Defensive responses of rice cultivars resistant to Cnaphalocrocis medinalis (Lepidoptera: Crambidae)
Journal
Arthropod-Plant Interactions
Journal Volume
13
Journal Issue
4
Pages
611-620
Date Issued
2019
Author(s)
Abstract
Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Crambidae) is an economically important pest of rice, Oryza sativa L. (Poaceae), throughout Asia, where damage caused by larvae, particularly during grain-filling stages, significantly increases yield losses. There is, therefore, a pressing need to develop cultivars that are resistant to C. medinalis. In this study, we assessed growth and mortality of first and third instar C. medinalis larvae fed on six rice cultivars that had previously been identified as resistant to the pest, and we quantified production of defense enzymes in plants exposed to herbivory. We found that mortality rates were highest in larvae fed on the resistant cultivars Baiqiaowan, Sasanishiki, Qingliu, and Kasalasu, while relative growth rates were lower for larvae fed on Baiqiaowan and Qingliu. Higher levels of phenylalanine ammonia lyase were expressed in the resistant cultivars. Qingliu plants exposed to herbivory by C. medinalis produced higher levels of jasmonyl isoleucine and salicylic acid (SA) than plants of the susceptible cultivar TN1, and levels of SA in Qingliu plants were intrinsically higher prior to feeding by C. medinalis.
Type
journal article