Location: Crop Protection and Management Research
Title: Searching for the solution to prevention of aflatoxin contamination and diseases in cultivated peanuts: A genetic and genomic approach Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 27, 2008
Publication Date: November 1, 2008
Citation: Guo, B.; Yu, J., Holbrook Jr., C. 2008. Searching for the solution to prevention of aflatoxin contamination and diseases in cultivated peanuts: A genetic and genomic approach [abstract]. Proceedings of the 3rd International Conference for Peanut Genomics and Biotechnology on Advances in Arachis through Genomics and Biotechnology (AAGB-2008), November 4-8,2008, ICRISAT, Hyderabad, India. Technical Abstract: The primary objective is finding a solution to pre-harvest aflatoxin contamination in peanuts grown in the Southeastern US and genetic improvement of peanut resistance to diseases (TSWV, stem rot and leaf spots). The goal is to develop genetic and genomic resources and tools for peanut genetic improvement for disease resistance. By achieving these goals, there are two approaches: ‘phenotype to genes/markers’ and ‘genes/markers to phenotype’. Experiments have been in progress to ‘phenotype’ genetic materials and to identify markers/genes by developing peanut cDNA libraries and sequencing of ESTs. We have constructed total 10 different cDNA libraries derived from developing peanut seeds and leaf tissues, and sequenced, processed, annotated, and assembled 45,000 ESTs. In collaboration with other scientists, we have assembled 13,824 ESTs and designed 8,402 70-mer oligos for microarray printing at J. Craig Venter Institute (JCVI, formerly TIGR). An exhaustive genome-wide search for homologs was conducted against Aspergillus flavus genome sequences for each oligonucleotide candidate to ensure its specificity for the targeted gene and to reduce cross-hybridization with non-target gene sequences. We also developed two mapping populations derived from Tifrunner x GT-C20 and SunOleic 97R x NC94022 which produced 205 and 413 F2 progenies, respectively and have been advanced by single seed descendant to the F4 generation and eventually to F6/F7 (RILs, recombinant inbred lines). Overall, we have released 21,777 seed ESTs (ES702769 – ES724546) and 16,931 leaf ESTs (ES751523 – ES768453) and identified several disease resistance genes including a putative TSWV and stem rot resistance genes. The developed EST database can be used to discover novel sequences or genes, to identify resistance-related genes and to detect the differences among alleles or markers between these resistant and susceptible peanut genotypes. It will be a valuable genomic resource for the peanut community.