Chapingo Autonomous University

This chapter contains sections titled: The Meaning of Heritability Response to Selection Covariances of Relatives Variance Among Selection Units Estimating Heritability as a Function of Variance Components Estimating Heritability from Parent-Offspring Regression Estimating Realized Heritability Examples of Heritability Estimates Appendices Literature Cited

Abstract. The Intergovernmental Technical Panel on Soils has completed the first State of the World's Soil Resources Report. Globally soil erosion was identified as the gravest threat, leading to deteriorating water quality in developed regions and to lowering of crop yields in many developing regions. We need to increase nitrogen and phosphorus fertilizer use in infertile tropical and semi-tropical soils – the regions where the most food insecurity among us are found – while reducing global use of these products overall. Stores of soil organic carbon are critical in the global carbon balance, and national governments must set specific targets to stabilize or ideally increase soil organic carbon stores. Finally the quality of soil information available for policy formulation must be improved – the regional assessments in the State of the World's Soil Resources Report frequently base their evaluations on studies from the 1990s based on observations made in the 1980s or earlier.

Summary Biochar ( BC ) amendment to soils is a proposed strategy to improve soil fertility and mitigate climate change. However, before this can become a recommended management practice, a better understanding of the impacts of BC on the soil biota is needed. We determined the effect of addition rates (0, 1, 5, 10 and 20% by mass) of a fast‐pyrolysis wood‐derived BC on the extraction efficiency ( EE ), abundance and temporal dynamics of phospholipid fatty acids ( PLFAs , microbial community biomarkers) in four temperate soils during a 1‐year incubation. Additionally, the effects on microbial mineralization/incorporation of BC‐C were determined by measuring CO 2 efflux and the BC contribution to CO 2 and PLFA‐C using the natural 13 C abundance difference between BC and soils. Biochar addition proportionally increased microbial abundance in all soils and altered the community composition, particularly at the greatest addition rate, towards a more gram‐negative bacteria‐dominated (relative to fungi and gram‐positive) community. Though chemically recalcitrant, the BC served as a substrate for microbial activity, more so at large addition rates and in soil with little organic matter. Microbial utilization of BC‐C for growth could only partially explain the observed increase in microbial biomass, suggesting that other, potentially abiotic, mechanisms were involved. The strong decrease in PLFA EE (−77%) in all soils with biochar addition emphasizes the need to measure and correct for EE when using PLFA biomarkers to estimate soil microbial responses to BC additions. Overall, our study provides support for BC use as a soil amendment that potentially stimulates microbial activity and growth.

META-R (multi-environment trial analysis in R) is a suite of R scripts linked by a graphical user interface (GUI) designed in Java language. The objective of META-R is to accurately analyze multi-environment plant breeding trials (METs) by fitting mixed and fixed linear models from experimental designs such as the randomized complete block design (RCBD) and the alpha-lattice/lattice designs. META-R simultaneously estimates the best linear and unbiased estimators (BLUEs) and the best linear and unbiased predictors (BLUPs). Additionally, it computes the variance-covariance parameters, as well as some statistical and genetic parameters such as the least significant difference (LSD) at 5% significance, the coefficient of variation in percentage (CV), the genetic variance, and the broad-sense heritability. These parameters are very important in the selection of top performing genotypes in plant breeding. META-R also computes the phenotypic and genetic correlations among environments and between traits, as well as their statistical significance. The genetic correlations between environments or traits can be visualized in a biplot graph or a tree diagram (dendrogram). Genetic correlations are very important for identifying environments with similar behavior or making indirect selection and identifying the most highly associated traits. META-R performs multi-environment analyses by using the residual maximum likelihood (REML) method; these analyses can be done by environment, across environments by grouping factors (stress conditions, nitrogen content, etc.) and across environments; the analyses across environments can be done with a pre-defined degree of heritability.

