Introgression of tsv1 improves tungro disease resistance of a rice variety BRRI dhan71

Abstract

Rice Tungro disease poses a threat to rice production in Asia. Marker assisted backcross breeding is the most feasible approach to address the tungro disease. We targeted to introgress tungro resistance locus tsv1 from Matatag 1 into a popular but tungro susceptible rice variety of Bangladesh, BRRI dhan71. The tsv1 locus was traced using two tightly linked markers RM336 and RM21801, and background genotyping was carried out using 7 K SNPs. A series of three back crosses followed by selfing resulted in identification of plants similar to BRRI dhan71. The background recovery varied at 91–95% with most of the lines having 95%. The disease screening of the lines showed moderate to high level of tungro resistance with a disease index score of ≤ 5. Introgression Lines (ILs) had medium slender grain type, and head rice recovery (59.2%), amylose content (20.1%), gel consistency (40.1 mm) and gelatinization temperature were within the acceptable range. AMMI and Kang’s stability analysis based on multi-location data revealed that multiple selected ILs outperformed BRRI dhan71 across the locations. IR144480-2-2-5, IR144483-1-2-4, IR144484-1-2-2 and IR144484-1-2-5 are the most promising lines. These lines will be further evaluated and nominated for varietal testing in Bangladesh.

Pyramiding of bacterial blight resistance genes into promising restorer BRRI31R line through marker-assisted backcross breeding and evaluation of agro-morphological and physiochemical characteristics of developed resistant restorer lines

“…MAS offers a simpler and more efficient method to improve rice cultivars or lines and marker-assisted introgression of major genes/QTLs has helped to develop resistant varieties against major diseases such as BB, blast, tungro etc. [ 8 , 29 , 50 – 52 ]. But conventional backcross cannot precisely transfer more than one gene into the cultivars and also the process needs a significant amount of time [ 38 , 53 , 54 ].…”

Endogenous like sequence Rice Tungro Bacilliform Virus (RTBV) fragments in the local rice genome and its role in controlling tungro disease

“…The endogenous like sequence RTBV is a copy of the RTBV fragment integrated into the whole rice genome. [20] Endogenous viruses are a sign that an exogenous RTBV virus infection has occurred in the past and these endogenous viruses can be passed from one generation to the next. The virus group that undergoes this process is the pararetrovirus group through a non-homologous end joining recombination process [1].…”

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“…MAS offers a simpler and more efficient method to improve rice cultivars or lines and marker-assisted introgression of major genes/QTLs has helped to develop resistant varieties against major diseases such as BB, blast, tungro etc. [8,29,[50][51][52]. But conventional backcross cannot precisely transfer more than one gene into the cultivars and also the process needs a significant amount of time [38,53,54].…”