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The goldenberry, Physalis peruviana L., is an important fruit in Colombia due to its export value and nutritional quality. However, commercial crops face challenges of fruit heterogeneity and the presence of diseases that reduce fruit yield and quality. These drawbacks could be handled through different breeding methods to develop uniform cultivars, for example, through anther culture, which is used to rapidly produce homozygous lines. However, the ploidy level may change when using this technique. Therefore, in this study, the level of ploidy of parental and the plants obtained by anther culture was determined by cytogenetics, flow cytometry, and single-simple repeat or microsatellites (SSR).Additionally, the homozygous condition of obtained plants and the degree of heterozygosity of parental plants were evaluated using SSR. Cytogenetic analysis showed parental plants with 48 chromosomes and anther culture generated plants with 24, 32 and 48 chromosomes, and mixoploids and average nuclear DNA content between 5.04 and 20.08 pg. Diploid, tetraploid, hexaploidy, and octoploid plants were identified by flow cytometry; the highest levels of ploidy (6x and 8x) correspond to mixoploid plants found by cytogenetics. The SSRs did not allow identifying ploidy due to the lack of a particular band pattern, however, they showed heterozygosity in most of the plants obtained by anther culture. It was concluded that the anther culture modified the ploidy level with respect to the parental plants, and that flow cytometry is efficient, precise, and less laborious, compared to cytogenetics, to determine the ploidy level of goldenberry in the laboratory.

The cape gooseberry (Physalis peruviana L.) is one of the most important Colombian exotic fruits. Chromosome doubling of anther-derived plants is a key factor in the application of double haploid technology for the genetic improvement of crops. In the present study, axillary buds from four haploid cape gooseberry genotypes were used to evaluate artificial chromosome doubling induced by colchicine and its effects on ploidy level and pollen fertility. Three concentrations of colchicine (5, 10 and 15 mM) and three exposure times (2, 4 and 6 h) were used to determine the best treatment for the generation of fertileB plants from axillary buds of haploid genotypes. The colchicine increased both the number of chromosomes, from 36 to 129, and the average chloroplasts in stomata guard cell, from 4.5 to 23.8. The optimal chromosome doubling of the haploids was obtained with the 5 mM colchicine solution and 2 h exposure time. This protocol produced chromosome doubling in over 60% of the regenerants of the four haploid genotypes, with a high level of fertility. Morphologically, the fertile mixoploid plants showed variation in the vegetative, flowering and fruit characteristics, as compared to the haploid plants.

Colombia requires blackberry genotypes with remarkable traits that improve the competitiveness of this product in the country. The objective of this work was to evaluate the characteristics of the quality attributes in fruits of ten Colombian blackberry genotypes in order to assess their potential in the berry markets but also as a genetic source to be included in breeding programs. The weight of fruits, the equatorial and longitudinal diameters, volume, firmness, color, juice content, flesh content, seed/fruit weight percentage, soluble solids content, acidity, pH and maturity index were evaluated in fruits collected during three different harvest periods in the province of Cundinamarca. Thirty fruits for every genotype and period were harvested and analyzed. These 10 evaluated genotypes showed important differences that allowed separating them into five different groups; however, genotypes 8, 4 and 6 showed the best results regarding size, color, juice content, total soluble solids content, maturity index, firmness and low acidity. These features make them good candidates for incorporating them into breeding programs. Nonetheless, their soluble solids content was considerably lower than values reported for genotypes Prime Ark, Natchez, Ouachita, and Osage that are recognized for these remarkable traits.

The potato (Solanum tuberosum L.) is the fourth most important crop food in the world and Colombia has one of the most important collections of potato germplasm in the world (the Colombian Central Collection-CCC). Little is known about its potential as a source of genetic diversity for molecular breeding programs. In this study, we analyzed 809 Andigenum group accessions from the CCC using 5968 SNPs to determine: 1) the genetic diversity and population structure of the Andigenum germplasm and 2) the usefulness of this collection to map qualitative traits across the potato genome. The genetic structure analysis based on principal components, cluster analyses, and Bayesian inference revealed that the CCC can be subdivided into two main groups associated with their ploidy level: Phureja (diploid) and Andigena (tetraploid). The Andigena population was more genetically diverse but less genetically substructured than the Phureja population (three vs. five subpopulations, respectively). The association mapping analysis of qualitative morphological data using 4666 SNPs showed 23 markers significantly associated with nine morphological traits. The present study showed that the CCC is a highly diverse germplasm collection genetically and phenotypically, useful to implement association mapping in order to identify genes related to traits of interest and to assist future potato genetic breeding programs.

El marchitamiento vascular ocasionado por el hongo Fusarium oxysporum se considera el principal limitante en la producción de uchuva (Physalis peruviana) en Colombia. Se han identificado genotipos de P. peruviana y la especie relacionada P. floridana con diferentes niveles de reacción a F. oxysporum. En el presente estudio, se evaluaron los genotipos con el fin de complementar el conocimiento de la diversidad citogenética en Physalis y el diseño de estrategias de hibridación como apoyo al mejoramiento del cultivo de la uchuva. Se determinó el número de cromosomas en células en división mitótica de ápices radicales de plantas cultivadas in vitro, para lo cual se estimó como hora mitótica promedio las 12:00 para P. peruviana, y las 10:00 para P. floridana. Se encontraron dotaciones cromosómicas de 2n = 4x = 48 y 2n = 2x = 24 para cada una de las dos especies. Adicionalmente, se realizó un análisis por citometría de flujo, en el cual se detectó variación en el contenido de ADN nuclear en P. peruviana con 2,33 pg para el genotipo 2n = 24 y entre 5,77 y 8,12 pg para los genotipos 2n = 48. En P. floridana el contenido de ADN fue 2,29 pg para el genotipo con número cromosómico 2n = 24 y 4,03 pg para el genotipo 2n = 48. Se encontró un efecto significativo (α = 0,01) del número de cromosomas sobre el contenido de ADN nuclear para las dos especies.

En este estudio se emplearon los marcadores moleculares SCAR-SDSP, SCAR T1 y W11, registrados como secuencias específicas, para discriminar el sexo en las plántulas de papaya y validar su efectividad en plantas florecidas en campo. El SCAR-SDSP amplificó una banda de 369 pares de bases en plantas machos y hermafroditas, lo que permitió corroborar los resultados obtenidos con este marcador, desarrollado en Corpoica en un estudio anterior que utilizó genotipos colombianos. Con el uso de los marcadores SCAR T1 y W11 combinados en una sola reacción, se diferenció el sexo de plantas hembras y hermafroditas. En la predicción de sexos, en una muestra ciega utilizando plántulas de dos meses de edad derivadas de semilla comercial, se observó una proporción de 1:1 de hembras:hermafroditas, lo esperado según el patrón de segregación en un cruce entre estos dos tipos de plantas. La amplificación con el marcador SCAR W11 generó una banda de 800 pares de bases en plantas machos y hermafroditas, independientemente del lugar de procedencia de la muestra. Sin embargo, cuando esta banda se secuenció y analizó con el programa BLAST mostró identidad de 98% entre las secuencias de machos y hermafroditas.