ABSTRACT
RESUMEN En 2005 se inició un programa de mejoramiento de arveja para aumentar la producción en cantidad y calidad en la Facultad de Ciencias Agrarias (FCA), Universidad Nacional de Rosario (UNR). Los primeros pasos fueron reunir una colección activa de germoplasma de todo el mundo y analizar la variabilidad genética a través de rasgos morfo-agronómicos y moleculares. En 2014, el Instituto Nacional de Tecnología Agropecuaria (INTA) y la FCAUNR unieron esfuerzos para promover el desarrollo local de genotipos de arveja adaptados a la región. Este programa, utilizando metodologías convencionales, ha obtenido hasta el momento una nueva variedad comercial (Primogénita FCA-INTA) de color de cotiledón verde, semi-áfila, con alta adaptación a las condiciones agroecológicas locales y alto potencial de rendimiento. El mejoramiento genético, sin embargo, es un proceso lento. El desarrollo de nuevas variedades requiere una década o más utilizando metodologías tradicionales, por lo que se propusieron diferentes alternativas para la reducción de este período. Los haploides duplicados y el cultivo in vitro han sido algunas de las metodologías desarrolladas, sin embargo, en legumbres no se han podido implementar de manera eficiente en los programas de mejoramiento. En este contexto, Speed Breeding surge como una tecnología que permite incrementar la eficiencia de los programas, reduciendo los costos y el trabajo requerido.
ABSTRACT A pea breeding program to increase production in quantity and quality was started in 2005 in the College of Agrarian Sciences (FCA), National University of Rosario (UNR). The first steps were to gather an active collection of germplasm from around the world and to analyze genetic variability through morpho-agronomic and molecular traits in order to set objectives. In 2014, the National Institute of Agropecuarian Technology (INTA) and the FCAUNR, joined forces to unite inter-institutional efforts for promoting the local development of pea genotypes adapted to the region. This program, using conventional methodologies, has so far obtained a new commercial line (Primogénita FCA-INTA) of green cotyledons, semileafless, with high adaptation to local agro ecological conditions and high yield potential. Breeding, nevertheless, is a slow process. Developing new pea varieties usually takes a decade or more when using traditional methodologies; thus, different alternatives were proposed for the reduction of this period. Doubled haploids and in vitro culture have been some of the methodologies developed; in pulses, however, they have not been efficiently implemented in breeding programs. In this context, Speed Breeding emerges as a technology that allows increasing the efficiency of the programs, while reducing costs and the required labor.
ABSTRACT
RESUMEN El mejoramiento convencional puede ser complementado mediante diferentes estrategias que incrementen la eficiencia de las metodologías y la tasa actual de aumento de los rendimientos a fin de satisfacer la demanda. El uso de marcadores moleculares con el objetivo de desarrollar mapas de ligamiento de la especie, el uso de Blup (Best Linear Unbiased Prediction) para una selección eficiente de progenitores a hibridar, el uso del cultivo in vitro para incrementar artificialmente el número de plantas F1 o el uso de fenotipificación digital para una eficiente caracterización digital que puede realizarse durante la regeneración periódica y rutinaria de accesiones en colecciones de germoplasma.
ABSTRACT Conventional breeding can be complemented by different strategies that increase the efficiency of the methodologies and the current rate of increase in yields in order to meet demand. The use of molecular markers with the aim of developing linkage maps of the species, the use of Blup (Best Linear Unbiased Prediction) for an efficient selection of progenitors to hybridize, the use of in vitro culture to artificially increase the number of F1 plants or the use of digital phenotyping for efficient digital characterization that can be performed during the periodic and routine regeneration of accessions in germplasm collections.
ABSTRACT
RESUMEN La lenteja (Lens culinaris Medik.) es una especie diploide autógama (2n=2x=14) perteneciente a la familia Fabaceae. Es uno de los cultivos más antiguos que se conocen, con 8.000 a 9.000 años de historia, y se encuentra entre los primeros domesticados en Medio Oriente. Las semillas tienen un alto valor nutricional. Este cultivo es un interesante sustituto del trigo en las rotaciones de cereales, pero su importancia es baja debido a la falta de buenas variedades con adaptación local. Uno de los principales problemas que enfrentan los mejoradores en nuestro país es la estrecha base genética del germoplasma cultivado y su bajo potencial de rendimiento. En 2004 se inició un programa de mejoramiento de lentejas para desarrollar nuevas variedades con adaptación a las condiciones predominantes en las áreas de cultivo de Argentina. El germoplasma se obtuvo del ICARDA (Centro Internacional de Investigación Agrícola en las Zonas Áridas) y de productores locales. Se utilizan métodos convencionales de mejoramiento basados en la hibridación y selección. Se han obtenido dos nuevas variedades, una del tipo macrosperma (Boyerito FCA) y la otra del tipo microsperma (Tacuarita FCA) mediante la aplicación de selección masal en poblaciones F2 provenientes de la hibridación de materiales seleccionados. Este programa complementa los métodos de mejora tradicional con técnicas biotecnológicas como la transgénesis, el uso de marcadores moleculares, el cultivo de embriones in vitro combinado con el método SSD para acortar el ciclo generacional, y el fenotipado digital.
