Resistance genes against plant-parasitic nematodes: a durable control strategy?

Abstract

Plant-parasitic nematodes are a major pest of all agricultural systems, causing extensive economic losses. Natural resistance (R) genes offer an alternative to chemical control and have been shown effectively to limit nematode damage to crops in the field. Whilst a number of resistant cultivars have conferred resistance against root-knot and cyst nematodes for many decades, an increasing number of reports of resistance-breaking nematode pathotypes are beginning to emerge. The forces affecting the emergence of virulent nematodes are complex, multifactorial and involve both the host and parasite of the plant-nematode interaction. This review provides an overview of the root-knot and cyst nematode R genes characterised to date, in addition to examining the evolutionary forces influencing nematode populations and the emergence of virulence. Finally, potential strategies to improve R gene durability in the field are outlined, and areas that would benefit from further research efforts are highlighted.

Mapping the H2 resistance effective against Globodera pallida pathotype Pa1 in tetraploid potato

“…To date, eight resistances against nematodes have been mapped in tomato and potato (Davies and Elling 2015 ). Cloned and well-characterised resistances include Hero from S. pimpinellifolium (Ganal et al 1995 ), Mi1 from S. peruvianum , Gro1 - 4 originating from S. spegazzinii (Paal et al 2004 ) and Gpa2 from S. tuberosum ssp.…”

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

“…The Florida‐endemic pathogen MF is of scientific interest because it overcomes resistances of common peach rootstocks such as ‘Okinawa,’ ‘Nemaguard,’ ‘Nemared’ and ‘Guardian’ (Handoo et al., ; Lecouls et al., ; Nyczepir & Beckman, ; Sharpe, ; Sherman & Lyrene, ). Nematodes have the potential to develop virulent, resistance‐breaking pathotypes as a consequence of selection pressure from monoculture of resistant plant cultivars (Castagnone‐Sereno, ; Davies & Elling, ); thus, there is imminent threat of resistance breakdown by nematode pathogens under prolonged plantings of a single source of resistance such as ‘Flordaguard’ rootstock for peach production systems in Florida. Because MF is a facultative meiotic parthenogen capable of sexual reproduction under stressful conditions, genetic variation arising from cross‐fertilization may facilitate a rapid adaptive response to host‐plant resistance (Castagnone‐Sereno, ; Handoo et al., ).…”

“…The Florida-endemic pathogen MF is of scientific interest because it overcomes resistances of common peach rootstocks such as 'Okinawa,' 'Nemaguard,' 'Nemared' and 'Guardian' (Handoo et al, 2004;Lecouls et al, 1997;Sharpe, 1967;Sherman & Lyrene, 1983). Nematodes have the potential to develop virulent, resistance-breaking pathotypes as a consequence of selection pressure from monoculture of resistant plant cultivars (Castagnone-Sereno, 2002;Davies & Elling, 2015); thus, there is imminent threat of resistance breakdown by nematode pathogens under prolonged plantings of a single source of resistance such as 'Flordaguard' rootstock for peach production systems in Florida.…”

Micro-Tuber Production in Diploid and Tetraploid Potato after Gamma Irradiation of <i>in Vitro</i> Cuttings for Mutation Induction

“…is the most important non-cereal crop worldwide and ranks the fourth after maize, rice and wheat [1]. Potato production faces major challenges including low multiplication rates in the field under conventional (biological) seed production and yield losses due to susceptibilities to diseases and pests such as late blight disease, potato cyst nematode and Colorado beetle [2]- [6]. In production fields, many traditional cultivars suffer from poor yield with reduced tuber size and carry undesirable traits, such as sunken eyes, susceptible to blight disease and cyst nematodes, which result in reduced yield and quality.…”