What is race specific resistance?
In ‘race-specific’ resistance, plants match single mendelian resistance genes with the ‘avirulence’ genes possessed by races of a pathogen. Plants also employ the more complex and evolutionarily more robust system of ‘nonhost resistance’ against a broad range of pathogenic species.
Which type of resistance is very specific to a particular race of pathogen?
Vertical resistance, in contrast, prevents the establishment of infection. This form of resistance is specific against particular pathogen races and can be controlled by one or a few loci.
What is race in plant pathology?
Although historically the term has been used inconsistently by plant pathologists, the modern trend is to use race to refer to “groups of host genotypes permitting characterization of virulence” (in simpler terms: grouping the parasitic fungi into races based on how strongly they affect particular host plants).
What is non host resistance?
Abstract. Nonhost resistance is a broad-spectrum plant defense that provides immunity to all members of a plant species against all isolates of a microorganism that is pathogenic to other plant species.
What is vertical resistance in plants?
A plant variety that exhibits a high degree of resistance to a single race, or strain, of a pathogen is said to be vertically resistant; this ability usually is controlled by one or a few plant genes.
What is gene for gene concept?
The gene for gene hypothesis states that for each gene controlling resistance in the host, there is corresponding gene controlling pathogenicity in the pathogen. The resistance of host is governed by dominant genes and virulence of pathogen by recessive genes.
When resistance is controlled by a single gene it is called?
The term vertical resistance, used commonly in context of plant selection, was first used by J.E. Vanderplank to describe single-gene resistance. This phenomenon is known as the gene-for-gene relationship, and it is the defining character of vertical resistance.
What is an example of genetic resistance?
For example, specific resistance genes against Puccinia graminis tritici incorporated into new wheat varieties frequently become obsolete within a few years due to the emergence of new races of the pathogen.
What does host resistance mean?
Introduction. Host resistance is broadly defined as the host’s ability to limit pathogen burden [1] and includes such diverse defences as physical barriers (e.g. skin), behavioural modifications or a rapid immune response.
What is Oligogenic resistance?
Horizontal resistance is polygenic, and acts against all races of blight. Vertical resistance, conferred by the R-genes, is oligogenic, and can be overcome by a change of race. Horizontal resistance slows down the rate at which disease increases in the field.