New members of Alternaria (Pleosporales, Pleosporaceae) collected from Apiaceae in Algeria.

Abstract

Alternaria species have often been reported as plant pathogens and are commonly isolated from diseased plant hosts. During an investigation of this genus in Algeria, seven Embellisia-like isolates were collected from Apiaceae. Phylogenetic analysis using sequences at four loci, the internal transcribed spacer of the rDNA region (ITS), glyceraldehyde-3-phosphate dehydrogenase (gpd), translation elongation factor 1-alpha (tef1), and RNA polymerase second largest subunit (rpb2), revealed that these isolates grouped into three sections, namely Embellisia, Embellisioides, and Eureka. Four isolates had significant differences with their closest species and were determined to be new species, namely Alternarialongiformis and A.radicicola spp. nov. The three other isolates of section Eureka were identified as A.eureka and A.hungarica, the latter species being described as a new record in Algeria. Detailed descriptions of new species are provided based on colony color, aspect, diameter, conidial size, septa, sporulation patterns and compared with other relevant Alternaria species within same sections. All these species were weakly pathogenic on carrot, coriander, and fennel under greenhouse experiments. Apiaceae may constitute a reservoir of Alternaria species that could represent potential pathogens for other plant families.