CHITIN IN MELOIDOGYNE-JAVANICA

The gelatinous matrix (GM) exuded from living females of Meloidogyne j avanica, which ultimately with the eggs forms the egg mass, was tested for the reported presence of chitin. Freshly exuded GM dissolved rapi dly when 5 % KOH was added to a perfusion slide containing the nematod e at 22 degrees C. The GM in egg masses was tougher but rapidly dissol ved in a solution of sodium hypochlorite. Further treatment of GM-free eggs with 5 % KOH at 105 degrees C over 24 h led to breakdown of the eggs. Egg shells resisted this treatment and gave a chitin-type electr on diffraction pattern when examined under the electron microscope and gave a positive test for chitosan. Chitin is not found in the GM and reports of its presence are probably due to egg shells or contaminatin g fungal hyphae which can be detected by the use of fluorochromes such as Calcofluor White under UV light.