The Didymellaceae was established in 2009 to accommodate Ascochyta, Didymella and Phoma, as well as several related phoma-like genera. The family contains numerous plant pathogenic, saprobic and endophytic species associated with a wide range of hosts. Ascochyta and Phoma are morphologically difficult to distinguish, and species from both genera have in the past been linked to Didymella sexual morphs. The aim of the present study was to clarify the generic delimitation in Didymellaceae by combing multi-locus phylogenetic analyses based on ITS, LSU, rpb2 and tub2, and morphological observations. The resulting phylogenetic tree revealed 17 well-supported monophyletic clades in Didymellaceae, leading to the introduction of nine genera, three species, two nomina nova and 84 combinations. Furthermore, 11 epitypes and seven neotypes were designated to help stabilise the taxonomy and use of names. As a result of these data, Ascochyta, Didymella and Phoma were delineated as three distinct genera, and the generic circumscriptions of Ascochyta, Didymella, Epicoccum and Phoma emended. Furthermore, the genus Microsphaeropsis, which is morphologically distinct from the members of Didymellaceae, grouped basal to the Didymellaceae, for which a new family Microsphaeropsidaceae was introduced.

Mycoplasma synoviae can cause worldwide respiratory diseases, synovitis, or subclinical symptoms in poultry. M. synoviae infection occurs throughout the yr and causes significant economic losses, including increased mortality, condemnations, medication, and live production cost. In the present study, the seroprevalence of M. synoviae among 44,395 non-vaccinated chickens from 21 provinces in China from 2010 to 2015 was estimated using ELISA. The overall seroprevalence was 41.19%. Seropositive rates in different yr ranged between 24.70 and 57.20%; the highest seropositive rate was observed in 2010, and the lowest was observed in 2013. The prevalence rates varied greatly in different provinces from 5.10 to 100%. Of the 463 commercial flocks tested, 375 (80.99%) were positive for M. synoviae by ELISA. The seasonal distribution ranged between 26.83% (in October) and 53.98% (in July). An investigation of chickens according to age further showed that M. synoviae can infect chickens at any age. Our findings indicate that M. synoviae infection is very common in China and should prompt further research into its prevalence to develop effective control and prevention strategies.

No abstract