ARS | Publication request: EFFECTS OF SORGHUM CULTIVARS WITH DIFFERENT LEVELS OF SORGOLEONE, AND WHEAT ROTATION, ON SOIL MICROORGANISM COMMUNITIES

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 5, 2004
Publication Date: June 1, 2004
Citation: Funnell, D., Pedersen, J.F. 2004. Effects of sorghum cultivars with different levels of sorgoleone, and wheat rotation, on soil microorganism communities. American Phytopathological Society Abstracts. 94:S32.

Technical Abstract: Sorghum produces sorgoleone, a toxic compound exuded from the roots with allelopathic properties. Cultivar 'Redlan' (a high sorgoleone producer) and cultivar 'RTx433' (a low sorgoleone producer) are being used in in vitro rotations with the wheat cultivar 'Lewjain' to assess possible affects on soil microorganism populations. Using soil collected from a nearby fallow sorghum field, the wheat and 2 sorghum cultivars were planted in the greenhouse for 4 cycles of 4 weeks each then rotated. During the first cycle, fungal and bacterial populations increased, with the greatest increases occurring in soils planted with wheat or with sorghum cultivar RTx433. Wet weight of aerial plant parts declined through the 4 cycles but those of sorghum cultivar RTx433 increased following rotation from wheat. Numbers of fluorescent pseudomonads increased following planting with wheat and sorghum over those found in fallow soil but were variable in following cycles. However, numbers of fluorescent pseudomonads were consistently highest in soil planted with sorghum cultivar RTx433. Characteristics of fluorescent Pseudomonas species will be assessed for potential antimicrobial activity.