Symbiotic N2(C2H2) Fixation by Bean

Westermann, D.T. and Kolar, J.J. (1978) Symbiotic N2(C2H2) Fixation by Bean. Crop Science. 18:986-990.

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Abstract

The response of bean (Phaseolus vulgaris L.) to N fertilization
under field conditions indicates different Rhizobia-cultivar
relationships or symbiotic N₂-fixation limitations
due to the cultivars. We have used the acetylene
reduction method to determine the relative seasonal
N₂(C₂H₂) fixation of several field-grown bean cultivars.
The relative nitrogenase activity was estimated from 3-
X 15-cm soil cores taken around the main root of a decapitated
plant. Activities rapidly increased from the
three node vegetative (V3) to early pod-filling (R3-R4)
growth stages, thereafter decreasing to zero at physiological
maturity (R9). Accumulated daily activity totals
showed a five- to sixfold difference in seasonal N₂(C₂H₂)
fixation between cultivars, which was significantly related
to the average nodule weight and to the plant dry weight
near physiological maturity. However, cultivars
similar plant dry weights had a two- to threefold difference
in relative N₂(C₂H₂) fixation. Seed yields and total-N
updates were also positively related. These observations
indicate that it may be possible to increase both the
symbiotic N₂ fixation and seed yields through plant breeding.

Item Type:	Article
NWISRL Publication Number:	0408
Subjects:	Irrigated crops > Bean / dry bean Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:52
Last Modified:	02 Feb 2017 16:10
Item ID:	339
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/339