Introgression of Bacterial Blight Resistance Genes (Xa21, xa13 and xa5) into CB 174 R, an Elite Restorer Line in Rice

Bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the major diseases causing a severe yield reduction in rice-growing regions. One dominant (Xa21) and two recessive genes (xa13 and xa5) were introgressed into CB 174 R through marker-assisted breeding. The present study found three (Xa21 + xa13 + xa5) and two (Xa21 + xa13 or Xa21 + xa5 or xa5 + xa13) gene-introgressed combinations in the early segregated materials through foreground selection. The identified homozygous/heterozygous individuals were forwarded to the next cycles of breeding to fix homozygous conditions for all three genes with an improved agronomic performance background and, thus, could be used as a donor source for a future rice breeding program.