The Dynamic Interaction between Oil Palm and Phytophthora palmivora in Bud Rot Disease: Insights from Transcriptomic Analysis and Network Modelling.

Bud Rot, caused by Phytophthora palmivora, is considered one of the main diseases affecting African oil palm (Elaeis guineensis). In this study, we investigated the in vitro molecular dynamics of the pathogen-host interaction by analyzing gene expression profiles from oil palm genotypes that were either susceptible or resistant to the disease. We observed distinct interactions of P. palmivora with resistant and susceptible oil palms through co-expression network analysis. When interacting with susceptible genotypes, P. palmivora exhibited upregulation of carbohydrate and sulfate transport genes. These genes demonstrated co-expression with apoplastic and cytoplasmic effectors, including cell wall degrading enzymes, elicitins, and RxLR motif effectors. The pathogen manipulated susceptible oil palm materials, exacerbating the response and compromising the phenylpropanoid pathway, ultimately leading to susceptibility. In contrast, resistant materials exhibited control over their response through putative Heat Shock Proteins (HSP) that maintained homeostasis between primary metabolism and biotic defense. Co-expressed genes related to flavonoids, WRKY transcripts, lectin-type receptors, and LRR receptors may play important roles in pathogen control. Overall, the study provides new knowledge of the molecular mechanisms underlying the interaction between E. guineensis and P. palmivora, which can contribute to controlling Bud Rot in oil palms and gives new insights into the interactions of P. palmivora with their hosts.

A Response Surface Methodology Study for Chlorella vulgaris Mixotrophic Culture Optimization.

Glycerol is a carbon source that produces good biomass under mixotrophic conditions. Enhancing the composition of culture media in algae biomass production improves growth rates, biomass yield, nutrient utilization efficiency, and overall cost-effectiveness. Among the key nutrients in the medium, nitrogen plays a pivotal role. Urea can be effectively used as a nitrogen source and is considered a low-cost form of nitrogen compared to other sources. Urea metabolism releases some CO2 in photosynthesis, and magnesium plays a major role in urea uptake. Magnesium is another key nutrient that is key in photosynthesis and other metabolic reactions. To maximize glycerol consumption in the mixotrophic system and to obtain high biomass and lipid productions, the variations in MgSO4·7H2O and urea concentrations were evaluated in the growth medium of the microalgae. A response surface methodology (RSM) using a central composite design (CCD) was designed to maximize glycerol consumption at the initial cellular growth rates (up to four days). The magnesium and urea supply varied from 0.3 to 1.7 g L-1. Response surface methodology was utilized to analyze the results, and the highest glycerol consumption rate, 770.2 mg L-1 d-1, was observed when C. vulgaris was grown at 1.7 g L-1 urea, 1.0 g L-1 MgSO4·7H2O. Using the optimal urea and magnesium concentrations with acetate, glucose, and glycerol as carbon sources, the same lipid content (10% average) was achieved on day 4 of mixotrophic C. vulgaris culture. Overall, the results show that mixotrophic growth of C. vulgaris using urea with an optimum magnesium concentration yields large amounts of fatty acids and that the carbon source greatly influences the profile of the fatty acids.

Identification of 'Candidatus Liberibacter asiaticus' the Huanglongbing Bacterium in citrus from Colombia.

Candidatus Liberibacter spp is the most prevalent microorganism in the citrus plant, associated with Citrus Huanglongbing (HLB), which is transmitted by the psyllid vector. In Colombia, the vector Diaphorina citri Kugayama has been reported in different regions, but "Ca. Liberibacter asiaticus" (CLas) has only been detected in insect vectors, not in citrus host plants. To identify the presence and quantify the pathogen in citrus tissues, we employed a combined strategy that involved three techniques based on polymerase chain reaction (PCR). First, we used endpoint PCR with specific primers for CLas (OI1-OI2c) to confirm the infection. Second, we used qPCR with specific primers CIT295a - CIT298 designed on 16S rDNA gene regions to quantify the pathogen load. Finally, we employed droplet digital PCR (ddPCR) to determine the copy number of the pathogen in citrus tissues using the ß-subunit of ribonucleotide reductase (RNR) gene (nrdB) that is specific to CLas. We identified the presence of CLas in citrus plants for the first time in Colombia and quantified its titer in the plant tissue. We employed ddPCR and qPCR to provide crucial information for the country's disease management, control strategies, and general crop health.

