Effect of Continuous Iron Pollution on Morphology and DNA Profile of Pleurotus tuber-regium

Aims: Iron, the fourth most abundant micronutrient in the soil has been classified as a metal of environmental concern, the study was to assess the effect of continuous iron pollution on growth and the molecular profile of Pleurotus tuber-regium.

Study design: Experimental research design.

Place and Duration of Study: The Bells University of Technology, between December 2019 and October 2020.

Methodology: P. tuber-regium sclerotia procured locally were seeded into 1 kg soil polluted with 20, 40, 60, and 80 mg kg-1 FeSO4 respectively. Watering was done with the respective Fe solutions for 59 days at the rate of 100ml/48hrs. The Stipe length, pileus diameter, fruitbody weight, and days for fruitbody emergence were recorded for each treatment. The concentration of iron in soil and mushroom was determined by Atomic Absorption Spectrophotometer (AAS). DNA extracted from the fruitbodies was subjected to Random Amplified Polymorphic DNA (RAPD) analysis using five RAPD primers and a cluster analysis was performed.

Results: Fruiting was achieved in all soils (0, 20, 40, 60, 80 mg kg-1) after 23±0.5, 17±1.0, 50±2.5, 58±1.0, and 59±2.0 days respectively. Iron had no significant effect on stipe length while pileus diameter and fruitbody weight increased only at 20mg kg-1. Iron concentration in the soil and mushroom increased as Fe pollution was increased. The bioaccumulation factor was higher in contaminated soil and was between 0.78 and 1.08. The RAPD primers amplified 53 band sizes ranging from 100 - 700 bp and the DNA was clustered in a major group. The percentage polymorphism was 16.9% indicating a low level of genetic variation.

Conclusion: The result indicated that continuous Fe pollution at the stated concentrations did not have any significant effect on the DNA profile of Pleurotus tuber-regium but the morphological growth of the mushroom was enhanced at low iron contamination levels.