Development of breeding lines with three pyramided resistance genes that confer broad-spectrum bacterial blight resistance and their molecular analysis in rice

Abstract

BackgroundThe development of resistant cultivars has been the most effective and economical strategy to control bacterial leaf blight (BB) disease of rice caused by Xanthomonas oryzae pv. oryzae (Xoo). Molecular markers have made it possible to identify and pyramid valuable genes of agronomic importance in resistance rice breeding. In this study, three resistance genes (Xa4 + xa5 + Xa21) were transferred from an indica donor (IRBB57), using a marker-assisted backcrossing (MAB) breeding strategy, into a BB-susceptible elite japonica rice cultivar, Mangeumbyeo, which is high yielding with good grain quality.ResultsOur analysis led to the development of three elite advanced backcross breeding lines (ABL) with three resistance genes by foreground and phenotypic selection in a japonica genetic background without linkage drag. The background genome recovery of the ABL expressed more than 92.1% using genome-wide SSR marker analysis. The pathogenicity assays of three resistance-gene-derived ABL were conducted under glasshouse conditions with the 18 isolates of Xoo prevalent in Korea. The ABL exhibited very small lesion lengths, indicating a hypersensitive reaction to all 18 isolates of Xoo, with agronomic and grain quality traits similar to those of the recurrent parent. Pyramiding the resistance genes Xa4, xa5 and Xa21 provided a higher resistance to Xoo than the introduction of the individual resistance genes. Additionally, the combination of two dominant and one recessive BB resistance gene did not express any negative effect on agronomic traits in the ABL.ConclusionsThe strategy of simultaneous foreground and phenotypic selection to introduce multiple R genes is very useful to reduce the cost and the time required for the isolation of desirable recombinants with target resistance genes in rice. The resistance-gene-derived ABL have practical breeding value without a yield penalty by providing broad-spectrum resistance against most of the existing isolates of BB in South Korea and will have a high impact on the yield stability and sustainability of rice productivity.Electronic supplementary materialThe online version of this article (doi:10.1186/1939-8433-6-5) contains supplementary material, which is available to authorized users.

Development and validation of SNP-based functional codominant markers for two major disease resistance genes in rice (O. sativa L.)

“…It has also been observed that the reported amino acid change is consistent among all 27 different resistant rice varieties tested and nine susceptible ones belonging to the Aus-Boro group (Iyer and McCouch 2004). This gene is also used in many bacterial resistance gene pyramiding programs worldwide (Sundaram et al 2008;Kottapalli et al 2010;Suh et al 2013). Recessive resistance genes are preferable, as those genes provide resistance to different pathogenic races with mechanisms of action different from those of the dominant resistance genes.…”

“…oryzae (Xoo) limits rice production up to 81 % (Kumar et al 2012). Thirty-eight different resistance genes have been identified to combat this serious disease of rice (Suh et al 2013). Among them, xa5 is one of the major recessive resistance genes that provide a high degree of resistance to a wide range of Xoo races (Suh et al 2013).…”

“…Thirty-eight different resistance genes have been identified to combat this serious disease of rice (Suh et al 2013). Among them, xa5 is one of the major recessive resistance genes that provide a high degree of resistance to a wide range of Xoo races (Suh et al 2013). The xa5 gene was cloned and characterized by Iyer and McCouch (2004), and it encodes a small subunit of transcription factor IIA.…”

Measurement of Phenotypic Variation for Control and Bacterial Leaf Blight Inoculated Rice Lines and Varieties

“…Different rice lines and varieties were taken for the study (Table 1) where the variety IRBB21 and BR-11 were considered as the resistant and susceptible cultivars for check [13][14][15] respectively. …”

Development of a muskmelon cultivar with improved resistance to gummy stem blight and desired agronomic traits using gene pyramiding

“…However, because of rapid changes in pathogen virulence or population biotype, the qualitative resistance is not durable (Suh et al 2013). One strategy for breeding cultivars with durable and broad-spectrum resistance is pyramiding resistance loci.…”