Jatropha curcas (L.) is a perennial plant of the spurge family (Euphorbiaceae). Recently, it has received much attention as a potential source of vegetable oil as a replacement for petroleum, and, in particular, the production of biodiesel. Despite the interest that is being shown in the large-scale cultivation of J. curcas, genetic resources remain poorly characterized and conserved and there has been very little plant breeding for improved traits. At present, the varieties being used to establish plantations in Africa and Asia are inedible. The meal obtained after the extraction of oil cannot, therefore, be used as a source of animal feed. Naturally existing edible varieties are, however, known to occur in Mexico. The toxic components of J. curcas seeds, the potential for plant breeding to generate improved varieties, and the suitability of J. curcas oil as a feedstock for biodiesel production are discussed.

Abstract Pincer complexes are useful tools for organic synthesis. Their high stability and easy functionalization have allowed the development of novel catalytic systems that have had a tremendous impact in different areas of chemistry. Thus, catalytic reactions are nowadays a fundamental part of several synthetic routes, as they allow “greener” procedures with high atom efficiency. In this context, pincer complexes have contributed to the establishment of novel and efficient catalytic reactions. Thus, herein we summarize the most recent relevant advances involving pincer complexes as catalysts.

Many Mexican pine ecosystems are characterized by great biological diversity and are strongly influenced by fire. We summarize fire ecology information for 35 taxa (including infraspecific taxa) in terms of nine types of fire traits: serotiny, seed germination after fire, grass stage, fast initial growth, thick bark, protected buds, self-pruning capacity, resprouting, and canopy recovery from scorch. The majority of Mexican pine species appear to be adapted to a predictable, stand-thinning fire regime. Current fire regimes are often altered from long-term historical patterns due to a combination of natural fires plus anthropogenic fires. Human-caused fires are the most common and burning practices have deep historic and socioeconomic roots. As a consequence, there are three main categories of fire conditions: (1) pine forests endangered by excessive anthropogenic fire (eventually leading to deforestation); (2) pine forests maintained by an appropriate fire regime; and (3) pine forests with insufficient fire or fire exclusion due to fire protection. For managers, conservationists, and landowners concerned with maintaining the important benefits associated with fire, such as fuel hazard reduction and nutrient cycling, different approaches are needed. While recognizing the difficult social and economic factors that foster forest degradation, we recommend basing fire management in pine forests upon a site-specific and species-specific understanding of the historical and ecological role of fire, trying to reduce excessive anthropogenic burning, maintain appropriate burning, and restore fire into fire-excluded forests. The interaction of fire with other resource uses, such as timber harvesting and livestock grazing, should also be balanced in a holistic ecosystem management approach. These changes must be made in the context of seeking alternative economic options for rural residents and by thoughtful planning to obtain as many ecological and economic benefits from fire as possible while minimizing negative impacts.

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.

Abstract We provide a review of sustainable coffee certifications and results from a quantitative analysis of the effects of Fair Trade, organic and combined Fair Trade/organic certifications on the livelihood strategies of 469 households and 18 cooperatives of Central America and Mexico. Certified households were also compared with a non-certified group in each country. To analyze the differences in coffee price, volume, gross revenue and education between certifications, we used the Kruskal–Wallis (K–W) non-parametric test and the Mann–Whitney U non-parametric test as a post-hoc procedure. Household savings, credit, food security and incidence of migration were analyzed through Pearson's chi-square test. Our study corroborated the conditions of economic poverty among small-scale coffee farmer households in Central America and Mexico. All certifications provided a higher price per pound and higher gross coffee revenue than non-certified coffee. However, the average volumes of coffee sold by individual households were low, and many certified farmers did not sell their entire production at certified prices. Certifications did not have a discernable effect on other livelihood-related variables, such as education, and incidence of migration at the household level, although they had a positive influence on savings and credit. Sales to certified markets offer farmers and cooperatives better prices, but the contribution derived from these premiums has limited effects on household livelihoods. This demonstrates that certifications will not single-handedly bring significant poverty alleviation to most coffee-farming families. Although certified coffee markets alone will not resolve the livelihood challenges faced by smallholder households, they could still contribute to broad-based sustainable livelihoods, rural development and conservation processes in coffee regions. This can be done by developing more active partnerships between farmers, cooperatives, certifications and environmental and rural development organizations and researchers in coffee regions. Certifications, especially Fair Trade/organic, have proven effective in supporting capacity building and in serving as networks that leverage global development funding for small-scale coffee-producing households.

