A Genetic Resource for Rice Improvement：introgression Library of Agronomic Traits for All AA Genome Species in Genus Oryza

Abstract

Background: Rice improvement depends on the availability of genetic variation, and AA genome Oryza species are the natural reservoir of favorable genes which are useful for rice breeding. Developing the introgression library using multiple AA genome species was rarely reported.Results: In this study, to systematically evaluate and utilize potentially valuable QTLs/genes or allelic variations, based on the evaluation and selection of agronomic traits, 6372 introgression lines (ILs) were raised by crossing 330 accessions of 7 AA genome species as the donor parents, with three elite cultivars of O. sativa, Dianjingyou 1, Yundao 1 and RD23 as the recurrent parents, respectively. Further, twenty-six, twenty-six and nineteen loci were detected in the multiple donors using 1,401 ILs in the Dianjingyou 1 background for grain length, grain width, and the ratio of grain length to grain width, respectively. Interestingly, ten loci had opposite effect on grain length in the different donors, so did grain width. Moreover, one locus for grain width, qGW3.1, was validated using the segregation population derived from the donor of O. glumaepatula. Conclusions: This introgression library provided the powerful resource for future rice improvement and genetic dissection of allelic variations. Selections of favorable alleles that are present in wild relatives proceed the driving force of the rice domestication.