Agronomic Traits of Breeding Lines Resistant to Brown Planthopper Developed through Marker-Assisted Selection and Backcross In Japonica Rice

Abstract

This study was carried out to develop a promising japonica rice variety resistant to brown planthopper(Bph) through marker-assisted selection(MAS) and backcross breeding methods. “Milyang 64” which is known as resistant japonica variety to Bph used as a donor parent and “Milyang 165”, the susceptible variety as a recurrent. Twenty three lines derived from “Milyang 165*3/Milyang 64” were developed using Sdh-1 marker selection during the period of backcrosses from BC1F1 to BC3F2. Developed lines were tested to confirm the grain productivity and other agronomic characteristics as well as exact reaction to Bph. Among the twenty three lines, fifteen lines showed homozygous-resistant reaction, and the remains are segregated. Lodging and its related characteristics here investigated were compared to those of parental materials. Heading date and culm length were most dramatically regressed to those of recurrent parental type but the other characteristics showed scatterred distribution between the donor and recurrent parents.