Taxonomy , Identification and Principal Species

‘On closer examination the root was found to be covered with excrescences varying from the size of a small pin’s head to that of a little Bean or Nutmeg.’ This observation, from one of the first accounts of root-knot nematodes on plants, was made by Berkeley (1855), an eminent Victorian scientist, on publishing his discovery of galls produced by nematodes on the roots of cucumbers growing in a garden frame at Nuneham, England. Miles Joseph Berkeley FRS (1803–1889), an ordained minister, expert draughtsman and pioneering zoologist, plant pathologist and mycologist (he authored over 6000 species), went on to describe the symptoms thus: ‘The tubercles were of a dirty cream colour, nearly globose, obscurely furfuraceous, and in almost every case were developed on one side of the root...’. Berkeley (Fig. 3.1) noted the enormous development of the vascular tissues within the galls and recorded the presence of ‘Vibrio’: