Infectivity variation of Discaria trinervis-nodulating Frankia in Patagonian soil according to season and storage conditions

EUGENIA E. CHAIA, MARIANA SOLANS, GERNOT VOBIS, LUIS L. WALL

PHYSIOLOGIA PLANTARUM

Blackwell Publishing

Lugar: Oxford; Año: 2007 vol. 130 p. 357 - 363

0031-9317

Changes in the infectious capacity of soilborne Frankia from the same site may depend on environmental conditions. To test this, we examined the effect of season of sampling, sample storage protocol and storage time. The nodulation capacity of Frankia from rhizospheric soils of Discaria trinervis (Hook et Arn.) Reiche (Rhamnaceae) growing in northwest Patagonia (Argentina) was measured using the most probable number method. Soil samples were collected seasonally and either stored moist at 4ºC or air dried at room temperature for few days. Old (air-dried) soil samples were also assayed. All soils nodulated D. trinervis seedlings. Nodulation units (NU) ranged from 44 (spring, moist storage) to about 1 ml of soil (summer moist, and summer and autumm, air-dried storage), with intermediate values in other samples. Soils stored for 12 years, 6 months or 1 week had similar NU. Frankia NU positively correlated with soil water content (r = 0.6, p