What is quantitative resistance?

Quantitative resistance can refer to an incomplete or partial level of resistance phenotype. It can also refer to a continuous distribution between resistant and susceptible phenotypes in a progeny, most often resulting from the segregation of alleles with variable effects at several loci.

Is disease resistance quantitative?

Quantitative disease resistance (QDR) causes the reduction, but not absence, of disease, and is a major type of disease resistance for many crop species. QDR results in a continuous distribution of disease scores across a segregating population, and is typically due to many genes with small effects.

Is disease resistance qualitative or quantitative?

Quantitative disease resistance (QDR) has been observed within many crop plants but is not as well understood as qualitative (monogenic) disease resistance and has not been used as extensively in breeding. Mapping quantitative trait loci (QTLs) is a powerful tool for genetic dissection of QDR.

What does disease resistance mean?

Disease resistance is the ability to prevent or reduce the presence of diseases in otherwise susceptible hosts. It can arise from genetic or environmental factors, such as incomplete penetrance. Disease tolerance is different as it is the ability of a host to limit the impact of disease on host health.

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 is plant breeding for disease resistance?

Disease control is achieved by use of plants that have been bred for good resistance to many diseases, and by plant cultivation approaches such as crop rotation, pathogen-free seed, appropriate planting date and plant density, control of field moisture, and pesticide use.

What is horizontal and vertical resistance?

Genetic resistance that is effective at preventing successful attack only by certain races of a pathogen is called specific (or vertical) resistance, whereas resistance that is effective at preventing successful attack by all races of a pathogen is called general (or horizontal) resistance.

What is animal disease resistance?

Disease resistance is the ability of animals to inhibit the growth of invading pathogens within the body, which is influenced by the interaction of the host immune system, host genetics, and the pathogens.

What is resistance to infection?

Resistance is defined as the ability to limit pathogen burden while tolerance is defined as the ability to limit the health impact caused by a given pathogen burden. The sum of these two mechanisms defines a host’s defensive capacity.

How is disease resistance inherited?

According to a study in Evolution, resistance to certain infectious diseases may be passed genetically from parent to child. The genetic resistance may be beneficial to families as those with the gene are both unlikely to suffer from disease and unlikely to carry the disease home.

How does genetic resistance work?

Bacteria can acquire antibiotic resistance genes from other bacteria in several ways. By undergoing a simple mating process called “conjugation,” bacteria can transfer genetic material, including genes encoding resistance to antibiotics (found on plasmids and transposons) from one bacterium to another.

How do plant resist disease?

Plant immune systems rely on their ability to recognize enemy molecules, carry out signal transduction, and respond defensively through pathways involving many genes and their products. Pathogens actively attempt to evade and interfere with response pathways, selecting for a decentralized, multicomponent immune system.

What do we know about quantitative disease resistance?

Quantitative disease resistance (QDR) is the type of resistance most widely used by maize breeders. The past decade has witnessed significant progress in fine-mapping and cloning of genes controlling QDR. The molecular mechanisms underlying QDR remain poorly understood and exploited.

Can quantitative trait loci map quantitative disease resistance?

Quantitative disease resistance (QDR) has been observed within many crop plants but is not as well understood as qualitative (monogenic) disease resistance and has not been used as extensively in breeding. Mapping quantitative trait loci (QTLs) is a powerful tool for genetic dissection of QDR.

Is maize disease resistance quantitative?

Quantitative Disease Resistance: Dissection and Adoption in Maize Maize is the world’s most produced crop, providing food, feed, and biofuel. Maize production is constantly threatened by the presence of devastating pathogens worldwide.

What are quantitative resistance loci (QTLs)?

Mapping quantitative trait loci (QTLs) is a powerful tool for genetic dissection of QDR. DNA markers tightly linked to quantitative resistance loci (QRLs) controlling QDR can be used for marker-assisted selection (MAS) to incorporate these valuable traits.