[01] Olasan Joseph Olalekan, Department of Botany, Biotechnology & Genetics Unit, Federal University of Agriculture, Makurdi, Nigeria. [02] Aguoru Celestine Uzoma, Department of Botany, Biotechnology & Genetics Unit, Federal University of Agriculture, Makurdi, Nigeria. [03] Omoigui Osabuohien Lucky, Department of Plant Breeding and Seed Science, Federal University of Agriculture, Makurdi, Nigeria. [04] Ekeruo Chibuike Godspower, Department of Plant Breeding and Seed Science, Federal University of Agriculture, Makurdi, Nigeria. [05] Ugbaa Sesugh Macsamuel, Department of Plant Breeding and Seed Science, Federal University of Agriculture, Makurdi, Nigeria.

Molecular genetic studies and QTL mapping for aflatoxin resistance in selected groundnut breeding lines were undertaken. One hundred (100) parental breeding lines and eleven (11) progenies in the F2 generation were screened pathologically. Healthy accessions were subjected to in vitro Aspergillus seed invasion test. A total of 500 molecular markers (215 SSRs, 205 SNP/EST and 80 RAPD markers) were screened for polymorphism on the parental lines followed by the use of polymorphic markers on the F2 lines. Phenotypic and genotypic data were loaded into Minitab 16.0 and ICIM QTLIciMapping 4.2 software for cluster analysis and QTL linkage map construction respectively. In total, 23 breeding lines were identified as promising Aspergillus resistant genotypes. SAMNUT 22 X ICGV-91324 progeny was unique in genetic make-up using all co-dominant markers. Some parents closely associated with resistant F2 genotypes were: ICGV-94379, ICGV-IS-13878, ICGV-IS-13875 and SAMNUT 25. QTL map constructed was 344.32cM long where the various markers are positioned at intervals. A total of 8 markers and QTLs were identified as the most likely linked to the polygenes controlling aflatoxin resistance. Five linkage groups are located at position 124.45cM on the map and they are: IPAHM39 (position 124.45cM), Y70 (position 124.45cM), GA101 (position 124.45cM), EX24 (position 124.45cM), GM1076 (position 124.45cM), GA5 (position 34.48cM), MS120 (position 34.48 cM) and GM2165 (position 344.32 cM). The highlighted groundnut genotypes and markers in this report are recommended in groundnut breeding for aflatoxin resistance in the quest to achieving safe groundnut consumption globally.

Aflatoxin Resistance, Groundnut Breeding, Polymorphic Markers, QTL Mapping

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