The hatching of cereal cyst nematode (Heterodera avenae) in response to different inorganic ions

ABSTRACT

Cereal cyst nematode is a major pest of small grain cereals, which causes huge yield losses to crops in China and other parts of the world. In this study, the effects of five inorganic ion concentrations on egg hatching of Heterodera avenae were studied. Results revealed that ZnCl₂ and FeCl₃ promoted hatching of induced and natural diapausing eggs. The cumulative hatching rates of eggs were 49 % and 13 % at 30 mM ZnCl₂ and 10 mM FeCl₃, respectively, which were higher than those of other treatments. The hatching ability promoted by ZnCl₂ is greater than by FeCl₃. Diapause induced eggs in ZnCl₂ continued to hatch after 10 days; however, those in FeCl₃ mainly hatched in the first two weeks. ZnCl₂ had obvious stimulating effects on the hatching of natural diapause and non–diapause free eggs at 15 and 30 mM concentrations. FeCl₃ promoted the hatching of natural diapause eggs; howevr, it inhibited hatching of non–diapause free eggs. Conversely, different concentrations of inorganic ions did not have any stimulatory effect on white female eggs. In the nematode life cycle, hatching is the critical stage because juveniles may be infected. The results of this study provide useful information the use of new fertilizers (including promoted hatching inorganic ions) applied before planting for controlling nematode diseases caused by H. avenae.

hatching rate; ion concentration; stimulus; plant–parasitic nematodes