Nitrogen Use Efficiency in Oil Palm Seedlings: Unraveling the Untapped Potential of Elevated External Ammonium Supply.

Ammonium (NH4+) is an essential nitrogen source for plants, but excessive exposure can trigger stress responses that vary among and within different plant species. This study investigated the phenotypic variations in response to ammonium nutrition in five oil palm genotypes seedlings. Nitrate nutrition was used as a reference for a non-stressful condition, and three different nitrogen concentrations (5, 10, and 15 mM) were examined. Control groups without external nitrogen application were included for each genotype. Several parameters were analyzed, including plant growth, root length, gas exchange, fluorescence, chlorophyll, reducing sugars, amino acids, proteins, and nitrogen uptake. The results revealed a significant genotype effect, particularly between the interspecific OxG hybrid and the Elaeis guinensis genotypes. Ammonium nutrition increased shoot growth in all genotypes compared to nitrate nutrition. Additionally, there was a trend towards increased primary root length, amino acids, proteins, and nitrogen uptake under ammonium supply. These findings are promising, particularly considering the recommendation to use ammonium with inhibitors for environmental sustainability.

Molecular network of the oil palm root response to aluminum stress.

BACKGROUND: The solubilization of aluminum ions (Al3+) that results from soil acidity (pH < 5.5) is a limiting factor in oil palm yield. Al can be uptaken by the plant roots affecting DNA replication and cell division and triggering root morphological alterations, nutrient and water deprivation. In different oil palm-producing countries, oil palm is planted in acidic soils, representing a challenge for achieving high productivity. Several studies have reported the morphological, physiological, and biochemical oil palm mechanisms in response to Al-stress. However, the molecular mechanisms are just partially understood. RESULTS: Differential gene expression and network analysis of four contrasting oil palm genotypes (IRHO 7001, CTR 3-0-12, CR 10-0-2, and CD 19 - 12) exposed to Al-stress helped to identify a set of genes and modules involved in oil palm early response to the metal. Networks including the ABA-independent transcription factors DREB1F and NAC and the calcium sensor Calmodulin-like (CML) that could induce the expression of internal detoxifying enzymes GRXC1, PER15, ROMT, ZSS1, BBI, and HS1 against Al-stress were identified. Also, some gene networks pinpoint the role of secondary metabolites like polyphenols, sesquiterpenoids, and antimicrobial components in reducing oxidative stress in oil palm seedlings. STOP1 expression could be the first step of the induction of common Al-response genes as an external detoxification mechanism mediated by ABA-dependent pathways. CONCLUSIONS: Twelve hub genes were validated in this study, supporting the reliability of the experimental design and network analysis. Differential expression analysis and systems biology approaches provide a better understanding of the molecular network mechanisms of the response to aluminum stress in oil palm roots. These findings settled a basis for further functional characterization of candidate genes associated with Al-stress in oil palm.

Parthenocarpy-related genes induced by naphthalene acetic acid in oil palm interspecific O × G [Elaeis oleifera (Kunth) Cortés × Elaeis guineensis Jacq.] hybrids.

Parthenocarpy is the development without fertilization of seedless fruits. In the oil palm industry, the development of parthenocarpic fruits is considered an attractive option to increase palm oil production. Previous studies have shown the application of synthetic auxins in Elaeis guineensis, and interspecific O×G hybrids (Elaeis oleifera (Kunth) Cortés × E. guineensis Jacq.) induces parthenocarpy. The aim of this study was to identify the molecular mechanism through transcriptomics and biology system approach to responding to how the application of NAA induces parthenocarpic fruits in oil palm O×G hybrids. The transcriptome changes were studied in three phenological stages (PS) of the inflorescences: i) PS 603, pre-anthesis III, ii) PS 607, anthesis, and iii) PS 700, fertilized female flower. Each PS was treated with NAA, Pollen, and control (any application). The expression profile was studied at three separate times: five minutes (T0), 24 hours (T1), and 48 h post-treatment (T2). The RNA sequencing (RNA seq) approach was used with 27 oil palm O×G hybrids for a total of 81 raw samples. RNA-Seq showed around 445,920 genes. Numerous differentially expressed genes (DEGs) were involved in pollination, flowering, seed development, hormone biosynthesis, and signal transduction. The expression of the most relevant transcription factors (TF) families was variable and dependent on the stage and time post-treatment. In general, NAA treatment expressed differentially more genes than Pollen. Indeed, the gene co-expression network of Pollen was built with fewer nodes than the NAA treatment. The transcriptional profiles of Auxin-responsive protein and Gibberellin-regulated genes involved in parthenocarpy phenomena agreed with those previously reported in other species. The expression of 13 DEGs was validated by RT-qPCR analysis. This detailed knowledge about the molecular mechanisms involved in parthenocarpy could be used to facilitate the future development of genome editing techniques that enable the production of parthenocarpic O×G hybrid cultivars without growth regulator application.

