| Abstract: | By scanning the whole genomic sequence of japonica rice using 45 known plant disease resistance (R) genes, we identified 2119 resistance gene homologs or ana- logs (RGAs) and verified that RGAs are not randomly dis- tributed but tend to cluster in the rice genome. The RGAs were classified into 21 families according to their functional domain based on Hidden Markov model (HMM). By com- paring the RGAs of japonica rice with the whole genomic sequence of indica rice, we found 702 RGAs allelic between the two subspecies and revealed that 671 (95.6%) of them have length difference (InDels) in their genomic sequences (including coding and non-coding regions) between the two subspecies, suggesting that RGAs are highly polymorphic between the two subspecies in rice. We also exploited 402 PCR-based and co-dominant candidate RGA markers by designing primer pairs on the regions flanking the InDels and validating them via e-PCR. The length differences of the candidate RGA markers between the two subspecies are from 1 to 742 bp, with an average of 10.26 bp. All related information of the RGAs is available from our web site (http://ibi.zju.edu.cn/RGAs/index.html). |
