N.V.Vavilov Institute of Plant Industry, B.Morskaya 44, St.-Petersburg 190000, Russia.

Abstract

The author compared antixenosis, antibiosis and degree of damage of 4 sorghum samples settled by 8 clones of greenbug that interacted with 3 genotypes of the host. The samples possessed both antixenosis and antibiosis to avirulent greenbug clones. Numeric value of damage was closely correlated with plant preference and fertility of pest. Close correlation between antixenosis and antibiosis of plants was revealed. The investigation of joint inheritance of different stability mechanisms in sample K-1362 (one dominant gene responsible for weak damage) shows coincidence in segregation on antixenosis, antibiosis and the degree of damage. The results of experiments indicate that antixenosis and antibiosis are different ways of manifestation of the same correlated gene pairs and can not be considered as genetically different components of stability.