Analysis of resistance genetics and mapping of resistance gene in a rice variety Duokang 1 to gall midge

Abstract

In 1993-1995,an international cooperation project was conducted by Guangdong Provincial Academy of Agricultural Sciences and International Rice Research Institute of further analyse the resistance genetics of Duokang 1, a rice variety got from South China resistant to four biotypes of rice gall midge Orseola oryzae Wood-Mason which is one of the major rice insect pests in Asian rice region. It was determined that the resistance of this variety to biotypes No. 1 and No. 4 was governed by single dominant gene tentatively named as GM-6(t) by the authors. Gene mappings were carried out on one hundred and sixty F3 progenies of the hybridized combination Duokang 1 × Fengyinzhan 1 (susceptible). Based on the principal of bulked segregation analysis (BSA),the resistant gene was tagged successfully for the first time by applying the RAPD marker OPM6(1. 4kb). After this RAPD product was labelled with 32P and used as a probe to detect the referential mapping population IR 64× Azucena,the resistant gene has been mapped between the RFLP markers RG 214 and RG 163 on the fourth rice chromosome. It is suggested that the screening for resistant rice varieties or accumulation of resistant gene to O. oryzae would be accelerately and accurately only by auxiliary selection of molecular marking without the damage test of this insect pest.