ABSTRACT Lentil (Lens culinaris Medik.) is a self-pollinating diploid (2n=2x=14) species belonging to the Fabaceae family. It is one of the oldest crops known, with 8,000 to 9,000 years of history and it is among the earliest domesticates from the Near East Fertile Crescent. The seeds have high nutritional value. This crop is an interesting substitute to wheat in cereal rotations but its importance is low due to a lack of suitable varieties with local adaptation. Some of the major problems that Argentinian lentil breeders face are the narrow genetic base of the current cultivated germplasm and its low yield potential. A lentil breeding program was initiated in 2004 to develop new varieties with adaptation to prevalent conditions in growing areas of Argentina. Germplasm was obtained from ICARDA (International Center for Agricultural Research in the Dry Areas) and local producers. Conventional breeding methods using hybridization and selection are being carried out to develop improved varieties, broad the genetic base, and isolate superior recombinant inbred lines. Two new varieties have been obtained, one of the macrosperm type (Boyerito FCA) and the other of the microsperm type (Tacuarita FCA) through the application of mass selection in F2 populations from the cross of selected materials. This program complements traditional breeding methods with biotechnological techniques such as transgenesis, use of molecular markers, in vitro embryo culture combined with the SSD method to shorten the breeding time, and digital phenotyping.
ABSTRACT
In breeding programs, a large number of F2 individuals are required to perform the selection process properly, but often few such plants are available. In order to obtain more F2 seeds, it is necessary to multiply the F1 plants. We developed a rapid, efficient and reproducible protocol for in vitro shoot regeneration and rooting of seeds using 6-benzylaminopurine. To optimize shoot regeneration, basic medium contained Murashige and Skoog (MS) salts with or without B5 Gamborg vitamins and different concentrations of 6-benzylaminopurine (25, 50 and 75 µM) using five genotypes. We found that modified MS (B5 vitamins + 25 µM 6-benzylaminopurine) is suitable for in vitro shoot regeneration of pea. Thirty-eight hybrid combinations were transferred onto selected medium to produce shoots that were used for root induction on MS medium supplemented with α-naphthalene-acetic acid. Elongated shoots were developed from all hybrid genotypes. This procedure can be used in pea breeding programs and will allow working with a large number of plants even when the F1 plants produce few seeds.
Subject(s)
Breeding/methods , Crosses, Genetic , Pisum sativum/growth & development , Hybridization, Genetic , Phylogeny , Plant Shoots/growth & development , Plant Shoots/physiology , RegenerationABSTRACT
We characterized 13 accessions of dry peas of different origins from various growing regions in Argentina, based on three replications of 20 plants cultivated in 2009 and 2010 in a greenhouse, with the objective of selecting those with favorable characteristics for use in breeding programs. Significant differences were found for length and width of stipule and pod, length of the internodes and leaflets, plant height, total number of nodes, number of nodes at the first pod, number of days to flowering and to harvest, number of pods and seeds per pod, 100-seed weight and grain diameter, demonstrating a high degree of genetic variability. Phenotypic correlation analysis demonstrated that large pods produced more seeds per pod, but the seed weight decreased. Plants with smaller number of nodes in the first pod were more productive. Estimates of genotypic correlation coefficients indicated a strong inherent association among the different traits. Clustering methods grouped the accessions into five clusters. Cluster 5 included two accessions and showed the highest values for length and width of stipules (4.9 and 4.5 cm, respectively), length of leaflets (7.43 cm) and days to flowering (122.6), while cluster 3, with one accession, and cluster 4, with two accessions, showed the highest values for number of seeds per pod (3.78 and 4.39), number of pods per plant (5.33 and 5.70), length of pods (5.54 and 5.72 cm), and width of pods (1.21 and 1.20 cm, respectively). We conclude that accessions in clusters 3 and 4 would be useful for crosses with other cultivars in pea breeding programs.