Nitrogen Partitioning and Mobilization Patterns in Bean Plants

Westermann, D.T. and Porter, L.K. and O'Deen, W.A. (1985) Nitrogen Partitioning and Mobilization Patterns in Bean Plants. Crop Science. 25:225-229.

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Abstract

The assimilation and distribution of N in the vegetative and
reproductive plant parts of edible grain legumes are important
processes determining final seed and protein yields. Limited information
is available describing these processes for beans
(Phaseolus vulgaris L.J. The objective of this study was to measure
the N partitioning and mobilization patterns in this important
grain legume. Two dry bean cultivars, '3512' and '3591',
were labeled with either K15NO3 or 15N2 at the late vegetative
(V5), early pod development (R2-R3), and seed filling (R6) developmental
stages in the greenhouse. Initial N partitioning was
evaluated on plants harvested 48 h after the start of labeling,
while the N mobilization patterns were evaluated on the 15NO3
labeled plants harvested at subsequent developmental stages and
at physiological maturity (R9). Both cultivars had similar dry
weight and N distribution patterns throughout development, but
3512 had a larger final seed yield while the final seed N concentrations
were greater for 3591. These differences developed
from R6 to R9 where the dry weight increase in 3591 had a N
concentration of 28.1 g kg-1 compared with 9.9 g kg-1 for 3512.
The relative proportion of 15N in each plant part was dependent
upon the growth stage and 15N source, and was independent of
cultivar. Greater proportions were found in the mature leaves
and roots of plants labeled with 15NO3, and in the seed and
nodules in those plants labeled with 15N2 at all growth stages.
Pods and seeds were major sinks from both 15N sources when
applied at R2-R3 and R6, respectively. The seed at R9 contained
64, 73, and 84% of the labeled-N applied at the V5, R2-R3, and
R6 growth stages, respectively. The seed contained an average
of 68% of the total plant N and 53% of the total plant dry weight
at R9. These data indicate that the photosynthetic and N2-fixation
activities during seed filling can have a significant influence
on the final seed N concentrations and yield.

Item Type:	Article
NWISRL Publication Number:	0544
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:	13 Jan 2017 22:14
Item ID:	433
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/433