Inheritance of resistance to the peach root‐knot nematode (Meloidogyne floridensis) in interspecific crosses between peach (Prunus persica) and its wild relative (Prunus kansuensis)

Abstract

The peach root‐knot nematode, Meloidogyne floridensis (MF), infects majority of available nematode‐resistant peach rootstocks which are mostly derived from peach (Prunus persica) and Chinese wild peach (P. davidiana). Interspecific hybridization of peach with its wild relative, Kansu peach (P. kansuensis), offers potential for broadening the resistance spectrum in standard peach rootstocks. We investigated the inheritance of resistance to MF in segregating populations of peach (‘Okinawa’ or ‘Flordaguard’) × P. kansuensis. A total of 379 individuals from 13 F2 and BC1F1 families were challenged with a pathogenic MF isolate “MFGnv14” and were classified as resistant (R) or susceptible (S) based on root galling intensity. Segregation analyses in F2 progeny revealed the involvement of a major locus with a dominant or recessive allele determining resistance in progeny segregating 3R:1S and 1R:3S, respectively. Testcrosses with a homozygous‐susceptible peach genotype (‘Flordaguard’ or ‘UFSharp’) confirmed P. kansuensis as a source of new resistance and the heterozygous allelic status of P. kansuensis at the locus conferring resistance to MF. We propose a single‐locus dominant/recessive model for the inheritance of resistance.

Breeding Climate-Resilient Bananas

“…A major gene conferring genetic resistance to M. incognita was identified on LG2 (Cao et al 2011) and cosegregates with a nucleotide-binding site-leucine rich repeat (NBS-LLR) gene (Cao et al 2014). In the same linkage group, a recent study has reported a major locus with dominant/recessive allele that confirms P. kansuensis as a source of resistance to this newly discovered threat in peach, M. floridensis, (Maquilan et al 2018a), this Mf gene, has been mapped in linkage group 2 (Maquilan et al 2018b). Whether the Mf, RMia and PkMi are distinct genes that are tightly linked in a single locus or are part of a single multi-allelic resistance locus is an open question that still needs further studies to elucidate (Saucet et al 2016).…”

Deciphering Resistance to Root-Knot Nematodes in Prunus for Rootstock Breeding: Sources, Genetics and Characterization of the Ma Locus

“…Additionally, a Chinese wild peach (P. kansuensis) has been shown to carry an R gene to M. incognita named PkMi [54,55], which is also located on LG2, but its relationship with RMia needs to be clarified. An accession of P. kansuensis has also been proposed by other authors as carrying a single-locus dominant (Mf )/recessive (mf ) model for the inheritance of resistance to M. floridensis [56], as the cognate Mf locus is also located on LG2 [57]. It will be important to determine the spectrum of this resistance towards other RKN species and to shed light on the relationship between the RMia, PkMi and Mf genes from peach resistance sources.…”

Susceptibility of Flordaguard peach rootstock to a resistant-breaking population of Meloidogyne floridensis and two populations of Meloidogyne arenaria

“…Flordaguard rootstock found growing in the UF stone fruit orchard. This isolate was used subsequently for genetic studies of resistance in peach rootstocks (Maquilan et al, 2018a(Maquilan et al, , 2018b, as well as comparative genomics of RKN (Szitenberg et al, 2017). The MfGnv14 inoculum used for the current study was collected after two cycles (6 months) of propagation on tomato, whereas the other M. floridensis isolates were maintained over 10 years on greenhouse grown tomato.…”

“…in Flordaguard (Maquilan et al, 2018a), Okinawa (Sharpe et al, 1969), and Flordaglo (Chaparro, per. comm.).…”

“…arenaria numerous trees had the characteristic red-leaf stems growing off the rootstock, which suggested the rootstock was true to variety. Furthermore, an isolate of M. floridensis , MFGnv14, was reported inducing severe root galling and reproducing on Flordaguard ( Maquilan et al, 2018a ). Most recently M .…”