Identification of Sources of Resistance for Peanut Aspergillus flavus Colonization and Aflatoxin Contamination

Abstract

Peanut aflatoxin contamination caused by Aspergillus flavus is a serious constraint for food safety and human health in Senegal. The present study aimed to identify sources of resistance for A. flavus colonization and aflatoxin contamination. Thus, seeds from 67 peanut genotypes were tested under laboratory conditions. Aqueous conidial suspension of an aflatoxinogenic strain of A. flavus was used for inoculation in Petri dishes containing ten seeds of each genotype, and data on incidence and severity were recorded. Total aflatoxin concentration in seeds was determined on 15th day after inoculation using mReader® method. Results showed a significant (p<0.001) variation of aflatoxin, incidence and severity among the tested peanut genotypes. Incidence ranged from 0 to 70% with a mean of 20.36 ± 0.8%. Out of the 67 genotypes, eight showed incidence less than 10%. Severity ranged from 0 to 44% with a mean value of 8.82 ± 0.45%. The genotype 12CS_104 showed aflatoxin concentration level in conformity with the European standard (4 ppb). Out of three clusters revealed by hierarchical classification based on disease incidence and severity, the cluster 1 contained 33 genotypes characterised by low incidence and severity values. These genotypes can be tested under field conditions to confirm their resistance to A flavus.

Peanut Seed Coat Acts as a Physical and Biochemical Barrier against Aspergillus flavus Infection

“…The outer epidermis of the seed coat is made up of a single layer of polygonal cells with thick cuticular walls with a wax layer in the junction between epidermal cells [20]. Genotypes with thicker seed coats, smaller hilum, and compact seed coat structures showed higher resistance to A. flavus infection [21,22]. In addition to the physical properties of the seed coat, the presence of secondary metabolites in the form of polyphenols has been reported in the peanut seed coat [23].…”

Aflatoxin contamination in groundnut (Arachis hypogaea L.); its causes and management

“…Also, some aflatoxin resistant genotypes have been identified for various resistance mechanism. Examples of resistant genotypes include 12CS-104 and 73-33 (Dieme et al 2018), ICG 12625 and ICG 4750 (Jiang et al, 2010); ICGV 98305, ICGV 98348, ICGV 98353 and Tifton 8 (Girdthai et al, 2010); Igola, Serenut 1, Serenut 2 and entry 99527 (Olwari et al, 2013); ICG 1471, NC3033, ICGV 88145 and GT-C20 (Korani et al, 2018). However, availability of resistant varieties will be the best solution for farmers to minimize aflatoxins contamination.…”

Comprehensive Evaluation of Chinese Peanut Mini-Mini Core Collection and QTL Mapping for Aflatoxin Resistance

“…Mixon and Rogers [7] were the rst to suggest using resistant peanut cultivars to control a atoxin contamination. Many peanut germplasm accessions with resistance to A. avus infection and toxin production were identi ed in the past ve decades [8][9][10][11]. In general, the resistance to a atoxin contamination in peanut consists of three components or mechanisms including: a) shell infection resistance, b) seed infection resistance, and c) a atoxin production resistance [12].…”