How Durable is Root Knot Nematode Resistance in Tomato?

Abstract

Among the plant parasitic nematodes, root knot nematode (RKN) is the most devastating in tomato growing regions. Controlling RKN mostly relies on nematicides. Since chemical application is limited due to adverse environmental effect, alternative approaches are required. Although there are some alternatives, but resistance cultivars are getting popularity in the farmer's field because of simplicity, cost-effective and environment safety. Genes conferring resistance to RKN have already been identified followed by the introgression into elite cultivars. Currently, natural resistance genes (R genes) are used in conventional breeding programmes. Simultaneously, molecular research is going on to characterize and map the linked markers for the detected resistant phenotypes. Currently, it is a prominent threat to maintain the durability of existing R genes. However, durability of host resistance govern by co-evolution of resistance genes from plants and (a)virulence genes from nematodes. So, understanding the mechanisms underlying co-evolution is essential for the durability of R genes. Here we review the existing potential natural resistance in tomato against RKN, currently used resistance mechanisms between RKN and tomato, influential factors of durability of natural resistance genes and opportunity to get more durable resistance in tomato.