Reply to Paterson, R.R.M. Comment on "Castillo et al. Ganoderma zonatum Is the Causal Agent of Basal Stem Rot in Oil Palm in Colombia. J. Fungi 2022, 8, 230".

Reader Q: There was no morphological information provided for the isolated specimens, and so it is not known if they are even Ganoderma [...].

Light Interception, Photosynthetic Performance, and Yield of Oil Palm Interspecific OxG Hybrid (Elaeis oleifera (Kunth) Cortés x Elaeis guineensis Jacq.) under Three Planting Densities.

Environmental conditions are crucial for crops' growth, development, and productivity. One of the most important physiological factors associated with the production of crops is the use of solar radiation for the photosynthesis process, which determines the amount of assimilates available for crop growth and yield. Three age classes (4, 6, and 14 years) and three planting densities (143, 128, and 115 palms ha-1) were evaluated in a commercial interspecific Elaeis Oleifera x Elaeis guineensis hybrid Coari x La Mé. The light interception patterns and the photosynthetic performance were determined. Measurements were taken of the leaf area, the number of leaves, and incident and photosynthetically transmitted active radiation. Also, photosynthetic rates, light, and yield were measured. The canopy extinction coefficient (Kc) was estimated using the Monsi and Saeki model. Under the evaluated conditions, the average Kc value for 4-year-old palms was 0.44; for the 6-year-old group of palms, the average value was 0.40, and 0.32 for the 14-year-old palms, with coefficients of determination (R2) greater than 0.8. A pattern associated with the age of the crop was observed, where the Kc decreased in groups of adult palms. The results showed increased Kc as the planting density decreased. No statistically significant differences were observed between planting densities or ages in the light and CO2 curves regarding photosynthesis. The leaf level in which the measurement was made influenced photosynthesis. Thus, the highest values of the photosynthesis parameters were observed in leaf 17. The crop yield tended to stabilize 8 years after planting under 143 and 128 palms per hectare, but 14 years after planting, the Fresh fruit bunch (FFB) production was still growing under 115 palms per hectare. The results showed that, up to year 14 after planting, the highest cumulative yield was achieved with 115 palms per hectare. This was partly caused by a sharp decline in production observed under 128 palms per hectare, which could indicate that in the long production cycle of the OxG hybrids, the 115-palms-per-hectare planting density would result in higher cumulative FFB production. Furthermore, the results showed that the optimum planting density for the hybrids of the present study would be 120 palms ha-1, corresponding to a planting distance of 9.8 m between plants.

Ganoderma zonatum Is the Causal Agent of Basal Stem Rot in Oil Palm in Colombia.

Basal stem rot (BSR), caused by Ganoderma spp., is one of the most important emerging oil palm diseases in Colombia, and is restricted to two oil palm production areas in the country. To identify the causal agent of the disease, basidiocarp of oil palms affected by BSR were used to prepare isolates, and their pathogenicity was then assessed in pre-nursery plants. Four-month-old oil palm seedlings were inoculated with rubber wood (Hevea brasiliensis) blocks colonized with dikaryotic mycelia of Ganoderma. The incidence, severity, and symptoms of the pathogen were assessed. A multiregional analysis (ITS, rpb2, and tef1-α) was carried out to identify the isolates; all isolates were determined to be Ganoderma zonatum. Phylogenetic analyses with the three regions yielded concordant phylogenetic information and supported the distinction of the isolates with high bootstrap support. Seven isolates (CPBsZN-01-29, CPBsZN-02-30, CPBsZN-03-31, CPBsZN-04-34, CPBsZN-05-35, CPBsZN-06-36, and CPBsZN-07-38) were pathogenic in oil palm, with incidences greater than 90% and a maximum severity of 34%, and the highest severity index was found in isolates CPBsZN-03-31, CPBsZN-04-34, and CPBsZN-06-36. The pathogen was recovered from inoculated oil palms in all cases. This study reveals the pathogenic association of Ganoderma zonatum with BSR in Colombia.

