Location of independent root-knot nematode resistance genes in plum and peach

Abstract

Prunus species express different ranges and levels of resistance to the root-knot nematodes (RKN) Meloidogyne spp. In Myrobalan plum ( Prunus cerasifera), the dominant Ma gene confers a high-level and wide-spectrum resistance to the predominant RKN, Meloidogyne arenaria, Meloidogyne incognita, Meloidogyne javanica and the isolate Meloidogyne sp. Florida which overcomes the resistance of the Amygdalus sources. In Japanese plum ( Prunus salicina), a similar wide-spectrum dominant resistance gene, termed R(jap), has been hypothesized from an intraspecific segregating cross. In peach, two crosses segregating for resistance to both M. incognita and M. arenaria were used to identify single genes that each control both RKN species in the Shalil ( R(Mia557)) and Nemared ( R(MiaNem)) sources. Localisation of these genes was made possible using the RFLP and SSR- saturated reference Prunus map TxE, combined with a BSA approach applied to some of the genes. The Ma1 allele carried by the Myrobalan plum accession P.2175 was localised on the linkage group 7 at an approximate distance of 2 cM from the SSR marker pchgms6. In the Japanese plum accession J.222, the gene R(jap) was mapped at the same position in co-segregation with the SSR markers pchgms6 and CPPCT022. The peach genes R(Mia557) and R(MiaNem), carried by two a priori unrelated resistance sources, were co-localized in a subtelomeric position on linkage group 2. This location was different from the more centromeric position previously proposed by Lu et al. (1999) for the resistance gene Mij to M. incognita and M. javanica in Nemared, near the SSR pchgms1 and the STS EAA/MCAT10. By contrast, R(Mia557) and R(MiaNem) were flanked by STS markers obtained by Yamamoto and Hayashi (2002) for the resistance gene Mia to M. incognita in the Japanese peach source Juseitou. Concordant results for the three independent sources, Shalil, Nemared and Juseitou, suggest that these peach RKN sources share at least one major gene resistance to M. incognita located in this subtelomeric position. We showed that plum and peach genes are independent and, thus, can be pyramided into interspecific hybrid rootstocks based on the plum and peach species.

Microsatellite genetic linkage maps of myrobalan plum and an almond-peach hybrid?location of root-knot nematode resistance genes

“…The slight differences in the order of two loci between both maps are attributable to sampling errors produced by the small number of individuals used for mapping and the proximity between these markers. The R MiaNem gene mapped to the same region of the map in both progenies, confirming the location previously established by Claverie et al (2004) and thus providing additional evidence for its telomeric position in G2 of the Prunus genome.…”

“…As all genes described so far to determine disease resistance to RKN coming from peach have been placed on linkage group 2 of Prunus (Lu et al 1998;Jáuregui 1998;Yamamoto et al 2001;Bliss et al 2002, Claverie et al 2004, only the microsatellites located on linkage group 2 in Prunus linkage maps were tested on the GN22⊗ population.…”

“…More recently two genes (Mia and Mja for resistance to MI and MJ, respectively) were found in the 'Akame' × 'Juseitou' F 2 population , and one gene (Mi) controlling MI was mentioned by Bliss et al (2002) in a peach × peach (PMP2) population. By using P.2175 × GN22 hybrids, we have detected a single dominant gene for resistance to both MI and MA in Nemared (designated R MiaNem 'resistance to M. incognita and M. arenaria from Nemared') which has been shown to be closely linked to Mia from Juseitou and thus might be the same gene (Claverie et al 2004).…”

The Impact of Plant-Parasitic Nematodes on Agriculture and Methods of Control

“…[87]. Using polymorphic sequencing analyses and genetic linkage mapping (RFLP, SSR) the Ma loci was precisely identiied in the Myrobalan plum linkage group 7, while in a Japanese plum variety, a Rjap gene was localized at the same position in co-segregation with SSR markers previously associated with rootknot nematode resistance [88]. In sweetpotato, 275 candidate resistance gene analogs have been identiied by degenerate PCR and molecular mining [89].…”

High-resolution mapping and chromosome landing at the root-knot nematode resistance locus Ma from Myrobalan plum using a large-insert BAC DNA library

“…Two reliable SCAR (sequence characterized amplified region) markers, SCAL19 and SCAFLP2, tightly linked to Ma, have been identified by bulked segregant analysis (BSA) and are currently used for marker-assisted selection (MAS) . Ma was then mapped on the linkage group 7 of the reference European Prunus map (Joobeur et al 1998;Aranzana et al 2002) in a 2.7 cM interval between the SSR (simple sequence repeats) marker pchgms6 and SCAL19 (Claverie et al 2004).…”