Digital terrain model (DTM) generation is essential to recreating terrain morphology once the external elements are removed. Traditional survey methods are still used to collect accurate geographic data on the land surface. Given the emergence of unmanned aerial vehicles (UAVs) equipped with low-cost digital cameras and better photogrammetric methods for digital mapping, efficient approaches are necessary to allow rapid land surveys with high accuracy. This paper provides a review, complemented with the authors’ experience, regarding the UAV photogrammetric process and field survey parameters for DTM generation using popular commercial photogrammetric software to process images obtained with fixed-wing or multicopter UAVs. We analyzed the quality and accuracy of the DTMs based on four categories: (i) the UAV system (UAV platforms and camera); (ii) flight planning and image acquisition (flight altitude, image overlap, UAV speed, orientation of the flight line, camera configuration, and georeferencing); (iii) photogrammetric DTM generation (software, image alignment, dense point cloud generation, and ground filtering); (iv) geomorphology and land use/cover. For flat terrain, UAV photogrammetry provided a horizontal root mean square error (RMSE) between 1 to 3 × the ground sample distance (GSD) and a vertical RMSE between 1 to 4.5 × GSD, and, for complex topography, a horizontal RMSE between 1 to 7 × GSD and a vertical RMSE between 1.5 to 5 × GSD. Finally, we stress that UAV photogrammetry can provide DTMs with high accuracy when the photogrammetric process variables are optimized.

Novel species of fungi described in the present study include the following from Australia: Neoseptorioides eucalypti gen. & sp. nov. from Eucalyptus radiata leaves, Phytophthora gondwanensis from soil, Diaporthe tulliensis from rotted stem ends of Theobroma cacao fruit, Diaporthe vawdreyi from fruit rot of Psidium guajava, Magnaporthiopsis agrostidis from rotted roots of Agrostis stolonifera and Semifissispora natalis from Eucalyptus leaf litter. Furthermore, Neopestalotiopsis egyptiaca is described from Mangifera indica leaves (Egypt), Roussoella mexicana from Coffea arabica leaves (Mexico), Calonectria monticola from soil (Thailand), Hygrocybe jackmanii from littoral sand dunes (Canada), Lindgomyces madisonensis from submerged decorticated wood (USA), Neofabraea brasiliensis from Malus domestica (Brazil), Geastrum diosiae from litter (Argentina), Ganoderma wiiroense on angiosperms (Ghana), Arthrinium gutiae from the gut of a grasshopper (India), Pyrenochaeta telephoni from the screen of a mobile phone (India) and Xenoleptographium phialoconidium gen. & sp. nov. on exposed xylem tissues of Gmelina arborea (Indonesia). Several novelties are introduced from Spain, namely Psathyrella complutensis on loamy soil, Chlorophyllum lusitanicum on nitrified grasslands (incl. Chlorophyllum arizonicum comb. nov.), Aspergillus citocrescens from cave sediment and Lotinia verna gen. & sp. nov. from muddy soil. Novel foliicolous taxa from South Africa include Phyllosticta carissicola from Carissa macrocarpa, Pseudopyricularia hagahagae from Cyperaceae and Zeloasperisporium searsiae from Searsia chirindensis. Furthermore, Neophaeococcomyces is introduced as a novel genus, with two new combinations, N. aloes and N. catenatus. Several foliicolous novelties are recorded from La Réunion, France, namely Ochroconis pandanicola from Pandanus utilis, Neosulcatispora agaves gen. & sp. nov. from Agave vera-cruz, Pilidium eucalyptorum from Eucalyptus robusta, Strelitziana syzygii from Syzygium jambos (incl. Strelitzianaceae fam. nov.) and Pseudobeltrania ocoteae from Ocotea obtusata (Beltraniaceae emend.). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

