Table 1.
Identity, host, location, isolation date and GenBank accession numbers for Phytophthora isolates used for morphological, physiological and phylogenetic analyses in this study.
n.a., not available.
Fig 1.
Symptoms of decline on Mediterranean maquis vegetation caused by Phytophthora spp.: a. Dead and dying trees of Juniperus phoeniceae with abnormal production of epicormic shoots; b. Mature tree of Juniperus oxycedrus showing severe wilting and red discoloration; c. Young tree of J. oxycedrus with red/bronze colour of foliage over the entire crown; d. Basal phloem lesion on a juniper tree extending up from below ground level; e. Collar and root rot on a young juniper tree; f. Extensive dieback and mortality of Pistacia lentiscus across site; g. Dieback and wilting of Asparagus albus.
Table 2.
Phytophthora species recovered from Mediterranean maquis ecosystems in this study, with host, location, number of isolates and GenBank accession numbers of representative specimens.
Fig 2.
One of the most parsimonious trees based on analysis of rDNA ITS sequence data showing phylogenetic relationships of Phytophthora species within ITS Clade 6.
Bayesian posterior probabilities (≥ 0.90, left) and bootstrap support values for maximum parsimony (≥ 70%, right) are given at the nodes. Ex-type cultures are in bold. The phylogram is rooted to Phytophthora cinnamomi (CBS 14422/KC478663). Sub-clades I–III are indicated on the right.
Table 3.
Morphological characters, morphometric data and temperature-growth relations on Carrot Agar of closely related Phytophthora species from Clade 6.
n.a., not available.
Fig 3.
One of the most parsimonious trees based on analysis of mitochondrial DNA cox1 sequence data showing phylogenetic relationships of Phytophthora species within ITS Clade 6.
Bayesian posterior probabilities (≥ 0.90, left) and bootstrap support values for maximum parsimony (≥ 70%, right) are given at the nodes. Ex-type cultures are in bold. The phylogram is rooted to Phytophthora cinnamomi (CBS 144.22/KC609419). Sub-clades I–III are indicated on the right.
Fig 4.
Colony morphology of Phytophthora crassamura isolate CBS 140357, P. megasperma isolate CBS 402.72 and P. ornamentata isolate CBS 140647 (from top to bottom) after 5 days growth at 20°C on Carrot Agar, V8-Agar, Potato-Dextrose Agar and Malt Extract Agar (from left to right).
Fig 5.
Morphological structures of Phytophthora crassamura formed on V8 Agar; a-h.
Sporangia produced in nonsterile soil extract water; a. Mature non-papillate, obpyriform, persistent sporangium with an external proliferation just below the base of the sporangium; b-d. Sporangia showing direct germination of sporangiophores; e. Ovoid sporangium releasing individual zoospores; f. Empty sporangium with nested and extended proliferation; g. Sporangium with internal proliferation and intercalary hyphal swelling close to the base; h. Internal extended proliferation; i-m. Mature oogonia with aplerotic and thick-walled oospores; i-j. Oogonia with amphigynous antheridia; k-m. Oogonia with paragynous antheridia; l-m. Aborted oospores with extremely thick wall. Scale bar = 20μm.
Fig 6.
Morphological structures of Phytophthora ornamentata formed on V8 Agar; a-e.
Sporangia produced in nonsterile soil extract water; a-b. Mature non-papillate, obpyriform to ovoid, persistent sporangia; c. Empty, elongated, ovoid sporangium showing both internal extended proliferation and formation of an additional basal sporangiophore; d-e. Sporangia that failed to form a basal septum and continue to grow with hyphae from the apex of the sporangia, which de facto have the status of hyphal swellings; f. Irregular catenulate hyphal swellings; g-h. Globose to subglobose hyphal swellings with radiating hyphae; i-m. Mature ornamented oogonia and antheridia with finger-like projections (arrow); i-j. Oogonia with amphigynous antheridia; k. Oogonium with paragynous antheridium; k-l. Same oogonium showing the ornamented protuberances on the surface of the oogonial wall; m. Mature bronze-brown oogonia. Scale bar = 20μm.
Fig 7.
Mean total root length of 1-year-old seedlings of Juniperus phoenicea (a) and Pistacia lentiscus (b) after 4 months growth in soil infested with Phytophthora spp. obtained in this study.
Different letters above bars indicate significant differences based on Tukey’s HSD test (P = 0.05). Bars represent standard errors.