Studies on the cereal nematodes, heterodera spp. and pratylenchus spp. in Turkey.

WOS:000346299700102Cereal cyst nematodes (CCN) and root lesion nematodes (RLN) are economically important in wheat production systems worldwide. Heterodera filipjevi is widely distributed in the Central Anatolia and East Anatolia whereas H. avenae and H. latipons were found in the eastern Mediterranean and south-eastern Anatolia region of Turkey. Pratylenchus thornei and P. neglectus are the predominant species of root-lesion nematodes in central, east and south-eastern Anatolia. RLN and CCN cause yield losses between 5-50%. The effect of temperatures on the incubation duration of cysts of H. avenae was investigated under in vitro conditions. A number of variables were assessed to optimize P. thornei screening including initial nematode density, inoculation volume, soil type, tube size, reference cultivars, harvest time and watering regime. Growth room experiments showed clear differentiation between the resistance and susceptible cultivars after 9 weeks in sandy growth medium (70:29:1 sand, field soil and organic matter) with small tubes (15x100 mm) with inoculation of 400 cultured P. thornei/plant. All H. avenae populations collected from south-eastern Anatolia were found to belong to Ha1 group Ha21 pathotype. The efficiency of some sources of resistance (CreR, Cre1, Cre2, Cre3, Cre7 and Cre8) in wheat against several H. avenae, H. filipjevi and H. latipons population was investigated in-vitro to resemble climate conditions in Turkey. Cre1, Cre3 and Cre7 genes induced resistance against both H. avenae and H. latipons populations. Plants with CreR and Cre8 genes revealed resistance against H. filipjevi. However, no gene was found to show resistance against all three nematode species together