Reaction of hybrid rice and component lines to rice black [Scotinophara coarctata (Fabricius), Hemiptera: Pentatomidae]

Abstract

A limiting factor to hybrid rice production in the Philippines is the susceptibility of hybrid rice component lines to diseases and insect pests. Rice black bug (Scotinophara coarctata Fabr.) is among the insect pests and is the newest addition to the list of major pest of rice. This study aims to determine the reaction of hybrid rice components lines to rice black bug (RBB).

Eighty-four hybrid rice component lines were evaluated for their reaction to RBB. Two batches of unreplicated preliminary screening of the line were done. Two sets of re-evaluation were also conducted. The standard evaluation system for rice (SES) was followed.

No lines showed resistance to RBB during the preliminary screening. Twenty-six lines which showed a moderately susceptible reaction were re-evaluated in a replicated experiment. Among them, R2-6 and IR60819R showed resistance, PR4B showed an intermediate reaction and GU199 showed a moderately susceptible reaction. These promising lines were further were further evaluated against RBB and results showed that R2-6 was rated highly resistant (HR), IR60819R was resistant (R), PR4B was moderately resistant (MR) and GUI99 was moderately susceptible (MS). Most of the hybrid rice component lines were susceptible to RBB.