Molecular characterisation of <italic>Aspergillus flavus</italic> isolates from peanut fields in India using AFLP

Abstract

Aflatoxin contamination of peanut, due to infection by Aspergillus flavus, is a major problem of rain-fed agriculture in India. In the present study, molecular characterisation of 187 Aspergillus flavus isolates, which were sampled from the peanut fields of Gujarat state in India, was performed using AFLP markers. On a pooled cluster analysis, the markers could successfully discriminate among the ‘A’, ‘B’ and ‘G’ group A. flavus isolates. PCoA analysis also showed equivalent results to the cluster analysis. Most of the isolates from one district could be clustered together, which indicated genetic similarity among the isolates. Further, a lot of genetic variability was observed within a district and within a group. The results of AMOVA test revealed that the variance within a population (84%) was more than that between two populations (16%). The isolates, when tested by indirect competitive ELISA, showed about 68.5% of them to be atoxigenic. Composite analysis between the aflatoxin production and AFLP data was found to be ineffective in separating the isolate types by aflatoxigenicity. Certain unique fragments, with respect to individual isolates, were also identified that may be used for development of SCAR marker to aid in rapid and precise identification of isolates.

Improvement of the Culture Medium for the Dichlorvos-Ammonia (DV-AM) Method to Selectively Detect Aflatoxigenic Fungi in Soil

“…Many researchers have reported the isolation of aflatoxigenic fungi from the soil in agricultural fields (e.g., cotton, peanut and maize fields), and the researchers usually used multiple procedures: (1) the isolation of Aspergillus section Flavi using Aspergillus flavus and parasiticus agar (AFPA) medium [16], modified rose Bengal agar (MRBA) medium [17], or coconut agar medium [18]; (2) the confirmation of aflatoxin production by the isolated strains with the use of thin layer chromatography (TLC), high-performance liquid chromatography (HPLC) [19,20,21,22], an enzyme-linked immunosorbent assay (ELISA) [23,24,25,26,27,28], and other methods; (3) the identification of aflatoxigenic fungi using a polymerase chain reaction (PCR) or a real-time PCR [29,30,31], and other methods. Since methods (1) and (3) are useful for discriminating fungi belonging to Aspergillus section Flavi, the ability of the fungi to produce aflatoxins need to be confirmed by another analytical method noted in method (2).…”

ALFP-FINGERPRINTING FOR PASPORTIZATION OF Aspergillus nige L-4, THE CITRIC ACID COMMERCIAL PRODUCER

“…For each pair of primers the AFLP patterns do not depend on the volume of the sample. Note, in 2015 in large scale investigation of biodiversity of Aspergillus flavus strain the unique AFLP patterns have been found, however, the practical aspects of this phenomenon was not under consideration [25].…”

ГЕНЕТИЧЕСКАЯ ПАСПОРТИЗАЦИЯ ШТАММА Aspergillus niger Л-4 — ПРОМЫШЛЕННОГО ПРОДУЦЕНТА ЛИМОННОЙ КИСЛОТЫ С ПОМОЩЬЮ ГЕНОМНОГО AFLP-ФИНГЕРПРИНТИНГА

“…AFLP-профили с использованием выбранной пары не зависят от объема вносимой пробы. Следует отметить, что в 2015 году при масштабном изучении генетического разнообразия штаммов Aspergillus flavus было отмечено формирование ими уникальных AFLPпрофилей, однако аспекты практического использования этого феномена не обсуждались (25).…”