Virulence of seven pathogenicbursaphelenchus xylophilusisolates inpinus pinasterandpinus radiataseedlings and its relation with multiplication

Abstract

Pine wilt disease (PWD) results from the complex interaction of three main factors: the pinewood nematode (PWN, Bursaphelenchus xylophilus (Steiner & Buhrer), Nickle), a vector (Monochamus spp.) and a host (mainly Pinus spp.), along the influence of external environmental factors. Human-mediated dispersal through the timber trade is also involved in the long-term spread of the disease (Robinet et al., 2011). Native to North America, PWN was first introduced into several Asian countries (Japan, 1905; China, 1982; Taiwan, 1985; Korea, 1988) through the importation of infested timber. In 1999, the disease was first detected in Europe, on the Setubal Peninsula in Portugal (Mota et al., 1999), and has since spread throughout Portuguese territory (Naves et al., 2015). In neighbouring Spain, the first outbreak was declared in 2008 (Robertson et al., 2011) and several outbreaks are still being eradicated in southern Pontevedra

Assessing Genetic Variation in Resistance to Pinewood Nematode (Bursaphelenchus xylophilus) in Pinus radiata D. Don Half-Sib Families

“…Many authors have emphasized the importance of using the most virulent isolate for selecting the most resistant genotypes in breeding programs [48]. Accordingly, we chose the isolate for this assay based on a previous study of isolates of diverse origins to determine the most virulent isolate for P. radiata [49].…”

Resistant and Susceptible Pinus thunbergii ParL. Show Highly Divergent Patterns of Differentially Expressed Genes during the Process of Infection by Bursaphelenchus xylophilus

“…For pines, RNA-Seq was an efficient method to generate functional genomic data due to the absence of a valid reference genome sequence [ 35 ]. To comprehensively understand the pathogenic mechanism and reduce the damage caused by PWD, the genetic analysis studies had been conducted after inoculating the pines with PWN, including such plants as P. densiflora [ 36 ], P. pinaster [ 37 ], P. massoniana [ 38 ] and P. radiata [ 39 ]. However, to our knowledge, although transcriptomic studies of PWD resistance in P. thunbergii had been reported, the information on PWN resistance genes in somatic plants was rare.…”

Molecular Defense Response of Pine Trees (Pinus spp.) to the Parasitic Nematode Bursaphelenchus xylophilus

“…In Portugal and Spain, the first steps for the implementation of a similar breeding program for Pinus pinaster have also been taken [ 11 , 12 , 15 ]. The complexity of the breeding programs may be increased by the co-occurrence of several PWN lineages [ 16 , 17 , 18 , 19 , 20 , 21 ].…”

“…Different PWN pathotypes have been identified in Japan, China, and the Iberian Peninsula [ 16 , 17 , 18 , 19 , 20 , 21 ] and PWN isolates collected from the same geographic areas showed distinct virulence levels within the same species or between pine species [ 16 , 17 , 18 ]. Furthermore, genetic diversity of such isolates seems to be increasing in these regions over the years [ 22 ].…”

“…Furthermore, genetic diversity of such isolates seems to be increasing in these regions over the years [ 22 ]. Therefore, the isolates used for inoculation assays should be carefully chosen, being previously tested for their virulence in the species of interest [ 16 ].…”