KUNMING, June 22 (Xinhua) -- Chinese researchers have found that the pearl oyster mushroom, a common edible mushroom, may originate from the Himalayas about 39 million years ago.

The evolutionary history and species delimitation of Pleurotus ostreatus or the pearl oyster mushroom have long been poorly understood.

Researchers from the Kunming Institute of Botany, Chinese Academy of Sciences ran a genetic analysis on P. ostreatus samples from Asia, Europe, North and South America and Africa.

The researchers reported in the journal IMA Fungus that they mapped the phylogenetic tree of 20 species under the P. ostreatus complex with seven of them identified for the first time.

During the late Eocene about 39 million years ago, the common ancestor of the P. ostreatus species probably originated from the Himalayas, using dead logs in broad-leaved and coniferous forests as its growing substrate.

Due to the uplift of the Qinghai-Tibet Plateau and the global cooling during the Late Miocene, P. ostreatus may have migrated from East Asia into North America across the North Atlantic Land Bridge or the Bering Land Bridge at different times.

The researchers said their study revealed the origin and evolution of the P. ostreatus species, providing important information for identifying new subspecies and breeding. Enditem