Plant hosts of the phytoplasmas and rickettsia-like-organisms associated with strawberry lethal yellows and green petal diseases

Abstract

Abstract. Candidatus Phytoplasma australiense (Ca. P. australiense) is associated with the plant diseases strawberry lethal yellows (SLY), strawberry green petal (SGP), papaya dieback (PDB), Australian grapevine yellows (AGY) and Phormium yellow leaf (PYL; New Zealand). Strawberry lethal yellows disease is also associated with a rickettsia-like-organism (RLO) or infrequently with the tomato big bud (TBB) phytoplasma, the latter being associated with a wide range of plant diseases throughout Australia. In contrast, the RLO has been identified only in association with SLY disease, and Ca. P. australiense has been detected only in a limited number of plant host species. The aim of this study was to identify plant hosts that are possible reservoirs of Ca. P. australiense and the SLY RLO. Thirty-one plant species from south-east Queensland were observed with disease between 2001 and 2003 and, of these, 18 species tested positive using phytoplasma-specific primers. The RLO was detected in diseased Jacksonia scoparia and Modiola caroliniana samples collected at Stanthorpe. The TBB phytoplasma was detected in 16 different plant species and Ca. P. australiense Australian grapevine yellows strain was detected in six species. The TBB phytoplasma was detected in plants collected at Nambour, Stanthorpe, Warwick and Brisbane. Ca. P. australiense was detected in plants collected at Nambour, Stanthorpe, Gatton and Allora. All four phytoplasmas were detected in diseased Gomphocarpus physocarpus plants collected at Toowoomba, Allora, Nambour and Gatton. These results indicated that the vector(s) of Ca. P. australiense are distributed throughout south-east Queensland and the diversity of phytoplasmas detected in G. physocarpus suggests it is a feeding source for phytoplasma insect vectors or it has a broad susceptibility to a range of phytoplasmas.

Emergence of Leuconostoc mesenteroides as a causative agent of oozing in carrots stored under non‐ventilated conditions

“…They have a diverse host range as endosymbionts, including arthropods, vertebrates and plants (Weinert et al ., ). Rickettsia ‐related organisms were found in diseased plants from various species (including in carrots) although it is not clear whether they are the actual disease agents (Franova et al ., ; Streten et al ., ; Luis‐Pantoja et al ., ). Reduction in the abundance of Rickettsiales in a CO 2 ‐rich atmosphere suggests that they are sensitive to high CO 2 concentration, similar to other Gram‐negative bacteria.…”

Symbiotic nitrogen fixation and endophytic bacterial community structure in Bt-transgenic chickpea (Cicer arietinum L)

“…Calothrix, Shinella, and Pseudaminobacter were classified at their respective species level. Since the diversity of plant associated Rickettsia and chickpea associated Mesorhizobium in Indian soil is poorly studied [44][45][46][47] , most of the reads belongs to above Genera were not matched with existing species. At the same time, we need to consider the limitations on taxonomic resolution and accuracy of V3-V4 sequences to adequately perform species-level associative studies.…”

New hosts of “Candidatus Phytoplasma australiense” in New Zealand

“…In Australia, "Ca. P. australiense" (16SrXII-B), Tomato big bud (16SrII-E) and Sweet potato little leaf strain V4 (16SrII-D) were all detected in balloon cottonbush (Streten et al 2005). Phytoplasmas belonging to subgroups 16SrI-B (Aster yellows), 16SrIII-B (Clover yellow edge) and 16SrXII-A (Stolbur) were detected in swan plants in Italy (Bertaccini et al 2006;d'Aquilio et al 2002).…”