ISSN:
1573-5036
Keywords:
colony morphology
;
deserts
;
N2-fixation
;
nodule relative efficiency
;
Rhizobium
;
uptake-hydrogenase
;
woody legumes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Psorothamnus spinosus seedlings were selected at random and excavated from 10×30 m quadrats along a 270 m transect in a southern Californian desert arroyo. Forty-six of the fifty seedlings excavated (92%) were nodulated. The mean number of nodules/plant was 7.0±3.6. Maximum rooting depth was 40 cm, and most (58.8%) of the nodules were found between 15 and 30 cm depth. The mean root/shoot ratio was 1.4±0.4. The rhizobial population density between 10 to 40 cm depth across all quadrats was non-detectable using a plant infection, most probable number method. All 70 isolates from field nodules were fast-growingRhizobium spp. Two colony morphologies were observed: wet, translucent, and wet, opaque. All isolates tested were effective on bothP. spinosus and another desert woody legume, mesquite (Prosopis glandulosa). Many isolates had a high relative efficiency, and seven of eight efficient isolates had uptake-hydrogenase activity. Root stimulation of the low rhizobial population found in the arroyo and subsequent root nodulation may be an important factor in seedling establishment by woody legumes in N-limited desert arroyo systems.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02371148
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