The aim of the present work is to characterize the pigments present in the kernel of four native maize varieties related to the races Arrocillo, Cónico, Peruano, and Purepecha to determine their possible use as natural dyes. Total anthocyanin content is determined by a conventional spectrophotometric method, and anthocyanin analysis is done by high-performance liquid chromatography. The stability of the pigment at pH is also evaluated. The four maize samples contained anthocyanin in both the pericarp and aleurone layer. Total anthocyanin content among samples ranged from 54 mg/100 g of sample to 115 mg/100 g of sample. Anthocyanin profiles are almost the same among the four samples. Differences are observed only in the relative percentage of each anthocyanin. The anthocyanins identified are cyanidin-3-glucoside, pelargonidin- 3-glucoside, peonidin-3-glucoside, cyanidin-3-(6" malonylglucoside), and cyanidin-3-(3",6"-dimalonylglucoside). Anthocyanin extracts showed similar behavior in solutions with different pH. From pH 1-6 lambdamax values are maintained almost constant; however, above this pH value, a marked increase is observed in the bathochromic shifts, but the bluish color did not continue to change above pH 8.

This paper analyses the process of globalization of agriculture and food. Its aim is to demonstrate that, inside of the homogeneous mainstream tendencies of this process dominated by transnational interests, interstices appear that open the way for small producers and middlemen developing certain products on the basis of specific qualities. Those interstices are made possible by the emergence of new patterns of consumption based on new socially shared values. The paper illustrates the argumentation with the case of the fair trade coffee network, which links producers from the ‘South’ with consumers in the ‘North’ around the values of solidarity and fairness. Because the network introduces the fair trade coffee into the large marketing channels in some European countries, it is built on the convergence of various interests among the agents involved in the filière. The paper analyses the ambivalence of the strategy that responds to market logic although it is also based on ethical principles. It finally raises questions about strategies based on specific qualities in the post‐Fordist era.

Corn yields vary spatially and temporally in the plots as a result of weather, altitude, variety, plant density, available water, nutrients, and planting date; these are the main factors that influence crop yield. In this study, different multispectral and red-green-blue (RGB) vegetation indices were analyzed, as well as the digitally estimated canopy cover and plant density, in order to estimate corn grain yield using a neural network model. The relative importance of the predictor variables was also analyzed. An experiment was established with five levels of nitrogen fertilization (140, 200, 260, 320, and 380 kg/ha) and four replicates, in a completely randomized block design, resulting in 20 experimental polygons. Crop information was captured using two sensors (Parrot Sequoia_4.9, and DJI FC6310_8.8) mounted on an unmanned aerial vehicle (UAV) for two flight dates at 47 and 79 days after sowing (DAS). The correlation coefficient between the plant density, obtained through the digital count of corn plants, and the corn grain yield was 0.94; this variable was the one with the highest relative importance in the yield estimation according to Garson’s algorithm. The canopy cover, digitally estimated, showed a correlation coefficient of 0.77 with respect to the corn grain yield, while the relative importance of this variable in the yield estimation was 0.080 and 0.093 for 47 and 79 DAS, respectively. The wide dynamic range vegetation index (WDRVI), plant density, and canopy cover showed the highest correlation coefficient and the smallest errors (R = 0.99, mean absolute error (MAE) = 0.028 t ha−1, root mean square error (RMSE) = 0.125 t ha−1) in the corn grain yield estimation at 47 DAS, with the WDRVI index and the density being the variables with the highest relative importance for this crop development date. For the 79 DAS flight, the combination of the normalized difference vegetation index (NDVI), normalized difference red edge (NDRE), WDRVI, excess green (EXG), triangular greenness index (TGI), and visible atmospherically resistant index (VARI), as well as plant density and canopy cover, generated the highest correlation coefficient and the smallest errors (R = 0.97, MAE = 0.249 t ha−1, RMSE = 0.425 t ha−1) in the corn grain yield estimation, where the density and the NDVI were the variables with the highest relative importance, with values of 0.295 and 0.184, respectively. However, the WDRVI, plant density, and canopy cover estimated the corn grain yield with acceptable precision (R = 0.96, MAE = 0.209 t ha−1, RMSE = 0.449 t ha−1). The generated neural network models provided a high correlation coefficient between the estimated and the observed corn grain yield, and also showed acceptable errors in the yield estimation. The spectral information registered through remote sensors mounted on unmanned aerial vehicles and its processing in vegetation indices, canopy cover, and plant density allowed the characterization and estimation of corn grain yield. Such information is very useful for decision-making and agricultural activities planning.

