BEHAVIOUR OF 9 POPULATIONS OF POTATO CYST NEMATODE HETERODERA ROSTOCHIENSIS TOWARDS 3 RESISTANT POTATO HYBRIDS

The numbers of larvae that invaded and of adult males and females produced in the roots of three hybrid potato varieties incorporating resistant genes from Solanum tuberosum s.sp. andigena, or S. multidissectum, or both were compared with those for a susceptible variety, Arran Banner, using inocula of larvae from nine populations of Heterodera rostochiensis. The numbers of larvae becoming adult were influenced by both the resistant host and the population used. Either (1) most larvae survived and many males and females were produced, (2) most larvae survived, but most became male and few became female, or (3) many larvae died, almost all the survivors became male and only a very few became female. These differences were probably determined by the size of the giant-cell groups the larvae were able to induce in the potato roots. © 1969 BRILL.