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Oil palm production is gaining importance in Central and South America. However, the main species Elaeis guineensis (Eg) is suffering severely from bud rod disease, restricting the potential cultivation areas. Therefore, breeding companies have started to work with interspecific Elaeis oleifera × Eg (Eo × Eg) hybrids which are tolerant to this disease. We performed association studies between candidate gene (CG) single nucleotide polymorphisms (SNP) and six production and 19 oil quality traits in 198 accessions of interspecific oil palm hybrids from five different origins. For this purpose, barcoded amplicons of initially 167 CG were produced from each genotype and sequenced with Ion Torrent. After sequence cleaning 115 SNP remained targeting 62 CG. The influence of the origins on the different traits was analyzed and a genetic diversity study was performed. Two generalized linear models (GLM) with principle component analysis (PCA) or structure (Q) matrixes as covariates and two mixed linear models (MLM) which included in addition a Kinship (K) matrix were applied for association mapping using GAPIT. False discovery rate (FDR) multiple testing corrections were applied in order to avoid Type I errors. However, with FDR adjusted p values no significant associations between SNP and traits were detected. If using unadjusted p values below 0.05, seven of the studied CG showed potential associations with production traits, while 23 CG may influence different quality traits. Under these conditions the current approach and the detected candidate genes could be exploited for selecting genotypes with superior CG alleles in Marker Assisted Selection systems.

A temporary immersion system was tested to accelerate the procurement of pre-basic seed category of two varieties for agroindustry, Superchola and Diacol-Capiro (Solanum tuberosum L.) in addition to the autotrophic hydroponic system. The results of the proposed system presented several advantages compared to in vitro produced seed and semi-hyroponic seedlings. The vegetative part was increased in the total number of node segments obtained by the bioreactor, 322 and 264 for Superchola and Diacol-Capiro respectively. These values corresponded to the production of 81 test tubes (1,8 x 14 cm), which occupied an area of 2041,2 cm2. The production cycle was also shorter than the traditional in vitro agar culture system in fifteen days. The multiplication rates for Superchola and Diacol-Capiro were 1:9 and 1:8. The production rate per area was > 366 minitubers per m2 in Superchola and 225 minituber per m2 in Diacol-Capiro. The average yield of 3.75 kg. m-2 is higher than those obtained in vitro and semi-hydroponic seedlings. Superchola achieved the best response with superior yields (tuber quantity) 20% over Diacol-Capiro. The cost/profit ratio of 1.27 defined Superchola as the most profitable under the proposed seed production system with a return of 0.27 USD per invested dollar. This system can be adapted for commercial in vitro potato seed propagation, La mayoría de los cultivares tradicionales de papa no están adaptadas a las condiciones del cultivo provocadas por el cambio climático, que hacen disminuir drásticamente los rendimientos e incluso perder completamente la cosecha en muchos lugares desfavorecidos. En países en vías de desarrollo, como en Latinoamérica, esta situación afecta a la base alimentaria de las comunidades, y al sostenimiento económico y social; los agricultores optan por migrar en búsqueda de otros medios de subsistencia. Ante esta problemática, se estableció un consorcio de ocho instituciones reconocidas de siete países para identificar y desarrollar cultivares de papa adaptados al cambio climático y desarrollar metodologías y herramientas moleculares eficientes que aceleren este proceso. El proyecto logró cultivares con mejor adaptación a condiciones ambientales adversas en zonas productoras y zonas desfavorecidas. Se mejoró la competitividad del cultivo de la papa, que aumentó la superficie de su cultivo, y se diversificó la producción agraria, asegurando el suministro de alimentos en zonas deprimidas. Los agricultores cuentan con cultivares, con buena adaptación a los cambios en temperatura, precipitación, y mayor resistencia al tizón tardío (Phytophthora infestans). Los investigadores disponen de metodologías adecuadas para la evaluación de resistencias a estreses bióticos y abióticos y disponen de marcadores moleculares útiles para predecir el comportamiento agronómico y la adaptación

