Genome wide molecular mapping introgression of stable QTLs and expressional quantitation of transcription factor genes in charcoal rot manifestation in sorghum bicolour L Moench

Abstract

Recombinant inbred lines derived from the cross IS22380 (susceptible) and E36-1 newline(resistant) were characterized for the morphological and biochemical components of charcoal newlinerot resistance and yield related traits at three locations over four rabi seasons revealed newlinesignificant differences among RILs and GxE interactions. A significant association among newlinerelevant traits was noticed at phenotypic and genotypic level with high heritability estimates. newlineA total of 141 polymorphic DNA markers (48/275 SSRs, 65/533 EST-SSRs, 28/410 RAPD) newlinewere genotyped to construct a genetic linkage map spanning 2905 cM and used for newlineComposite Interval Mapping of QTLs. Stable QTLs were detected lodging percent (xtxp176 newlinextxp312 (CR1) number of internodes crossed by the fungus (xtxp297-xiabt273 (CR2) and newlinelength of infection (xtxp275-xtxp241(CR3): the additive effect at all these loci was contributed newlineby E36-1. Two major QTLs of plant height and three QTLs of plant yield accounted for 38% newlineand 41% phenotypic variance respectively. On LG-I, the genomic region flanked by xtxp274 newlinexiabt29 harbored a common QTL. Three stable QTLs, CR1, CR2 and CR3 collectively newlinecontributing 43% of phenotypic variation were introgressed into M35-1 and SPV86 newlinebackgrounds: at BC1F1 with 2285 and 2033 marker and at BC2F1 5989 and 6002 marker newlinepoints in M35-1 and SPV86 backgrounds were screened to identify progenies harboring all newlinethe three QTLs. newlineExpressional quantitation of 185 transcription factor genes was done in charcoal rot newlinechallenged and control tissue of E36-1 and SPV86 genotypes at 75 DAS and 90 DAS where newline142 genes up regulated in both genotypes while eight genes of five family viz., AP2 newline(PTSb00019.1, PTSb00022.1, PTSb00024.1 WRKY (PTSb00331.1), HMG (PTSb00179.1, newlinePTSb00185.1) ARF (PTSb00033.1) and bHLH (PTSb00349.1) were up regulated in pathogen newlinechallenged tissues. Two genes of WRKY family (PTSb00328.1 and PTSb00331.1) were newlinesignificantly up regulated in resistant genotype alone: these understandings would help in newlinedeveloping strategies for resistance breeding in sorghu