Ethylene production as an indicator of germination and vigor loss in stored rice seed infested by Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae)

Abstract

Germination and vigor of stored “Taichung Native 1” (TN1) rice seed was significantly reduced by Rhyzopertha dominica (F.) infestation. Seed germination decreased by about 34, 51 and 66% with 6, 7 and 8 weeks of infestation, respectively. Ethylene produced by growing seedlings, the shoot length, and dry weights of seedlings grown from infested seeds decreased significantly with an increase in the duration of infestation. Ethylene produced by 4-day-old rice seedlings was highly correlated with shoot growth ( r = 0.99) and to a lesser extent with the dry weight of seedlings when 17-days old ( r = 0.72). The study revealed that ethylene produced during early shoot growth can be used for comparing insect infestation in rice seed stored under otherwise identical conditions.