Three hundred yeasts isolated from tropical fruits were screened in relation to secretion of pectinases. Twenty-one isolates were able to produce polygalacturonase and among them seven isolates could secrete pectin lyase. None of the isolates was able to secrete pectin methylesterase. The pectinolytic yeasts identified belonged to six different genera. Kluyveromyces wickerhamii isolated from the fruit mangaba (Hancornia speciosa) secreted the highest amount of polygalacturonase, followed by K. marxianus and Stephanoascus smithiae. The yeast Debaryomyces hansenii produced the greatest decrease in viscosity while only 3% of the glycosidic linkages were hydrolysed, indicating that the enzyme secreted was an endo-polygalacturonase. The hydrolysis of pectin by polygalacturonase secreted by S. smithiae suggested an exo-splitting mechanism. The other yeast species studied showed low polygalacturonase activity.

Vasconcellea species, often referred to as highland papayas, consist of a group of fruit species that are closely related to the common papaya (Carica papaya). The genus deserves special attention as a number of species show potential as raw material in the tropical fruit industry, fresh or in processed products, or as genetic resources in papaya breeding programs. Some species show a very restricted distribution and are included in the IUCN Red List. This study on Vasconcellea distribution and diversity compiled collection data from five Vasconcellea projects and retrieved data from 62 herbaria, resulting in a total of 1,553 georeferenced collection sites, in 16 countries, including all 21 currently known Vasconcellea species. Spatial analysis of species richness clearly shows that Ecuador, Colombia and Peru are areas of high Vasconcellea diversity. Combination of species occurrence data with climatic data delimitates the potential distribution of each species and allows the modeling of potential richness at continent level. Based on these modeled richness maps, Ecuador appears to be the country with the highest potential Vasconcellea diversity. Despite differences in sampling densities, its neighboring countries, Peru and Colombia, possess high modeled species richness as well. A combination of observed richness maps and modeled potential richness maps makes it possible to identify important collection gaps. A Principal Component Analysis (PCA) of climate data at the collection sites allows us to define climatic preferences and adaptability of the different Vasconcellea species and to compare them with those of the common papaya

El lulo (Solanum quitoense Lam.) es un frutal andino importante en Colombia, con oferta deficitaria e importación desde Ecuador, para suplir la demanda nacional. La siembra se desarrolla casi exclusivamente con materiales locales, con existencia de un solo cultivar mejorado en el país. El cultivo se realiza con base en el conocimiento tradicional y recomendaciones técnicas; su sustento investigativo es escaso y en la mayoría de los casos apoya aspectos y problemas puntuales. Se estudió el estado actual de las investigaciones relacionadas con el conocimiento sobre esta especie, para su análisis y el diseño de procesos que apoyen el desarrollo de sistemas de producción sostenibles y eficientes de la misma, desde la óptica ambiental y productiva, como también actividades de valor agregado y poscosecha. En la revisión actual se presenta la información relacionada con los componentes de la función productiva: genotipo, ambiente e interacción genotipo X ambiente.

<p>A fin de conocer la variabilidad cualitativa y cuantitativa de 111 poblaciones de la colección nacional de referencia del género <em>Capsicum</em>, a cargo de Corpoica en el Centro de Investigación “La Selva”, se analizaron las especies <em>C. annuum</em>, <em>C. baccatum</em>, <em>C. chinense</em>, <em>C</em>. <em>frutescens</em>, <em>C. pubescens </em>y <em>C. </em>spp. (silvestres). Se aplicó una lista de descriptores con 69 atributos, 47 cualitativos y 22 cuantitativos, a partir de los cuales se encontró amplia variabilidad cualitativa con polimorfismos en 45 de las 47 variables, así como 146 estados (morfoalelos) diferentes frente a 176 que han sido reconocidos y publicados. Esto indica que la metapoblación posee 3,1 morfoalelos por atributo en promedio con un intervalo intraespecífico entre 1,5 para los silvestres y 2,6 para <em>C. annuum </em>y <em>C. chinense</em>. El fenograma cualitativo mostró una similaridad mínima del 48% entre poblaciones lo cual, considerado en forma conjunta con el porcentaje total de morfoalelos, denota que hay arreglos variables en las poblaciones individuales. Se detectó variabilidad cuantitativa en la metapoblación para todas las características de esta índole. Los polimorfismos cuantitativos se relacionaron principalmente con atributos del fruto en las especies domesticadas y del follaje en las silvestres. En estas últimas se halló una contribución importante a la variabilidad de los atributos del fruto relacionados con la atracción de pájaros frugívoros dispersores de la semilla. La variabilidad cualitativa y cuantitativa encontrada en las poblaciones de <em>Capsicum </em>evaluadas indica que se cuenta con suficiente germoplasma de calidad para programas de fitomejoramiento.</p><p> </p><p><strong>Phenotypic variation in chili and sweet pepper populations of the Capsicum genera in the national Colombian collection </strong></p><p>To determine the qualitative and quantitative variability of 111 populations from the national Capsicum germplasm collection, an experiment was carried out to analyse C. annum, C. baccatum, C. chinense, C frutescens, C. pubescens, and C. spp. (wild) at Corpoica’s “La Selva” Research Center located at Rionegro (Antioquia, Colombia). A list of descriptors with 69 characteristics was used: 47 qualitative and 22 quantitative. A wide qualitative variability was found with 45 out of the 47 variables being polymorphic; and 146 descriptor states (morphoalleles) out of the 176 recognised and published. This indicates that in the metapopulation on the average there are 3.1 morphoalleles per variable, with a range at species level between1.5, in the wild species, and 2.6 in C. annum and C. chinense. The qualitative phenogram indicated a minimum similarity of 48% between accessions, which considered jointly with the % of total morphoalleles, points out the diverse variable arrangements at individual populations level. Quantitative variability was observed at the metapopulation level for all registered characteristics. The quantitative variability was mainly related to fruit attributes for domesticated species, and with foliage characters for wild populations. Fruit attributes related to bird attraction for seed dispersion contributed significantly to quantitative variability. The wide qualitative and quantitative variability studied in Capsicum populations point out the potential of the evaluated germplasm for breeding purposes.</p>

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