title: Identification and linkage analysis of a new rice bacterial blight resistance gene from XM14, a mutant line from IR24.
abstract: Bacterial blight caused byXanthomonas oryzaepv.oryzae(Xoo) is a chief factor limiting rice productivity worldwide. XM14, a rice mutant line resistant toXoo, has been obtained by treating IR24, which is susceptible to six PhilippineXooraces and six JapaneseXooraces, with N-methyl-N-nitrosourea. XM14 showed resistance to six JapaneseXooraces. The F2population from XM14 × IR24 clearly showed 1 resistant : 3 susceptible segregation, suggesting control of resistance by a recessive gene. The approximate chromosomal location of the resistance gene was determined using 10 plants with shortest lesion length in the F2population from XM14 × Koshihikari, which is susceptible to JapaneseXooraces. DNA marker-assisted analysis revealed that the gene was located on chromosome 3. IAS16 line carries IR24 genetic background with a Japonica cultivar Asominori segment of chromosome 3, on which the resistance gene locus was thought to be located. The F2population from IAS16 × XM14 showed a discrete distribution. Linkage analysis indicated that the gene is located around the centromeric region. The resistance gene in XM14 was a new gene, namedXA42. This gene is expected to be useful for resistance breeding programs and for genetic analysis ofXooresistance.
authors: United Graduate School of Agricultural Sciences, Kagoshima University , 1-21-24 Korimoto, Kagoshima, Kagoshima 890-0065 , Japan.
authors: Constantine
authors: C
authors: Busungu
authors: Institute of Gene Research, Kagoshima University , 1-21-24 Korimoto, Kagoshima, Kagoshima 890-0065 , Japan.
authors: Satoru
authors: S
authors: Taura
authors: Faculty of Agriculture, Kagoshima University , 1-21-24 Korimoto, Kagoshima, Kagoshima 890-0065 , Japan.
authors: Jun-Ichi
authors: JI
authors: Sakagami
authors: Faculty of Agriculture, Kagoshima University , 1-21-24 Korimoto, Kagoshima, Kagoshima 890-0065 , Japan.
authors: Katsuyuki
authors: K
authors: Ichitani
keywords: DNA marker; Oryza sativa; Xanthomonas oryzae pv. oryzae; mutation; resistance by a recessive gene