Organic acids are abundant constituents of ripe fruits and are responsible for their sourness. In addition, they contribute to their flavour. In many fruits, the most abundant organic acids are malic and citric. The aims of this review are two-fold. The first is to provide a clear overview of malic and citric acids in the flesh of fruits. The abundance of different organic acids in commercially grown fruits is described. How this abundance changes during fruit development is outlined. The metabolic pathways used in the synthesis and dissimilation of malic and citric acids in fruits are described. The functions of malic and citric acids in the flesh of fruits are discussed. Secondly, how environmental and cultural practices can alter the organic acid content of fruits is considered.

The aim of the present study was to elucidate the time course according to which changes in circulating concentrations of progesterone influence pulsatile secretion of LH and secretion of 17 beta-estradiol. Our working hypothesis was that changing the dose of progesterone would result in changes in frequency of LH pulses and secretion of 17 beta-estradiol within 72 h. Five days after behavioral estrus, thirty-three cows were randomly assigned to one of five groups: 1) control, no treatment (CONT, n = 5); 2) treatment with two progesterone-releasing intravaginal devices (PRIDs) for 11 days (2PRID, 5-6 ng/ml plasma progesterone, n = 7); 3) treatment with a 0.5 PRID for 11 days (0.5PRID, 1-2 ng/ml plasma progesterone, n = 7); 4) treatment with 2 PRIDs for 8 days followed by treatment with a 0.5 PRID for 3 days (2-0.5PRID, n = 7); and 5) treatment with a 0.5 PRID for 8 days followed by treatment with 2 PRIDs for 3 days (0.5-2PRID, n = 7). Cows subject to PRID treatments received injections of prostaglandin F2 alpha on Days 1 and 2 (Day 0 = day of initiation of PRID treatments, fifth day of the estrous cycle in CONT cows) to lyse the existing corpus luteum. Cows were bled for 12 h at 15-min intervals on Day 7.5 of the treatment period (twelfth day of the estrous cycle in CONT cows). The dose of progesterone was changed on Day 8 in cows that were assigned to the 2-0.5PRID and 0.5-2PRID groups, and blood collections continued an additional 72 h to characterize profiles of circulating concentrations of LH and 17 beta-estradiol. Cows treated with a 0.5 PRID had a greater (p < 0.05) number of LH pulses and higher (p < 0.05) concentrations of 17 beta-estradiol throughout the entire blood collection period than cows in the 2PRID and CONT groups. An increase in the number of LH pulses was detected within 6 h after the change from the high to the low dose of progesterone (2-0.5PRID), and frequency of LH pulses was similar to that of cows in the 0.5PRID group for the remainder of the period of blood collection. LH pulse frequency declined within 6 h after the shift from the low to the high dose of progesterone (0.5-2PRID) and was similar to that of cows in the 2PRID group by 12 h after the dose was changed. Within 6 h after the dose of progesterone was changed, circulating concentrations of 17 beta-estradiol increased (p < 0.05) in cows shifted from the high to low dose (2-0.5PRID) and declined (p < 0.05) after the dose of progesterone was changed from low to high (0.5-2PRID). We conclude that changing the circulating concentrations of progesterone concurrently affects frequency of pulsatile LH release and secretion of 17 beta-estradiol within 6-24 h.

