Comparative Resistance of Multiple Insect-Resistant Soybean Genotypes to the Soybean Looper12

Publisher Website
Google Scholar
Abstract
Four soybean, Glycine max (L.) Merr., plant populations with Mexican bean beetle, Epilachna varivestis Mulsant, and corn earworm, Heliothis zea (Boddie), resistance derived from PI227687 and PI229358 were evaluated for resistance to the soybean looper, Pseudoplusia includens (Walker), in the laboratory, field, and greenhouse. Foliage of plants from N77-9002 and N77-9003, derived from PI227687, was less preferred for feeding than that of N77-9004 and N77-9005, derived from PI229358, in laboratory leaf disc tests. P. includens larval field plot populations were slightly higher in N77-9004 and -9005 than in N77-9002 and -9003. In laboratory no-choice tests, the most resistant subline of N77-9003 was more resistant than the most resistant subline of each of the other three populations, based on larval weight, length of developmental period, and percent mortality. P. includens larvae fed PI227687 foliage suffered 100% mortality, both early (days 3 to 7) and late (days 18 to 25) in larval life, whereas larvae fed PI229358 foliage suffered 50% mortality only in instars immediately preceding pupation. Weights of P. includens larvae fed postbloom PI227687 foliage were 42% less than those fed prebloom foliage, compared with weight differences of 32% for larvae fed post- and pre-bloom PI229358 foliage.