TreeBASE Search-Analyses for study 13930

@ARTICLE{TreeBASE2Ref21768, author = {Julia Christine Meitz-Hopkins and M. C. Pretorius and Chris Frederik Jakobus Spies and Laura Huisman and Wilhelm J Botha and Shaun D. Langenhoven and Adele McLeod}, title = {Phytophthora species distribution in South African citrus production regions}, year = {2013}, keywords = {root rot, Phytophthora ITS clade 6, branch cancer}, doi = {}, url = {http://}, pmid = {}, journal = {European Journal of Plant Pathology}, volume = {}, number = {}, pages = {}, abstract = {Several Phytophthora spp. are known to cause a range of symptoms on citrus, resulting in significant crop losses worldwide. In South Africa, Phytophthora remains a destructive disease of citrus, but the species and their distribution have not been well documented. A total of 162 Phytophthora isolates were collected from 61 citrus orchards in seven provinces (Eastern Cape, Kwazulu-Natal, Limpopo, Mpumalanga, Northern Cape, North West and Western Cape). Phytophthora nicotianae was the predominant species (76% of isolates) and occurred in 82% of the orchards in all of the provinces, followed by Phytophthora citrophthora (22% of isolates in 30% of orchards). The P. citrophthora isolates were further subdivided into subgroups G1 and G2 sensu Cohen et al. (2004), with most of the isolates belonging to the G1 subgroup. Other identified Phytophthora species included P. multivora in the Western Cape Province, and a putative new species in the Eastern Cape Province with high sequence similarity to Phytophthora taxon Sisuluriver. Phytophthora palmivora, a known citrus pathogen, was not identified. Most of the P. nicotianae isolates (79%) were of the A1 mating type. The P. citrophthora isolates were mostly sterile (64%), including most of the G1 isolates. The remaining G1 isolates belonged to the A1 mating type, whereas most A2 isolates belonged to the G2 group. Soil inoculation with Phytophthora isolates representing P. nicotianae and the P. citrophthora subgroups revealed variation in virulence within species, with G2 isolates and one P. nicotianae isolate being among the most virulent isolates towards rough lemon seedlings} }