Pyramiding of blast and bacterial leaf blight resistance genes into rice cultivar RD6 using marker assisted selection

Abstract

Blast caused by the fungus Magnaporthe oryzae (Hebert) Barr. and bacterial leaf blight (BLB) caused byXanthomonas oryzae pv. oryzae (Xoo) are two major diseases of rice (Oryza sativa). The use of varietal resistance is the most appropriate strategy for controlling the diseases, and molecular assisted selection can potentially accelerate breeding programs. The objective of this study was to pyramid genes conferring resistance to blast and bacterial leaf blight diseases to rice cultivar RD6, using molecular assisted selection. Near-isogenic lines (NIL) derived from two blast resistant crosses (RD6 × P0489 and RD6 × Jao Hom Nin) were pyramided with IR62266 (xa5), to transfer bacterial leaf blight resistance to RD6 introgression lines. Five flanking sets of simple sequence repeat (SSR) markers (RM319/RM212, RM48/RM207, RM224/RM144, RM313/RM277 and RM122/RM159: four for blast and one for BLB resistance) were used for screening of introgression lines carrying five quantitative trait loci (QTLs) from the BC 1 F 2 generation through to BC 2 F 2:3 generation, and 12 pyramiding lines were identified. Gene validation for blast and bacterial leaf blight diseases was accomplished using artificial inoculation under greenhouse conditions. BC 2 F 2:3 2-8-2-24 and BC 2 F 2:3 2-8-2-25 showed greater levels of blast broad spectrum resistance (BSR) whereas BC 2 F 2:3 2-8-2-36 expressed the highest of bacterial leaf blight resistance with a high blast BSR.

Pathotype profiling, distribution and virulence analysis of Xanthomonas oryzae pv. oryzae causing bacterial blight disease of rice in Bangladesh

“…Deployment of varietal resistance is the most suitable environment-friendly and economic strategy for controlling rice diseases (Pinta et al, 2013). The study of Xoo races is essential to developing rice cultivars resistant to a wide range of Xoo races.…”

Pyramiding approach for development of blast and bacterial leaf blight resistant, and drought tolerant rice variety through marker-assisted selection

“…Marker assisted selection Parental survey was carried out to identi ed markers polymorphic to blast resistance genes (RM6836, RM8225), bacterial leaf blight (Xa13Prom, pTA248, RM164 ) and drought tolerance (RM520, RM511, RM1261), these markers are also linked to the genes/QTLs of interest and were similarly used on the same traits by Ashkani et al (2011); Pinta et al (2013); Miah et al (2016); Khan et al (2015); Shamsudin et al (2016). In F 1 generation, crosses between Putra-1 (blast resistance) and MR219-PL-137 drought tolerance cultivars and between Putra-1 and IRBB60 (bacterial leaf blight) was carried out, true F 1 were those plants with heterozygous ampli cation.…”

“…Some primers polymorphic to the different genes responsible for blast resistance, bacterial leaf blight and drought tolerance were selected through the gramene data base. Linked markers associated with the genes of interest were selected from published article for foreground selection which included; Blast resistance (Ashkani et al (2011), Pinta et al (2013), Miah et al (2016), drought tolerance (Shamsudin et al 2016). Some of the primers were mapped by Miah et al (2016), for blast resistance, (Miah et al 2016) and (Shamsudin et al 2016) for drought tolerance, and bacterial leaf blight (Pinta et al 2013;He et al 2006;Khan et al 2015;Pradhan et al 2015)as indicated in Table 1.…”

Improvement of a RD6 Rice Variety for Blast Resistance and Salt Tolerance through Marker-Assisted Backcrossing

“…Comprising 83% of total glutinous rice production in these areas, consumers have developed a preference for its superior characteristics. However, the RD6 variety suffers from several production constraints, including biotic stress responsible for both rice blast [40] and bacterial blight disease [41]. Current research has attempted to eliminate sustainable infection-resistant production practices by pyramiding multiple resistant genes [42].…”