Assessment of Inoculation Methods of Thielaviopsis paradoxa (De Seynes) Höhn into Oil Palm Seedlings under Greenhouse Conditions.

Oil palm (Elaeis guineensis Jacq. and Elaeis Oleifera Cortes) is one of the most important oil crops in the world. Colombia is the fourth-largest oil palm producer worldwide. However, oil palm diseases are a significant factor affecting yield. Thielaviopsis paradoxa (De Seynes) Höhn is a pathogen that affects young palm trees, causing spear rot. Four disease establishment methods were studied to replicate, in a controlled environment, the symptoms of the disease found in the field. Young palm trees were inoculated with a suspension of endoconidia using either local infiltration, drip, scissor cut, or direct contact with agar blocks bearing mycelia and conidia. The effects of the inoculation methods were studied in dose-method-disease severity experiments conducted in a greenhouse under controlled conditions. All four methods resulted in T. paradoxa infections and the development of symptoms of the disease. The disease severity was correlated with the method and dose of inoculation. In trials to test Koch's postulates, T. paradoxa was isolated from areas of disease progression in the inoculated trees, but the teleomorph Ceratocystis paradoxa (Dade) Moreau was not observed. A photographic record of the infection process at different times post-infection was compiled. Given that establishing the disease through artificial inoculation is essential for assessing plant pathogenesis, this study determined that the local infiltration method (1 × 106 endoconidia mL-1) and a 3-7 day incubation period were critical for the development of symptoms as severe as those observed in natural infections in the field.

Genomic Variability of Phytophthora palmivora Isolates from Different Oil Palm Cultivation Regions in Colombia.

Palm oil is the most consumed vegetable oil globally, and Colombia is the largest palm oil producer in South America and fourth worldwide. However, oil palm plantations in Colombia are affected by bud rot disease caused by the oomycete Phytophthora palmivora, leading to significant economic losses. Infection processes by plant pathogens involve the secretion of effector molecules, which alter the functioning or structure of host cells. Current long-read sequencing technologies provide the information needed to produce high-quality genome assemblies, enabling a comprehensive annotation of effectors. Here, we describe the development of genomic resources for P. palmivora, including a high-quality genome assembly based on long and short-read sequencing data, intraspecies variability for 12 isolates from different oil palm cultivation regions in Colombia, and a catalog of over 1,000 candidate effector proteins. A total of 45,416 genes were annotated from the new genome assembled in 2,322 contigs adding to 165.5 Mbp, which represents an improvement of two times more gene models, 33 times better contiguity, and 11 times less fragmentation compared with currently available genomic resources for the species. Analysis of nucleotide evolution in paralogs suggests a recent whole-genome duplication event. Genetic differences were identified among isolates showing variable virulence levels. We expect that these novel genomic resources contribute to the characterization of the species and the understanding of the interaction of P. palmivora with oil palm and could be further exploited as tools for the development of effective strategies for disease control.

Simultaneous transcriptome analysis of oil palm clones and Phytophthora palmivora reveals oil palm defense strategies.

Phytophthora palmivora is an oomycete that causes oil palm bud rot disease. To understand the molecular mechanisms of this disease, palm clones with contrasting responses (Ortet 34, resistant and Ortet 57, susceptible) were inoculated with P. palmivora, and RNAseq gene expression analysis was performed. The transcriptome was obtained by sequencing using Illumina HiSeq2500 technology during the asymptomatic phase (24, 72 and 120 hours postinfection, hpi). A simultaneous analysis of differentially expressed gene (DEG) profiles in palm and P. palmivora was carried out. Additionally, Gene Ontology (GO) and gene network analysis revealed differences in the transcriptional profile of the two ortets, where a high specificity of the pathogen to colonize the susceptible ortet was found. The transcriptional analysis provided an overview of the genes involved in the recognition and signaling of this pathosystem, where different transcription factors, phytohormones, proteins associated with cell wall hardening and nitrogen metabolism contribute to the resistance of oil palm to P. palmivora. This research provides a description of the molecular response of oil palm to P. palmivora, thus becoming an important source of molecular markers for the study of genotypes resistant to bud rot disease.