Plants growing in natural habitats are exposed to multiple environmental stresses resulting from abiotic factors such as heat, drought, and cold, which have a significant impact on cultivated potato. We have evaluated in two Solanum tuberosumvarieties, Soprano and Kondor, the adaptation to different abiotic stresses as heat, cold, and drought. For this purpose plants of both varieties were stressed, and when they showed symptoms, RNA extraction was carried out and a cDNA library for each sample was constructed. The objective of this study was to detect and analyse the genes involved in the responses to abiotic stresses in potato.The assay generated transcriptome sequences from both varieties, and a total of 5.579.655 reads and 8420 putative candidate genes were generated. 4.027 of the candidate genes were polymorphic and presented a different number of patterns defined by a varying number of SNPs. Many of the generated candidate genes showed differential expression, since the candidate gene was present in the stressed plant, but not in the control plant. The application of this methodology allows us to detect numerous candidate genes or specific alleles/allele combinations, which are differentially expressed in specific samples after the application of different abiotic stresses. This will be useful to identify superior alleles which can be used in Marker Assisted Selection for resistance and tolerance to abiotic stresses, Las plantas que crecen en hábitats naturales están expuestas a múltiples estreses ambientales resultantes de factores abióticos como el calor, la sequía y el frío, que tienen un impacto significativo en la papa cultivada. Se ha evaluado en dos variedades de Solanum tuberosumL. Soprano y Kondor, la adaptación a diferentesestreses abióticos como calor, frío y sequía. Para ello, las plantas de ambas variedades fueron estresadas y cuando mostraron síntomas se llevó a cabo la extracción de ARN y se construyó una biblioteca de ADNc para cada muestra. El objetivo de este estudio fue detectar y analizar los genes involucrados en las respuestas al estrés abiótico en papa. El ensayo generó secuencias de transcriptomas de ambas variedades, con un total de 5579655 lecturas y 8420 genes candidatos posibles. 4027 de los genes candidatos fueron polimórficos y presentaron un número diferente de patrones definidos por un número variable de SNPs. Muchos de los genes candidatos generados mostraron una expresión diferencial, ya que el gen candidato estaba presente en la planta estresada, pero no en la control. La aplicación de esta metodología nos permite detectar numerosos genes candidatos o combinaciones específicas de alelos, que se expresan diferencialmente después de la aplicación de diferentes estreses abióticos. Esto será útil para identificar alelos superiores que se pueden usar en la Selección Asistida por Marcadores para la resistencia y tolerancia a estreses abióticos

Background: Tuber yield and starch content of the cultivated potato are complex traits of decisive importance for breeding improved varieties. Natural variation of tuber yield and starch content depends on the environment and on multiple, mostly unknown genetic factors. Dissection and molecular identification of the genes and their natural allelic variants controlling these complex traits will lead to the development of diagnostic DNA-based markers, by which precision and efficiency of selection can be increased (precision breeding). Results: Three case-control populations were assembled from tetraploid potato cultivars based on maximizing the differences between high and low tuber yield (TY), starch content (TSC) and starch yield (TSY, arithmetic product of TY and TSC). The case-control populations were genotyped by restriction-site associated DNA sequencing (RADseq) and the 8.3 k SolCAP SNP genotyping array. The allele frequencies of single nucleotide polymorphisms (SNPs) were compared between cases and controls. RADseq identified, depending on data filtering criteria, between 6664 and 450 genes with one or more differential SNPs for one, two or all three traits. Differential SNPs in 275 genes were detected using the SolCAP array. A genome wide association study using the SolCAP array on an independent, unselected population identified SNPs associated with tuber starch content in 117 genes. Physical mapping of the genes containing differential or associated SNPs, and comparisons between the two genome wide genotyping methods and two different populations identified genome segments on all twelve potato chromosomes harboring one or more quantitative trait loci (QTL) for TY, TSC and TSY. Conclusions: Several hundred genes control tuber yield and starch content in potato. They are unequally distributed on all potato chromosomes, forming clusters between 0.5-4 Mbp width. The largest fraction of these genes had unknown function, followed by genes with putative signallin