Characterization of peanut mutants and molecular markers associated with resistance to pod rot diseases and aflatoxin contamination by RAPD and ISSR

Abstract: Ten peanut mutants: RT-6, RT-7, RT-8, RT-9, RT-10, RT-11, RT-12, RT-13, RT-14 and RT-15 and their parent variety (Giza 5) were evaluated for their reaction against pod rot pathogens, invasion by aflatoxigenic fungi and aflatoxin contamination under greenhouse and field conditions during 2004 and 2005 summer seasons. All peanut mutants exhibited significant decrease in percentages of pod rot diseases, occurrence of aflatoxigenic fungi and aflatoxin contamination compared to Giza 5. Mutants RT-10, RT-12 and RT-7 were highly resistant against all categories of pod rot diseases and had the lowest levels of aflatoxin B1 and/or B2 under soil infestation with aflatoxigenic fungi: Aspergillus flavus and A. parasiticus, separately or in mixture in greenhouse and came free from any contamination with aflatoxin under field conditions compared to Giza 5 and the other mutants. The mean values of pod yield m-2 in the entire mutants were significantly higher compared to parent variety, Giza 5, except the mutant RT-15 which did not differ significantly from the parent variety in pod yield. RT-9 increased significantly but the mutants RT-14 and RT-15 had significant decrease in 100-pod weight compared to Giza 5. The fancy pods percentage (FP %) increased significantly in the two mutants RT-8 and RT-11, while, the total sound mature kernels percentage (TSMK %) in all mutants did not differ significantly from the original variety (Giza 5). The oil content of all mutants decreased significantly than Giza 5. Several molecular markers associated with pod rot resistance/susceptibility in mutants and Giza 5 were obtained by the RAPD primers. The ISSRs did not reveal any marker (positive or negative) associated with pod rot resistance/susceptibility in the mutants and their parent variety. RAPD and ISSR combined data indicated that the three most closely related mutants were RT-7, RT-10 and RT-12.
Publication year 2007
Pages 301-320
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