Mechanochemistry is considered an alternative attractive greener approach to prepare diverse molecular compounds and has become an important synthetic tool in different fields (e.g., physics, chemistry, and material science) since is considered an ecofriendly procedure that can be carried out under solvent free conditions or in the presence of minimal quantities of solvent (catalytic amounts). Being able to substitute, in many cases, classical solution reactions often requiring significant amounts of solvents. These sustainable methods have had an enormous impact on a great variety of chemistry fields, including catalysis, organic synthesis, metal complexes formation, preparation of multicomponent pharmaceutical solid forms, etc. In this sense, we are interested in highlighting the advantages of mechanochemical methods on the obtaining of pharmaceutical cocrystals. Hence, in this review, we describe and discuss the relevance of mechanochemical procedures in the formation of multicomponent solid forms focusing on pharmaceutical cocrystals. Additionally, at the end of this paper, we collect a chronological survey of the most representative scientific papers reporting the mechanochemical synthesis of cocrystals.

Native amaranth protein (APN) is a nutritional ingredient with potential applications for the structuration and functionalization of food products. However, its solubility is poor, which limits its use in the food industry. The effect of ultrasonication (US) at 50% amplitude for 10 min (APUS), pH-shifting at pH 2 and 12 (APpH2 and APpH12), and the combination of both (APpH2US and APpH12US) on the structural, physicochemical, and functional properties of APN were investigated. Alkaline pH-shifting combined with US decreased the hydrodynamic diameter of APN from 1167.0 ± 15.6 nm to 438.3 ± 8.4 nm (APpH12US), whereas acidic pH-shifting increased the hydrodynamic diameter up to 2490.0 ± 5.3 nm (APpH2). Fractions of α-helix, β-sheet, β-turn, and random coil structures of APN were affected by pH12-shifting and US, but pH2-shifting did not. Exposed sulfhydryl groups of the APN diminished, while disulfide bonds increased as a result of pH-shifting alone or combined with US. Zeta potential values revealed that the isoelectric point of APN (4.0) was increased for APpH12 (4.2) and APpH12US (4.5) and decreased for APUS (3.5). The highest solubility was achieved by APpH12US. Foaming capacity and stability were significantly increased in all treatments, except APpH2.

O objetivo deste trabalho foi avaliar a utilização do método Famacha como estratégia auxiliar no controle do parasita Haemonchus contortus em ovinos e caprinos no Brasil. A principal característica deste método é a identificação de animais resistentes e resilientes no rebanho, sendo possível a seleção de animais que não necessitam receber tratamento antiparasitário. Além do acompanhamento clínico, foram determinados valores de hematócrito e ovos por grama de fezes (OPG). Ao término do experimento, foi determinada uma considerável redução (75,6%) na utilização de medicação antiparasitária nos ovinos, quando comparado com o controle profilático de tratamento do rebanho todo em intervalos de 30 dias dos anos anteriores. O método Famacha, embora também indicado para uso em caprinos, requer pequenas adaptações para sua melhor aplicabilidade. O método Famacha pode ser utilizado no Brasil com o objetivo de racionalizar o uso dos compostos antiparasitários, preservando sua eficácia por períodos prolongados.

La eterna discusión de que método usar cuando se inicia una investigación, no ha llegado a su fin, dado que las ciencias duras o exactas exponen que el rigor científico debe llevar una serie de pasos secuenciados hasta aceptar o no aceptar una hipótesis, en tanto que las ciencias filosóficas privilegian el uso de herramientas y técnicas basadas en la etnografía para tratar de entender el fenómeno y el objeto de la investigación, en razón de ello este ensayo pretende ayudar a los jóvenes investigadores a tener mayor claridad en cuanto a seleccionar su método de evaluación en una investigación, sin ser excluyente un método del otro, sino más bien complementarios.