Two new species of Diversispora (arbuscular mycorrhizal fungi; Glomeromycota) colonizing roots of endemic shrubs on nickel mine tailings in New Caledonia

Diversispora cerifera and Diversispora succinacia are new arbuscular mycorrhizal fungal species that have been isolated and propagated from spores extracted from rhizosphere soils of native vegetation that had naturally established from seeds on a nickel mine tailing test basin in New Caledonia. Interestingly, these species were not recorded from ultramafic soils of maquis vegetation endemic to New Caledonia surrounding the tailing basin. In greenhouse trap and single-species cultures, the fungi produced numerous spores, which were formed terminally or intercalary on subtending hyphae. Spores of D. cerifera are white-yellow with a waxy appearance and 70–100–120 µm in diameter; spores of D. succinacia are translucent, amber in color, and 60–80–110 µm in diameter; both species have three spore wall layers. A phylogenetic analysis placed D. cerifera in a clade sister to D. succinacia. The same analysis showed that the sister species of D. succinacia is D. sabulosa.