INVESTIGADORES
CASTAGNO Luis Nazareno
congresos y reuniones científicas
Título:
Tolerancia a salinidad y alcalinidad de aislamientos de rizobios de suelos de la Pampa Deprimida del Salado: una alternativa sustentable para mejorar la calidad de los inoculantes para Lotus tenuis en la región
Autor/es:
BERGOTTINI VM; CASTAGNO LN; PAZ RC; RUIZ OA; ESTRELLA MJ
Lugar:
Chascomús, Buenos Aires, Argentina
Reunión:
Taller; IV Taller Interdisciplinario de Lotus: Aspectos genéticos, moleculares y ecofisiológicos de Lotus spp. y sus simbiontes; 2008
Resumen:
The Salado river Basin (SRB) is the most important area for cattle ranch production in Argentina. This activity is based on the use of natural pastures because the edaphic and climatic conditions restrict the implantation and persistence of”traditional legumes”in saline-alkaline lowlands (30% of the total area). L. tenuis is an exotic legume well adapted to these conditions, but in spite of its successful naturalization, the survival of this species during the seedling stage is limited and is a critical step for further implantation (Miñón et al., 1990). With the aim to improve seedling survival and forage quality of this legume, the genetic diversity of native rizobia that stablish symbiosis with L. tenuis was evaluated, for further selection of isolates with a better symbiotic efficiency than commercial inoculants in saline soils. A high genetic diversity was found among the rizobia of the SRB (Estrella et al., 2007). The symbiotic performance of one native isolate was superior to that strains recommended for commercial formulations of inoculants tested under control and salt stress conditions. RFLP analysis of 16S rDNA genes of native isolates with better symbiotic performance revealed that the taxonomy of Lotus tenuis symbionts in not only restricted to Mesorhizobium loti species, the type specie to L. tenuis and L. corniculatus (Saeki and Kouchi. 2000), and can involve others species and genus. It can be concluded that populations of rizobia in soils of the SRB are a source of genetic and symbiotic variability that can be used to obtain high quality inoculants for L. tenuis.