Heterodera hainanensis n. sp. (Nematoda: Heteroderinae) from bamboo in Hainan Province, China – a new cyst nematode in the Afenestrata group

Abstract

Heterodera hainanensis n. sp. is described and illustrated from bamboo (Phyllostachys pubescens) based on morphology and molecular analyses of rRNA D2D3 region of LSU and ITS. This new species belongs to the Afenestrata group and is characterised by lemon-shaped cyst with prominent vulval cone and vulval cone without fenestration and bullae but with weak and furcate underbridge. The second-stage juvenile (J2) has two lip annuli, a 15.8-17.5 μm long stylet with rounded knobs sloping slightly posteriorly, three incisures in the lateral field and a conical tail with hyaline portion forming 52.3-71.1% of the tail length. Heterodera hainanensis n. sp. most closely resembles species in the Afenestrata group but is distinguished from these species by a number of characters, including cyst shape and size, the presence of an underbridge, vulval slit length, J2 stylet length, stylet knobs shape, incisure number and lip annule number. Molecular analysis reveals that this species has unique LSU D2D3 and ITS rRNA sequences and RFLP-ITS-rRNA profiles, and it is most closest to H. koreana in dendrograms inferred from both markers. A key to all species of the Afenestrata group is presented.