Differences in Resistance to Stone Leek Leafminer Biotype B among Japanese Bunching Onion Varieties and Lines

Abstract

The degree of resistance of the highly resistant Japanese bunching onion (Allium fistulosum L.) line ‘D8s’ against stone leek leafminer (Liriomyza chinensis (Kato)) biotype A to L. chinensis biotype B was evaluated by laboratory and field experiments. In the laboratory experiment, population growth rate, feeding preference, and oviposition preference of biotypes A and B of L. chinensis were investigated. The population growth rates of biotypes A and B on a highly resistant ‘D8s’ line against L. chinensis were significantly lower than on the susceptible variety ‘Chouetsu’. However, the effect of population density control of biotype B on ‘D8s’ was significantly lower than that of biotype A. The period required until next-generation adults emerged on ‘D8s’ was longer than those on susceptible varieties for both biotypes. Feeding and oviposition preferences were examined using ‘D8s’ and other susceptible varieties. The numbers of feeding punctures and eggs laid by biotypes A and B on ‘D8s’ were lower than those on the other varieties. Next, we investigated the field resistance of ‘D8s’ against larvae from July to October 2022. In the experimental field, biotype A adults were not detected but biotype B adults were present. The degree of damage by L. chinensis larvae on ‘D8s’ was significantly lower than on the other control varieties. These results indicate that ‘D8s’ is a breeding material with resistance against L. chinensis biotypes A and B.