RESUMO
En este trabajo se diferencian a los recursos fitogenéticos in situ y ex situ para protección y conservación, de aquellos recursos que colecciona, mantiene y utiliza el hombre para su subsistencia desarrollando variedades cultivadas obtenidas por cualquier método de selección artificial. La imprecisión, confusión y distorsión encontradas en muchos trabajos relacionados al tema aquí planteado, con respecto a la terminología, su significado, sus alcances y sus consecuencias, motivaron el desarrollo de este trabajo de opinión. En mejoramiento, las colecciones de trabajo son utilizadas como una fuente de variabilidad y adaptación. En ese proceso de obtención de cultivares, indefectiblemente, se utiliza sólo una parte de la variabilidad genética del inicio, que se restringe en cada ciclo selectivo. La confusión mencionada con respecto a la pérdida de variabilidad genética se debe a que las mayores probabilidades de éxito en un programa de mejoramiento estarán asociadas a la disponibilidad de una amplia variabilidad genética en la colección de trabajo base del mejoramiento y no en el cultivar obtenido. La diversidad genética se conserva y protege en otro ámbito y con otras disciplinas. La variabilidad genética se re-utiliza y elimina selectivamente para obtener nuevos cultivares en los procesos de selección artificial. El hombre, al obtener variedades primitivas o nuevos cultivares modernos, siempre perdió variabilidad genética con respecto a la población que le dio origen, como consecuencia del mismo proceso selectivo. Ante ese contexto, respetando la biodiversidad, se puede mantener la productividad agrícola a largo plazo con el aporte concreto del mejoramiento genético.
This paper differentiates plant genetic resources maintained in situ and ex situ for protection and conservation, from those resources that man collects, maintains and uses for his subsistence by developing cultivated varieties through any artificial selection method. The imprecision, confusion and distortion found in many papers related to the issue raised here with respect to terminology, its meaning, its scope and its consequences, motivated the development of this opinion work. In plant breeding working collections are used as a source of variability and adaptation. In this process, unfailingly, only a part of the genetic variability is used, which is restricted in each selective cycle since the purpose of this process is to obtain new cultivars. In the selection process there is always a loss of genetic variability with respect to the population that gave rise to it. The confusion mentioned with respect to the loss of genetic variability resides in the following: the greater probabilities of success in a plant breeding program will be associated to the availability of a wide genetic variability in the starting elite collection and not in the obtained cultivar. One of the reiterated concepts attributes the loss of genetic variability to the advent of new cultivars and the narrow genetic base that they represent. The loss of genetic variability is a consequence of the achievement of genetic progress in plant breeding. In this context, the respect for diversity in protected areas and agrobiodiversity in agricultural areas, is the way for producing profitable yields while maintaining the long-term productivity as a result of the implementation of plant breeding.
RESUMO
Collection of Bromus catharticus Vahl was carried out in the Argentine humid and sub-humid central area. Sixty-eight natural populations are conserved for medium and long term in Pergamino Germplasm Bank and in IRB Germplasm Bank, and ten morphological and agronomic traits were evaluated in the field during two years. There was variability for the traits considered among the accessions. Those populations from the subhumid area showed differences in valuable attributes for breeding. Exploration of marginal areas for this species might be an effective way to add variability to this collection.
Coletas de Bromus catharticus Vahl foram conduzidas nas areas úmidas e sub-úmidas centrais da Argentina. Sessenta e oito populações naturais foram mantidas por médio e longo períodos nos bancos de germoplasma Pergamino e IRB, e dez características morfológicas agronômicas foram avaliadas em campo durante dois anos. Foi observada variabilidade para as características entre os acessos. As populações da região sub-úmida mostraram diferenças para características importantes para o melhoramento. A exploração de áreas marginais para esta espécie pode ser um modo efetivo de adicionar variabilidade para esta coleção de germoplasma.
RESUMO
Collection of Bromus catharticus Vahl was carried out in the Argentine humid and sub-humid central area. Sixty-eight natural populations are conserved for medium and long term in Pergamino Germplasm Bank and in IRB Germplasm Bank, and ten morphological and agronomic traits were evaluated in the field during two years. There was variability for the traits considered among the accessions. Those populations from the subhumid area showed differences in valuable attributes for breeding. Exploration of marginal areas for this species might be an effective way to add variability to this collection.
Coletas de Bromus catharticus Vahl foram conduzidas nas areas úmidas e sub-úmidas centrais da Argentina. Sessenta e oito populações naturais foram mantidas por médio e longo períodos nos bancos de germoplasma Pergamino e IRB, e dez características morfológicas agronômicas foram avaliadas em campo durante dois anos. Foi observada variabilidade para as características entre os acessos. As populações da região sub-úmida mostraram diferenças para características importantes para o melhoramento. A exploração de áreas marginais para esta espécie pode ser um modo efetivo de adicionar variabilidade para esta coleção de germoplasma.