Plant & Animal Genomes XVII Conference Plant & Animal Genomes XVII ConferenceJanuary 10-14, 2009
Town & Country Convention Center
San Diego, CA
Genes and alleles of wild rice species have been expected to be agronomically useful resources that would genetically improve the present cultivated rice. However, despite the possible agronomic importance of the genetic resources, the amount and characteristics of those resources were largely unknown. In order to clarify the amount of genes that were retained in wild rice species but lost in the cultivated rice, we compared the japonica rice genome with sets of bacterial artificial chromosome end sequences (BESs) obtained from Oryza nivara and O. rufipogon as well as the African cultivated rice species, O. glaberrim. We found that about four to five percent of the BESs of the two wild rice species, and about seven percent of the African rice could not map to the japonica genome. These results indicate that a substantial number of genes have been lost in the japonica rice lineage, while their wild brethren still possess their counterpart genes. In addition, our BLASTX searches against the non-redundant protein sequence database showed that disease resistant related proteins were significantly overrepresented in the wild rice specific genomic portions. Our results showed that cultivated rice lost a significant number of genes resulted from dynamic genomic deletions, and that wild rice species possessed these lost genes that would give possibly important agronomic traits to the japonica rice.