathology 143, 69–83, 2015) remain entirely valid.