Morphological and histopatological study of Pratylenchus pseudocoffeae on Chrysanthemum in Mahallat region

In order to identify the plant parasitic nematodes of Chrysanthemum in greenhouses and open fields in Mahallat region located in Markazi province in Iran, about 67 soil and root samples were collected during 2007 and 2008. The nematodes were extracted by centrifugal technique, killed, fixed and transferred to glycerine. Morphological and morphometrical characters were studied by light microscope. In our study, one of the most important nematodes was root-lesion nematode Pratylenchus pseudocoffeae. Root tissues were invaded by the nematode, which caused distinct necrosis and large cavities within cortical parenchyma. All developmental stages were observed in the root tissues. Morphometrics of P. pseudocoffeae is characterised by a labial region with three annuli, vulva located at 79-82% of body, long differentiated post-vulval uterine sac, tail sub hemispherical or bluntly pointed with smooth terminus, presence of males, spermatheca oblong. The species resembles P. coffeae, P. gutierrezi and P. penetrans from which it differs by a number of morphometric features (position of the vulva, the shape of the tail tip and head shape). This is a new occurrence and first record of the species in Iran and becomes the third world record after his original description.