Pyramiding of three bacterial blight resistance genes for broad-spectrum resistance in deepwater rice variety, Jalmagna

Abstract

BackgroundJalmagna is a popular deepwater rice variety with farmers of India because of its good yield under waterlogged condition. However, the variety is highly susceptible to bacterial blight (BB) disease. The development of resistant cultivars has been the most effective and economical strategy to control the disease under deepwater situation. Three resistance genes (xa5 + xa13 + Xa21) were transferred from Swarna BB pyramid line, using a marker-assisted backcrossing (MAB) breeding strategy, into the BB-susceptible elite deepwater cultivar, Jalmagna.ResultsMolecular marker integrated backcross breeding program has been employed to transfer three major BB resistance genes (Xa21, xa13 and xa5) into Jalmagna variety. During backcross generations, markers closely linked to the three genes were used to select plants possessing these resistance genes and markers polymorphic between donor and recurrent parent were used to select plants that have maximum contribution from the recurrent parent genome. A selected BC3F1 plant was selfed to generate homozygous BC3F2 plants with different combinations of BB resistance genes. The three-gene pyramid and two gene pyramid lines exhibited high levels of resistance against the BB pathogen. Under conditions of BB infection, the three-gene pyramided lines exhibited a significant yield advantage over Jalmagna. The selected pyramided lines showed all agro-morphologic traits of Jalmagna without compromising the yield.ConclusionThe three major BB resistance genes pyramided lines exhibited high level of resistance and are expected to provide durable resistance under deep water situation where control through chemicals is less effective. High similarity in agro-morphologic traits and absence of antagonistic effects for yield and other characters were observed in the best pyramided lines.

Marker Assisted Selection for Bacterial Leaf Blight Rice Mutant Lines Resistant

“…It was occured T base-pair deletion and early stopped coding at 60 and 67 bp after translation initiation region in hd(t) mutant compared to parent plant (Shang et al 2012). Pradhan et al (2015) mentioned that backrossing of Jalmagna rice was found 100 BC1F1 plants showed presence Xa5, and 91 of plants showed presence of Xa13 and Xa21 from 360 BC1F1 seeds. The blight attack is characterized by changes in the appearance of plants, starting immediately Mira,68,70,71,72,73,74 with wilting in most tissues (especially the leaves), followed by chlorosis fast (in a few days), became brown and dead tissues on the surface could be seen.…”

Application and utilization of marker assisted selection for biotic stress resistance in hybrid rice (Oryza sativaL.)

“…Kinoshita (1995) reported that the combination of resistance genes into rice varieties is good way to develop durable resistance to BB disease. Recently, Pradhan et al (2015) cited that a three-gene combination appeared to be the most effective with Xa21 contributing the largest component of resistance to BB. Therefore, in our future studies, we will use the identified hybrid lines with at least three gene combinations for phenotypic selection.…”

Markers Assisted Selection for Pyramiding of Gallmidge Resistance Genes in Kavya, a Popular Rice Variety

“…Genes leading to different races or biotypes being resistant to a disease or insect pest can be effectively pyramided using tightly linked molecular markers to develop lines with multi-race or multi-biotype resistances (Sundaram, et al, 2008;Rajapurohit, et al, 2010;Divya, et al, 2015 andPradhan, et al, 2015). These multi-race or multi-biotype resistant genotypes proved to be more durable than any single-race or single-biotype resistance.…”

“…These multi-race or multi-biotype resistant genotypes proved to be more durable than any single-race or single-biotype resistance. Several researchers have reported the successful application of MAS in rice for targeted improvement of varieties and hybrid rice parental lines (Sundaram et al, 2009;Basavaraj et al, 2010;Rajpurohit et al, 2010;Hari et al, 2011;2013;Khanna et al, 2015;Ellur et al, 2015;Pradhan et al, 2015 andBhaskar et al, 2015).…”