Observation on Hirschmanniella species associated with rice in West Bengal.

摘要

Hirschmanniella species were isolated from the roots and soil around the roots of rice grown in various locations in West Bengal, India, characterized by different agro-ecological conditions, i.e. Birbhum (red and laterite zone), Coochbehar (terai zone), Burdwan (Gangetic old alluvial zone), Kakdeep (coastal zone), and Malda, Gayeshpur, Chakdah, Ranaghat and Krishnanagar (new alluvial zone). H. oryzae and H. mucronata were the most dominant among the isolated species. H. mucronata was found to be more widespread than H. oryzae. In Nadia, both were isolated from rice. H. mucronata female and male specimens had bodies 1.69-1.92 and 1.46-1.79 mm long, respectively. Body length, body width, tail length, anal body width and distance of oesophagus-intestinal were moderately variable characters. The stylet length (22.9-26.35 micro m) and vulva percentage (46.23-55.23%) in females were the least variable characters. In males, the stylet length was also the least variable (23.1-24.6 micro m). Thus, the stylet length in both sexes and vulva percentage in females can be considered as stable characters for the identification of this species. H. mucronata can also be distinguished from H. oryzae and H. gracilis by its hemispherical lip region (flattened in the latter species).