Fungal flora and aflatoxin contamination in Pakistani wheat kernels (Triticum aestivum L.) and their attribution in seed germination

Abstract

This study aimed to isolate fungal pathogens and to subsequently quantify aflatoxin (AF; B + B + G + G) contamination in wheat crops grown in Pakistan. Accordingly, a total of 185 wheat samples were collected from different areas of Pakistan and numerous potent fungal pathogens were isolated. AF contamination attributed to the presence of intoxicating fungal pathogens and resulting metabolic activities were quantified using a high performance liquid chromatography-fluorescence detector coupled with postcolumn derivatization. Additionally, the effect of fungal pathogens on seed germination was also examined. The results obtained showed that 50% of tested wheat samples were found to be contaminated with a diverse range of fungal species. The rate of recurrence of fungal pathogens were Aspergillus 31%, Penicillium 9%, Fusarium 8%, Rhizopus 3%, and Alternaria 2%. The presence of Tilletia indica and Claviceps purpurea species was found to be inevident in all tested wheat samples. AFB contamination was detected in 48 (26.0%) samples and AFB in 13 (7.0%) samples. AFG and AFG were not found in any of the tested samples. The contamination range of AFB and AFB was 0.05-4.78 μg/kg and 0.02-0.48 μg/kg, respectively. The total amount of AFs (B + B) found in 48 (26.0%) samples had a mean level of 0.53 ± 0.40 μg/kg and a contamination range of 0.02-5.26 μg/kg. The overall results showed that in 137 (74.0%) samples, AFs were not found within detectable limits. Furthermore, in 180 (97.2%) samples, AF levels were found to be below the maximum tolerated levels (MTL) recommended by the European Union (4 μg/kg). In five (2.7%) samples, AF contamination was higher than the MTL of the European Union. However, these samples were fit for human consumption with reference to the MTL (20 μg/kg) assigned by the USA (Food and Drug Administration and Food and Agriculture Organization) and Pakistan (Pakistan Standards and Quality Control Authority). Germination rates in healthy and contaminated wheat kernels were 84.6% and 45.2%, respectively. Based on the obtained results, it was concluded that the levels of fungal pathogen and AF contamination in Pakistani-grown wheat are not a potential threat to consumer health. However, control procedures along with a strict monitoring policy are mandatory to further minimize the prevalence of fungal carriers and the potency of AFs in crops cultivated in Pakistan.

Key Global Actions for Mycotoxin Management in Wheat and Other Small Grains

“…Aflatoxins are associated with multiple medical abnormalities in humans and domesticated animals, most prominently with liver cancer and liver failure, but also with immune system depression and stunting in infants and children [ 218 ]. Since 2010, aflatoxins have been reported in wheat or wheat products from Algeria [ 136 ], Bangladesh [ 219 ], China [ 220 ], Iran [ 221 ], Israel [ 222 ], Kenya [ 223 ], Kuwait [ 224 ], Malaysia [ 225 ], Pakistan [ 226 ], Tunisia [ 227 ], and Turkey [ 228 ]. Such contamination most commonly occurs post-harvest rather than in the field.…”

Prevalence and Concentration of Mycotoxins in Animal Feed in the Middle East and North Africa (MENA): A Systematic Review and Meta-Analysis

“…In the search for the full text of the remaining articles, no complete text was found for 108, and they were left out of the study. Finally, out of 132 full-text articles reviewed, 49 were identified as eligible and entered into the meta-analysis ( Table S1 ) [ 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 ].…”

Physiological quality and aflatoxin presence in wheat seeds treated with fungicides and adjuvants during crop development

“…These results are different from the ones obtained by Marini et al (2011), who studied the physiological quality of CD 111 and CD 108 wheat varieties from COODETEC, and observed decrease in germination rate in relation to increased Carboxim Tiram fungicide doses, including the recommended 270 mg L -1 dose. Asghar et al (2016) concluded that seedborne diseases have been found to affect the growth and productivity of crop plants as the liable pathogens attack and destroy the seedlings. Fusarium and Alternaria spp.…”

“…Therefore, the possibility of cereal crops contamination such as wheat, barley, rye, millet and their by-products is a result from direct contact with initial or environmental sources, even when grains are kept under high humid conditions, and consequently cause deterioration (RAZDARI et al, 2014). Asghar et al (2016) studied the isolate fungal pathogens and to subsequently quantify aflatoxin (AF;B1 þ B2 þ G1 þ G2) contamination in wheat crops grown in Pakistan. Accordingly, a total of 185 wheat samples were collected from different areas of Pakistan and numerous potent fungal pathogens were isolated.…”