title: Relationship between Psidium species (Myrtaceae) by resistance gene analog markers: focus on nematode resistance.
abstract: Guava (Psidium guajava L.) crop is severely affected by the nematode Meloidogyne enterolobii. Native Psidium species have been reported as sources of resistance against this nematode. Knowledge on the molecular relationship between Psidium species based on plant resistance gene analogs (RGA) can be useful in the genetic breeding of guava for resistance to M. enterolobii. In this study, RGA markers from conserved domains, and structural features of plant R genes, were employed to characterize Psidium species and establish genetic proximity, with a focus on nematode resistance. SSR markers were also applied owing to their neutral nature, thus differing from RGA markers. For this, species reported as sources of resistance to M. enterolobii, such as P. cattleianum and P. friedrichsthalianum, as well as species occurring in the Atlantic Rainforest and susceptible genotypes, were investigated. In 10 evaluated Psidium species, high interspecific genetic variability was verified through RGA and SSR markers, with intraspecific variation in P. guajava higher with SSR, as was expected. Resistant species were clustered by RGA markers, and differential amplicons among genotypes resistant and susceptible to M. enterolobii were identified. Knowledge on the molecular relationships between Psidium species constitutes useful information for breeding of the guava tree, providing direction for hybridization and material for rootstocks. Additionally, the genetic relationship between native species, which have been little studied, and P. guajava were estimated by RGAs, which were confirmed as important markers for genetic diversity related to pathogen resistance.
authors.affiliation: Departmento de Produção Vegetal, Centro de Ciências Agrárias e Exatas, Universidade Federal do Espírito Santo, Alegre, ES, Brasil.
authors.forename: L R
authors.initials: LR
authors.lastname: Noia
authors.affiliation: Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Escola Nacional de Botânica Tropical, Rio de Janeiro, RJ, Brasil.
authors.forename: A C
authors.initials: AC
authors.lastname: Tuler
authors.affiliation: Departmento de Produção Vegetal, Centro de Ciências Agrárias e Exatas, Universidade Federal do Espírito Santo, Alegre, ES, Brasil.
authors.forename: A
authors.initials: A
authors.lastname: Ferreira
authors.affiliation: Departmento de Biologia, Centro de Ciências Exatas, Naturais e da Saúde, Universidade Federal do Espírito Santo, ES, Brasil marcia.ferreira@ufes.br.
authors.forename: M F S
authors.initials: MF
authors.lastname: Ferreira
mesh_terms: D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D060467:Disease Resistance; D019143:Evolution, Molecular; D005819:Genetic Markers / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D018895:Microsatellite Repeats; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000469:parasitology*; D010940:Plant Proteins / Q000235:genetics*; D031647:Psidium / Q000145:classification* / Q000235:genetics / Q000469:parasitology; D014431:Tylenchoidea / Q000472:pathogenicity*
chemical_list: D005819:Genetic Markers; D010940:Plant Proteins