Incidence of Cereal Cyst Nematodes (Heterodera avenae type B and H. filipjevi) in southwestern Iran

A survey of cereal fields of Khuzestan province during ۲۰۰۸-۲۰۱۱ revealed that cereal cyst nematodes (CCNs) are widely distributed in this region. The CCNs were present in ۳۷ and ۳۵% of the ۲۰۰ samples collected from wheat and barley fields respectively. The species were identified as Heterodera avenae type B and H. filipjevi the morphological and morphometric identifications of which were confirmed by rRNA-ITS RFLP. Population density of CCNs ranged from ۲ to ۱۰۳ cysts (mean ۱۸)/۱۰۰ g of dried soil with an average of ۳۹۵ (۰-۳۴۰۰) J۲ and eggs in wheat samples. Whilst the number of cysts in barley samples were counted ۳-۷۱ cysts (mean ۱۱) /۱۰۰ g soil, the J۲ and eggs averaged ۱۶۶ (۰-۹۰۰). The lowest and the highest rates of infestation (۸ and ۸۳%) were observed in the regions of Ahvaz and Behbahan respectively. The number of J۲ and eggs of CCNs in some regions were greater than the damage threshold level considered for CCNs and it is likely they could cause economic yield loss in these regions.

Keywords:

Cereal cyst nematodes , distribution , Iran , Khuzestan