De aantasting van enige Solanumsoorten en enige kruisingen tussen Solanum demissum en S. tuberosum door het stengelaaltje ditylenchus dipsaci (Kuhn) Filipjev

Summary

The infestation of some Solanum species and of crossies between Solanum demissum and S. tuberosum by the stem eelworm Ditylenchus dipsaci (Kühn) Filipjev

The reaction to infestation by stem eelworms of tubers and stems of someSolanum species and crossies between someSolanum demissum strains and the potato variety “Frühmölle” was investigated. The tubers were inoculated by putting the eelworms into an incision; the stems by putting them between young parts at the top of young shoots.

The infestation after inoculation of tubers of theSolanum species investigated is determined by:

• 1. the affinity of the stem eelworms for the species or strain;

• 2. defence reactions of the infested tissue.

Defence reactions consist in suberization of the walls of parenchyma cells in the neighbourhood of the infestation and the development of cork and gum layers, forming tissues of different morphological structure in different species or strains.

In shoots no defence reactions were found.

The results with regard to affinity and defence reactions in different species and strains were:

Hosts	Affinity	Defence reactions
Solanum demissum, strain 25 ........	great	strong
„ „ „ 33 ........	great	noue
Solanum antipoviezii strain 82 .......	some	faily strong
„ „ „ 10 .......	little	strong
Solanum chacoense .............	little	strong
Aya papa (S. andigenum) ..........	some	strong
Some crossies (S. demissum× „ Frühmölle”) .	some	none
Other crossies ...............	great	some
„Eersteling” ...............	great	strong

Three new hosts of the stem eelworm are recorded:

• 1. Solanum demissum Lindl.

• 2. Solanum antipoviczii Buk.

• 3. Solanum andigenum Juz. etBuk.