Resistance of Maize Inbreds to Pink Stem Borer

Abstract

The most important insect pest of maize (Zea mays L.) in southern Europe is the pink stem borer (Sesamia nonagrioides Lef.). The objective of this work was to identify sources of resistance to stem and ear damage by the pink stem borer. One hundred twenty‐one inbreds from seven germplasm groups (American, Argentine, European, Lancaster, Northern Flint, Reid, and Other), divided according to their maturity grouping (very early, early, midscason, and late), were evaluated for several years under artificial infestation at Pontevedra (northwestern Spain). Twelve traits were recorded to measure stem and ear damage. Stem and ear damage resistance traits were not correlated, therefore simultaneous selection for the two types of resistance within the same population should be carried out. Eight very early, two early, seven midseason, and four late inbreds were resistant to stem‐damage. The Reid germplasm group was more resistant to stem attack than the other groups. Therefore, the best Reid inbreds could be used to form a stem‐damage resistant Reid synthetic, which could be a source of new stem‐damage resistant varieties. Simultaneously, the best non‐Reid inbreds could be used for making a non‐Reid stem‐damage resistant synthetic. Thirteen very early, 10 early, two midseason, and three late inbreds performed better than the others against ear attack. Only seven inbreds (A509, A635, CO125, EA2024, EP39, Oh43, and PB130) were resistant to both stem and ear damage. These inbreds could be used as sources of resistance to pink stem borer in a breeding program.