The Potential Antagonistic Effects Of Fatty Acids And Plants Infected With Nematode On Meloidogyne Incognita

The present study consists of three sections. First, the effects of eight fatty acids (butyric, caproic, caprylic, capric, lauric, myristic, palmitic and oleic acids) on the reproduction of Meloidogyne incognita (root-knot nematode) and cucumber growth were estimated. Second, potential antagonism towards to M. incognita of butyric, caproic, caprylic, capric, lauric, myristic, palmitic oleic and linoleic acids was evaluated via egg hatch, second stage-juveniles (J2) mortality and J2chemotaxis. Finally, the effects of volatile organic compounds (VOCs) from roots of Meloidogyne incognita infected cumber on M. incognita penetration to the conspecific were preliminarily conducted. All these studies might give deep insight into the integrated control of root-knot nematode.The results showed:1) Caprylic, capric and oleic acids in the two replicated experiments, whereas cucumber biomass was not adversely affected by the tested FAs and was even significantly increased by lauric, palmitic and oleic acids treatments.2) All nine tested fatty acids showed apparent inhibitory effects on egg hatching on day21in the two replicated experiments, especially capric acid at all tested levels.3) Caproic, caprylic, capric, lauric, myristic, and palmitic acids caused significantly higher mortality of the second-stage juvenile of M. incognita than the other three FAs, and both caprylic and capric acids resulted in approximately50%mortality (2000μmol/L) after a24h exposure.4) Second-stage juveniles of M. incognita were chemotactic towards to butyric and palmitic acids treatments (only in one experiment). There is no difference observed in other fatty acids treatments and control.5) VOCs from donor plants inoculated with M. incognita significantly reduced the amount of M. incognita penetrated to conspecific receiver plant (t=3.199, P=0.002, df=70).