First record of Cretaceous wood rotting fungi in China
Structurally preserved petrified woods contain not only information of wood anatomy, but
also plenty of physiological and ecological information, including trace
fossils of insect boring, fungal hyphae and other micro-organisms. Study of
these permineralized plants is helpful to reveal the ecological and
co-evolutionary relationships among plants, insects, fungi and other organisms
in geological past. Abundant and diverse Cretaceous wood fossils have been
recorded in China. However, previous studies of petrified wood mainly focused
on their anatomy and taxonomy, little work has been reported on the fungal
remains and the interaction between the wood hosts and fungi.
In recent years, a research team led
by Prof. WANG Yongdong from the Nanjing Institute of Geology and Paleontology
of the Chinese Academy of Sciences, and Dr. Tian Ning, an associate professor
from Shenyang Normal University, carried out a comprehensive study on the
Mesozoic wood fossils containing fungal mycelia with some update discoveries. Recently,
two new reports from this team have been published on the journals Cretaceous Research and Acta Geologica Sinica (Chinese Edition)(cover story).
Well-preserved fossil mycelium
consisting of clamp-bearing septate hyphae is found in a petrified conifer wood
(Cupressinoxylon baomiqiaoense Zheng et Zhang) from the Lower Cretaceous Yunshan Formation in Heilongjiang
Province, NE China. The fungal hyphae are tubular in shape with septa and
typical clamp-connections. Taxonomically, the occurrence of clamp-connections
indicates that the present fungal remains should be referred to the
Basidiomycota. Ecologically, the present fossil mycelium is proposed to be a
saprotroph, i.e. a wood rotting fungus.
The decomposition of the tracheary
middle lamina of the wood host strongly implies that the present fungal
mycelium to be a white-rotting fungus. Additionally, similar basidiomyceous
fossils with white rot function were found in fossil conifer wood of Agathoxylon sp. from the
Lower Cretaceous Guantou Formation in Xinchang of Zhejiang Province, SE China.
The present new finding of
basidiomyceous fossils represents the first unequivocal records of Cretaceous
wood-rotting fungi, provides increasing data on the fossil diversity of fungi
in China, and contributes to further understanding the plant-fungal interaction
in the Cretaceous terrestrial ecosystem.
Reference:
Tian
Ning*, Wang Yongdong*, Zheng Shaolin, Zhu Zhipeng, 2019. White-rotting fungus
with clamp-connections in a coniferous wood from the Cretaceous of Heilongjiang
Province, NE China. Cretaceous
Research, doi.org/10.1016/j.cretres.2018.11.011 (*authors for
correspondence)
Zhu
Zhipeng, Li Fengshuo, Xie Aowei, Tian Ning, Wang Yongdong, 2018. New record of
Early Cretaceous petrified wood with fungal infection in Xinchang of Zhejiang
Province, Acta Geologica Sinica-Chinese Edition, 92: 1149-1162 (cover story).
Fungal hyphae from the Early Cretaceous petrified wood in Heilongjiang Province, NE China (Image by TIAN Ning)
Fungal hyphae from the Early Cretaceous petrified wood in Heilongjiang Province, NE China (Image by TIAN Ning)
Fungal hyphae from the Early Cretaceous petrified wood in Zhejiang Province, SE China (Image by ZHU Zhipeng)
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