Marker-assisted Introgression of Broad-spectrum Disease Resistance Genes of Pigm and Xa23 into Rice Restorer

Rice blast and bacterial blight are the two most serious and destructive disease problems in rice production, respectively. In this study, Pigm gene with a broad spectrum resistance to blast from GM4 as donor parent were introgressed into eight restorer lines with high quality, leading to the improvement of blast resistance by marker-assisted selection (MAS) and artificial inoculation identification. PCR-based molecular marker M26205 tightly linked to Pigm gene was used to select the foreground and the cross populations. A total of 118 rice germplasm accessions from 14 countries were selected to identify, results showed that only eight varieties amplify the fragment with 800bp, whereas others cannot amplify bands, but two bands contained the specific fragment with 1000 bp and 800 bp were amplified in GM4 using the marker M26205. Nine F-7 lines carrying Pigm of 49 derivate lines were screened with marker M26205 from eight combinations of GM4 and restorer lines. Nine isolates of M. oryzae from Zhejiang were selected to perform the resistance of nine lines to blast. Artificial inoculation demonstrated that nine lines are resistant or moderately resistant to rice blast. The investigation of agronomic traits of nine lines indicated that Pigm gene has a negative effect on the number of tiller and 1000 grain weight, but a positive effect on the grain numbers of panicle and the seed setting rate. The line of D3, which possessed the homozygous Pigm were crossed with FH450 (as donor parent) carrying Xa23 gene. The marker C189 tightly linked to Xa23 gene was used to identify the progeny of the cross generation. 12 stable promising lines possessing high level of resistance to blast and bacterial blight have been identified through marker-assisted breeding. (C) 2017 Friends Science Publishers