Visualization of Phytophthora palmivora Infection in Oil Palm Leaflets with Fluorescent Proteins and Cell Viability Markers.

Bud rot (BR) is the most devastating disease affecting oil palm (Elaeis guineensis) crops in Colombia. Its causal agent, Phytophthora palmivora, initiates the infection in immature oil palm leaflets producing necrotic lesions, followed by colonization of opportunistic necrotrophs, which increases disease damage. To improve the characterization of the disease, we transformed P. palmivora using Agrobacterium tumefaciens-mediated transformation (ATMT) to include the fluorescent proteins CFP-SKL (peroxisomal localization), eGFP and mRFP1 (cytoplasmic localization). The stability of some transformants was confirmed by Southern blot analysis and single zoospore cultures; additionally, virulence and in vitro growth were compared to the wild-type isolate to select transformants with the greatest resemblance to the WT isolate. GFP-tagged P. palmivora was useful to identify all of the infective structures that are commonly formed by hemibiotrophic oomycetes, including apoplastic colonization and haustorium formation. Finally, we detected cell death responses associated with immature oil palm tissues that showed reduced susceptibility to P. palmivora infection, indicating that these tissues could exhibit age-related resistance. The aim of this research is to improve the characterization of the initial disease stages and generate cell biology tools that may be useful for developing methodologies for early identification of oil palm materials resistant or susceptible to BR.

Rna-seq: a glanee at technologies and methodologies / RNA-Seq: un vistazo sobre las tecnologías y metodologías

RNA Sequencing (RNA-Seq) is a newly born tool that has revolutionized the post-genomic era. The data produced by RNA-Seq, sequencing technologies and use of bioinformatics are exploding rapidly. In recent years, RNA-Seq has been the method of choice for profiling dynamic transcriptome taking advantage of high throughput sequencing technologies. RNA-Seq studies have shown the transcriptome magnitude, notion and complexity. From 2008, as its introduction year, the relevant reports on RNA-Seq have been multiplied by more than 2822 times just in 6 years. RNA-Seq also contributes a more accurate gene expression and transcript isoform estimation than other methods. Furthermore, some of the potential applications for RNA-Seq cannot be conducted by other methods and as yet are unique to RNA-Seq. As RNA-Seq approaches increase in speed and decrease in cost, more distinct researches are applied and become more common and accurate. RNA-Seq is a cross and interdisciplinary method that interconnects biology to other scientific topics. This article describes RNA-Seq approach, technologies, methodologies, implementation, and methods done so far in characterizing and profiling transcriptomes.

En los últimos años, la técnica RNA-Seq ha tenido un desarrollo acelerado y se ha convertido en el método de elección para el estudio y la caracterización de los transcriptomas dinámicos, aprovechando las tecnologías de secuenciación de alto rendimiento. Estudios aplicando RNA-Seq han mostrado la magnitud, noción y complejidad del transcripotma. A partir de 2008, año de introducción de la técnica, los estudios con RNA-Seq se han multiplicados por más de 2822 veces sólo en 6 años. Al compararse con otros métodos, los estudios empleando RNA-Seq contribuyen a una estimación más precisa de la expresión génica y de las isoformas de los transcriptos. Además, algunas de las aplicaciones potenciales de RNA-Seq no se pueden llevar a cabo con otros métodos. El uso de RNA-Seq aumenta la velocidad de obtención de información y disminuye los costos, logrando con su uso, que investigaciones diversas se vuelvan más frecuentes y precisas. RNA-Seq es un método interdisciplinario que interconecta la biología a otros temas científicos. En este artículo se describe el planteamiento de la tecnología RNA-Seq, metodologías y los métodos realizados en la caracterización de transcriptomas.

