Determinants of nodulation competitiveness in Rhizobium etli. Final report for period September 30, 1996--September 29, 1999

Technical Report · Tue Jan 04 04:00:00 EST 2000

DOI:https://doi.org/10.2172/765240· OSTI ID:765240

Handelsman, Jo ^[1]

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1. University of Wisconsin-Madison, Madison, WI 53706, USA

Nitrogen is a major limiting nutrient in crop production. Chemical fertilizers, which are used extensively to meet crop nitrogen requirements, contribute to the high energy inputs of modern agriculture and cause human health and environmental problems. Legumes and their bacterial associates have long been used in crop rotations to replenish soil nitrogen, but effective and reliable biological nitrogen fixation for beans is prevented by the lack of nodulation competitiveness of many Rhizobium strains used as inoculants. The result is that the inoculant strains will not occupy the host's nodules and no benefit will be derived from inoculation. Many indigenous soil strains of Rhizobium etli bv. phaseoli, the symbiont of bean, nodulate but fix little or no nitrogen, and therefore the nodulation competitiveness problem is significant for achieving maximum nitrogen benefit from bean crops. This project was directed toward developing an understanding of the basis of nodulation competitiveness.

• Research Organization: Univ. of Wisconsin-Madison, Madison, WI 53706, USA (US)
• Sponsoring Organization: USDOE Office of Energy Research (ER) (US)
• DOE Contract Number: FG02-96ER20248
• OSTI ID: 765240
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AGRICULTURE
BEANS
CROPS
FERTILIZERS
NITROGEN
NITROGEN FIXATION
NUTRIENTS
RHIZOBIUM
SOILS
STRAINS