Neofusicoccum and Phytophthora Species: An Emerging Threat to Fig Trees ( Ficus carica ) in Italy, With the Description of

ABSTRACT

Monitoring surveys, conducted in four Italian regions (Apulia, Marche, Sardinia and Veneto), revealed the widespread occurrence of young and mature fig trees ( Ficus carica ) showing sudden death, crown thinning, shoot blight, branch dieback, cankers and root rot symptoms. Given the widespread distribution and severity of these symptoms, a study was conducted to identify the main causal agents. To achieve this goal, 86 samples including fine roots with rhizosphere (11) and branches with bleeding and sunken cankers (75) were collected from 11 symptomatic fig trees. Isolations performed on universal and selective growth medium yielded colonies belonging to three families: Botryosphaeriaceae , Diaporthaceae (Ascomycetes) and Peronosporaceae (Oomycetes). Based on morphobiometric data and DNA nucleotide sequences, seven species, namely Botryosphaeria dothidea (14 isolates), Diaporthe cinerascens (10), Neofusicoccum australe (9), Neofusicoccum mediterraneaum (10), Neofusicoccum parvum (28), Phytophthora citricola (3) and Phytophthora plurivora (6) were identified. In addition, two isolates of a new putative Phytophthora species obtained from the rhizosphere including symptomatic fine roots of fig trees in Apulia region are described here as Phytophthora messapica sp. nov. For Phytophthora species, N. australe and N. mediterraneaum (reported here for the first time on fig trees worldwide), Koch's postulates were satisfied by inoculating 5‐year‐old fig trees under controlled conditions. Sixty days after inoculation, all inoculated plants showed the same symptoms as those observed in the field. Overall, the data obtained highlights the involvement of multiple Botryosphaeriaceae and Phytophthora species in the aetiology of the emerging diseases affecting fig trees in Italy.