Changes in the structure of wheat (Triticum aestivum L.) roots in varieties susceptible and resistant to infestation by Heterodera avenae Woll.

Abstract

The structure of wheat roots of the "susceptible" variety Capa and "resistant" variety AUS 10894 infested by Heterodera avenae was studied. The processes leading to the formation of syncytia and the range of reactions of the studied varieties to infection are described. In both varieties, necrosis of cells surrounding the nematode, and in the wheat variety AUS 10894, in addition, necrotic changes in cells surrounding syncytia were found. The syncytia formed in the resistant variety degenerated early. The cells adjacent to the syncytia underwent divisions. Cell divisions also took place in the pericycle. They led to the formation of more numerous lateral roots, especially in plants from the susceptible variety. It seems that the earlier degeneration of syncytia and the accompanying necrotic changes in the tissues surrounding the syncytia observed in wheat of the AUS 10894 variety can be taken as signs of host resistance reactions.