Effects of piperidine and piperideine alkaloids from the venom of red imported fire ants, Solenopsis invicta Buren, on Pythium ultimum Trow growth in vitro and the application of piperideine alkaloids to control cucumber damping-off in the greenhouse.
BACKGROUND
Pythium ultimum is a plant pathogen that causes significant yield losses on many economically important crops. Chemical treatment has been used for disease control. In searching for alternatives, venom piperidine and piperideine alkaloids from red imported fire ants were tested against P. ultimum in vitro, and piperideines were employed to control cucumber damping-off in the greenhouse as drench treatments. Results Piperidine and piperideine alkaloids of the red imported fire ant significantly inhibited mycelium growth of P. ultimum. Piperidine alkaloids were stable at both room and elevated temperatures. The inhibitory activity positively correlated with the concentrations of piperidine alkaloids in the medium, and the EC(50) = 17.0 µg ml(-1). Germination of sporangia of P. ultimum was negatively correlated with the concentrations of piperidine alkaloids in the medium, and the EC(50) = 12.3 µg ml(-1). The piperideine alkaloid drenching treatment significantly improved seedling emergence and seedling height of cucumber.


CONCLUSIONS
This is the first report describing the use of venom alkaloids from the red imported fire ant to inhibit P. ultimum in the laboratory and the application of piperideine alkaloids to control damping-off disease caused by P. ultimum in the greenhouse. These findings may lead to the development of a new group of fungicides.
Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences, Baoding, Hebei Province, China.
Shezeng
S
Li
Xixuan
X
Jin
Jian
J
Chen
D000470:Alkaloids / Q000302:isolation & purification / Q000633:toxicity*; D000818:Animals; D000862:Ant Venoms / Q000737:chemistry*; D018553:Cucumis sativus; D025282:Mycelium / Q000187:drug effects / Q000254:growth & development; D010571:Pest Control / Q000379:methods; D010880:Piperidines / Q000302:isolation & purification / Q000633:toxicity*; D011775:Pythium / Q000187:drug effects* / Q000254:growth & development; D013696:Temperature
D000470:Alkaloids; D000862:Ant Venoms; D010880:Piperidines; C032727:piperidine