Agronomy Review: Cereal Root Interactions with Soilborne Pathogens

Flashcards reviewing cereal root interactions with soilborne pathogens, including genetic resistance, molecular leads, and host-induced gene silencing.

Name some of the soilborne phytopathogenic nematodes discussed in the review.

Pratylenchus and Heterodera (of wheat and barley), and Meloidogyne graminicola (of rice)

Name the necrotrophic fungal pathogens discussed in relation to wheat and barley.

Rhizoctonia solani AG-8 and Fusarium spp.

Approximately what increase in wheat yields per year is estimated to meet consumer demands for the next 5 to 15 years?

A 1% increase in wheat yields per year

Name some of the soilborne pathogens discussed in relation to resistance prospects in wheat, barley, and rice.

Rhizoctonia solani, Fusarium culmorum, Pratylenchus neglectus, P. thornei, Hereodera avenae, and Meloidogyne graminicola.

Name some of the countries noted for barley production.

Russia, the Middle East, Europe, Australia, UK, North, Central and South America, and Asia

Plant-parasitic nematodes are thought to cause how much in losses per year worldwide?

$100–800 billion per year worldwide

Which nematodes belong to the genus Meloidogyne?

Root-knot nematodes

Root-knot nematodes enter the root at which zone?

The zone of elongation

Name the soilborne fungal pathogens to which wheat and barley are generally susceptible.

Fusarium culmorum and R. solani AG-8

What are some management options for soilborne diseases of small-grain cereals?

Rotation, application of appropriate amounts of fertilizers, fungicide seed treatments, tillage, and use of partially-resistant crop genotypes

What is the DORN1 protein?

A plasma membrane-bound receptor that senses extracellular ATP released during cellular damage

What are some mapping approaches enabling the screening of populations with a genetically wider range of individuals?

Populations for association mapping (diversity panel) or accessions enriched for the trait of interest (FIGS).

What are some sources of genetic resistance to Meloidogyne graminicola in rice?

Oryza glaberrima and O. longistaminata

What are some native sources of resistance to cereal cyst nematodes?

The Cre genes

Resistance to P. neglectus and P. thornei in wheat and barley cultivars was better described as __.

Tolerance

Association mapping using which markers resulted in three clusters of markers for resistance to P. neglectus and P. thornei?

Simple sequence repeat (SSR) markers

On which chromosome was a major QTL for Pratylenchus resistance also associated with partial resistance to F. culmorum and R. solani AG-8?

Chr 5A

Proceeding from a trait or locus to a gene of interest is now more feasible with whole genome sequencing, sequencing of coding portions of the genome, and global sequencing of expressed genes to identify what?

Candidate resistance genes

The Cre3 genes from wheat encode which type of proteins?

Nucleotide binding site leucine-rich repeat (NBS LRR) proteins

What is gene silencing?

Inhibition of specific genes by hybridization with complementary inhibitory RNA (RNAi).