Diversidad y estructura genética de accesiones de palma de aceite (Elaeis guineesis Jacq.)provenientes de Camerún / Diversity and genetic structure of oil palm accession (Elaeis guineesis Jacq.) from Cameroon

La palma de aceite Elaeis guineesis Jacq. posee gran importancia debido al aceite que se extrae de sus frutos, del cual se obtienen derivados refinados de gran valor comercial como el biodiesel, entre otros. Esta investigación buscó determinar la estructura y diversidad genética de 311 muestras de palma de aceite proveniente de la República de Camerún mediante 10 marcadores microsatélite. Los resultados mostraron valores promedio para el número medio de alelos por locus de Na=8.433 y un número efectivo de alelos por locus de Ne=4.756; las diferencias entre estos valores permiten inferir que los 106 alelos encontrados para estas poblaciones son considerados alelos raros. Adicionalmente, el valor de diversidad genética fue alto (valor medio de He= 0.781) respecto a reportes de varios autores. La varianza molecular obtenida evidenció que el mayor porcentaje (80 %) se encuentra dentro de los individuos. Los análisis mostraron que no se definió ningún tipo de estructura poblacional, lo que permitió inferir un alto flujo genético entre las zonas geográficas, esto corroborado por los altos valores de diversidad genética obtenidos. Los 311 genotipos evaluados fueron definidos como una población natural heterogénea heterocigota, apta para favorecer el aumento de la base genética de las poblaciones cultivadas de palma de aceite.

Oil palm Elaeis guineesis Jacq. is of great importance because of the oil extracted from its fruits, whose refined derivatives are commercially valuable as biodiesel, among others uses. This study sought to determine the structure and genetic diversity of 311 oil palm samples from the Republic of Cameroon with 10 microsatellite markers. The results showed values for the average number of alleles per locus of Na= 8.433 and effective number of alleles per locus of Ne= 4.756; from the differences between these values, it can be inferred that the 106 alleles found for these populations could be considered rare alleles. Additionally the value of genetic diversity was high (mean value of He= 0.781) compared to reports of several authors. The obtained molecular variance showed that the highest percentage (80 %) was found within the individuals. The analysis did not show any defined population structure, which allowed us to infer a high gene flow among the geographic zones, corroborated it by the high genetic diversity values obtained. The 311 genotypes were defined as a heterogeneous heterozygous natural population suitable to increase the genetic base of oil palm cultivated populations.

BIOCHEMICAL AND PHYSIOLOGICAL CHARACTERIZATION OF OIL PALM INTERSPECIFIC HYBRIDS (Elaeis oleifera x Elaeis guineensis) GROWN IN HYDROPONICS / Caracterización ecofisiológica y bioquímica de híbridos interespecíficos de palma de aceite (Elaeis oleifera x Elaeis guineensis) crecidos en medio hidropónico

The interspecific hybrid, Elaeis oleifera x Elaeis guineensis (OxG) is an alternative for improving the competitiveness and sustainability of the Latin American oil palm agro-industry, because of its partial resistance to some lethal diseases and also because of the high quality of its oil. A comparative characterization was conducted of the physiological and biochemical performance of seedlings of six OxG hybrids grown in hydroponics. Gas exchange, vegetative growth, protein, sugar and photosynthetic pigment content, and antioxidant system activity were determined. With the exception of gas exchange, the other variables showed significant differences between materials. The ´U1273´ and ´U1737´ materials showed greater vegetative growth with no expression of biochemical traits, while the ´U1914´and ´U1990´ materials showed high levels of reducing and total sugars, photosynthetic pigments, and antioxidant system activities, characteristics that could confer them adaptation to stress conditions. With the standardized hydroponics technique, the optimal conditions for the growth of seedlings were ensured, the differences between materials were established, so those with promising features from the physiological and biochemical standpoint were identified. Finally, it could be used to study in a simple, fast, clean and inexpensive way, the effect of levels and sources of mineral nutrients on the growth and development of oil palm.

El híbrido interespecífico Elaeis oleifera x Elaeis guineensis (OxG) es una alternativa para mejorar la competitividad y sostenibilidad de la agroindustria de la palma de aceite latinoamericana, debido a su resistencia parcial a enfermedades letales y a que su aceite es de muy alta calidad. Se realizó la caracterización comparativa del desempeño fisiológico y bioquímico de seis híbridos OxG crecidos en medio hidropónico. Se hicieron determinaciones de intercambio de gases, crecimiento vegetativo, proteínas, azúcares, contenido de pigmentos fotosintéticos y actividad del sistema antioxidante enzimático. Con excepción de las variables de intercambio de gases, las otras variables mostraron diferencias significativas entre materiales. Los materiales ´U1273´ y ´U1737´ mostraron mayor crecimiento vegetativo sin expresar cualidades desde el punto de vista bioquímico, mientras los materiales ´U1914´ y ´U1990´ mostraron altos niveles de azúcares totales y reductores, compuestos fotosintéticos y actividades del sistema antioxidante, características que podrían conferirles adaptación a condiciones de estrés.

