The potato eelworm hatching factor. 1. The preparation of concentrates of the hatching factor and a method of bioassay

Abstract

Crude solid concentrates of the potato eelworm hatching factor were prepd. by leaching the roots of growing tomato plants with water, adsorbing the factor on charcoal and eluting with aqueous acetone. The hatching of eelworm cysts by the factor was studied. There is a marked variation in hatchability with strain of cysts and season, with a decrease in hatchability in winter. This is not affected by conditions of storage. Per cent hatching is increased by pre-soaking and temp.; 3 weeks soaking and 24[degree]C are optimal. Number of larvae hatched is proportional to concn. of the factor up to a certain point above which it decreases. A reliable biological assay method for the hatching factor is descr., using the optimal conditions and a reference standard prepn.