Fecha/hora: 11/06/2024 17:01:11

Biblioteca(s): 	INIA La Estanzuela.	
Fecha corriente: 	21/02/2014	
Fecha de la última actualización: 	06/07/2021	
Autoria: 	REBUFFO, M.; CONSORTIUM LOTASSA; CONSORTIUM LESIS.	
Afiliación: 	MONICA IRENE REBUFFO GFELLER, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay.	
Título: 	Breeding temperate legumes: advances and challenges.	
Año de publicación: 	2007	
Fuente/Imprenta: 	Lotus Newsletter, 2007, Volume 37, Issue 3, pages 105.	
ISSN: 	1510-7809	
Idioma: 	Inglés	
Contenido: 	Abstract: Conventional breeding is an efficient tool with factors with low environmental effect, where the phenotype expression is closer to the genotype. On the other hand, selection for abiotic stresses involves complex characteristics restricting progress of conventional breeding 
programs. The study of the responses of several perennial legumes to selection for water and saline stress, Al tolerance and P availability is developed in the frame of the Projects LOTASSA (FP6-2003-INCO-DEV2 PL-517617) and LESIS (FTG-787/2005). Their 
approach involves the characterization and selection of naturalized populations for the identification of superior germplasm, as well as their metabolic and molecular analysis in order to develop strategies that could spead conventional breeding in the future. The 
presentation describes the approach and first results. The physiological responses of the main cultivated species to Al, saline and water stress are evaluated. Divergent selection is carried out in Lotus corniculatus (Lc) and diploid L. uliginosus (=L. pedunculatus) (Lu) for 
tolerance to water stress and Al tolerance, and the development of contrasting populations for root characteristics (root branching and density), the characterization of natural populations of L. glaber (=L. tenuis), Trifolium repens (Tr) and T. pratense (Tp) for water stress, L. glaber for saline stress. Chilean and Uruguayan naturalized populations of Lc, Tr and Tp are evaluated for water stress and prevailing diseases. Results show that there is genetic variability within the Lc, Lu and Lg germplasm for Al tolerance, water and saline stress, respectively, to be used in the selection process. Lc ultivar San Gabriel (Uruguay) was more sensitive to Al toxicity than Brasilian germplasm; the membrane potential in root cortex cells remains unchanged between pH 4.4 and 6 for the most tolerant Brasilian selections. Although saline stress stunted foliar and root growth, the evaluation at young stages (40 days) showed Lg entries collected in saline soils of Buenos Aires Province (Argentine) that produced 50% more forage than less adapted germplasm. There are differential responses of Chilean Lg accessions to water stress in leaf rate appearance, stem elongation and stem dry weight. Water stress (40% field capacity) was imposed for six months to Lc cultivar San Gabriel and INIA Draco. Contrasting phenotypes were identified through regrowth production (2.15 and 4.13 g/plant of fresh weight for sensitive and tolerant selections, respectively). Differences between sensitive and tolerant selections were larger for Lu (2.96 and 7.72 g FW/plant). Proline is one of the metabolite that shows high consistency with the response to water stress in several species of Lotus as well as in Tp. The 
isotopic discrimination (?13C/12C) has a good correlation with water use efficiency for the cultivated Lotus species.	
Thesagro: 	LEGUMINOSA FORRAJERA; MEJORAMIENTO DE PASTURAS.	
Categoría del tema: 	F01 Cultivo	
URL: 	http://www.ainfo.inia.uy/digital/bitstream/item/15795/1/Lotus-Newsletter-2007-Volume-37-3-105.pdf	
Registro original: 	INIA La Estanzuela (LE)	
Ejemplares: 	LE - (34453-1) - PXI - PC - DD - PP/Lotus newsletter/2007/37 -  -  - DIS