Marker assisted introgression of bacterial blight resistant gene into submergence tolerance rice variety BRRI dhan52

Abstract

BRRI dhan52 is a uniquire submergence tolerant rice variety containing prominant genetic background of BR11, a mega rainfed lowland rice (RLR) variety of Bangladesh, but is susceptible to bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo). The variety is considerably popular in the southern part of Bangladesh due to its high yield in flash flood condition and comparatvely medium slender grain. Molecular markers linked to BB resistance genes (Xa genes) and submergence QTL (SUB1) were utilized in a marker-aided selection program to develop elite breeding lines with broad-spectrum resistance to bacterial blight. Sequence tagged site (STS) and simple sequence repeat (SSR) markers were essentially used to detect the genes for BB and submergence as well. In backcross generation, markers closely linked to Xa21 and SUB1 QTL were used to select desirable plants possessing these resistance genes (foreground selection) and microsatellite markers polymorphic between donor and recurrent parent were also used to select plants that have maximum contribution from the recurrent parent genome (background selection). In BC1F1 generation, three best plants consiquently were selected from previously selected ten double heterozygous (Xa21 and SUB1 QTL) plants. The percentage of recipient genome recovery in the best plant 1, 2 and 3 were 78.7%, 75.83% and 75.4%, respectively. Eventually this work illustrates the successful application of marker-assisted breeding for introgression of bacterial blight resistant gene into a rice variety of Bangladesh.

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

“…Genomic regions responding to adaptive intonations in rice under submergence have been mapped, validated and successfully deployed in several intolerant genotypes [24][25][26][27][28][29][30][31][32]. The Sub1 gene exerts two weeks of submergence tolerance in mapped on chromosome-9, along with other minor QTLs in the Indian rice landrace FR13A [33][34][35][36][37].…”

“…FR13A is utilized as a donor of Sub1 in several rice improvement programs [4,9,28]. Popular rice varieties, Ranjit et al [24], BRRI Dhan52 [25], Aiswarya et al [27], Swarna et al [28], CO 3 [30], IR64 [32], Chehrang [32] and CR 1009 [32], etc., have been introgressed with Sub1 through the markers-assisted selection (MAS)/MAB approach. A submergence tolerant version of mega rice variety, Swarna Sub1 [28], has similar agro-morphology as Swarna, yielding a 2-fold or higher yield advantage over parent under 10 or more days' vegetative stage flooding [8,28].…”