Investigation and Assessment of Genetic Diversity among Pleurotus spp. Isolates from Jordan

Pleurotus is considered an important genus that belongs to the family Pleurotaceae and includes the
edible King Oyster mushroom (Pleurotus eryngii). In the present study, 19 Pleurotus isolates were
collected from two locations in the north of Jordan (Tell ar-Rumman and Um-Qais). The morphological
characteristics among collected isolates revealed that there was a morphological similarity among the
collected isolates. Nucleotide sequence analysis of the internal transcribed spacer (ITS1–5.8S rDNA–
ITS4 region) and 28S nuclear large subunit (nLSU) in the ribosomal DNA gene of the isolated stains
showed that all of them share over 98% sequence similarity with P. eryngii. Genetic diversity among
the collected strains was assessed using inter simple sequence repeat (ISSR) analysis using 18
different primer pairs. Using this approach, 141 out of 196 bands obtained were considered
polymorphic and the highest percentage of polymorphism was observed using primer UBC827
(92.3%) with an overall Polymorphism Information Content (PIC) value of 70.56%. Cluster analysis
showed that the Jordanian Pleurotus isolates fall into two main clades with a coefficient of similarity
values ranging from 0.59 to 0.74 with a clear clustering based on collection sites. The results of the
present study reveal that molecular techniques of ISSR and rDNA sequencing can greatly aid in
classification and identification of Pleurotus spp. in Jordan. Phylogenetic analysis revealed a clear
association with geographical distribution and collection sites. In future, selection for suitable
techniques for a large scale production and commercialization accompanied with breeding strategies
with strains of other related populations is needed for king oyster mushroom in Jordan.