Quantitative trait locus analysis and construction of consensus genetic map for foliar disease resistance based on two recombinant inbred line populations in cultivated groundnut ( Arachis hypogaea L.) uri icon

abstract

  • Late leaf spot (LLS) and rust have the greatest impact on yield losses worldwide in groundnut (Arachis hypogaea L.). With the objective of identifying tightly linked markers to these diseases, a total of 3,097 simple sequence repeats (SSRs) were screened on the parents of two recombinant inbred line (RIL) populations, namely TAG 24 x GPBD 4 (RIL-4) and TG 26 x GPBD 4 (RIL-5), and segregation data were obtained for 209 marker loci for each of the mapping populations. Linkage map analysis of the 209 loci resulted in the mapping of 188 and 181 loci in RIL-4 and RIL-5 respectively. Using 143 markers common to the two maps, a consensus map with 225 SSR loci and total map distance of 1,152.9 cM was developed. Comprehensive quantitative trait locus (QTL) analysis detected a total of 28 QTL for LLS and 15 QTL for rust. A major QTL for LLS, namely QTL(LLS)01 (GM1573/GM1009-pPGPseq8D09), with 10.27-62.34% phenotypic variance explained (PVE) was detected in all the six environments in the RIL-4 population. In the case of rust resistance, in addition to marker IPAHM103 identified earlier, four new markers (GM2009, GM1536, GM2301 and GM2079) showed significant association with the major QTL (82.96% PVE). Localization of 42 QTL for LLS and rust on the consensus map identified two candidate genomic regions conferring resistance to LLS and rust. One region present on linkage group AhXV contained three QTL each for LLS (up to 67.98% PVE) and rust (up to 82.96% PVE). The second candidate genomic region contained the major QTL with up to 62.34% PVE for LLS. Molecular markers associated with the major QTL for resistance to LLS and rust can be deployed in molecular breeding for developing groundnut varieties with enhanced resistance to foliar diseases.
  • Late leaf spot (LLS) and rust have thegreatest impact on yield losses worldwide in groundnut(Arachis hypogaea L.). With the objective ofidentifying tightly linked markers to these diseases, atotal of 3,097 simple sequence repeats (SSRs) werescreened on the parents of two recombinant inbred line(RIL) populations, namely TAG 24 9 GPBD 4 (RIL-4) and TG 26 9 GPBD 4 (RIL-5), and segregationdata were obtained for 209 marker loci for each of themapping populations. Linkage map analysis of the 209loci resulted in the mapping of 188 and 181 loci inRIL-4 and RIL-5 respectively. Using 143 markers common to the two maps, a consensus map with 225SSR loci and total map distance of 1,152.9 cM wasdeveloped. Comprehensive quantitative trait locus(QTL) analysis detected a total of 28 QTL for LLS and15 QTL for rust. A major QTL for LLS, namelyQTLLLS01 (GM1573/GM1009-pPGPseq8D09), with10.27?62.34% phenotypic variance explained (PVE)was detected in all the six environments in the RIL-4population. In the case of rust resistance, in addition tomarker IPAHM103 identified earlier, four new markers(GM2009, GM1536, GM2301 and GM2079)showed significant association with the major QTL(82.96% PVE). Localization of 42 QTL for LLS andrust on the consensus map identified two candidategenomic regions conferring resistance to LLS and rust.One region present on linkage group AhXV contained three QTL each for LLS (up to 67.98% PVE) and rust(up to 82.96% PVE). The second candidate genomicregion contained the major QTL with up to 62.34%PVE for LLS. Molecular markers associated with themajor QTL for resistance to LLS and rust can bedeployed in molecular breeding for developinggroundnut varieties with enhanced resistance to foliardiseases

publication date

  • 2012
  • 2012
  • 2012