| Dawn redwood (Metasequoia glyptostroboides Hu et cheng) is Taxodiaceae Metasequoia plant. Since Metasequoia glyptostroboides is beautiful, straight, growing quickly, and adaptable, so many people love it very much. As greening and ornamental trees, it was introduced to many provinces in china. In recent years, Metasequoia has spread to nearly all over theChina. Among them, because of its natural climatic conditions conducive to the growth of Metasequoia, coupled with the historical discovery of Metasequoia, Metasequoia planting area has covered all counties in Hubei Province. Metasequoia disease exist commonly in recent years with a wide range of occurrence and aggravating trend, Metasequoia blight can be seen everywhere, especially.In this study, we collected Metasequoia diseased leaves samples in Wuhan, Xiangyang, Jingmen, Qianjiang, Lichuan, isolated and identified the pathogenic fungus. The results showed that Metasequoia blight was caused by Pestalotiopsis. According to morphological character,71 strains of 84 isolates were Pestalotiopsis, Pestalotiopsis disseminata 20 strains, Pestalotiopsis microspora 24 strains, Pestalotiopsis heterocornis 8 strains, Pestalotiopsis cocculi 8 strains, Pestalotiopsis maculiformans 6 strains, Pestalotiopsis neglecta 1 strain, Pestalotiopsis coffeae 2 strains, Pestalotiopsis uvicola 1 strain and Pestalotiopsis sydowiana 1 strains, respectively. Molecular identification with universal primers ITS4 and ITS5, bt2a and bt2b amplified ITS sequences and beta-tubulin gene sequences, phylogenetic tree based on the homologous sequences in NCBI was obviously unable to identify each strain. So the pathogenic strains identified by morphological characteristics of species as the main foundation, molecular biology identification only as a supplementary means.Pestalotiopsis sp. isolated from Metasequoia blight disease leaves, was growing well in the range of pH from 5 to 9, that means the fungi have a strong adaptability to environment of pH.Choosing 10 kinds of chemicals and Pestalotiopsis microspora as the test strain, the experimental results show that, the best inhibition effect on myceliar growth of Pestalotiopsis microspora was carbendazim, with EC502.64μg/mL, followed by prochloraz. |
