Open AccessGenetic Diversity and a PCR-Based Method for Xanthomonas axonopodis Detection in Passion Fruit
Author(s) -
Carla F Munhoz,
Bernard Weiss,
Luiz Ricardo Hanai,
Maria Imaculada Zucchi,
Maria Helena Pelegrinelli Fungaro,
André Luíz Martinez de Oliveira,
Cláudia Barros Monteiro-Vitorello,
Maria Lúcia Carneiro Vieira
Publication year - 2011
Publication title -
phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.264
H-Index - 131
eISSN - 1943-7684
pISSN - 0031-949X
DOI - 10.1094/phyto-06-10-0169
Subject(s) - biology , analysis of molecular variance , passion fruit , genetic diversity , intergenic region , xanthomonas , population , polymerase chain reaction , genetics , genotype , dendrogram , veterinary medicine , horticulture , botany , genetic variation , genetic structure , bacteria , gene , sociology , medicine , demography , genome
Xanthomonas axonopodis pv. passiflorae causes bacterial spot in passion fruit. It attacks the purple and yellow passion fruit as well as the sweet passion fruit. The diversity of 87 isolates of pv. passiflorae collected from across 22 fruit orchards in Brazil was evaluated using molecular profiles and statistical procedures, including an unweighted pair-group method with arithmetical averages-based dendrogram, analysis of molecular variance (AMOVA), and an assigning test that provides information on genetic structure at the population level. Isolates from another eight pathovars were included in the molecular analyses and all were shown to have a distinct repetitive sequence-based polymerase chain reaction profile. Amplified fragment length polymorphism technique revealed considerable diversity among isolates of pv. passiflorae, and AMOVA showed that most of the variance (49.4%) was due to differences between localities. Cluster analysis revealed that most genotypic clusters were homogeneous and that variance was associated primarily with geographic origin. The disease adversely affects fruit production and may kill infected plants. A method for rapid diagnosis of the pathogen, even before the disease symptoms become evident, has value for producers. Here, a set of primers (Xapas) was designed by exploiting a single-nucleotide polymorphism between the sequences of the intergenic 16S-23S rRNA spacer region of the pathovars. Xapas was shown to effectively detect all pv. passiflorae isolates and is recommended for disease diagnosis in passion fruit orchards.