Introgression of bacterial leaf blight (BLB) resistant gene, Xa7 into MARDI elite variety, MR219 by marker assisted backcrossing (MABC) approach

Abstract

Bacterial leaf blight (BLB) is one of the major rice diseases in Malaysia. This disease causes substantial yield loss as high as 70%. Development of rice varieties which inherited BLB resistant traits is a crucial approach to promote and sustain rice industry in Malaysia. Hence, this study aims were to enhance BLB disease resistant characters of high yielding commercial variety MR219 through backcross breeding approach with supporting tool of marker-assisted selection (MAS). Broad spectrum BLB resistance gene, Xa7 from donor parent IRBB7 were introgressed into the susceptible MR219 (recurrent parent) using two flanking markers ID7 and ID15. At BC3F4, we managed to generate 19 introgressed lines with homozygous Xa7 gene and showed resistant characteristics as donor parent when it was challenged with Xanthomonas oryzae pv. oryzae through artificial inoculation. Recurrent parent MR219 and control variety, MR263 were found to be severely infected by the disease. The improved lines exhibited similar morphological and yield performance characters as to the elite variety, MR219. Two lines, PB-2-107 and PB-2-34 were chosen to be potential lines because of their outstanding performances compared to parent, MR219. This study demonstrates a success story of MAS application in development of improved disease resistance lines of rice against BLB disease.

Establishment of Functional PCR-Based Markers against Bacterial Leaf Blight Disease in Rice Landraces of Yunnan Province of China

“…It is an established fact that genetic approaches to incorporate broad-spectrum resistance against rice pathogens can prevent the yield losses [42]. In fact, a significant number of resistance genes associated with bacterial blight disease have been identified; however, due to the emergence of highly pathogenic strains, the resistance developed through various breeding approaches is at higher risk [11,43]. The incorporation of R genes into rice is an effective and sustainable strategy to manage the bacterial blight in rice.…”

Identification of Bacterial Blight Resistance Genes Introgressed Individuals in the Segregating Population of Rice

“…The Xa21 gene and in combination with other gene-introgressed individuals, showed higher levels of tolerance than any of the other combinations. Several studies have also successfully introgressed/pyramided BB resistance genes into their parental lines, PR36944-700 (TGMS) [11], PRR78 and KMR3 (restorers) and IR58025B and Pusa 6B (maintainers) [12,13], MTU 1010 [14], JGL1798 [15], and MR219 [16]. The identified promising gene-introgressed individuals in a high-yielding agronomic background will be further advanced and could be a potential resource for breeders to use in their breeding programs.…”

Pyramiding Submergence Tolerance and Three Bacterial Blight Resistance Genes in Popular Rice Variety Hasanta through Marker-Assisted Backcross Breeding

“…Target traits in F 1 , IC 1 F 1 and BC generations were traced using trait linked-DNA markers, Sub1bc2 with 0.0 cm distant to Sub1 [2], pTA248 lying 0.2 cm distant to Xa21 [23,67], xa13prom with 0 cm distant to xa13 [13,44,55] and RM122 with 0.4 cm distance to xa5 [65] (Table 2). Moreover, genome recovery of the RP was monitored with 108 polymorphic SSR markers (Table 3 and Table S2) that uniformly span entire rice genome [13,34,68,69]. These 108 SSRs were selected from 421 SSRs based on the polymorphism survey between Hasanta and Swarna Sub1.…”