Biochemical and physiological responses of oil palm to bud rot caused by Phytophthora palmivora.

In recent years, global consumption of palm oil has increased significantly, reaching almost 43 million tons in 2010. The sustainability of oil palm (Elaeis guineensis) cultivation has been compromised because of the bud rot disease whose initial symptoms are caused by Phytophthora palmivora. There was a significant incidence of the disease, from an initial stage 1 of the disease to the highest stage 5, that affected photosynthetic parameters, content of pigments, sugars, polyamines, enzymatic antioxidant activities, phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) and ß-(1,3) glucanase (ß-Gluc, EC 3.2.1.39). In healthy palms photosynthesis was 13.29 µmol CO2 m(-2) s(-1) in average, while in stage 5 the average photosynthesis was around 3.66 µmol CO2 m(-2) s(-1). Additionally, total chlorophyll was reduced by half at the last stage of the disease. On the contrary, the contents of putrescine, spermine and spermidine increased three, nine and twelve times with respect to stage 5, respectively. Antioxidant enzyme activities, as well as the phenylalanine ammonia-lyase and ß-(1,3) glucanase showed an increase as the severity of the disease increased, with the latter increasing from 0.71 EAU in healthy palms to 2.60 EAU in plants at stage 5 of the disease. The peroxidase (POD, EC 1.11.1.7) enzymatic activity and the content of spermidine were the most sensitive indicators of disease.

Lipase activity, mesocarp oil content, and iodine value in oil palm fruits of Elaeis guineensis, Elaeis oleifera, and the interspecific hybrid O×G (E. oleifera × E. guineensis).

BACKGROUND: One factor affecting crude palm oil quality is the formation of free fatty acids (FFA), often attributed to the hydrolytic action of mesocarp lipase. The aim of this work was to evaluate the enzyme behavior and to look toward new genotypes with low FFA production, high yield, and better oil quality. RESULTS: Lipase activity was strongly activated at low temperatures (5 °C). At this temperature PLL, SOO, POL, and POO (P, palmitic; L, linoleic; S, stearic; O, oleic) were the most hydrolyzed triacylglycerols in Elaeis guineensis fruits. Ethylene production decreased from 36 nL g(-1) h(-1) at room temperature to 2 nL g(-1) h(-1) at 5 °C. Lipase activity of E. guineensis, the E. oleifera × E. guineensis (O×G) hybrid, and E. oleifera were 52.7%, 32.9%, and <0.6% FFA, respectively. The E. guineensis showed oil in the mesocarp of 54.7%, followed by the O×G hybrid (47.0%), and E. oleifera (13.6%), and the iodine values were 52.0, 66.3, and 77.4 g I(2) 100 g(-1), respectively. CONCLUSIONS: This work allowed the identification of interspecific O×G hybrids as promising crosses with less lipase activity and higher iodine value than E. guineensis. Although O×G crosses produce less oil in the mesocarp than commercial E. guineensis; this feature could be improved by further breeding to introduce new genes from E. oleifera into the hybrids.

Nuevo modelo de pago del seguro integral de salud en los departamentos de Apurímac, Ayacucho y Cajamarca / New payment model comprehensive health insurance in the departments of Apurimac, Ayacucho and Cajamarca

El documento describe el mecanismo por el cual paga a los establecimientos de salud, utilizando la nueva lógica interna del proceso de aseguramiento para toda la población pobre y pobre extrema, independientemente de su edad y sexo. Además, incluye la nueva estructura del plan de beneficios para un mayor número y proporción de intervenciones de prevención y rehabilitación

Nuevo modelo de pago del seguro integral de salud en los departamentos de Apurímac, Ayacucho y Cajamarca / New payment model comprehensive health insurance in the departments of Apurimac, Ayacucho and Cajamarca

El presente documento describe el mecanismo por el cual paga a los establecimientos de salud, utilizando la nueva lógica interna del proceso de aseguramiento para toda la población pobre y pobre extrema, independientemente de su edad y sexo. Además, incluye la nueva estructura del plan de beneficios para un mayor número y proporción de intervenciones de prevención y rehabilitación(AU)