Fecha/hora: 16/06/2024 04:14:13

Biblioteca(s): 	INIA Tacuarembó.	
Fecha corriente: 	21/02/2014	
Fecha de la última actualización: 	27/11/2019	
Autoria: 	HOWIESON, J.G.; YATES, R.J.; O'HARA, G.W.; RYDER, M.; REAL, D.	
Afiliación: 	JOHN G. HOWIESON, Centre for Rhizobium Studies, Murdoch University, Australia. Department of Agriculture Western Australia, Baron-Hay Court, South Perth, Australia.; R.J. YATES, Centre for Rhizobium Studies, Murdoch University, Australia.; GRAHAM W. O'HARA, Centre for Rhizobium Studies, Murdoch University, Australia.; M. RYDER, Te Anau Cottage, Borredaile Trust, Post Bag 3795, Marondera, Zimbabwe.; DANIEL REAL FERREIRO, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay.	
Título: 	The interactions of Rhizobium leguminosarum biovar trifolii in nodulation of annual and perennial Trifolium spp. from diverse centres of origin.	
Año de publicación: 	2005	
Fuente/Imprenta: 	Australian Journal of Experimental Agriculture, 2005, v. 45, no. 2-3, p. 199-207.	
DOI: 	10.1071/EA03167	
Idioma: 	Inglés	
Notas: 	Article history: Submitted: 8 August 2003 // Accepted: 21 April 2004 // Published: 14 April 2005.	
Contenido: 	The release of effective inocula for new perennial clovers into cropping zones where subterranean clover is important might compromise N2 fixation by this valuable annual clover if symbiosis between the new inoculants and subterranean clover is not optimal. To assist our understanding of the interactions between clovers and their microsymbionts, rhizobial strains and clovers from South and equatorial Africa, North and South America, and the Euro?Mediterranean regions were tested. Glasshouse-based studies of the cross-inoculation characteristics of 38 strains of Rhizobium leguminosarum bv. trifolii associated with 38 genotypes of annual and perennial Trifolium spp. from these world centres of diversity were undertaken. Less than 7.5% of the perennial clover symbioses were effective whereas 40% of associations were effective for many of the annual clover species of Euro?Mediterranean origin. There was substantial specificity within the African clovers for effective nodulation. Rhizobial strains from the South American perennial T. polymorphum or from the African clovers were unable to nodulate subterranean clover effectively. Also, 7 of the 17 strains from these regions were unable to form nodules with the less promiscuous Mediterranean annual clovers, T. glanduliferum and T. isthmocarpum. Fifty-three of about 400 cross-inoculation treatments examined, which included annual and perennial clovers, were incapable of forming nodules, while only 65 formed effective nodules. There are 2 barriers to effective nodulation: a ?geographic? barrier representing the broad centres of clover diversity, across which few host-strain combinations were effective; and, within each region, a significant ?phenological? barrier between annual and perennial species. Clovers and their rhizobia from within the Euro?Mediterranean region of diversity were more able to cross the phenological barrier than genotypes from the other regions. It appears that only the relatively promiscuous clovers, whether annual or perennial, have been commercialised to date. The data indicate that, for perennial clovers, it will be a substantial challenge to develop inocula that do not adversely affect N2 fixation by subterranean clover and other annual clovers available commercially, especially if the perennial clovers were originally from Africa or America. Some future strategies for development of inoculants for clovers are proposed.	
Palabras-Clave: 	PASTURE.	
Categoría del tema: 	A50 Investigación agraria	
Registro original: 	INIA Tacuarembó (TBO)	
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