Evaluación agronómica y sensorial de fríjol (Phaseolus vulgaris L. ) mejorado nutricionalmente en el norte del departamento del Cesar, Colombia / Agronomic and sensory evaluation of nutritionally improved beans (Phaseolus vulgaris L.) in northern Cesar department, Colombia

Objetivo: evaluar las características agronómicas y sensoriales de varios genotipos de fríjol (Phaseolus vulgaris L.) biofortificado, con respecto a un tradicional, para seleccionar el de mejores posibilidades de adopción. Materiales y metódos: el estudio se desarrolló en el Cesar (Colombia) y comprendió tres fases: 1) evaluación de la aceptación de semillas de 35 líneas de fríjol biofortificado por 331 productores y consumidores, 2) evaluación agronómica y nutricional, de las nueve líneas mejor calificadas y 3) evaluación sensorial por 273 personas comparativamente con un testigo regional. A los cuatro genotipos con mejores resultados agronómicos y nutricionales se les aplicaron pruebas de aceptabilidad, al mejor valorado, además pruebas de preferencia y discriminación triangular. Resultados: los de mejor aceptación por tipo de semilla fueron dos genotipos de cada color: negro, crema, rojo y rosado moteado. Los cuatro con mejor rendimiento, sanidad, contenidos de hierro y zinc incluyeron un genotipo de cada color; frente a un patrón local no presentaron diferencias de aceptabilidad por olor, color y sabor (p>0,05), pero si por textura y consistencia (p<0,05) a favor de los biofortificados, sobresaliendo el negro. Con este último y el patrón local se preparó una receta, los evaluadores discriminaron entre los dos y hubo diferencias en la aceptabilidad de algunas características sensoriales, a favor del biofortificado. Conclusiones: los genotipos de fríjol biofortificado presentaron mejor rendimiento, sanidad, contenidos de hierro y zinc que el patrón local, los cuatro mejor valorados presentaron algunas diferencias sensoriales frente al testigo, a favor de los biofortificados, sobresaliendo el genotipo negro.

Objective: agronomic and sensory evaluation of nutritionally enhanced beans and a traditional bean was completed to determine the genotype most likely to be adopted. Materials and methods: the study was completed in Cesar (Colombia), and comprised three phases: 1) evaluation of the acceptance of 35 biofortified bean seeds by 331 bean producers and consumers, 2) agronomic and nutritional evaluation of the eight highest rated beans, and 3) sensorial evaluation by 273 persons in comparison with a regional bean. The four genotypes with the best agronomic and nutritional results were evaluated with acceptability tests, and for the best rated, preference tests and triangular discrimination were also applied. Results: the most accepted seeds were two each of the following colors: black, cream, red and pink striped. The four best beans with respect to yield, food safety, and iron and zinc contents included a genotype of each color. Compared with a local bean, the four had the same acceptability scores for smell, color and taste (p> 0.05), and different scores for texture and consistency (p <0.05), favoring the biofortified beans, and the black line in particular. With the black bean and a local bean, a recipe was prepared. Evaluators discriminated between the two beans and there were differences in the acceptability of certain sensory characteristics in favor of the biofortified line. Conclusions: biofortified bean genotypes showed better yield, food safety, and iron and zinc content than the local bean. The four best presented some sensorial differences compared to the control, in favor of the biofortified bean, and specifically the black genotype.

Extensive diversity and inter-genepool introgression in a world-wide collection of indeterminate snap bean accessions.

Common bean can be grown as a grain crop (dry beans) or as a fresh vegetable (snap beans/green beans), both items being important in nutritional terms for providing essential minerals and vitamins to the diet. Snap beans are thought to be derived predominantly from dry beans of the Andean genepool and to be of a recent European origin; however, the existence of Mesoamerican genepool characteristics especially in traditional indeterminate growth habit snap beans indicates a wider origin. The objective of this study was to evaluate genetic diversity within a set of 120 indeterminate (pole type) snap beans and 7 control genotypes representing each genepool using amplified fragment length polymorphism (AFLP) and simple sequence repeat or microsatellite (SSR) markers. The genotypes were predominantly from Asia, Europe and the United States but included some varieties from Latin America and Africa. AFLP polymorphism ranged from 53.2 to 67.7% while SSR polymorphism averaged 95.3% for the 32 fluorescent and 11 non-fluorescent markers evaluated and total expected heterozygosity was higher for SSR markers (0.521) than for AFLP markers (0.209). Both marker systems grouped the genotypes into two genepools with Andean and Mesoamerican controls, respectively, with the Mesoamerican group being predominant in terms of the number of genotypes assigned to this genepool. Phaseolin alleles were not tightly associated with genepool assignment indicating that introgression of this locus had occurred between the genepools, especially with phaseolin "S" in the Andean group (23.5%) and phaseolins "T" and "C" in the Mesoamerican group (12.2 and 8.2%, respectively). The implications of these results on the origin of pole type snap beans and on breeding strategies for this horticultural crop are discussed.

Induction and identification of a small-granule, high-amylose mutant in cassava (Manihot esculenta Crantz).

Only two mutations have been described in the literature, so far, regarding starch and root quality traits in cassava. This article reports on an induced mutation in this crop, first identified in 2006. Botanical seed from five different cassava families were irradiated with gamma rays. Seed was germinated, transplanted to the field (M1 plants), and self-pollinated to produce the M2 generation. Abnormal types regarding starch granule morphology were identified during the single plant evaluation of M2 genotypes. To confirm these characteristics, selected genotypes were cloned and a second evaluation, based on cloned plants obtained from vegetative multiplication, was completed in September 2007. Two M2 genotypes presented small starch granules, but only one could be fully characterized, presenting a granule size of 5.80 +/- 0.33 microm compared with three commercial clones with granule sizes ranging from 13.97 +/- 0.12 to 18.73 +/- 0.10 microm and higher-than-normal amylose content (up to 30.1% in cloned plants harvested in 2007, as compared with the typical values for "normal" cassava starch of around 19.8%). The gels produced by the starch of these plants did not show any viscosity when analyzed with the rapid viscoanalyzers (5% suspension), and the gels had low clarity. Low viscosity could be observed at higher concentrations (8 or 10% suspensions). Preliminary results suggest that the mutation may be due to a lesion in a gene encoding one of the isoforms of isoamylase (probably isa1 or isa2).