Mango Fruit Detachment of Trees after Applying a Blend Composed of HNO3 and Charcoal Activated.

As young workers prefer urban labors and migrate to USA and Canada, mango harvesting is becoming scarce on Mexican coasts. This seasonal labor is becoming expensive and when many orchards produce fruit simultaneously, grower losses increase. In this research, an innovative fruit detachment method was tested after applying a viscous paste to the pedicel of mango fruits hanging in the tree. Activated carbon or charcoal (AC), was mixed with different amounts of nitric acid to provide three AC composite blends named: light, medium, and dense. The nanomaterial was applied with a brush to the fruit pedicel/peduncle taking up to 4 h before the mango fruits felt to a net below the tree canopy. Mango detachment experiments indicated that the medium blend was the most efficient in releasing the fruit, taking an average of 2 h. The dense nano-material decreased latex exudation to 7% of the fruits. Fruit maturity emerged as a crucial factor for detachment time, followed by mango weight.

Multi-Criteria Analysis for the Prioritization of Areas for the In Situ Conservation of Crataegus L., an Underutilized Fruit Tree in Mexico.

Complementary ex situ and in situ conservation, including the on-farm alternative, is a highly desired and dynamic strategy that allows the natural evolution of the conserved germplasm. Due to the high costs involved, in addition to the limitations of both economic and human resources, in situ conservation must focus on areas where the greatest benefits are obtained, and the efforts made result in better impacts. Therefore, using spatial multi-criteria analysis and expert knowledge, 22 and 23 criteria were obtained as important for the conservation of wild and cultivated hawthorn, respectively. Criteria weights were calculated by the analytic hierarchy process and expert knowledge. The results showed species richness, phenotypic and ecogeographic diversity, and areas not covered by the official protected areas network were the most important criteria for in situ conservation of wild hawthorn. Prioritized areas were particularly focused in Chiapas, State of Mexico and Morelos. The prioritized areas for the in situ conservation of cultivated hawthorn were mostly defined by criteria such as number of cultivated varieties, number of uses, phenotypic diversity, ecogeographical diversity, and areas with rainfed agriculture. These areas were located mainly in Puebla. From this study, we propose a list of priority areas for the in situ conservation of both cultivated and wild hawthorn.

The avocado genome informs deep angiosperm phylogeny, highlights introgressive hybridization, and reveals pathogen-influenced gene space adaptation.

The avocado, Persea americana, is a fruit crop of immense importance to Mexican agriculture with an increasing demand worldwide. Avocado lies in the anciently diverged magnoliid clade of angiosperms, which has a controversial phylogenetic position relative to eudicots and monocots. We sequenced the nuclear genomes of the Mexican avocado race, P. americana var. drymifolia, and the most commercially popular hybrid cultivar, Hass, and anchored the latter to chromosomes using a genetic map. Resequencing of Guatemalan and West Indian varieties revealed that ∼39% of the Hass genome represents Guatemalan source regions introgressed into a Mexican race background. Some introgressed blocks are extremely large, consistent with the recent origin of the cultivar. The avocado lineage experienced 2 lineage-specific polyploidy events during its evolutionary history. Although gene-tree/species-tree phylogenomic results are inconclusive, syntenic ortholog distances to other species place avocado as sister to the enormous monocot and eudicot lineages combined. Duplicate genes descending from polyploidy augmented the transcription factor diversity of avocado, while tandem duplicates enhanced the secondary metabolism of the species. Phenylpropanoid biosynthesis, known to be elicited by Colletotrichum (anthracnose) pathogen infection in avocado, is one enriched function among tandems. Furthermore, transcriptome data show that tandem duplicates are significantly up- and down-regulated in response to anthracnose infection, whereas polyploid duplicates are not, supporting the general view that collections of tandem duplicates contribute evolutionarily recent "tuning knobs" in the genome adaptive landscapes of given species.

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.

Estimación de la variabilidad interna de muestras de poblacionales mediante análisis de componentes principales / Estimate of internal variability of population samples by means of principal component analysis

Se propone una nueva fórmula para describir la variación interna de grupos o poblaciones utilizando m variables con un solo dato. Esta fórmula esta basada en el análisis de componentes principales (ACP), ya que este análisis permite reducir la dimensionalidad con mínima pérdida de información, y en la idea empírica de la varianza, la dispersión de los individuos con respecto a su media. A partir de la proyección de individuos en un ACP se observa la dispersión de individuos en planos con dimensionalidad reducida, los componentes principales (CP) necesarios para explicar 50 por ciento de la varianza total. Una variable categórica es usada para dividir a todos los individuos en k grupos de n individuos cada uno dentro de un mismo ACP, teniendo para cada uno de los k grupos un valor que se puede comparar con los otros para determinar la homogeneidad de cada grupo. Además, es posible detectar, mediante el cálculo adicional del error estándar de esta fórmula, si se presentan individuos atípicos dentro de cada uno de estos grupos