LAUSR

The yield loss in peanut due to peanut bud necrosis disease ranges from 30 to 80%. Quantitative trait loci (QTL) were mapped using 108 RILs from a cross between JL-24 × NRCGCS-85. Phenotyping of these RILs was performed at natural hotspot under field conditions in 2017 post-rainy and 2018 rainy seasons. Significant variations were observed among the RILs confirming polygenic control and additive type of gene action for the disease. After screening of 1980 SSR markers, 227 were found polymorphic between the parents. Out of them 49 polymorphic markers effectively amplified codominant amplicons between homozygotes (parent) and heterozygotes (F1s). Linkage maps with 49 markers showed eight linkages having 47 markers. Using inclusive composite interval mapping, two major QTLs, namely QTLPBND-01 and QTLPBND-02 for PBND resistance, were detected, explaining 12.38–16.88% of phenotypic variance. Besides, superior RILs, (JL 24 × NRCGCS 85)-26-13 and (JL 24 × NRCGCS 85)-10-12 were identified with 26% and 17% higher pod yield over JL 24 and resistant to PBND with less than 5% disease scoring. These two RILs also contains two freshly identified QTLs. Among three tightly linked markers, AHS0006 associated with QTLPBND-01 was found stable and to code for sialyl transferase-like protein 1 responsible for protein glycosylation and sialyl transferase activity. This is also the first report of stlp 1 gene associated with PBND resistance, which will help in accelerating the genomic breeding approaches for PBND resistance in peanut in the future.