ISSN:
1573-1561
Keywords:
Actinomycetes
;
agar plate screening
;
bioassay
;
fermentation
;
microbial isolates
;
phytotoxin
;
weed control
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract Agar plate screening of 220 isolates of soil actinomycetes for phytotoxin production resulted in selection of six isolates that inhibited (≥70%) one or both indicator plants for further studies. Cell-free broth of the two isolates, diluted in a 1:1 ratio, significantly reduced seed germination and radicle growth of six plants species on filter paper bioassay. Both isolates were inhibitory to velvetleaf (Abutilon theophrasti), a difficult weed to control. Phytotoxin from cell-free fermentation broth of one of the isolates (no. 48), sequestered by solvent extraction, was bioassayed on filter paper. Seed germination and growth of cress (Lepidium sativum) and barnyard-grass (Echinochloa crusgalli) were severely reduced at 1.5 and 3.0 mg/ml concentration, respectively. Solvent extract of mycelia was marginally inhibitory indicating that the phytotoxin was largely extracellular.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022502724711
